Dietary Lysine Requirement is Greater in Latethan in Early-Gestation in Sows

Posted in: Ontario Pork, Pork Insight Articles by admin on August 13, 2010 | No Comments

The objective of this study was to determine the lysine requirement of a population of 2nd and 3rd parity sows in early- (day 24 – 45)
and late- (day 86 – 110) gestation. Pregnant Hypor Hybrid (Hypor Inc) sows (n=7; 185.7±9.6 kg BW) were  adapted to individual intakes of a semi-synthetic diet containing 14.0 MJME/kg. Each sow received 6 different test diets, in random order, from 60 –150% of the requirement suggested by NRC (1998) in early- and from 60 –185% of the requirement suggested by NRC (1998) in late-gestation. Actual dietary lysine intakes ranged from 7.5 – 19.3 g/d in early- and 8.1 – 23.7 g/d in  late-gestation. Differences between the dietary lysine requirement for earlyand late-gestation was determined by measuring oxidation of the indicator amino acid L-[1-13C]-phenylalanine (Phe) during a primed-constant oral infusion. The average number of piglets born alive was 13.7±1.9, but ranged from 4 to 20. The average piglet birth weight was 1.5±0.1 kg. Sows gained 600 g/d from breeding and weighed 258.8±8.3 kg before farrowing. Breakpoint analysis of Phe oxidation indicated that the lysine requirement of 2nd parity sows was 13.1 g/d and 18.7 g/d in early- and late-gestation, respectively. For 3rd parity sows, the dietary lysine requirement was 8.2 g/d and 13.0 g/d for early- and late-gestation, respectively. Phase feeding at least two diets would improve productivity by more correctly providing the necessary nutrients for the growth of the placenta, the piglets, and the mammary gland.

Dietary Lysine Requirement is Greater in Latethan in Early-Gestation in Sows

Posted in: Ontario Pork, Pork Insight Articles by admin on August 12, 2010 | No Comments

The objective of this study was to determine the lysine requirement of a population of 2nd and 3rd parity sows in early- (day 24 – 45) and late- (day 86 – 110) gestation. Pregnant Hypor Hybrid (Hypor Inc) sows (n=7; 185.7±9.6 kg BW) were adapted to individual intakes of a semi-synthetic diet containing 14.0 MJME/kg. Each sow received 6 different test diets, in random order, from 60 –150% of the requirement suggested by NRC (1998) in early- and from 60 – 185% of the requirement suggested by NRC (1998) in late-gestation. Actual dietary lysine intakes ranged from 7.5 – 19.3 g/d in early- and 8.1 – 23.7 g/d in late-gestation. Differences between the dietary lysine requirement for early and late-gestation was determined by measuring oxidation of the indicator amino acid L-[1-13C]-phenylalanine (Phe) during a primed-constant oral infusion. The average number of piglets born alive was 13.7±1.9, but ranged from 4 to 20. The average piglet birth weight was 1.5±0.1 kg. Sows gained 600 g/d from breeding and weighed 258.8±8.3 kg before farrowing. Breakpoint analysis of Phe oxidation indicated that the lysine requirement of 2nd parity sows was 13.1 g/d and 18.7 g/d in early- and late-gestation, respectively. For 3rd parity sows, the dietary lysine requirement was 8.2 g/d and 13.0 g/d for early- and late-gestation, respectively.  The dietary requirement for lysine in gestation was greater than previously reported by NRC (1998). Phase feeding at least two diets would improve productivity by more correctly providing the necessary nutrients for the growth of the placenta, the piglets, and the mammary gland.

Free space utilization of sows in free access stalls

Posted in: Prairie Swine Centre by admin on August 4, 2010 | No Comments

With announcements by the largest producer/packers in both the USA and Canada that they will transition all of their production facilities to group housing for sows over the next ten years, all North American producers are anticipating a change to group housing. This can be a challenging step for producers, and it is made more difficult by the lack of scientific information currently available on the implementation and design of alternative systems. Group housing systems can be complex to initiate and require greater input from stockmen, however when done correctly, can produce sows that are able to socially interact with one another and have the freedom to move. Sows currently housed in gestation stalls have almost no opportunity to exercise and perform natural behaviours, leading to a possible decline in well-being. It has previously been suggested that exercise is required to maintain bone composition and strength, and when exercise is insufficient, calcium will be mobilized from the bone itself (Lanyon, 1984 and 1987). Exercise is important to allow the development of bone and muscle to their maximum potential. Decreased muscular strength (which is commonly observed in confined sows) can contribute towards difficulty in lying and standing, and higher susceptibility to lameness due to increased slipping. Lack of exercise in confined housing has also been shown to cause bone weakness in other species. For example, confined laying hens have significantly weaker humeri and tibiae than birds housed in non restrictive environments (Knowles and Broom, 1990). One possible alternative to gestation crates are free access or walk-in/lock-in stalls. This system provides sows with opportunities to interact as a group in a communal area, or remain alone in a free access stall. There is some concern regarding the degree to which sows use free space group areas, and how to avoid aggression, particularly when new sows are mixed into a group. This study investigates the implementation of walk-in/lock-in stalls for group housed sows. More specifically, the objectives of this study were to compare two different pen configurations by determining the proportion and type (size/parity) of sows that are using the free space areas of the walk-in/lock-in stalls, and also how sows utilize the free space areas.

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Comparative evaluation of infrared radiant and forced-air convection heating systems for hog barns

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Comparative evaluation of infrared radiant and forced-air convection heating systems for hog barns

The overall goal of this study was to compare a gas-fired infrared radiant heating system with a conventional forced-air convection heater for supplying supplemental heat to pig production rooms. Forced-convection air heaters that are widely used in commercial barns typically heat the air near the ceiling, and in turn the heated air had to be physically moved using fans and inlets to the animal occupied zones. A radiant heater transmits heat to surfaces (i.e. floor, pen wall, animals, etc) through radiation heat transfer, thus facilitating the heating process at the pig’s level and at the same time the heated surfaces serve as a thermal reservoir that help maintain the setpoint conditions in the room. Because of this difference in mode of heat transfer, it is hypothesized that infra-red radiant heating could help reduce heating costs in pig production rooms.

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Nutritional Value of Flaxseed for Swine and its Effects on Carcass Fatty Acid Profile

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Canada, or more specifically Western Canada, is the largest producer of flaxseed in the world, producing over 0.9 million tonnes last year.  Almost 75 % of the crop will be exported, more than 60 % going to Belgium. Flaxseed possesses properties which make it unique as a feed ingredient for swine. One of its nutritional attributes is, of course, the oil (also called linseed oil) which is rich in omega-3 fatty acids.  Flaxseed contains 41% oil and the oil contains 57 % omega-3 fatty acids (primarily alpha linolenic acid or ALA) making it the richest plant-based source of ALA.

Prairie Swine Centre, in collaboration with Agriculture and Agri-Food Canada, Lacombe Research Centre, the University of Alberta and the University of Saskatchewan, has conducted a series of experiments examining the use of flaxseed as an ingredient in swine diets. The overall objective of these series of experiments was to develop low-cost feeding protocols which will result in a consistent enrichment of the carcass with ALA without compromising growth or carcass quality.

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Expression of chemokine decoy receptors and their ligands at the porcine maternal–fetal interface

Posted in: Ontario Pork, Pork Insight Articles, Production by admin on August 3, 2010 | No Comments

Successful pregnancy requires coordinated maternal–fetal cross-talk to establish vascular connections that support conceptus growth. In pigs, two waves of spontaneous fetal loss occur and 30–40% of conceptuses are lost before parturition. Previous studies associated these losses with decreased angiogenic and increased inflammatory cytokines. Chemokines, a sub-category of cytokines, and decoy receptors control leukocyte trafficking, angiogenesis and development. The availability of chemokines is regulated by three non-signalling decoy receptors: chemokine decoy receptor (D6), Duffy antigen receptor for chemokines (DARC) and Chemocentryx decoy receptor (CCX CKR). We hypothesized that the expression of these receptors and their chemokine ligands regulate the porcine pregnancy success or failure. Here, we describe for the first time the transcription and translation of all three decoy receptors and several chemokine ligands in endometrium and trophoblast associated with healthy and arresting conceptuses at gestation day (gd) 20 and gd50. Among decoy receptors, transcripts for DARC were significantly reduced in endometrium, whereas that for CCX CKR were significantly increased in endometrium and trophoblast at gd50
arresting compared with healthy sites. However, western blot analysis revealed no differences in decoy receptor expression between healthy and arresting tissues. Transcripts for decoy receptor ligands CCL2, CCL3, CCL4, CCL5, CCL11, CCL19, CCL21, CXCL2 and CXCL8 were stable between healthy and arresting littermates. Quantification by SearchLight chemiluminescent protein array confirmed ligand expression at the protein level. These data indicate that decoy receptors and ligands are expressed at the porcine maternal–fetal interface and dysregulation of decoy receptor (DARC and CCX CKR) transcripts occurs at sites of fetal arrest.

Conjugated linoleic acid differentially regulates fat deposition in backfat and longissimus muscle of finishing pigs

Posted in: Production by admin on July 30, 2010 | No Comments

This experiment was conducted to investigate the effects of extracellular CLA on proliferationand differentiation of cultured adipocytes and its dietary supplementation on backfat and intramuscular fat deposition in finishing pigs. Seven-day-old Duroc × Landrace × Large White pigs were killed to obtain adipocytes for culture. Adding 3 forms of CLA (cis-9, trans-11 CLA, trans-10, cis-12 CLA, or CLA mixture) at concentrations of 50, 100, 150, 200, 250, 300, 350, and 400 μM to culture medium for 10 d increased cell differentiation (P < 0.05). In addition, 3 forms of CLA enhanced cell proliferation (P < 0.05) at 50 to 350 μM and inhibited cell proliferation (P < 0.05) at a concentration of 400 μM. Seventy-two Duroc × Landrace × Large White crossbred gilts weighing 60.7 } 2.8 kg were randomly assigned to 1 of the 3 dietary treatment (control, 1.25% CLA, and 2.5% CLA). The pigs were slaughtered at 100.0 } 5.7 kg. Dietary CLA increased lean percentage (3.5 to 4.7%; P = 0.07), intramuscularfat content (P < 0.05), and shear force (P < 0.05), but reduced 10th- and first-rib backfat depth (P ≤ 0.05) and lipid oxidation (P < 0.05). The adipocyte diameter in backfat or LM was not affected by CLA. Supplemented CLA reduced Δ9-desaturase activity (P < 0.05) in backfat and LM, as well as fatty acid synthetase activity and lipoprotein lipase activity in backfat, but enhanced (P < 0.05) adipocyte fatty acid binding protein mRNA content in LM. These data indicate that dietary CLA regulates fat deposition by affecting adipocyte proliferation, adipocyte differentiation, gene expression, and key metabolic enzymes of lipid metabolism.

For more information the full article can be found at http://jas.fass.org/

Comparison of the Effectiveness and Economic Costs of Two Production Scale Polyacrylamide Assisted Solid/Liquid Separation Systems for the Treatment of Liquid Swine Manure

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This study evaluated and compared the effectiveness and economic costs of a polyacrylamide (PAM) assisted continuous gravity belt thickener and a PAM assisted inclined stationary gravity screen separator equipped with a backwash spraybar, each in tandem with an inclined stationary gravity screen-roll press separator to separate the solid and liquid components of liquid swine manure (raw slurry) under production scale operating conditions. The separation systems were operated from June through December processing 7,222,725 L (1,908,048 gal) of raw untreated slurry (RS1). Both treatments, gravity belt thickener and gravity screen, showed significant reductions of 84.9% and 97.8% for Settleable Solids, 93.2% and 93.7% for Total Suspended Solids, 63.7% and 69.5% for Chemical Oxygen Demand, 23.3% and 31.8% for total Nitrogen, and 52.3% and 60.5% for total Phosphorus, respectively, in the treated effluent. The cost for separation with the gravity belt thickener system was 0.474 per L (1.791 per gal) of raw slurry. The separation cost for the gravity screen system was 0.402 per L (1.518 per gal) of raw slurry. Application costs for irrigating the separated effluent generated from either system added another 0.061 per L (0.234  per gal) of raw slurry. Either of these solid liquid separation systems would be an effective and economically viable alternative to current disposal methods while providing additional operational and environmental benefits.

Characterization of an experimental water-cooled cover for sows

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Heat stress relief for sows in hot and humid climates remains a challenge. This study investigates a cooling method that is intended to enhance heat dissipation from sows. The experimental device was an aluminium cover (1.5 m long by 0.65 m wide and either 0.8 m or 0.95 m high) fitted with water-cooled pipes (25 mm diameter, spaced at 100 mm, 150 mm or 200 mm) and attached to the frame of the gestation sow crate. Performance was evaluated for cooling water temperatures of 15 or 20 °C under ambient summer conditions. Results showed the black-globe temperature (BGT) in the simulated sow-occupied zone (SOZ) was reduced by the addition of the aluminium canopy by 3 °C at 200 mm tube spacing and 37 °C ambient temperatures. The narrower the tube spacing the greater the cooling potential, with the 100 mm tube spacing yielding a SOZ BGT reduction of 6.1 °C at 39 °C ambient temperatures. The results demonstrated that the larger temperature difference between ambient air and inlet water the greater the effect of the heat exchange, and that water of 20 °C or cooler could be used as the cooling water supply. The cooling potential with a 0.8 m high canopy was greater than that at 0.95 m. It was concluded that the cooling efficiency of the water-cooled cover was affected by the inlet water, the surrounding environment, and the structure and size of the canopy.

For more information the full article can be found at  http://www.sciencedirect.com/science/journal/15375110

Carcass and meat quality characteristics of immunocastrated male, surgically castrated male, entire male and female pigs

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The aim of the study was to evaluate the effect of immunocastration on meat and carcass quality compared with meat from females, entire and surgically castrated males. One hundred and eighteen (Landrace _ Duroc) _ Pietrain crossbred pigs were assigned to four experimental groups: entire males (EM), females (FE), surgically castrated males (CM) and vaccinated males (IM). Pigs were reared in two pens per sex and slaughtered at an average of 180 days of age. Carcass and meat quality characteristics such as testis size and length, fat depth, lean content, proportion of the carcass represented by each joint, pH, colour and intramuscular fat were evaluated. There was a significant reduction in the size of these sexual organs in IM compared with EM. CM and IM were fatter than FE and EM in the loin area but, in the ham area, CM was the fattest and EM the leanest, while IM and FE were in between. Intramuscular fat of IM (2.1%) was no different from the other sexes evaluated, although it was higher in CM (2.5%) with respect to FE (1.7%) and EM (1.8%). There was no difference between the IM and other treatment groups in meat quality. Regarding ours results we can conclude that from the point of view of meat and carcass quality the immunocastration could be a good alternative to the surgical castration.

For more information the full article can be found at http://www.sciencedirect.com/science/journal/03091740