Manure Application Technology and the Impact on Nitrogen Dynamics

Posted in: Ontario Pork, Pork Insight Articles by admin on July 21, 2011 | No Comments

This study attempted to find the agronmic value and loss of nitrogen from different application methods and timing methods of swine manure.  The areas that were tested were ammonia volatilization, soil inorganic nitrogen levels, and nitrogen uptake and yield for corn. Some of the different application methods were pretilage with aerator, deep or shallow injection, surface applied with the crop in and without the crop in, different rates of nitrogen per hector as well as others methods. The timing was tested by doing experiments in late summer, fall, spring, and side dress. This study found that deep or shallow injecting resulted in virtually no ammonia volatilization, and the aerator treatment had lower emissions than the surface applied treatment. Soil inorganic N was found to be generally similar regardless of manure application method. The study found that manure application method and application timing significantly affected the amount of nitrogen lost by volatilization except under cool wet conditions in which the application method had no effect.

Pork production improvement expected from the use of new genetic markers

Posted in: Production by admin on July 14, 2011 | No Comments

Background

 Breeders have been using gene markers since the 1990s to remove genes known to negatively impact pork production. Genes like the porcine stress syndrome (HAL) and the NAPOLE gene (RN-) have been identified and are commonly selected against in most breeding herds so the deleterious genes are removed from their herds. In this manner commercial pork producers do not have to address these genes in their breeding herds because their genetic supplier has already managed the genes for them.

Today, swine breeders have new gene marker tools commercially available to them at relatively low costs. These new gene markers are for traits that include feed efficiency, growth, backfat and pork quality and litter size.

Two companies, DNA LandMarks, a BASF Plant Sciences company that performs genetic testing located in Quebec, Canada and GeneSeek Inc., a molecular biology company in the US, have purchased the licensing agreements from the researchers who originally developed them. Included in the group of available tests are markers developed in Max Rothschild’s lab at Iowa State University, which is responsible for developing tests for litter size, pork quality and feed efficiency, backfat and growth rate. A breeder wanting to screen animals can simply submit a blood or tissue sample (whole blood, blood blotter cards, ear notches, docked tails, or tissue obtained through a new ear tagging system from Typifix are all examples of sources of DNA that can be used to run these tests) and have the marker genotypes determined on as many animals as they desire. The costs for these tests are relatively inexpensive and as technology improves it is likely that more and more tests can be offered and prices for these tests typically decline.

As an example, we discuss the commercially available tests from DNA Landmarks (http://www.dnalandmarks.com/english/livestock_overview.html)

Markers for growth rate, feed efficiency, feed intake, and backfat

 Three markers associated with growth rate and feed efficiency are available. These markers are MC4R, HMGA1, and CCKAR. Briefly, the MC4R locus impacts growth and leanness in the pig. The name MC4R is taken from the gene’s name Melanocortin-4 receptor. There are two alleles or variants for this marker, A and G. The A allele is associated with fast growth while the G variant is associated with lean and efficient growth. The producer and breeder can decide if they wish to choose the “fast” growth form of the gene or the “lean/efficient growth” form of the gene. Pigs that are homozygous for the fast growth alleles (i.e. AA) have been shown to reach market weight 3 days sooner compared to pigs that are homozygous for the lean allele. If producers chose to select for the MC4R lean alleles (i.e. GG) pigs will have 8% less backfat and eat significantly less feed (improving feed efficiency). In Table 1 research results are shown indicating the effects of MC4R in two different populations of pigs. These results have been well validated and are effective in all breeds except Hampshire.

The second marker available is HMGA1. The abbreviation HMGA1 is taken from the gene’s name, High-mobility group A. This gene marker is highly associated with backfat and lean growth. HMGA1 variants are consistently associated with fat deposition, growth rate, and lean mass percentage traits across several pig populations. With this particular marker, producers need to remember that the T allele is the beneficial allele and the one that should be selected for to reduce backfat and thereby improve lean percentage. Producers can test and select animals which are likely to be leaner and produce offspring that are leaner. Thus, selection of the beneficial alleles will reduce backfat and improve percentage lean in terminal market animals that are from breeders that have incorporated the beneficial alleles into their breeding program. Improvement in feed efficiency should also occur when selecting for the beneficial allele of this marker because a reduction in the amount of fat deposited reduces the amount of feed needed to add weight to the animal.

The last gene marker in this group is CCKAR. CCKAR is an abbreviation for cholecystokinin type A receptor. This marker is associated with the control of feed intake, hunger control, and obesity. There are two genetic alleles or variants, G and A, for this marker. In this case the G allele is dominant to the A allele. Pigs that have at least one copy of the G allele (i.e. can be GG or GA) for this marker have, on average, about 5% higher daily feed intake, 3% higher daily gain, and 3% fewer days to reach market weight, when compared to homozygotes (i.e. AA) for the A allele.

Markers for meat quality

 Production of high quality pork to meet both domestic and export market demand has been a selection goal of most swine breeders in recent years. Many niche market programs are in place to meet white tablecloth and export demand for quality pork. In the past several years, markers have been identified which improve pork quality.

Two genetic marker tests that impact pork quality have been licensed to DNA Landmarks from ISU. The two markers associated with meat quality offered in this package include PRKAG3 and CAST.

The PRKAG3 is an abbreviation for protein kinase, AMP activated, gamma 3 subunit. This marker is associated with muscle glycogen content and meat quality. Producers and breeders can select for animals that have the higher pH and better meat color from of the gene. Other variations of this gene have been referred to as the Rendement Napole (RN) gene marker. The RN gene marker has been shown to cause low ultimate pH and reduced water holding capacity in pork. This gene marker has been largely observed in purebred Hampshire or crossbred animals involving Hampshire. Hence, this gene was also known as the Hampshire effect. Another variation of this gene has been identified and is what DNA Landmarks is offering in the PRKAG3 gene, which determines the presence of the 199Ile, A-nucleotide variant, which is the one that is preferred.

This marker is also associated with lower glycogen, higher ultimate pH (about .1) and favorable color in loin and ham tissues. Animals possessing this beneficial genotype have a pH of nearly 0.1 higher in their loin and ham samples than those that are homozygous for the non-beneficial allele. Thus, producers should select animals that have at least one copy of the A allele with the ultimate goal of having the genotype of all animals be AA.  The effects of this marker have been observed in all major pig breeds and this test would be very useful in breeds like the Berkshire and Duroc to remove the unwanted forms of the gene.

The second meat quality genetic marker is called CAST, which is an abbreviation for Calpastatin. Calpastatin is responsible for inhibiting enzymes called proteases that affect meat tenderness after harvest. Two variants have been identified within the CAST gene area. This gene impacts firmness, juiciness, Instron force, cooking loss, chewiness, and tenderness scores. Breeders should select for the favorable CAST A allele.

ESR marker for litter size

Increasing litter size is one way to improve production efficiency of a pork operation using fewer sows and less feed. Selection for increased litter size is responsible for the large gains breeders have made in this trait in the last 20 years.

One gene called ESR, the Estrogen Receptor, is associated with litter size in pigs and has been used for many years by a large pig breeding company. It was first discovered in Meishan pigs (Figure 1). Estrogen is a key female hormone that plays a key role in many reproductive functions in the sow including embryo survival, fetal development, fertility, maintenance of fertility, and secondary sexual characteristics. Based on all of the fertility traits that have been shown to be impacted by estrogen, it is easy to believe that this gene for the hormone receptor is associated with litter size in swine. Animals that carry one copy of the favorable variation of the gene will, on average, have 0.4 more pigs per litter. Sows that are homozygotes (2 copies) for this marker would on average have 0.8 pigs per litter. This test has been shown to be effective in breeds or lines involving Large White or Yorkshire breeds and crossbred sows that have this breed involved in them.

Where do breeders begin when considering the use of the molecular markers?

Our advice to producers is to begin testing their herd boars and/or boars in the boar studs they use to make pure matings. For boars used in the development of terminal sire lines, the best approach would be to determine the status of all herd boars and boars in the boar stud for the markers impacting growth, backfat, and feed efficiency including MC4R, HMGA1 and CCKAR. Additionally, the same approach could be used to examine the status of herd boars or boars in the boar stud for the markers used to improve meat quality including PRKAG3 and CAST. Similarly, all boars used to make maternal purebred matings should be tested using the ESR marker used to improve litter size.

Once the results are obtained, breeders can determine what the frequency of the alleles, both good and bad, are for the breeds or lines of sires in the boar stud. This information can be used to determine if further testing of females from each breed or line is necessary.  Breeders can determine which alleles they would like to fix or be sure that all animals have two copies of in a given breed or line of animals.  Selection of the preferred animals and culling of those without the desirable alleles can then be done.

How can the marker information be used to develop breeding programs?

Many of these markers or genes are best used in combination. Use of all five, MC4R, PRKAG3, CAST, CCKAR and HGMA1, would be beneficial for overall terminal line development to improve growth, leanness and meat quality. Using MC4R (growth allele) and HGMA1 could be used for to develop a line that grows fast and has some backfat improvement. Similarly, selecting animals that have the MC4R (lean allele) and HMGA1 could be used together for make even faster progress in improving leanness and efficiency in breeding stock. The PRKAG3 and CAST could be used in combination to improve meat quality. Furthermore, some breeders may choose to select animals for all of the growth and meat quality markers to develop lines of pure breed animals that excel in the production of lean, high quality pork. Maternal lines should be developed that have the favorable alleles for the ESR gene marker. This will enhance the chances of the lines having large litters, which are extremely important to production efficiency and overall profitability of any pork operation.

Breeders and producers should work to develop the best multi-gene combination for their lines that meets customer needs for both maternal and terminal lines.

Marker test costs

The cost for the marker tests varies depending on how many tests are done. Check the DNA Landmarks web site for more information on the market tests and cost information http://www.dnalandmarks.com/english/livestock_overview.html.

While testing is not inexpensive, especially if attempting whole herd tests, useful information can be obtained by testing sub populations of animals at a much lower cost. This allows a strategy to be put in place before entire whole herd testing programs are required to determine status for all of the markers available.

Combined or used in thoughtful combinations these gene markers offer real benefits for future genetic and economic improvement for swine breeders and commercial pork producers.

Figure 1. The Meishan breed of pigs which originated in China and is known for their outstanding litter size, longevity and other reproductive traits. This breed has made significant contributions to the discovery of molecular markers for a variety of economically important reproduction traits in swine.

Table 1. Example effects of the MC4R molecular marker in pigs.

Glimmer of hope Down Under

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Australian pig producers have suffered the same problems as their Canadian counterparts, with low hog prices and high feed costs, says consultant John Riley.  But now, a weakening of the Aussie dollar and a downward trend in feed costs has resulted in optimism that the worst is over.  However, producers need a sustained period of profitability to regain confidence and invest in new technology, he believes.

The number of pigs slaughtered in Australia in June 2008 fell by around 14 % compared with the same period in 2007.  The pigs slaughtered totalled just 406,000, the lowest monthly number for well over a decade.  The low number of pigs forward has resulted in prices increasing to $2.80 per kilogram for a 75 kg carcass.  With an anticipated drop in the national sow breeding herd from 286,000 in June 2007 to approximately 250,000 in June 2008, the industry is hopeful that improved prices will continue through to early in 2009.

The record grain sorghum harvest in Queensland and NSW and promising planting conditions for wheat and barley in the southern states and Western Australia has resulted in feed costs easing downwards slightly.  With the northern hemisphere harvest well advanced, producers are hoping that the downward trend in feed prices will continue.  If the Australian industry is to avoid further contraction a significant period of profitable production is essential.

Over the last twelve months or so most businesses have increased their liabilities to remain in production and there is a real concern that, as the economic climate improves, financial institutions will put pressure on businesses to reduce their debt load resulting in more producers exiting the industry.

By Australian standards, 2008 has been a long cold winter.  On many units, pig accommodation is designed to meet high summer temperatures not low winter temperatures.  Most sheds are fitted with cooling systems but not heating systems and in the last quarter improvements in income in the market place and the marginal reduction in the price of feed have been eaten up by poorer feed conversion efficiency in the grower herd and increased pre-weaning piglet mortality.   

The fall in the value of the Australian dollar from 98 cents US earlier in the year to currently around 86 cents has had limited effect on the level of processed pig meat reaching Australia. The level of imports from both your country and Denmark have fallen significantly, imports from Canada have fallen by some 6% shipped weight.  The expected market opportunities for Australian pig meat have not materialised as the USA have increased their volume landed in Australia by nearly 8% year on year to over 31,000 tonnes shipped weight. The level of exports fell as the Australia dollar almost reached parity with the US dollar.  With the fall in the value of our dollar, industry is hoping that export volumes to both Singapore and Japan will increase. It will, however, be a slow process recapturing market share lost to our competitors.  

On the home front, the sale of the Hyfarm breeding company’s interests have been finalised and the breeding company in which UK-based JSR Health Bred were a major partner has exited the industry. At the same time as Hyfarm left the industry PIC Australia has purchased a 7,000 sow, farrow to finish unit from Nippon Meat Packers Australia Pty Ltd.  The Japanese company, which has a substantial interest in the beef feed lot industry, developed the state of the art piggery in 2000 to supply both the domestic and export market.  PIC Australia is owned by the CHM Alliance, whose members also have interests in the poultry industry and cotton production.  The acquisition of the Nippon unit at Tong Park in Queensland makes them one of the largest operators in Australia after the 40,000 sow QAF holdings in New South Wales and Victoria.

Australia, as an island, albeit a very large island, is very protective of its animal health status and applies stringent bio-security protocols.  There has been no importation of porcine genetic material since about 1990.  In the opinion of some experts the policy has resulted in a lack of heterosis in the national pig breeding herd.  The average number of pigs weaned per sow in a small sample of herds recorded with the industry’s pork organisation Australian Pork Ltd (APL) is 20.73.  On a visit to Holland in July, I had the opportunity to meet with a representative of the international breeding organisation Topigs and visit several of their client’s production units.  Arjan Neerhof, the Breeding Program Manager at Topigs, claimed (and his client’s production records confirmed) that commercial units using the Topigs 20 line were averaging 26.8 pigs weaned per sow per year with the top 10% achieving 29.8 pigs weaned compared with an average of 23.5 for the top 10% in the APL sample.

The Dutch industry is producing six more weaned pigs per sow per year than Australian producers with the same level of feed usage.  If Australia is to compete successfully on the world market, the experts referred to earlier argue that the importation of genetics is a high priority providing our stringent bio-security regulations can be met.

The Australian industry takes great pride in its green and clean image but earlier this year a supply of zinc oxide from China imported on an out of date certificate of analysis, caused a major residue alert in Western Australia.  The zinc oxide contained high levels of lead contamination (>85,000 ppm).  Tests on pigs fed diets containing the zinc oxide were found to have high levels of lead in red offal which was disposed of, at considerable expense, before it entered the food supply chain.

After months of despondency the rise in pig meat price and the marginal fall in feed price provide a glimmer of hope for the Australian industry.  For the industry to regain confidence and invest in new technologies, a lengthy period of profitability is essential.

Management strategies to maximize weaning weight

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While the traditional key performance indicator in sow units is weaned pigs per sow per year, the pork industry is now considering weaning weight with the same level of importance, says Dr. Juan Carlos Pinilla and his colleagues at pig breeding company PIC.  Speaking at the 2008 American Association of Swine Veterinarians, he notes that heavier weaning weights are positively correlated with growth rate, feed efficiency and pounds of saleable pork. Current estimates of milk yield are 22 to 26 lbs (10-12kg) of milk per sow per day, says Dr Pinilla.  Many factors influence this number: health, environment, genetic potential, mammary gland stimu­lation (lactation length, number and weight of the nursing piglets), nutrition, feed intake, body condition, and water intake.  His presentation described strate­gies to wean heavier piglets by maximizing milk pro­duction based on common practices utilized by some successful commercial systems in North America.

Maximizing milk production

Number of functional teats

To maximize litter weaning weight, it is necessary to select replacement gilts for number and quality of their teats.  “The standard is to cull gilts with less than 12 teats, but too many producers do not have this standard in their operations,” believes Dr Pinilla.  “Generally, modern dam lines have more than 12 teats, in fact, more than 85% of gilts selected in our Genetic Nucleus show 14 or more teats at selection.”  Recogniz­ing that the heritability of teat number is low and genetic improvement will take time genetic sup­pliers still have the responsibility to improve this trait, he feels.

Gilt growth rate and weight at breeding

In gilts, there is a significant correlation be­tween the ADG in the period from 65 to 195 lbs (30-88kg) and the weaning weight of their litters.  The current higher milk yield potential, and consequently the potential to wean heavier piglets, could be partially explained by larger body size and more mammary tis­sue in modern genotypes.

Beside the effects on retention rate and litter size, the current recommendation to breed gilts after they achieve 300 lbs (136kg) minimum to get farrowing weight to 400 lbs (181kg), will produce additional benefits.  “Gilts bred in that window will gain less body weight during their first gestation and consequently they lose less body weight during their first lactation and are able to retain weight, or even gain some weight, dur­ing P2 and P3, versus gilts bred at lighter weights,” explains Dr. Pinilla.  “As a practical consequence, weaning weights could be increased due to higher milk yields.”

Controlled weight gain in gestation

It is well documented that excess weight gain in gestation limits the feed intake during lactation and increases the sow’s body weight loss.  Farm management must be aware of that and manage gesta­tion feeding to limit excess body weight gain.  “During their first gestation the female should gain around 80 lbs (36kg) of body weight.  From P1 to P6, an average of 35 lbs (16kg) increase in body weight per gestation is acceptable,” believes Dr. Pinilla.   “A maximum of 12% of lost weight during the first lac­tation and a maximum of 8% average in older parity sows are considered as the limit body weight loss com­patible with high performance.”  

In a project to control annualized sow mortality, the impact of gestational body weight gain control was seen in terms of reduction in production cost per weaned piglet, with no negative effect on the litter weight gain in farrowing.  Annualized sow mortality effectively was reduced from 13% to 5%.  “A rule of thumb was derived from that experience: every lb of reduction in the daily usage of gestation diet from 7.0 lbs per day to 4.5 lbs per day can be translated into 1.0 to 1.1 lbs/day of additional feed intake in farrow­ing and every additional lb of average feed intake in farrowing in turn can be translated into 20-22 extra lbs of piglets weaned per sow per year,” explains Dr. Pinilla.

Number and weight of piglets nursed

Litter size (number and weight of the piglets nursed) is the major individual factor in the determination of milk production. “From a production management point of view, plan to have more than 50% of the sows wean­ing 11 or more piglets, particularly since milk yield is more than 50% greater when litter size increased from 6 to 12 piglets, advises Dr. Pinilla.  “The female is able to react to a higher milk requirement by eating more feed.  Suckled glands will be larger and more productive in subsequent lacta­tions than un-suckled or poorly suckled glands.”   Lower performance in farrowing can be traced to the practice of loading P1 females with just 9 to 10 piglets in order to “prevent extensive catabolism”.   The current recommenda­tion is to load gilts with 12 strong and heavy piglets and support that with proper feeding management, cooler rooms, limited cross fostering, and water availability, he notes.

The most recent and promising tool to produce heavier litters is to let the sows farrow naturally and/or limit the use of farrowing induction to risky sows (fat, lame or older than P5).  Data collected from a commercial farm suggests that every additional day of gestation results in piglets weighing 0.15 extra lbs (70g) per day, in the range from 113 to 118 days. Consequently those heavier piglets at birth have greater opportunity to vigorously suckle the teats, survive and gain weight and be weaned at a heavier weight.

Dr Pinilla also advises drying off piglets after birth to prevent chilling, measures to control the incidence of diarrhoea and split suckling, especially where litter size is high.  “Farms where split-suckling has been fully implemented have seen increased survivability and weaning weight, and less variation in weaning weights,” he says.

Lactation length

It is well-known that increasing lacta­tion length increases weaning weight.   “PIC research has shown that for every addi­tional day in farrowing with their mother, weaning weight increases an average of 0.56 lbs/day/piglet (250g), which is in turn related to a reduction in the age to market, Dr. Pinilla explains.  He recommends a minimum of 20 days at weaning, recognizing that this may require additional farrowing places to be constructed in some cases.  “A reduction in the breeding target, and consequently the average sow inventory, is not as cost effective as adding more farrowing spaces,” he stresses.

Maximize lactation feed intake

It is critical to prevent and/or to control situations lead­ing to off-feed sows, stresses Dr. Pinilla.  “Proper hygiene measures associ­ated around farrowing, such as room sanitation, a clean sleeving process, and individual treatment of fever and lameness are a must.  Also, check the availability of fresh, cool and clean water is a daily duty in farrowing, mak­ing sure the sows have a minimum water flow rate of 0.5 gal (2 litres) per minute.”

Data from a commercial system suggests that a mild restriction for 3 days followed by full feed­ing from day 4 through the end of lactation results in increased feed intake and reduced body weight loss, Dr Pinilla explains.  “Based on these data, the recommendation for feeding PIC sows is to scale feed at 4.0, 4.0, and 6.0 lbs per day for days 0, 1, and 2 of lactation followed by ad-libitum access to feed.  This pattern ensures the maximum aver­age daily feed intake, milk yield, litter weight gain, and minimum body weight loss.”

Alternatives to the traditional hand feeding systems include the use of self feeders, which are able increase the average daily feed intake by about 7% compared with hand feeding systems and are less de­manding in labour.  However, no feeding protocol or feeder design will work unless qualified staff gets the sows up two or three times a day to stimulate them to eat, believes Dr. Pinilla.  “Other key duties are clean­ing the feeders to prevent mould, adjusting the heat lamps height or simply turning them off when needed and checking room ventilation and temperature,” he says. “Caretakers must be able to ‘read’ the sow and piglet behaviour and make adjustments to ensure the sows eating enough feed to wean healthy and heavy piglets.”

Cross fostering

Cross-fostering is a common and preferred manage­ment tool.  While it provides opportunities to the smaller piglets in a room to get enough milk to grow, in too many situations the staff tends to use the fostering too much and/or too often, Dr Pinilla believes.  “Create the light litters as soon as possible after all pigs have received colostrum and before the social order is established, sometime during the first 12-16 hours of life,”, he advises.  “When the equalization by size is made after day 1, the benefits are limited because it is a disruption of the normal process of nursing, sows get nervous and mastitis can become a problem.”  Nurse sows to raise the fall-behinds can be created from day 4 to 7, moving a fresh sow from the next younger room, he says.  “It is important to limit the fostering to a maximum of 10-15% of the litters disrupted after day 4-7 of age.”

Individual sow feeding stalls offer simple but effective system

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One of the major benefits of sow stalls is the ability to feed each sow individually, according to body condition and stage of pregnancy.  Group housing systems have varying capabilities for individual feeding and this factor needs to be considered when choosing which method to use. Perhaps the simplest approach to controlling feed intake and protecting sows from bullying while feeding is to use individual feeding stalls with a locking rear gate.  These have been used in traditional straw yard systems in Europe for at least 50 years, typically with a group size of 5-10 sows. The system comprises a bedded lying area providing about 15 ft²/sow, a solid floored scrape-through dunging area and then the feeding stalls.  Pen dimensions are primarily determined by the width of the feeding stall, which is usually 20”, so that for a group of six sows the pen width would be 10ft, making the lying area 9ft deep.  Overall space requirement relative to other systems is high, at 36 to 40 ft²/ sow, making the capital cost of a building quite high. Also, feeding is usually by hand, making it rather labour intensive.  However, the system can be easily constructed using farm labour, which made it very popular in the 1960s and 1970s.  Then, as average unit size grew, this labour-intensive method started to be replaced with new methods of more automated group housing.

Cafeteria feeding popular in Denmark

Despite the advent of these new methods, such as electronic sow feeding (ESF) and trickle feeding, many Danish producers have opted for a system adapted from the old sow yards in order to benefit from the simplicity and reliability at the expense of some extra labour input and the relatively high initial cost.  They developed the “Cafeteria” system, which has a row of individual feeders that is used by each pen of sows in turn.  This design allows sows to be housed in larger groups because the layout is not constrained by the feeder dimensions.  It also reduces the cost significantly by utilizing one feeder for up to 8 groups of sows. The building design is simple, with straw bedded yards, usually holding sows bred within a week of each other, a scrape-through dunging area and then the row of feeders.  Producers using the system say that it is easy to operate, has no complicated equipment and requires little maintenance.

The major drawback in some people’s eyes is the higher labour input compared to other methods. Although automatically filled feed dispensers are used, the same amount of feed has to be dispensed to each sow in the group because sows often use a different feeder at each feeding session.  Therefore, the operator may have to give additional feed by hand to individual sows according to body condition.  Also, because there are multiple groups of sows using the same feeders, the operator must be present over an extended period of time to feed all the sows.  If locking rear gates are used, he must unlock the gates to release the sows after feeding, then place the sows back in their pen before letting another group out to feed.  The dispensers are filled while one group of sows is feeding, ready for the next group.

Klaxon signals eating time

Another apparent disadvantage of the cafeteria system is the stress caused by making sows wait for feed while they watch other groups go to the trough.  However, having watched this system in action, it is clear that sows become conditioned to feeding at a particular time and don’t get excited until very close to the time they are released.  This conditioning is quickly developed providing the operator follows a specific routine.  At one farm I visited, the operator used a klaxon to signal feeding times for each group – one blast for the first group, two for the second group and so on.  It was amazing to watch the reactions of the sows; those that were not due to be fed didn’t respond at all.  Certainly, if there is any stress, it isn’t reflected in the performance results, which appear to be similar to other types of sow housing.

Handling of solid manure and straw requires a significant labour input, but hard manual work is avoided by the use of machinery.  In addition, using straw adds cost, too.  Notwithstanding the list of disadvantages, the system is now widely used in Denmark because of its simplicity and reliability, although much less so in other European countries.

Slatted floors save space

Another method involves combining individual feeding stalls with a slatted exercise and dunging area, a system that has been adopted by producers in Denmark and a number of other countries. Generally termed “free access stalls”, this method saves space by utilizing the feeding stall as a lying area. It requires each sow to have its own stall, which makes the system rather expensive, despite the lower overall space requirement compared to the cafeteria system. The free access stalls must have a mechanism that locks the rear gate when the sow is in the stall but allows her to release it as she backs out, otherwise sows may attempt to enter another sow’s stall at feeding time. Layouts for free access stall systems usually involve two rows of stalls backing onto a common dunging area. Group size may range from 10-30 sows per pen.

Slatted free access stalls reduce labour requirement dramatically, but have some disadvantages for the sow.  First, although free to leave the stall and roam in the dunging area, sows often spend the majority of their time locked in the stall, because there is no bedding to root in.  While supporters of sow stalls always suggest this is because the sow feels protected in the stall and is happier there, the real reason is the sterile outside environment with a lack of things to do.  The second drawback is the potential for foot and leg injuries in slatted pens, especially after sows are mixed.  Very high quality slats with rounded edges can help to minimize this problem, but there is no doubt that injuries are significantly higher than in bedded systems.

Both dry feed and liquid feed can be used in free access stalls, usually dispensed automatically. Where dry feed is given, sow body condition can be controlled by adding additional feed by hand, but this is not possible with wet feeding.  Alternatively, sows can be grouped by condition at the time of mixing and the feed level adjusted for the group as a whole.

Other aspects of management vary between the cafeteria system and free access stalls.  In the latter system, where sows spend a lot of their time in the stalls, jobs such as scanning and vaccination are easier.  Because each sow has its own stall, they can be locked in at feeding time and the particular task carried out when convenient.  In a cafeteria system, where several groups use each set of feeding stalls, the tasks have to be carried out on sows while they are in the lying area, which is less easy.

Conclusions

These two systems using individual feeding stalls offer very straightforward options for housing groups of sows that are easy to understand by producers and have a low maintenance requirement.  Those with a phobia about electronics are especially drawn to them!  The systems can be built with either solid or bedded floors and can accommodate a range of group sizes, with about 40 being the practical maximum in most cases.  They are especially suitable for small-to medium sized units, typically up to 1000 sows. Their primary disadvantages compared to other alternatives are the higher labour input and relatively high capital cost.

Photo captions:

1. Danish Free access stalls-1 – A bedded free access stall system in Denmark

1. Chore-Time_GestationStall.jpg – A slatted free access stall system (photo courtesy Chore Time)

Dutch ESF design works well in Alberta

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A layout for group sow housing with electronic feeders that came from Holland has been working well for six years at Plain Lake Colony, Two Hills, Alberta.  And, while there are a few things that he’d do differently with the benefit of experience, Hog Boss Ben Hofer says that he is very happy with the system and wouldn’t go back to sow stalls.  In 2002, the Colony replaced its old 120-sow farrow to finish barn and constructed a new1200-sow unit producing isowean pigs.  “We felt that sooner or later, we would be forced into using group housing, but we were also optimistic about its potential,” says Hofer, who is a Director of Alberta Pork.  “We thought we could learn from the experiences in Europe and build a good system.”  Having looked at both electronic feeding (ESF) and floor feeding, he felt that sow welfare was much better in the ESF system.

The decision was taken to use slatted floors rather than straw bedding, something the Dutch have a lot of experience with. All parts of the pen are slatted, apart from the lying areas. Overall pen size is 54ft x 25ft, providing a total of 24 square feet per sow and there are 6 separate lying areas divided by concrete walls, three each side of a slatted dunging area. The Nedap feeders, from Holland, are located at the front of the pen, adjacent to the access alleyway, so that they can easily be observed.  “We chose the Nedap feeder because it had the fewest moving parts and the least amount of electronics on the feeder itself, which means less maintenance,” Hofer explains.  “Also, some people advised us to have a feeder with a sensor on the back gate to avoid sows returning to the feeder soon after eating, but we don’t believe that’s necessary with the layout we have.” When sows leave the feeder after eating, they have to walk along a slatted alley, where the drinkers are located, and around the back of the pen, in order to return to the feeding area, which prevents constant re-visiting of the feeder by dominant sows.  “This allows less dominant sows easier access to the feeder,” notes Hofer.

Each week about 60 sows are bred in order to achieve the farrowing target of 56 per week, with sows being transferred to the group pens within 7 days of breeding.  These “fixed” groups, with sows that were all bred in the same week, are much easier to manage.  A boar is taken into the pen to check for returns at 18-24 days and again three weeks later.  Scanning takes place at 30 days and again at around 56 days. Sows that are not pregnant are removed and returned to the breeding area.

Prior to breeding, gilts are housed in two large training pens adjacent to the breeding area, which each have two electronic feeders. Gilts enter the unit in groups of 40 at a weight of 110-115kg and there are 80 gilts per pen.  Any gilt that does not learn to feed quickly is placed in the feeder, but there have been very few problems with training, Ben Hofer notes.  “Less than 1% of gilts have failed to use the feeder,” he explains.  “Of the first 600 gilts, only one needed to be culled for this reason, so it’s hardly worth mentioning.”  Vasectomized boars are used for stimulation and are used to breed gilts at least once prior to natural service at second or third heat. This practice has been shown to increase first litter size.  After breeding, gilts are mixed in the weekly groups with sows, a practice that Hofer says he would prefer to avoid.  “If we did this again, I would have three large groups so that gilts and parity 1 sows could be housed separately from older sows,” he says. 

The benefits of individual feeding are apparent from the very even body condition of sows in the groups.  Feed levels are regularly adjusted according to condition and the feeder ensures accurate feed delivery.  Feed is dispensed in drops of 70 grams, every 20 seconds for sows and every 30 seconds for gilts, together with 50ml of water.   The feeding cycle starts at 9.00pm, which means that, by morning, the majority of sows have fed, allowing the operator to identify any that have failed to feed. “The computer prints out an attention list and sometimes there will be 4-5 sows that have not eaten,” explains Hofer.  “We don’t worry if they miss one day because most sows will eat the day after, but on day two we’ll check on the sows.”  The most common reasons for feeding not taking place are lost electronic ear tags, sows that are lame and sows on heat, he says.

Experience with the system has been very positive and production runs at around 26 pigs weaned per sow, despite a roof collapse last year that put a bit of a dent in the figures.  “It’s a nice environment to work in,” Hofer comments.  “You can walk in and work with the sows whenever you want and they are very quiet.” He also notes that sows get more exercise than those in stalls, which means that they have better muscle condition, leading to fewer problems at farrowing.  Observing and understanding sow behaviour is the key to successful management, Hofer says.  “You have to handle the animals and listen to what they are telling you, not tell them what to do!” he exclaims.

The only major aspect of the system that he would change is the type of slat. “We installed finishing slats and they are too narrow, which means we get some leg problems when sows fight after mixing,” he says. “I would prefer a slat that’s 5 to 6 inches wide, with a three-quarter inch gap to provide better support for the sow’s feet and to minimize injuries.”  Another minor problem occurs when pens are part filled. “The sows tend to dung in any area that is not used for lying, which then needs cleaning out manually,” notes Hofer. 

The need for maintenance and repair of electronic feeders is often cited as a problem, but experience at Plain Lake has been generally positive. “We had some initial problems with the electronic boards, but they were changed and have been working without a hitch for the last three years,” says Hofer.  “The only other thing we occasionally have a problem with is the springs on the entry and exit gates, but they are easy to change.” The barn staff does the maintenance themselves, with guidance from the manufacturer by phone if required.  “We’ve figured it out ourselves because most electricians and computer guys don’t understand it,” Hofer adds.

Overall, the verdict is that the system is a success and the design works well. Gilts and sows have adapted well to the feeders and production is good. Not only that but sows are calm and quiet to work with, spending most of their time asleep in the lying areas.  “Learning to get used to the system was a bigger learning experience for the people than the pigs,” Hofer laughs.

Photo captions:

1. Nedap feeder – The Nedap electronic feeder note the exit race that takes sows away from the feeding area once they have eaten

1. Gilt pen – One of the two gilt pens showing the layout of the lying area with the slatted area in between

1. Sows in lying area – Sows resting in the lying area

Controlling energy costs in the barn

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 As we approach winter in tight financial times in the swine industry, producer’s thoughts are turning to how to best manage their heating and ventilation systems to keep their utility and energy expenses in line.

There are few publicly available production cost summaries.  One of the best is the information from the Center for Farm Financial Management at the University of Minnesota (www.finbin.umn.edu).  For the 4 year period of 2004-2007, wean-to-finish cooperators in this record program reported an average fuel and oil expense of $1.43 per pig and a utilities expense of $1.04 per pig.  Fuel and oil includes both propane and any diesel and gasoline charged to the swine unit for such items as tractors, lawn mowers, power washers, generators, pickups, etc.  Utilities include electricity and telephone/internet.  Surprisingly, both fuel and oil and utilities varied little for the 4 year period.  There was no indication in the data set of what the mix is of curtain sided versus tunnel wean-finish facilities.

Finishers of feeder pigs reported fuel and oil expenses of $0.71/pig and utility expenses of $0.62/pig.  For farrow-weaning cooperators (average inventory of 950 sows), the fuel and oil expense was $0.49 per pig weaned while utilities were $1.03/pig weaned.

Once facilities are tightened for winter operation and have the appropriate insulation in the ceiling and side walls, the major causes of excessive heating expenses are:

1. improper minimum ventilation rates
2. improper furnace sizing
3. improper temperature selection

As I work with a large number of different types of facilities and production systems in the upper Midwest and Canada, I continually find that producers have a very limited knowledge of their ventilation system.  In most situations, they don’t have any idea of the capacity of their system, nor do they fully understand the impact of small ventilation mistakes on propane usage.

The MWPS (Midwest Plan Service) recommends the following minimum ventilation rates for moisture control in swine facilities:

            Weaning – 30 lb (13.6 kg)        2 cfm/pig

            30-75 lb (13.6- 34 kg)             3 cfm/pig

            75-150 lb (34-68 kg)               7 cfm/pig

            >150 lb (> 68 kg)                     10 cfm/pig

            Gestating female                       12 cfm/female

            Farrowing                                 20 cfm/crate

These numbers don’t mean much to most producers until you add in the approximate capacity of various sized fans.  While such items as shutters, discharge cones, hoods, etc have an impact on the capacity of exhaust fans in negative pressure systems, the following rough estimates are valuable starting points for producers trying to understand their ventilation systems:

                        Fan blade diameter, in.  Approximate CFM

12                                                                                        1200

14                                            2000

16                                                                                        2500

20                                                                                        4500

24                                                                                        6000

36                                                                                        12000

Suppose that you have a 300 head weaned pig room, and there is a 12” fan running as the minimum fan.  This fan has the capacity for 4 cfm per pig, which is twice the recommended minimum ventilation rate.  Either this fan needs to be replaced with a smaller fan, or it needs to be connected to a variable speed controller and set to operate at 50% of its rated output.  Notice that I didn’t say 50% of its rated speed or 50% on the controller.  Generally small variable speed fans achieve 50% of their rated output at approximately 65-70% of their rated rpms.  Twenty four (24) in. diameter fans often achieve 50% of their rated output at 60-65% of their maximum rpms.

There is quite a bit of variation between ventilation controllers on how they control variable speed fans.  Depending on the controller specifics, a 50% setting as the minimum speed may or may not be anywhere close to the intended 50% operating performance.

Improper furnace sizing is usually the result of installation of a furnace that is too large for the facility.  A furnace is large enough if is shuts off occasionally on the coldest day of the year.  When furnaces are too large, the end result is rooms that have large temperature variations when the furnace operates.  Many times this results in the temperature at the controller temperature probe rising beyond the room set point, resulting in the ventilation system increasing the ventilation rate to remove the extra heat, which means the room cools and the process starts again.

Most ventilation controllers log the high and low temperature for the last day or since the controller was last reset.  Using the controller’s temperature logs, the high, low and set point temperatures should recorded on a daily basis.  When the facility is operating in the heating mode, the daily high temperature should never be at or above the set point temperature.  If the high gets to or above the set point, this suggests that the ventilation system responded by exhausting the heat just added to the room with the furnace.  To prevent this from happening, as a starting point, set the furnace to shut off at 2^oF (1^oC) below the room set point temperature.

Many producers make the mistake of assuming that the set point temperature for the controller will be the room temperature at the temperature probe.  This is not the case.  In cold weather, if the furnace is set to turn off 2^oF below the set point, the room temperature should be 2^oF colder than set point as the furnace ‘OFF’ temperature is the control point for the room.

As pigs grow and produce increasing amounts of heat, the ventilation system responds by increasing the ventilation rate.  If stage 1 is variable speed and has a 2^oF bandwidth, when stage 1 is operating at 100% speed, the room must be 2^oF warmer than set point.  This is because the controller is set to not attain 100% speed unless the room is 2^oF warmer.  Set point is just the decision point from which the controller makes decisions as to which devices to operate in the ventilation and heating system.

Photo caption:  Nursery heater-1 – Having more furnace or heater capacity than required leads to more variable temperatures and higher energy bills

Can we feed mycotoxin contaminated feed to pigs?

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Deoxynivalenol (DON) is a mycotoxin produced by fungi which may contaminate cereal grains, including barley and wheat.  The contamination is especially problematic when wet, warm conditions prevail during the growing season.  The ingestion of grain that is severely contaminated by DON will cause overt symptoms such as vomiting (hence the common name “vomitoxin”).  Less dramatic, but more frequently observed symptoms, reduced feed intake and growth, will result when pigs consume feed with a lower concentration of the mycotoxin.  The Canadian Feed Inspection Agency suggests that 1 ppm mycotoxin in feed is a safe upper limit for swine.

There are several feed additives available which reportedly reduce the impact of the mycotoxin on the pig.  Modes of action vary, and include; binding the mycotoxin in the gut and preventing absorption, chemically transforming the toxin to decrease its toxicity, or enhancing immune system function. 

The overall objective of this experiment was to determine the effect of these feed additives on the performance of nursery pigs fed diets contaminated with DON.

We used 5 nurseries for this experiment, 24 pens per nursery and 4 pigs per pen.  Pigs were fed starter diets for 14 days before being offered the treatment diets (BW 9.02 ± 0.36 kg) for the next 14 days.  All starter diets contained in-feed antibiotics. 

Treatment diets were formulated to meet or exceed all requirements for pigs of this age.  A positive control diet contained no contaminated corn, while the negative control diet was formulated with contaminated corn but no feed additives.  Samples of corn which were pre-analyzed and shown to contain DON were used for 70% of the corn (35% in the final diet) in diets 2 to 12 to provide 2 ppm DON in the final diet. This concentration was chosen because a preliminary experiment indicated this amount would cause a measurable reduction in feed intake but would not be fatal.

Performance results are shown in Table 1.  Pigs on the positive control tended to be heavier than those on the negative control by day 22 (0.50 kg, P = 0.09).  Overall, pigs consuming diets contaminated with DON had reduced ADG and ADFI compared to those consuming the positive control diet free of DON (P < 0.001).  Weekly measurements of body weight and feed intake showed that the decline in feed intake preceded the decline in growth (data not shown).

Average daily gain and ADFI of pigs on the positive control was superior to those consuming the DON contaminated diet, regardless of the feed additive used.  None of the feed additives ameliorated the effects of DON on feed intake or gain.  Feed efficiency was unaffected by treatment (P > 0.05).

Based on a literature search and our preliminary experiment which indicated that 2 ppm would elicit a detectable decrease in feed intake but was non-fatal, we formulated the treatment diets to this level.  Analyses of the diets indicated a mean concentration in the DON containing diets of 1.99 ppm, however, the individual diet concentrations ranged from 1.57 to 2.61 ppm. 

The 1 tonne totes of contaminated corn were initially sampled from about 10 different locations within each tote to a depth of about 1 metre.  These samples, composited by tote, were sent to two different labs for analyses for DON and moulds.  The results were extremely variable, within and between the labs.  Results from lab “A” ranged from 2.4 to 5.5 ppm with a mean of 4.5 while the results from lab “B” were 2.2 to 9.6 ppm and a mean of 6.9.  We didn’t use the totes which displayed the most variability, however, the DON concentrations in our diets were still quite variable (Table 1). 

The above illustrates the difficulty of working with mycotoxins.  Obtaining representative samples for mycotoxin testing is very difficult, however it is imperative that a good sample is obtained or the results will be irrelevant.  It has been estimated that almost 90% of the error associated with mycotoxin testing can be attributed to the method used to obtain the original sample.  Because contamination within a field may be localized, a truck-load which has come directly from a field at harvest is likely to contain only discrete areas of contamination.  Moreover, mycotoxin contaminated grains are heavier, thus within a truckload or during storage, some stratification may occur. 

The “Grain Inspection, Packers and Stockyards Administration (GIPSA) of the USDA only recognizes samples which have been obtained using a probe.  Moreover, at least 4 samples should be taken from each lot, preferably 7 to 9, depending on the size and thickness of the trailer.  A 2000 to 2500 gram sample should be obtained.  This sample should be ground and then subsampled to obtain the approximately 100 gram sample required by the lab.  Producers are advised to contact the laboratory they will be using for the analyses to obtain specific sampling procedures and amounts required.

In summary, when nursery pigs were fed diets contaminated with approximately 2 ppm DON, feed intake declined by 10 % and growth by 7%.  None of the feed additives mitigated this response, however, actual concentrations of DON in the test diets varied. This variability is an illustration of the difficulties inherent in correct sampling and analysis for mycotoxins. 

Acknowledgements

Strategic funding was provided by Sask Pork, Alberta Pork, Manitoba Pork Council and Saskatchewan Agriculture and Food Development Fund.

Pork Insight was developed to address producer and industry needs for timely and accurate information related to pork production and is designed to help you find the information to help you fine -tune your operation. The Pork Insight database can be found online at www.prairieswine.com 

Table 1:  Analyzed concentrations of DON in treatment diets and effect on performance of nursery pigs (initial BW 9.02 kg).

^aDay 22 of the experiment, day 36 post-weaning.

^bUsed exclusively non-contaminated corn.

^cNegligible

^dFormulated to contain 2 ppm DON

^eDifferent from Trt 1, (positive control; P < 0.05).

^fDifferent from Trt 2, (negative control; P < 0.05).

Antibiotic-free pork production can be profitable

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As the market for pork becomes more and more differentiated, retailers and processors are looking for opportunities to meet the demand from consumers for products which meet their aspirations in terms of welfare, food safety and the environment.  This trend is well-developed in Europe where there is a wide range of pork categories such as outdoor reared, antibiotic free and organic.  Now antibiotic-free pork production is increasing significantly in the USA.  The question for producers is whether any loss in production efficiency and the additional costs involved are offset by the price premium received. European experience suggests that the additional cost per pig is in the region of $5.24.  However, a paper presented at the recent American Association of Swine Veterinarians by Darwin Kohler, James Schneider, and Chad Bierman demonstrated that removal of antibiotics on one farm did not lead to a significant loss of performance.

“The use of antibiotics in livestock feeds is meeting with increasing opposition,” note the authors. “The controversy revolves around the level of antibiotic fed to livestock for non-therapeutic use, which in turn causes an increase in bacterial resistance in humans and known allergic reactions or toxicity.”  The consumers of meat products today are asking for a more ‘natural’ food product.

European opposition has been stronger than in the US.  A ban of over-the-counter antibiotics was implemented in Sweden in 1986, Norway in 1992, Finland in 1996, Denmark in 1998, and Poland and Switzerland in 1999.  Current EU regulations state that antimicrobials used in either human or in veterinary therapeutic medicine are prohibited from use as feed-additive growth promoters in livestock.

Based on experience in Sweden and expert opinions, the likely performance effects of removing antibiotics and the cost implications are shown in Table 1.

Table 1: Technical assumptions of antibiotic ban

Trait                                        Most likely change

PSY                                         Decreased 1 pig

Weaning age                             Increased 1 week

Wean to 25kg                          Increased 5 days

FCR 25-114kg                                    Increased 1.5%

Pre-wean mortality                   Increased 1.5%

Grow/finish mortality                 Increased 0.49%

Net additives cost                     Increased $0.25/pig

Total cost/pig                            Increased $5.24/pig

Today, one form of antibiotic free (ABF) pork production is beginning to be used in the United States, note the authors.  It is based on no birth-to-market antibiotic use of any kind, no growth promotants, no natural or artificial hormones, no ionophores, no animal proteins and no animal by-products. “Can antibiotic free (ABF) pork production be more successful in the United States than indicated in Table 1?” they ask.

Case study farm shows little effect on performance

The case study reported in the paper is a 1,000-sow farrow to finish conventional confinement system.  This system has been closed to live animal introduction since 1996.  Management was interested in pursuing ABF pork production.  Small amounts of antibiotic had been used or needed in their herd, and a premium was being offered for antibiotic free pork.  Pigs are vaccinated for Mycoplasma hyopneumoniae and the herd is PRRS stable.  Gilts are raised internally and there is an off-site boar stud.  Since December 2004 no antibiotics, growth promotants, or animal by-products have been used in pigs from birth to market.  The farm maintains records of inoculations, illnesses and injuries, treatments, etc.  Very few pigs require treatment.  If prohibited medication is used in treatment, the pigs are marked for identification and are sent to conventional markets.  “Products such as zinc, copper, probiotics, enzymes, botanicals, enzymes, mannan oligosaccharides, egg antibodies, oil of oregano, and organic acids are allowed to be used in place of antibiotics in the ABF program,” explain the authors.  “However, these products are not necessary in this herd and are not in use as replacements for antibiotics.”

Table 2 shows the sow herd performance before and after ABF.  The ABF program does allow for antibiotic usage in the sow herd.  Antibiotic usage in the sow herd changed little over the six-year period.  Comparisons of traits between the ‘before ABF’ and ‘after ABF’ periods are both positive and negative and show no consistent advantage to the use of antibiotics.  Pigs had received an antibiotic at birth before ABF.  The expectation would be an increase in pre-weaning mortality. An increase from 8.2% to 9.9% did occur but was not reflected in pigs weaned per mated female per year.  Adjusted 21-day litter weaning weight is 13 pounds (5.9kg) heavier after ABF with an increase in pounds weaned per sow per year of 8%.  Only pre-weaning mortality was in agreement with the negative predictions shown in Table 1.

Table 2: Sow herd performance before and after ABF production

                                                            Before ABF                After ABF

                                                            Jul 02 – Dec 04                      Jan 05 – Jun 07

Average total pigs/litter                  11.4                             11.4

Average pigs born alive /litter                     10.4                             10.6

Pre-wean mortality (%)                   8.2                               9.9

Average age at weaning                            18.2                             20.5

Farrowing rate                                            93                               91.6

Litters/mated female/year                           2.56                             2.52

Pig wnd/mated female/year                        23.8                             23.8

Table 3 shows the herd’s finishing performance before and after ABF. Although previous reports show poorer performance with ABF production, few differences are noted here.  Only feed conversion showed a noticeable drop in performance.

Table 3: Finishing performance before and after ABF

Grow finish trait                                             2002 – 2004                2005 – 2007

Av. Lwt. of pigs entered (kg)                                18.2                             21.1

Av. Lwt of pigs sold (kg)                                      114.5                           118.4

Av. days to market                                               114.6                           115.2

Av. daily feed intake (kg/day)                    2.22                             2.36

Av. daily gain (g/day)                                            839                              839

Feed conversion ratio                                           2.65                             2.69*

*Feed conversion adjusted to common entry and sale weight

The only significant difference is in FCR and the authors calculated this to add $0.68 to production cost.  Finisher death loss was slightly higher after ABF resulting in a cost increase of $0.07 per market hog.  Average drug cost before ABF of $0.18 per market hog resulted in a saving after ABF.  Pigs were no longer sold grade and yield during the last three years therefore carcass yield and percent lean were assumed to be unchanged.

ABF premium gives bigger margins

Additional ABF premium was calculated as the difference received in harvest price by this herd versus other similar herds and selling grade and yield to the same market that this herd had been selling to before ABF.  Using this method, the additional ABF premium was estimated to be $4.26 per head in 2005 and 2006.  “The ABF premium tends to inversely fluctuate with the base grade and yield price and is much higher today when market prices are lower than in the previous two years, note the authors.  “Current additional ABF premium for November 2007 is $16.62 per head.”   Overall, taking the differences in performance and costs into account, there was a net average benefit of $7.89 for ABF production compared to the period when antibiotics were used.

Little or no differences in production numbers were observed on this farm.  The increase in cost of production has been shown to be $0.32 per head.  “Success is attributed to the use of appropriate genetics, maintaining a closed herd and maintaining a high level of biosecurity to keep pathogens out,” say the authors.  “Good management in areas of proper husbandry, nutrition management, environmental control, prompt treatment or removal of sick pigs and attention to detail is essential.”  Not only does this case study illustrate the feasibility of ABF production, but it demonstrates significant profit potential in today’s niche markets, they conclude.

Water medication systems

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Increasingly, pork production systems around the world are using drinking water as the delivery mechanism for a variety of nutritional and health related products. These products can range from acidifiers and probiotics at weaning to vaccines to antimicrobials to nutritional supplements, etc. throughout the growth process.

Delivery of these products via the drinking water system most often relies on a pump and mixing chamber to incorporate these materials into the drinking water. In the US, most medicators are based on a fixed ratio of 1 part stock solution per 128 parts drinking water.

With the increased usage of water delivered products has come an increase in the risks associated with these delivery systems. The following are common mistakes made by US producers in using water as the delivery mechanism for a variety of products.

Many products, especially vaccines, require that the pigs consume the product within 4-6 hours of reconstitution. Recent data from Iowa State University suggests that 100% of weaned pigs will visit a nipple drinker within a 4-6 hour time period beginning at 8 am. Thus, timing of delivery of the product to the drinking water is of critical importance if all pigs in a population are to receive an adequate amount of the product.

Figure 1:  Effect of season on 24-hour water usage pattern in a 1200 head wean-finish facility 5 months after weaning in central Nebraska. Data courtesy Dicamusa.com

In thermo-neutral conditions, both feed and water usage generally begin increasing around 6 am in the morning, with a mid-morning peak around 10 am, followed by the day’s peak in disappearance at 2-3 pm. By 6 pm, both feed and water intake have returned to a relatively low level. There is very little feed or water intake during the night. Drinking water disappearance, and by association feed disappearance, is minimal during late evening and early morning hours.

If pigs are grown to slaughter in warm conditions (summer conditions in much of the upper Midwest), these patterns change. Feed and water intake now begins at approximately 4 am, with the morning peak at 8-9 am. This morning peak is followed by a mid-day decline in feed and water disappearance, with a resumption in intake in the early evening hours. Even in these conditions, there is limited drinking water usage during late evening or early morning hours.

In North America, commonly used water medicators are often rated at a capacity of up to 26.5 litres (7 US gal)/minute. In almost every instance, they are connected to water lines in the facilities that have a capacity of 21 liters (5.5 gal) per minute (19 mm/3/4” inside diameter piping). This suggests that the sizing of the water delivery pipes in the facility are the limit to water flow. However, it is quite common to see water medication devices connected to water delivery lines with 13 mm (1/2”) diameter hoses, which have a capacity of only 9.5 liters (2.5 US gal)/minute. A common complaint by producers who make this mistake is ‘my pigs don’t like the medicine in the water because water intake always decreases when I water medicate’. The real cause of the decline in drinking water is the restriction in water flow associated with the water medication device connection.

A second common mistake is a stock solution reservoir that is too small. Many producers assume that water usage is relatively stable throughout a 24-hour period. If the pig’s drinking water usage is 4 litres (1.1 US gal) per day and there are 1000 pigs in the facility, the total stock solution required at 1:128 dilution is 31.25 litres (8.3 US gal). If the stock solution reservoir is filled twice daily, this suggests that a 16 litre (4.2 US gal) capacity reservoir is adequate. In reality, almost 70% of the drinking water is consumed from 6 am to 4 pm. If the reservoir is filled at 7 am and 5 pm, the capacity of the reservoir needs to be at least 22 (5.8 gal) litres or there is a risk that the reservoir will be empty prior to the next recharge, resulting in pigs drinking water that has no stock solution added.

Many producers fail to account for the impact of pressure regulators on water flow. If the incoming water line pressure is 275 kPa (40 psi) and a regulator is used to lower the line pressure to 140 kPa (20 psi), water flow is reduced to 71% of what it was at the original pressure. This suggests that sizing of water lines is even more important than many producers think.

Water filters are often installed in delivery lines to deal with sediment issues associated with the on-site well, etc. In some instances, the location of the filters makes them very difficult to routinely flush or clean, while in others, a routine of regular maintenance is not planned for.

Finally, don’t overlook the water meter as a flow restrictor in the water line. Many swine facility contractors install water meters with 16 mm (5/8”) orifices that have 19 mm (¾”) NPT connectors. These meters are generally $50-75 cheaper than meters with larger orifices.

Photo Captions:

Medicator-1 – Two medicators for 2400 wean-finish pigs with 125 litre (33 gal) stock solution reservoir

Medicator-2 – Water medicator rated at 26.5 litres (7 gal)/minute incorrectly connected to 19 mm (3/4”) inside diameter piping with 13 mm (1/2”) washing machine hose.

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