Comparison of a wheat-based diet supplemented with purified β-glucans, with an oat-based diet on nutrient digestibility, nitrogen utilization, distal gastrointestinal tract composition, and manure odor and ammonia emissions from finishing pigs

Posted in: Environment, Production by admin on August 5, 2011 | No Comments

It was hypothesized that supplementation of an oat-extracted mixed-linkage (1→3), (1→4)-β-d-glucan (β-glucans) to a wheat-based diet may beneficially mitigate manure odor and ammonia emissions associated with intensive pig production, without depressing nutrient digestibility as has been observed with oat-based diets. An experiment was conducted to investigate the effect of dietary β-glucan source and the inclusion of an enzyme composite containing β-glucanase on energy and nutrient digestibility, N utilization, distal gastrointestinal tract (GIT) fermentation, and manure emissions from finisher boars. Twenty-eight boars (BW = 74.2 kg) were assigned to 1 of 4 dietary treatments (n = 7/treatment): 1) an oat-based diet (oat), 2) an oat diet + enzyme composite (OE), 3) a wheat-based diet + purified β-glucans (WG), and 4) a wheat-based diet + purified β-glucans + enzyme composite. The wheat-based diets containing purified β-glucans were formulated to contain concentrations of total β-glucans comparable with the oat based diet. Consumption of the WG diet resulted in a greater digestibility of GE and an increase in the urine: feces N excretion ratio compared with the oat diet. In the distal GIT, pigs offered the WG diet contained fewer bifidobacteria and lactobacilli compared with the oat diet. Pigs offered the WG diet had increased manure odor emissions compared with the oat diet. In conclusion, although supplementing wheat-based diets with extracted oat-β-glucan did not reduce nutrient digestibility, there was a negligible effect in beneficially influencing manure emissions from pigs when compared with a conventional oat formulation.

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

The effects of housing system and feeding level on the joint-specific prevalence of osteochondrosis in fattening pigs

Posted in: Environment, Production by admin on August 4, 2011 | No Comments

Osteochondrosis (OC) is seen as the main cause of leg weakness in pigs, leading to welfare problems and economic losses. Environmental factors in pig husbandry, such as the housing system and feeding strategy are expected to influence the prevalence of OC. Therefore, this study investigated the effects of housing system and feeding strategy on the prevalence and severity of OC. In the experiment 345 pigs were used. At an age of 69 days intact boars and gilts were separated and assigned to groups of five or six individuals. A two by two factorial design of housing system and feeding strategy was applied. The housing system was either a conventional concrete floor partial slatted, or a deep litter floor with extra space allowance. The feeding strategy was either ad libitum or restricted to 80% of ad libitum. Pigs were slaughtered at the age of 161–176 days. In total, five joints of the left front and hind limbs were macroscopically assessed for OC on a five-point scale, ranged from no OC through (semi-)loose cartilage fragments. The prevalence of OC in the experimental population was 41.4%, and 12.4% of the individuals had severe lesions. The tarsocrural joint was most affected (30.2%) by OC. OC scores between the different joints were not correlated. Medial sections of joints were most affected (63– 100%). Boars were more affected than gilts in the elbow joint. Conventionally housed pigs were more affected than deep litter housed pigs. Ad libitum fed pigs had more OC than restrictedly fed pigs. OC was most prevalent with 57.5% in the pigs on the conventional floor with ad libitum feeding. OC was least prevalent with 33.7% in pigs kept in deep litter housing with restricted feeding. The sex, housing system and feeding strategy did not affect OC in the femoropatellar, metacarpophalangeal, and metatarsophalangeal joints. Our results demonstrate that the OC prevalence can be reduced by applying deep litter floors with extra space allowance and/or restricted feeding in fattening pigs.

For more information the full article can be found at http://www.journals.elsevierhealth.com/periodicals/livsci

Fumonisin B1 and implications in nursery swine productivity: A quantitative exposure assessment

Posted in: Environment, Production by admin on July 29, 2011 | No Comments

This study estimated the long-term exposure of fumonisin B1 (FB1) in nursery swine diets and associated toxicological adverse effects on negative productivity potential using quantitative exposure assessment. Fumonisin B1 is a mycotoxin produced by Fusarium verticillioides and Fusarium proliferatum and is a common biological contaminant of corn (Zea mays L.) and other grains. Acute effects from FB1 exposures are well recognized and managed in the swine industry, but practices to limit prolonged low-dose exposures to FB1 have been less fully considered and may negatively affect production efficiency. Deterministic (single-point estimates) and stochastic (probabilistic) modeling were performed for comparative analyses of FB1 exposures originating from genetically engineered Bacillus thuringiensis (Bt)-corn, conventional non-Bt corn, and distillers dried grains with solubles (DDGS). Six feeding scenarios differing in the source of corn in diets were modeled to assess variation in FB1 exposure representing a mixture of Bt and non-Bt grain and DDGS (blended); Bt grain and Bt DDGS; non- Bt grain and non-Bt DDGS; Bt and non-Bt grain; Bt grain; and non-Bt grain. Long-term exposure estimates (49-d duration) were compared with chronic levels of concern (LOC). The first LOC (LOC1; 1 mg of FB1/kg of diet, least observed adverse effects concentration) represents a decrease in ADG. Concentrations of 5 mg of FB1/kg of diet represent the second LOC (LOC2), which showed pulmonary pathological alterations and a significant dose-dependent increase in pulmonary weight. Estimates indicated LOC1 was frequently exceeded regardless of feeding scenario, but LOC2 was not attained. Diets where the corn fraction was entirely from Bt-corn showed the least FB1 exposure (exceeding LOC1 in 35% of occasions), whereas a blended diet or diets using non-Bt grain and DDGS sources more commonly exceeded this threshold (95% of occasions). Based on these estimates, under blended corn source feeding conditions, swine populations in nursery facilities may frequently exhibit incipient effects (i.e., LOC1) of FB1 toxicity; however, impacts on production efficiency remain uncertain.

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

The relevance of purebred information for predicting genetic merit of survival at birth of crossbred piglets

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The objective of this study was to infer (co)variance components for piglet survival at birth in purebred and crossbred pigs. Data were from 13,643 (1,213 litters) crossbred and 30,919 (3,162 litters) purebred pigs, produced by mating the same 168 purebred boars to 460 Large White-derived crossbred females and 1,413 purebred sows, respectively. The outcome variable was piglet survival at birth as a binary trait. A Bayesian bivariate threshold model was implemented via Gibbs sampling. Flat priors were assigned to the effects of sex, parity of the dam, litter size, and year month of birth. Gaussian priors were assigned to litter, dam, and sire effects. Marginal posterior means of the sire and dam variances for liability of piglet survival in purebred were 0.018 and 0.077, respectively. For crossbred, sire and dam variance estimates were 0.030 and 0.120, respectively. The posterior means of the heritability of liability of survival in purebred and crossbred and of the genetic correlation between these traits were 0.049, 0.091, and 0.248, respectively. The greatest 95% confidence region (−0.406, 0.821) for the genetic correlation between purebred and crossbred liabilities of piglet survival included zero. Results suggest that the expected genetic progress for piglet survival in crossbreds when selection is based on purebred information may be nil.

Influence of benzoic acid and phytase in low-phosphorus diets on bone characteristics in growing-finishing pigs

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In 2 simultaneous experiments (Exp.1 and Exp. 2), the effects of benzoic acid (BA) and phytase (Phy) in low-P diets on bone metabolism, bone composition, and bone stability in growing and growing- finishing pigs were examined. Experiment 1 was conducted with 16 crossbred gilts in the BW range of 25 to 66 kg of BW, whereas in Exp. 2, 32 crossbred gilts (25 to 108 kg of BW) were used. All pigs were individually housed in pens and restrictively fed 1 of 4 diets throughout the experiment. Total P content of the wheat-soybean diets was 4 g/kg (all values on an as-fed basis). The experimental diets were 1) unsupplemented control diet; 2) control diet with 0.5% BA; 3) Phy diet with 750 Phy units (FTU) of Phy/kg and no BA; and 4) PhyBA, control diet with 750 FTU of Phy/kg and 0.5% BA. Blood samples were taken at the beginning of the experiment, wk 3 (only for pigs in Exp. 1), wk 6, and before slaughter to determine P and Ca in serum and concentrations of total alkaline phosphatase, serum crosslaps (marker for bone resorption), and osteocalcin (marker for bone formation). Ash, P, and Ca contents of bones and bone stability were examined using the left metatarsal bones and tibia of the pigs after slaughter. Benzoic acid did not influence any of the blood variables. The addition of Phy increased P concentration in serum from 2.71 to 3.03mmol/L at wk 3 and content of serum crosslaps from 0.39 to 0.45ng/mL at wk 6 and decreased osteocalcin at wk 6 by 160 ng/mL. No long-term effect of diets on serum mineral concentrations, alkaline phosphatase, and bone markers in serum could be detected. Benzoic acid negatively affected Ca content in bones and distal bone mineral density, especially in the younger pigs. In the control diet with 0.5% BA and the control diet with 750 FTU of Phy/kg and 0.5% BA, the CA content in bones and distal bone mineral density were reduced by 6 and 11%, respectively. Throughout the whole growing and finishing period, Phy increased ash, P, and Ca contents in bones by 29.4, 4.8, and 11.6 g/kg of DM, respectively. Bone mineral density and bone mineral content were greater in diets with Phy, as well as breaking strength of tibia (+22%) and metatarsal bones (+27%). The results of this study indicate that for a healthy skeleton, BA should not be used in low-P diets without the addition of Phy.

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

Group housing of sows in early pregnancy: A review of success and risk factors

Posted in: Environment, Production, Welfare by admin on July 26, 2011 | No Comments

A recent telephone survey of 735 Dutch farmers with group housing of sows in early pregnancy suggested a wide variation in reproductive success, irrespective of husbandry system. The reason for these differences between farms is not known, but of great importance to the pig industry which is moving worldwide from individual to group housing systems, mainly for animal welfare reasons. Therefore, the aim of this review is to list the most likely success and risk factors for group housing of sows in early pregnancy, in relation to reproduction (such as pregnancy rate) and animal welfare (such as aggression and health). The review first considers a limited number of group housing comparisons and finds that the results of the few studies performed are not very conclusive, neither on fertility nor on leg problems, longevity and welfare of sows. As a consequence, it is hard to draw any significant practical conclusions, and the review proceeds to look at studies in which single factors were addressed. For the effects on fertility it is concluded that especially factors causing chronic stress (e.g. due to unfavourable social, management or climatic conditions) and a low feed intake may impact reproductive performance. The vulnerable period lies in weeks 2 and 3 of pregnancy. On leg problems and longevity an important factor seems to be the quality of the floor, regardless of other aspects of the housing system. The use of straw seems to be advantageous. Finally, on aggression it is argued that this will never be eliminated from systems in which sows are housed as a group. However, it can be properly managed and key factors in this are a gradual familiarisation of unfamiliar animals, sufficient space and pen structure during initial mixing, minimizing opportunities for dominant sows to steal food from subordinates, the provision of a good quality floor and the use of straw bedding. The review concludes with a series of practical recommendations to improve welfare and reproduction in group housed sows.

For more information the full article can be found at http://www.journals.elsevierhealth.com/periodicals/livsci

Neonatal piglet traits of importance for survival in crates and indoor pens

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The primary aim of the present study was to investigate whether the same piglet traits contributed to the same causes of neonatal piglet mortality in crates (CT) and pens (PN). Gilts originating from 2 distinct genetic groups that differed in breeding value for piglet survival rate at d 5 (SR5) were used. These were distributed to farrow in either PN or CT as follows: high-SR5 and CT (n = 30); low-SR5 and CT (n = 27); high-SR5 and PN (n = 22); and low-SR5 and PN (n = 24). Data on individual piglets were collected at birth, including interbirth interval; birth order; birth weight; rectal temperature at birth, 2 h after birth, and 24 h after birth; cordal plasma lactate; and latency to first suckle. Based on autopsy, causes of mortality were divided into stillborn, bitten to death, starvation, crushed, disease, and other causes. Potential risk factors of dying were estimated using a GLM with a logit link function. No significant effect of housing was observed on the odds of a piglet being stillborn, being crushed, or dying of starvation. No significant differences were observed between the 2 genetic groups for any category of mortality. Piglet traits for pre- and postnatal survival were the same for CT and PN. The odds of being stillborn were increased in piglets born late in the birth order, after a long interbirth interval, and with a lighter birth weight. The lighter the birth weight of the piglets, the greater were the odds of being crushed and dying of starvation. The lower the rectal temperature 2 h after birth, the greater were the odds of being crushed, starving, or dying of diseases. Increased cordal plasma lactate increased the odds of dying from starvation. In both CT and PN, the birth weight, body temperature 2 h after birth, and birth process were important traits related to crushing, starvation, and disease. Neither housing nor breeding value influenced mortality or traits of importance for the inborn viability of piglets. The results emphasize that the microclimate in the PN for newborn piglets and its heat-preserving properties are more important for survival than whether the sow is crated or penned. 

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Survey among Belgian pig producers about the introduction of group housing systems for gestating sows

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There is a global move from individual to group housing of gestating sows. In the European Union, individual gestating stalls will be banned by 2013. Just like in other industrialized regions, these stalls have been the standard housing system for intensively kept sows from the 1960s onward in the Flemish region of Belgium. Because the socioeconomic consequences for the pig industry may be far-reaching and because farmer attitude may influence the realization of the hoped-for improvement in animal welfare in practice, we conducted a survey from 2003 until 2009 among representative samples of Flemish pig producers every 2 yr. The share of farms with group housing increased from 10.5% in 2003 to 29.8% in 2007, but then dropped to 24.6% in 2009. It appears that after 2005 users of old group housing systems in particular stopped farming. Because sow herd size increased more on farms with vs. without group housing and because the proportion of the herd that was group-housed also tended to increase between 2003 to 2009, the change to group housing took place faster when expressed at the level of the sow (from 9.1% in 2003 to 34.1% in 2009) instead of farm. The percentage of farmers planning to convert to group housing within 2 yr was 4.1% in 2003, and 6 to 7% thereafter. These were typically young farmers with a large sow herd and with a likely successor. Free access stalls were the most common group housing system (31% of farms, 37% of sows). Their popularity is expected to increase further at the expense of electronic feeding stations, ad libitum feeding, and stalls/troughs with manual feed delivery. User satisfaction was generally high but depended on whether or not all gestating sows were kept in group, the provisioning of environmental enrichment, the age, and type of system. The main criteria for choosing a certain group housing system were the investment costs and sow health and welfare. The importance of economic reasons and type of labor decreased with the age of the system. In 2003 and 2005 the main reason for not having converted to group housing was that farmers would stop keeping sows by 2013. In 2007 and 2009 the reasons mainly concerned uncertainty about the future and maximally delaying the conversion. Belgium is one of the European Union countries where the pig industry is expected to undergo drastic changes during the few years remaining before the ban on individual housing 

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

Performance and phosphorus balance of pigs fed diets formulated on the basis of values for standardized total tract digestibility of phosphorus

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Three experiments were conducted to test the hypotheses that pigs fed diets that are equal in digestible phosphorus (P) will perform equally regardless of the concentration of total P in the diets, and that the addition of microbial phytase, distillers dried grains with solubles (DDGS), or a combination of phytase and DDGS will result in a reduction in P excretion. In Exp. 1, a P-free diet and 6 diets containing corn, soybean meal (SBM), or DDGS without or with microbial phytase (500 phytase units per kg) were formulated. Diets were fed for 12 d to 42 pigs (initial BW = 13.5kg) housed in metabolism cages that allowed for total collections of feces. Basal endogenous P losses were determined to be 199 mg/kg of DMI for pigs fed the P-free diet. Addition of phytase increased the standardized total tract digestibility (STTD) of P in corn (64.4 vs. 26.4%) and SBM (74.9 vs. 48.3%), but there was no effect of the addition of phytase on the STTD of P in DDGS (75.5 vs. 72.9%). In Exp. 2, a total of 160 pigs (initial BW = 11.25kg; 4 pigs/pen) were allotted to 4 corn- and SBM-based diets with 2 amounts of phytase (0 or 500 phytase units per kg) and 2 amounts of DDGS (0 or 20%) in a 2 × 2 factorial arrangement of treatments. All diets were formulated to contain 0.32% STTD of P according to the STTD values determined in Exp. 1. Diets were fed for 21 d and results indicated that inclusion of phytase in the diet containing no DDGS tended to decrease G:F, but inclusion of 20% DDGS in the diets tended to increase ADG, ADFI, and final BW. In Exp. 3, the diets used in Exp. 2 were fed to 24 pigs (initial BW = 14.6kg) that were placed in metabolism cages individually. Feces and urine were collected for 5 d. Phytase and DDGS increased the apparent total tract digestibility of P in the diets. Absorption of P was greater in pigs fed corn-SBM-DDGS diets than pigs fed corn-SBM diets, and phytase, DDGS, or the combination of phytase and DDGS reduced P excretion. In conclusion, the addition of phytase increased the STTD of P in corn and SBM, but had no effect on the STTD of P in DDGS. Diets may be formulated based on STTD values without compromising pig performance, and dietary phytase, DDGS, or the combination of phytase and DDGS will reduce P excretion by growing pigs. 

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Effect of phytase and xylanase supplementation or particle size on nutrient digestibility of diets containing distillers dried grains with solubles cofermented from wheat and corn in ileal-cannulated grower pigs

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Nutrient digestibility in distillers dried grains with solubles (DDGS) is limited by physical constraints such as particle size and by biochemical limitations such as phytate and fiber or nonstarch polysaccharides (NSP). To determine the separate effects of these limitations on nutrient digestibility, ground DDGS (383 μm) supplemented with phytase (0 or 250 units/kg of feed) and xylanase (0 or 4,000 units/kg of feed) was evaluated in a 2 × 2 factorial arrangement of treatments together with unground DDGS (517 μm) and an N-free diet in a 6 × 6 Latin square. Cofermented wheat and corn DDGS contained 8.6% moisture, 31.0% CP, 1.04% Lys, 8.0% ether extract, 2.0% starch, 40% NDF, and 0.85% P (as-is basis). Diets contained 43.7% DDGS as the sole source of AA; the digesta from pigs fed the N-free diet served to subtract basal endogenous AA losses and as control for energy digestibility. Six ileal-cannulated barrows (37.1kg of BW) were fed 6 diets at 2.8 × maintenance for DE in six 9-d periods. Feces and ileal digesta were collected for 2 d each. The apparent ileal digestibility (AID) of GE and apparent total tract digestibility (ATTD) of GE and NDF were 2.3, 0.5, and 5.1%-units greater for the ground than unground DDGS diet, respectively. Consequently, the ATTD of GE was 1.3%-units greater and the DE content was 0.06 Mcal/kg greater for ground than unground DDGS, respectively. Grinding of DDGS did not affect the ATTD of crude fiber, ADF, P, and Ca in diets. Grinding of DDGS increased the AID of most AA in diets including Lys, Met, and Thr by 6.9, 1.1, and 1.7%-units, respectively. Grinding of DDGS increased the SID of Lys by 6.2%-units and SID content of Lys and Thr by 0.06 and 0.02%-units, respectively. Phytase and xylanase did not interact to affect nutrient digestibility. Phytase increased the ATTD of P by 10.5%-units, but did not affect AA digestibility. Xylanase did not affect nutrient digestibility. In conclusion, particle size is an important physical characteristic affecting digestibility of energy and AA, but not P in DDGS. Phytate in DDGS limits digestibility of P, but not energy and AA. The substrate for xylanase in DDGS did not hinder energy and AA digestibility.

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