Granulomatous lymphadenitis associated with Actinobacillus pleuropneumoniae serotype 2 in slaughter barrows

Posted in: Production by admin on August 22, 2011 | No Comments

This study evaluated the occurrence of granulomatous lymphadenitis and its association with Actinobacillus spp. in 151 653 slaughtered pigs. Markedly enlarged pulmonary hilar, mediastinal, mandibular or hepatic lymph nodes were detected in 6 castrated males. The cut surfaces showed multifocal yellow-white lesions. Histologically, gram-negative bacilli were visible in the centers of the lesions with asteroid bodies, epithelioid cells, and multinucleated giant cells. Dense fibrous connective tissue surrounded these granulomatous lesions. Immunohistochemically, the organisms reacted with polyclonal antibodies against Actinobacillus pleuropneumoniae serotype 2 in all 6 barrows. The organism was isolated from the lymph nodes of all 6 animals. The results indicate that the granulomatous lymphadenitis was associated with A. pleuropneumoniae serotype 2 and the disorder had a tendency to occur in slaughter barrows.

Peracute selenium toxicosis followed by sudden death in growing and finishing pigs

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Fattening pigs (n = 751) showed progressive apathy, paralysis, and sudden death after accidental ingestion of excessive concentrations of selenium in mineral feed. Selenium concentrations of 1.09 to 1.32 mg/L in the serum confirmed the diagnosis. Within 3 d all pigs had died spontaneously or were euthanized due to the grave prognosis and on welfare grounds.

Prevalence of Clostridium difficile in retail pork

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Clostridium difficile was isolated from 1.8% (7/393) of retail pork samples obtained from 4 Canadian provinces. Five ribotypes and 3 toxinotypes were identified. Three isolates were indistinguishable from the international outbreak strain ribotype 027 and were toxinotype III. Although the implications for food safety practices remain elusive, the frequency of toxigenic isolates and isolates indistinguishable from known human pathogenic strains suggests contaminated pork may be a source of C. difficile in humans

An investigation into human pandemic influenza virus (H1N1) 2009 on an Alberta swine farm

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On May 2, 2009 the Canadian Food Inspection Agency notified the World Organization for Animal Health that an emerging novel influenza A virus (pandemic H1N1 2009) had been confirmed on a swine farm in Alberta. Over a 4-week period pigs in this farrow-to-finish operation were clinically affected by respiratory disease consistent with an influenza A virus infection and the presence of active viral infection was confirmed in all production areas by real-time polymerase chain reaction (RT-PCR). Despite clinical recovery of animals, there was reluctance by purchasers to receive animals from this operation due to concerns about the effect on both domestic and international markets. The owner decided to depopulate the entire herd due to impending welfare issues associated with overcrowding and economic concerns resulting from the inability to market these animals. Carcasses were rendered or composted and did not enter the human food or animal feed chain. The source of virus in this herd was determined to be an infected human. Zoonotic transmission to 2 individuals responding to the outbreak was suspected and recommendations to prevent occupational exposure are discussed.

Full text is available by subscribing to the Canadian Veterinary Journal

Epidemiological investigation of femoral fractures in market pigs and the associated economic implications

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The cause of an increased number of femoral fractures in market pigs from a single producer is described. Blood chemical, bone ash, radiographic, and feed analyses revealed that the fractures were caused by insufficient calcium in the diet. Associated economic and welfare implications are discussed.

Decreased mortality of weaned pigs with Streptococcus suis with the use of in-water potassium penicillin G

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This study evaluated the efficacy of potassium penicillin G in drinking water of weaned pigs to reduce mortality and spread of infection caused by Streptococcus suis. A total of 896 18-day-old weaned pigs were randomly assigned to either treatment with potassium penicillin G in-water (Treated), or no treatment (Control). The outcomes analyzed were total mortality, mortality due to S. suis, and overall counts of S. suis colonies. The risk of mortality due to S. suis and total mortality were significantly increased in the Control group compared with Treated pigs. Bacterial culture of posterior pharyngeal swabs indicated that Control pigs were significantly more likely to have $ 1000 colonies of S. suis per plate than were Treated pigs. This study demonstrates that potassium penicillin G administered in drinking water is effective in reducing mortality associated with S. suis infection and reducing tonsillar carriage of S. suis.

Crop Nitrogen and Phosphorus Utilization following Application of Slurry from Swine Fed Traditional or Low Phytate Corn Diets

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Field application of swine (Sus scrofa) slurry provides essential nutrients for crop production. The N to P ratio for slurry is lower than needed by most crops resulting in P accumulation when applied at N rates required for crop growth. Low phytate corn (Zea mays L.) (LPC) contains similar amounts of total P but less phytate P than traditional corn (TC) resulting in improved P bioavailability and reduced P excretion by monogastric animals. While manure from swine-fed LPC diets has a higher N to P ratio than that from TC diets, field studies comparing crop utilization of nutrients from LPC manure have not been conducted. A field study was conducted to compare N and P utilization by no-tillage rainfed sorghum [Sorghum bicolor (L.) Moench.] receiving three annual surface applications of nutrients (inorganic fertilizer, LPC slurry, and TC slurry) and by irrigated corn receiving one incorporated application of nutrients. Sorghum grain and total dry matter N utilization exhibited a year by treatment interaction but total dry matter N utilization was similar for both manure types in all years (61.2 % for TC and 53.8 % for LPC). Grain P utilization was similar for inorganic fertilizer and manure but differed among years (44.4% in 1999, 25.1% in 2000, and 57.0% in 2001). Corn grain N and P utilization did not differ among nutrient sources in the year of application (50.7% for N and 40.4 for P) and increased little in the year following application (62.2 % for N and 50.2 % for P). Crop N and P utilization from LPC manure and TC manure was similar and nutrient guidelines developed for TC swine slurry should also apply for LPC slurry.

PDF provided from Agron. J. 100:4 pp: 997-1004 (2008), with permission, copyright American Society of Agronomy.

Incorporation of oats into swine diets

Posted in: Production by admin on August 12, 2011 | No Comments

Introduction

The high fibre content of oats, which are widely grown in Western Canada, has historically limited their use as an energy source in swine rations. In fact, oats have been shown to have approximately 10% less digestible energy (DE) than barley and 17% and 19% less DE than wheat and corn respectively. However, a recent seminar given at the Western Nutrition Conference in Saskatoon (September, 2007) showed that grower and finisher pigs can be fed diets containing up to 25% oats without compromising growth performance.

This article will review the nutritional profile of oats and will provide recommendations for how oats can be used in swine diets to reduce feeding costs while maintaining performance.

An overview of oats

Canada is the second largest producer of oats (3.3mt) after Russia (4.6mt), but before the USA (1.7mt), Poland (1.2mt) and Finland (1.2mt). Oats are a common crop in Canada and conditions in Manitoba are thought to be ideal. Oats were the third most important crop in the US but are currently in decline.

In comparison to other cereals, oats have a high fibre content as the hull comprises about 23% of the whole grain. Thus, they are lower in energy value than other cereals, making them a popular cereal for ruminants and horses, but traditionally less so for poultry and pigs. Additionally, the nutritional composition varies widely with variety, climate and fertilization.

Oats have a high oil level and relatively good protein quality compared with other cereals. The fibre fraction is highly lignified, resulting in reduced digestibility. The soluble fibre in oats is largely due to non-digestible b-glucans located primarily in the endosperm cell wall. In general, oat fibre has a low water holding capacity and is therefore not particularly good at reducing constipation in monogastric animals.

Table 1: Nutritional composition of oats in comparison to barley

                               Nutrient                      Barley             Oats

                          Dry matter (%)                      87                    87

                          Crude protein (%)                 9.5                  10.5

                          Crude Fibre (%)                    4.7                  11.6

                          NDF (%)                             17.5                 38.4

                          Oil (%)                                  1.7                   5.2

                          Ash (%)                                2.2                   2.5

                          DE (MJ/kg)                           13                  11.0

                          NE (MJ/kg)                          9.6                   8.2

        Source: Atlas & INRA, 2002

The feeding value of oats

As with other high fibre ingredients, the feeding value of oats is best determined by assessing how inclusion affects the overall diet’s fibre level. This is because, as fibre increases, the transit rate of digesta through the gut of pigs decreases, resulting in a reduction in performance through reduced digestibility and increased mucus production. As a result of this, oats must be limit fed depending on the animal’s stage of development.

Table 2: Potential savings when including oats into various hog rations

Stage of                  No oats           Oats at % limit           Savings           Recommended

animal                    ($/MT)                   ($/MT)                 ($/MT)           maximum oat limit

                                                                                                                        (% of diet)

Grower pigs                $235                         $228                         $7                             25

Finisher pigs                $229                         $222                         $7                             25

Dry sows                    $222                         $217                         $5                             20

Diets assume the following prices/MT: Wheat $215; Barley $205; Soya $300; Oats $170.

Table 2 shows that there is a potential to save on feeding costs but that the highest savings can be realized with growing and finishing pigs. Due to limited research examining the nutritional value of oats within sow diets, a conservative limit of 20% is recommended.  Assuming a herd size of 250 sows, farrow to finish, this could equate to a feed savings of approximately $660 per month or $8000 per year.

Oats and Net Energy

An important point to remember is that higher oat inclusions only works when diets are formulated to net energy (NE) and digestible amino acids. Again, this is because of the high fibre percentage, because diets formulated to ME or DE will decrease in NE as oat levels increase. Reducing NE through inclusion of high fibre ingredients has been shown time and again to reduce performance.

Table 3: Effect of dietary level of oats on grower and finisher pig growth performance^{1, 2}

                                                                                Level of oats (%)

                                                0                            25                          50                 P-value

Grower (27.5 – 67.5kg)    

      Daily gain (kg)                   0.83                       0.83                       0.85                 0.67

      Daily intake (kg)                1.88                       1.87                       1.89                 0.85

      FCR                                  2.27                       2.26                       2.25                 0.78

      NE                                    2027                      2025                      2041

      NE w/out tallow                 n/a                         1991                      1955

Finisher (67.5 – 80kg)

      Daily gain (kg)                   1.16                       1.16                       1.17                 0.78

      Daily intake (kg)                2.89^a                      2.84^a                      3.08^b                0.01

      FCR                                  2.51                       2.49                       2.70                 0.06

      NE                                    2033                      2058                      2075

      NE w/out tallow                 n/a                         1997                      1960

¹ Source: Zalinko et al., 2007 Proc. W. Nutr. Conf. pp 253

² Values within a row not sharing similar superscripts differ significantly

One should note that in the study outlined in Table 3, NE levels were balanced by inclusion of tallow. If this had been ignored the amount of energy each pig consumed per kg of gain would have been sub-optimal and growth would have deteriorated. However, if tallow or vegetable oil cannot be handled in a given on-farm mixing system, adequate levels of dietary energy can be obtained by using wheat or corn with similar financial savings being realized.

Some points to consider

What are the nutrient levels?

It is generally a good idea to send a sample of your oats for nutrient analysis. This will allow for more accurate formulation and will prevent the feeding of rations containing excess amounts of NDF (Neutral Detergent Fibre).

Will you be pelleting your feed?

Oats tend to give a poorer pellet quality than other cereals because the fibrous husk tends to give pellets fracture lines. Thus, one should consider limiting oats to 7.5% of the diet and apply a fine grind if pellets are manufactured.

Should you include an enzyme?

In Europe, where high fibre ingredients such as mill run are commonly used in pig rations, so too are enzymes. However, inclusion costs of enzymes in North America are much higher than in Europe, which typically limits their addition into starter rations.

So does it make financial sense to use an enzyme? A recent article published by researchers at the University of Saskatchewan examined the effect of supplementing grower and finisher diets containing 40% oats with a mixed β-glucanase / xylanase enzyme product. The study showed that crude protein, dry matter and gross energy digestibilities all increased by 3% as a result of enzyme supplementation. If enzyme inclusion costs approximately $3/tonne, nutrient digestibility would have to improve by around 2% to break even. Based on this study, and many other enzyme focused studies, it would seem likely that enzyme inclusion would make economic sense when diets are formulated to contain high levels of oats. 

Conclusions

Inclusion of oats at the levels recommended in this article is nutritionally and economically viable. However, in order to reap these benefits, one must be mindful of the method of formulation being applied to their rations. The NE system combined with digestible amino acids currently used by Nutrition Partners is a good way of ensuring the risk of reduced nutrient digestibility and animal performance is minimized.

Effects of chronic stress: A comparison between tethered and loose sows

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The present study aimed to investigate whether long-lasting, recurrent tethering of sows leads to enduring effects on measures that may be indicative of chronic stress. Sows that had experienced tethering for about 1.5 or 4.5 years and age-matched sows kept in a social housing system (loose sows) were compared. Immediately after slaughter, blood samples were taken to measure plasma cortisol levels, and the brain, spleen, and adrenals were dissected and weighed. Gene expression in the frontal cortex and hippocampus was analyzed. Plasma cortisol levels were higher in the tethered sows than in the loose sows. The older, but not the younger, tethered sows had heavier adrenal glands than their loose counterparts. The weight of the spleen was not affected by the housing conditions, but the pituitary gland was lighter in tethered sows than in loose sows. Microarray analyses revealed an increased expression of β-globin mRNA in the hippocampus and to a lesser extent in the frontal cortex of the older tethered sows, compared with the older loose sows. Taken together, the findings indicate that chronically stressed pigs develop depression-like symptoms. However, it can be questioned whether the pig subjected to repeated, long-term stress can be regarded an animal model of major depression.

To view this complete article please visit: http://www.journals.elsevier.com/physiology-and-behavior/

Prenatal flavor exposure affects growth, health and behavior of newly weaned piglets

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Young animals can learn about flavors from the maternal diet that appear in the amniotic fluid and mother’s milk, which may reduce neophobia for similarly flavored food types at weaning. Flavor learning may be beneficial for piglets, which after the rather abrupt weaning in pig husbandry frequently show a period of anorexia, reduced health, and stress-induced behaviors. We investigated the effects of pre- and postnatal flavor exposure through the maternal diet on acceptance of a similarly flavored food and subsequent growth, health and behavior of newly weaned piglets. Sows were offered anise-flavored (F) or control (C) food during late gestation. Piglets were cross-fostered after birth, with each sow fostering 5 piglets from an F sow and 5 from a C sow. During lactation, sows were offered F or C food, resulting in FF, CF, FC and CC piglets. Piglets were weaned on day 25 and were given both control and flavored food for two weeks using a double food choice approach. The flavored food was not preferred. Yet, prenatally exposed animals showed a higher food intake and a higher body weight in the first days after weaning, and a lower occurrence of diarrhoea than non-exposed piglets. Prenatal exposure also increased the latency to fight, and reduced oral manipulation of pen mates and mounting during the first two weeks after weaning. Prenatal exposure, but not postnatal exposure alone, to anisic flavor through the maternal diet reduced weaning-associated problems in piglets and enhanced their health and welfare in the period after weaning.

To view this complete article please visit: http://www.journals.elsevier.com/physiology-and-behavior/