Lactulose as a marker of intestinal barrier function in pigs after weaning

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

Intestinal barrier function in pigs after weaning is almost exclusively determined in terminal experiments with Ussing chambers. Alternatively, the recovery in urine of orally administered lactulose can be used to assess intestinal permeability in living animals. This experiment was designed to study the barrier function of the small intestine of pigs over time after weaning. The aim was to relate paracellular barrier function (measured by lactulose recovery in the urine) with macromolecular transport [measured by horseradish peroxidase (HRP) using Ussing chambers] and bacterial translocation to assess whether lactulose recovery is related to possible causes of infection and disease. Forty gonadectomized male pigs (6.7 kg) were weaned (d 0) at a mean age of 19 d, fitted with urine collection bags, and individually housed. Pigs were dosed by oral gavage with a marker solution containing lactulose (disaccharide) and the monosaccharides l-rhamnose, 3-Omethylglucose, and d-xylose at 2 h and at 4, 8, and 12 d after weaning. The recovery of sugars in the urine was determined over 18 h after each oral gavage. The day after each permeability test, the intestines of 10 pigs were dissected to determine bacterial translocation to the mesenteric lymph nodes and jejunal permeability for HRP in Ussing chambers. Recovery of l-rhamnose in urine was affected by feed intake and by the time after weaning. Recovery of lactulose from the urine was greater at 4, 8, and 12 d after weaning compared with the first day after weaning and was negatively correlated with feed intake. The mean translocation of aerobic bacteria to the mesenteric lymph nodes was greater at 5 and 13 d after weaning compared with d 1. Lactulose recovery showed no correlation with permeability for HRP nor with bacterial translocation. Although both lactulose recovery and bacterial translocation increased over time after weaning, lactulose recovery did not correlate with the permeability for HRP nor bacterial translocation within a pig. Therefore, we conclude that lactulose recovery in the urine of pigs after weaning is not associated with risk factors for infections. However, it appears to be possible to measure paracellular barrier function with orally administered lactulose in pigs shortly after weaning. Further studies will reveal whether this variable is relevant for the long-term performance or health of pigs after weaning.

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

Effect of source and quantity of dietary vitamin D in maternal and creep diets on bone metabolism and growth in piglets

Posted in: Production by admin on | No Comments

Piglets are born with reduced plasma concentrations of 25-hydroxycholecalciferol (25-OH-D3) and are thus highly predisposed to vitamin D deficiency. Furthermore, sow milk contains little vitamin D, and the slow intestinal vitamin D absorption of sows limits the efficacy of dietary vitamin D supplementation. Hence, the neonate depends, to a large extent, on the vitamin D stores built up in fetal tissues from maternal sources. The current study was undertaken to evaluate whether the source and quantity of dietary vitamin D provided to the gestating and lactating sow, and also directly in the form of creep feed to the piglet, would influence the vitamin D status, growth performance, and skeletal development of piglets. A total of 39 primiparous and multiparous sows were randomly assigned to 1 of 3 dietary treatments (13 in each treatment), supplemented with either 5 or 50 μg of the commonly used cholecalciferol (vitamin D3) or 50 μg of 25-OH-D3 per kilogram of feed. By wk 3 of lactation, piglets were offered a creep diet with vitamin D supplementation according to the treatment of the dam, and they were offered the same creep diets after weaning at d 35 of age until they reached a BW of approximately 20 kg. When dietary 25-OH-D3 was provided, circulating concentrations of 25-OH-D3 in piglet serum increased as early as d 21 and later at d 33 and 77, indicating greater body stores in those animals. Bone-breaking strength and cortical bone mineral content and density at the tibial midshaft of piglets were reduced when vitamin D3 was supplemented at 5 μg/kg compared with the bone traits of other groups, but no differences were observed between the 2 other groups. After weaning, ADFI was greater and growth performance tended to improve when doses of 50 μg/kg were administered, regardless of the vitamin D source. In conclusion, supplementation of the diet with 50 μg/kg of either source of vitamin D was proved to be adequate in meeting the needs of gestating sows and in permitting the accumulation of vitamin D in J ANIM SCI 2011, 89:1347-1357fetal tissues, as well as for normal skeletal mineralization and growth in the offspring. Furthermore, the markedly improved vitamin D status of piglets whose mothers received 25-OH-D3 possibly resulted from greater tissue reserves present at birth and a greater availability of vitamin D when released from those stores.

Statistical tools to detect genetic variation for a sex dimorphism in piglet birth weight

Posted in: Production by admin on | No Comments

Sex differences in birth weight contribute to within-litter variability, which itself is connected to piglet survival. Therefore, we studied whether the sex difference in piglet birth weight is a genetically variable sex dimorphism. For that purpose a linear mixed model including sex-specific additive genetic effects was set up. A hypothesis testing problem was defined to detect whether these genetic effects significantly differ between sexes. In a second step, the effect of sex-linked genes was studied explicitly by partitioning the additive genetic effects into autosomal and gonosomal effects. Furthermore, a definition of heritability for the sex difference of a randomly chosen pair of littermates with opposite sex was given. The proposed models were applied separately to a Landrace and Large White data set. Significant genetic variability for the sex dimorphism was found in Landrace but not in Large White. Heritability estimates were at 3 to 5% depending on the model. The X-chromosomal genetic variation was not significant at all, whereas the Y-chromosome significantly contributed to the genetic variation in Landrace with a corresponding SD of 34 g. It can be concluded that the sex dimorphism of piglet birth weight is genetically variable and a potential target of genetic improvement.

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

Claw lesions in lactating sows on commercial farms were associated with postural behavior but not with suboptimal reproductive performance or culling risk

Posted in: Production, Welfare by admin on | No Comments

Claw lesions in lactating sows on 3 commercial farms were assessed in 6 areas of each of a sow’s 8 claws to investigate the relationship between claw lesions and stage of lactation. In addition, the relationships between claw lesions and postural behavior, reproductive performance or culling risk were investigated. We used a 5-point score method (0, 1, 2, 3 or 4) for each claw area and overgrown heel was additionally scored. Total sow-lesion score (TSLS) for each sow was obtained by summing the scores for the 6 areas of the 8 claws. The highest claw lesion score for each sow was defined as the highest claw lesion score (HCLS) recorded in the 48 claw areas. We recorded the relative frequency (%) of postural behavior by point sampling at 15-min intervals over a 6 h period. Linear mixed-effects models were used for statistical analyses. Of the 308 sows observed, mean TSLS was 17.3±0.40. Proportions of sows with HCLS 0, 1, 2, 3 and 4 were 0.0, 43.5, 50.6, 4.9 and 1.0%, respectively. The heel area had the highest proportions of claw-lesion score 2 or higher between the 6 areas. There were more claw-lesion scores of 2, 3, and 4 in the hind limbs of lateral claws than in the front limbs. High TSLS or HCLS was not related to the stage of lactation and no differences were found between HCLS groups or TSLS groups for overall culling risk after weaning. There were no differences between TSLS groups for adjusted 21-day litter weight, preweaning mortality or weaning-to-first-mating interval. No differences were found between HCLS groups for the sow performance, although sows in the high TSLS group had a higher farrowing percentage than those in the low TSLS group. There were no differences between HCLS groups for postural behavior, but sows in the high-TSLS group had the highest relative frequency of lying posture and the lowest frequency of standing posture. In summary, claw lesions in lactating sows were not related to negative reproductive performance and culling risk, but there was a relationship with postural behavior.

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

Growth performance and antibiotic tolerance patterns of nursery and finishing pigs fed growth-promoting levels of antibiotics

Posted in: Meat Quality, Production by admin on | No Comments

The objective of this study was to evaluate the impact of growth-promoting levels of antibiotics in diets for nursery and finishing pigs on growth performance and antibiotic tolerance patterns. Gilts (n=200, initial body weight was 6.2±0.003 kg), were allotted based on body weight to one of four treatments in a 2×2 factorial randomized complete block design. Nursery treatments consisted of feeding no antibiotics (CON) or an antibiotic diet (ANTI) containing chlortetracycline (CTC; 55mg/kg). At the end of the nursery phase, one-half of the pigs receiving CON were switched to a diet containing antibiotic (virginiamycin; VIR, 11 mg/kg) and one-half of the pigs receiving ANTI were switched to CON for the remainder of the trial. This created four treatments for the finishing phase, consisting of: control in nursery and finishing (CC), antibiotic in nursery, control in finishing (AC), control in nursery, antibiotic in finishing (CA), or antibiotics throughout (AT). The pigs were weighed at the diet changes during the nursery (weeks 1, 3, and 5) and finishing (weeks 7, 9, 13, 17, and 20) phases. Fecal samples were collected at all diet changes for isolation of fecal coliforms and Enterococcus and subsequently tested for tolerance to CTC and VIR. After 1 week, CON pigs weighed less (7.09 vs. 7.28 kg) and had lower ADG(149 vs. 180 g/day) and ADFI (174 vs. 192 g/day) than ANTI pigs. No performance differences were observed during the remainder of the study. At the initiation of the study (week 0), the ability of coliforms to grow in the presence of CTC and VIR, respectively, were 68 and 73% and increased to 90 and 96% at week 19 (time effect). At week 17, tolerance of coliforms to CTC was greater for CA (98%) than AC (86%, time×treatment effect, Pb0.004). Enterococcus tolerance to CTC at week 7 was lower for CC (55%) compared to AT (76%), AC (74%) and CA (83%, time×treatment effect). At week 9, Enterococcus tolerant to CTC and VIR, respectively, was lower for CC (15 and 18%) than AT (31 and 40%), AC (35 and 35%), and CA (44 and 43%, time×treatment effect). Antibiotic growth promoters had little impact on growth performance in clean, isolated facilities with high labor inputs. The tolerance of bacteria to antibiotics fluctuated over time and persisted regardless of the use of antibiotic growth promoters.

Effect of dietary regime and group structure on pig performance and the variation in weight and growth rate from weaning to 20 weeks of age

Posted in: Production by admin on | No Comments

This study aimed to improve lifetime pig performance and reduce variation in growth rate between pigs using managerial and nutritional practices. The experiment (2×2×2 factorial) compared uniform and mixed weight grouping (SD of weight in group at weaning 0.7 kg and 1.6 kg respectively), offering pigs a high (12 kg) or low (6 kg) allowance of starter diets post weaning and either a special (DE 14.5 MJ/kg, total lysine 11 g/kg) or normal (DE 13.5 MJ/kg, total lysine 9.5 g/kg) finishing diet. Over six time replicates, 960 pigs (Landrace×Large White) were randomly allocated at weaning (28±2 days of age) into groups of 20 according to weight and sex and these groups were split at 10 weeks of age (transfer to finishing accommodation) into two groups of 10. Finishing diet was offered from 11 weeks of age. The FCR of pigs (wean–7 weeks of age) was significantly improved when a high allowance of starter diets was offered (1.25) compared with a low allowance (1.34). However, between 7 and 10 weeks of age a high allowance of starter diets only improved the FCR of pigs in uniform groups. A special finishing diet improved the ADG of pigs during finish (11–20 weeks of age) (860 g/day) compared with a normal finishing diet (827 g/day). The coefficient of variation (CV) of weight at 10 and 15 weeks of age was significantly lower for pigs in uniform weight groups compared with that of pigs in mixed weight groups. A three-way interaction was observed on the CV of ADG (weaning–20 weeks of age) and FCR (11–20 weeks of age). The lowest CV of ADG (weaning—20 weeks of age) and lowest FCR (11–20 weeks of age) were achieved when uniform grouped pigs were offered a high allowance of starter diets post weaning and a special finishing diet (0.117 and 2.43 respectively) whereas the highest values were observed when mixed weight groups of pigs were offered a low allowance of starter diets post weaning and a normal finishing diet (0.162 and 2.70 respectively). In conclusion, although uniform grouping appears to aid the reduction in slaughter weight variation and improve FCR, its effect is dependent on dietary regime. Overall, from weaning to 20 weeks of age, uniformly grouped pigs offered a high allowance of starter diets post weaning and a special finishing diet had a low CV of ADG and the most efficient FCR.

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

The performance response of pigs of different wean weights to ‘high’ or ‘low’ input dietary regimes between weaning and 20 weeks of age

Posted in: Production by admin on | No Comments

In a 3×2×2 factorial design, this study aimed to compare the lifetime performance of light (average of 7.1 kg), medium (average of 8.9 kg) or heavy (average of 10.4 kg) wean weight pigs when offered either a high (12 kg/pig) or low (6 kg/pig) allowance of starter diets post weaning and either a normal (DE 13.5 MJ/kg, total lysine 9.5 g/kg) or special (DE 14.5 MJ/kg, and total lysine 11 g/kg) finishing diet from 11 weeks of age. Over six time replicates, 720 pigs (Landrace×Large White) were randomly allocated at weaning (28±2 days of age), into groups of 20 which were balanced for sex. These groups were split into two groups of ten at 10 weeks of age (transferred to finishing accommodation). The 20-week weight (88.9 kg), ADG (702 g/day) and ADFI (1841 g/day) between wean and 20 weeks of age was greater for heavy weight pigs (Pb0.001) than for light weight pigs (82.2 kg, 692 and 1715 g/day respectively). However, on a per kg of body weight basis the feed intake/kg (39 g/day/kg) and growth rate/kg (14.8 g/day/kg) of light weight pigs was greater than that of heavy weight pigs (37.4 and 14.4 g/day/kg respectively). A high allowance of starter diets increased 10-week weight, ADG and reduced ADFI and FCR between weaning and 10 weeks of age compared with that of pigs offered a low allowance. There were significant interactions between starter diet allowance and finishing diet on finishing pig performance. The 20-week weight and ADG (11 to 20 weeks) of pigs offered a high allowance of starter diets increased when they were offered a special finishing diet compared with a normal finishing diet. However, that of pigs offered a low allowance of starter diets was lowered when they were offered a special finishing diet compared with a normal finishing diet. On the other hand, the ADFI of pigs offered a high allowance of starter diets was similar whether they were offered a normal (1977 g/day) or special (1976 g/day) finishing diet, whereas those offered a low allowance of starter diets had an increased ADFI (2091 g/day) when offered a normal finishing diet compared with a special finishing diet (1903 g/day). In conclusion, when the ‘nutrient density’ of the diet changed, in particular towards lower supplies, pig weight and growth rate were poorer. In addition light weight pigs at weaning were found to convert feed as efficiently as heavy weight pigs throughout their lifetime. Furthermore, their lifetime growth rate and feed intake on a ‘per kg of body weight’ basis was higher than that of heavy pigs.

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

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 | 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

Management routines at the time of farrowing—effects on teat success and postnatal piglet mortality from loose housed sows

Posted in: Production by admin on | No Comments

The aim of this experiment was to study the effects of six different management routines at the time of farrowing on latency to first suckle, heat loss, weight gain and postnatal mortality. A total of 872 piglets from 67 loose housed sows in a commercial pig unit were subjected to one of six different management routines: control (CON n=14), no treatment; (CREEP n=13), placed in creep area; (UDDER n=10), placed at the udder; (DRY n=10), dried and placed back where found; (DRYCREEP n=9), dried and placed in creep area; and (DRYUDD n=11), dried and placed at the udder. The latency from birth to first suckle, rectal temperature at birth, 2 hours and 24 hours were measured for each piglet, in addition to weight at birth, 2 hours and 24 hours. Latency from birth to first suckle was shortest for piglets in the DRYUDD treatment, followed by the UDDER treatment. More live born piglets died in the UDDER treatment compared to the other treatments, but there were no other differences between the treatments with regards to postnatal mortality. There was a significant interaction between treatment and batch, with a significantly lower postnatal mortality in the DRYUDD treatment than CON in batch 2, but not in batch 1 and 3. Large litter sizes resulted in a higher postnatal mortality in all treatments, and tended to reduce latency to suckle. In conclusion, drying the piglets after birth and placing them at the udder resulted in reduced postnatal mortality in batch 2, but not in the other two batches. Despite having the largest mean litter size of the treatments, less than 10% of the piglets in DRYUDD died, which is remarkably low for loose housed sows. Regardless of treatment, several piglet-related factors were found to be highly important for postnatal mortality, such as the number of functional teats per piglet, birth weight, the latency from birth to first suckle, and rectal temperature at 2 hours after birth.

Effect of pen mates on growth, backfat depth, and longissimus muscle area of swine

Posted in: Meat Quality, Production by admin on | No Comments

Records on final BW (kg), backfat depth (cm), and LM area (cm2) of pigs from a University of Nebraska Large White/Landrace composite population were analyzed to estimate the effects of pen mates. Measurements were at approximately 180 d of age for 3,524 pigs in 351 pens (9 to 11 pigs per pen) farrowed from 1999 to 2005. The area of each pen was 8.13 m2. The full model (M1) included the fixed effects of contemporary group, sex, line, and the covariates of age and inbreeding coefficient, and included random direct genetic, genetic pen-mate, permanent environmental, pen, litter, and residual effects. A derivativefree algorithm was used to obtain REML estimates of variance components for final BW adjusted to 180 d of age with M1 and 7 reduced models, and with 4 reduced models for the carcass traits. For final BW, likelihood ratio tests showed that M1 did not fit the data better than model 2 (permanent environmental effect omitted from M1) or model 3 (pen omitted from M1). Model 2 was not significantly (P > 0.05) better than model 3, which shows that variance attributable to pen effects and permanent environmental effects cannot be separated. Large sampling variances of estimates of the pen component of variance for models with pen-mate effects also indicate an inability to separate pen effects from the effects of pen mates. When pen-mate genetic effects were not in the model, estimates of components of variance and the fit of the data were the same for models 4 (included both permanent environmental and pen effects), 6 (included pen effects), and 7 (included permanent environmental effects), which shows that including both pen and permanent environmental effects was no better than including one or the other. Models 4, 6, and 7 were significantly better than model 8, which did not include pen-mate effects and pen effects, implying that pen effects are important. The estimate of pen variance with model 2 was approximately (number of pen mates − 1) times the estimate of variance of pen-mate permanent environmental effects with model 3. Patterns of estimates of variance components with models 2, 5, 6, and 8 for backfat depth and LM area were similar to those for final BW. Estimates of direct genetic variance and phenotypic variance were similar for all models. Estimates of heritability for direct genetic effects were approximately 0.40 for final BW, 0.45 for backfat depth, and 0.27 for LM area. Estimates of heritability for pen-mate genetic effects were 0.001 for the 3 traits for models including either pen or permanent environmental effects. Under the management conditions for this experiment, the conclusion is that the model for genetic evaluation should include litter effects and either pen effects or pen-mate permanent environmental effects and possibly genetic pen-mate effects, in general agreement with the results of studies of different populations at other locations.

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