Effect of the duration of commercial journeys between rearing farms and growing–finishing farms on the physiological stress response of weaned piglets

To find the effect of journey duration on the stress levels of weaned piglets a combination of physiological welfare indicators was used. One hundred and thirty-six piglets were monitored in two replicates of a short (0.6 h) and a long (8.3 h) commercial transport from a rearing to a growing–finishing farm. Variables studied were haematocrit, red blood cell count (RBC), total white blood cell count (WBC), differential WBC counts, serum pig's major acute phase protein (Pig-MAP), haptoglobin (Hp), cortisol, glucose, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), total protein, and albumin before loading and immediately after unloading. A marked increase in leucocytes (P < 0.01) and a tendency to lower eosinophil concentrations (P = 0.086) were observed in those piglets transported during the short journeys. On the other hand, the decrease in lymphocytes was particularly remarkable in the long journeys (P < 0.01). No increase in Hp concentrations after the transports was found, but an increase in Pig-MAP concentrations was observed at the end of the long journeys (P < 0.001). Cortisol concentrations did not show significant changes in either short or long journeys. According to CPK (P < 0.05) and LDH activities, some physical fatigue was detected at the end of transports, particularly in the short journeys. The decrease in haematocrit values in the short journeys (P < 0.05), and the absence of variations in RBC, albumin, and total protein concentrations would indicate that the loss of body water during both transport durations was reduced. Sex did not affect the response of piglets to transport, which could be attributable to the young age of the animals. Changes in albumin concentrations (P < 0.05), together with the tendencies to higher WBC (P = 0.092) and neutrophil counts (P = 0.076), suggest a more marked response to the stress of transport in heterozygous for the halothane gene (Nn) piglets than in homozygous negative (NN) piglets. Overall results indicate that, although transports were generally stressful, it is unclear which of the two durations was more detrimental for piglet welfare, and suggest a different stress response to transport with respect to that of older pigs.     

Effect of the type of farrowing room on the welfare and productive performance of lactating sows and of piglets during tropical winter

The objective of this study was to evaluate the behavior and performance of sows and piglets kept in different types of farrowing rooms: conventional farrowing room with jugglers and cages (CFR), CFR with a heated floor for the piglets alongside the sows (CFR+HF) and semi‐outdoor farrowing room without a cage or heating floor but with access to a fenced field (SFR) during the tropical winter. Twenty‐seven multiparous sows were allocated in three treatments and nine repetitions during 21 days. The relative humidity was higher at CFR and CFR+HF. The temperature of thigh and chest in contact with the floor and the neck were higher (P < 0.01) in conventional systems. Sows maintained in the CFR spent (P < 0.01) more time feeding and drinking. The heating floor increased (P < 0.01) the nursing behavior but did not affect (P > 0.09) the sows’ and piglets’ performances. SFR decreased the backfat thickness (P = 0.03) and lactation efficiency, but did not affect milk production (P > 0.12) or piglet performance (P > 0.09). It is concluded that during tropical winter, conventional farrowing systems ensure better piglet performance compared to SFR but this last seems to improve the behavior of sows. The heating floor favors nursing and does not affect the welfare of sows.     

Comparison of sow farrowing characteristics between a Chinese breed and three French breeds

Sow farrowing characteristics, including litter size, stillbirth, kinetics of births and piglet weight traits, were compared in 4 populations: Meishan (MS), Large White (LW), Duroc × Large White (DU × LW) and Laconie (LA). The kinetics of births was characterised by farrowing duration (FD), birth interval (BI), and farrowing irregularity, estimated by the standard deviation of BI (SDBI). The within-litter distribution of piglet birth weights was described by different traits including the mean (MBW) and standard deviation (SDBW) of birth weight. Additional characteristics of the sow were also analysed: weight at farrowing (SWF), gestation length (GEST), and birth assistance (BA). The data set included 47 MS, 605 LW, 55 DU × LW and 160 LA litters. For analyses, multivariate methods were used, including principal component analyses (PCA) and multiple factorial analyses (MFA). These methods allowed the relative importance of between-breed and within-breed variability of the correlation structure to be estimated and the homogeneity between populations (by comparison of the 4 breed correlation structures) to be investigated. Though most of the variability was observed within-breed (97%), between-breed variation appeared to be highly significant (P < 0.0001). This variation was essentially due to the Meishan breed departing from others, because of the lower weight at farrowing and, to a lesser extent, to the lower number of stillbirths and lower piglet mean and standard deviation in birth weight. Litter size did not contribute much to the variability between breeds. The rather strong correlations related to between-breed structures (r > 0.70) indicated that the correlation pattern was similar among breeds. Stillbirth was independent from litter size and appeared as closely associated with farrowing duration in the French breeds.     

Factors affecting piglet mortality in loose farrowing systems on commercial farms

Crating sows in farrowing systems greatly restricts their normal behaviour (e.g. movement, nest-building, leaving the nest site for defecation), which is usually justified by the assumption that piglet mortality is higher with loose-housed sows. Based on experiments showing that this is not the case, farrowing crates were banned in Switzerland in 1997, with a 10-year transitional period. Since then, many farms have introduced loose farrowing systems, enabling an analysis of risk factors for piglet mortality in crateless farrowing systems based on a large sample size. Data from a Swiss sow recording scheme (UFA2000) were analysed using generalised linear mixed-effects models with an underlying Poisson distribution. Average total piglet mortality for the years 2002 and 2003 on 99 farms (N = 12457 litters) with loose farrowing systems amounted to 1.36 liveborn piglets per litter. The number of crushed piglets was 0.64 piglets per litter, whereas the number of piglets that died for other reasons was 0.72 piglets per litter.Herd size, pen size, possibility of confinement of the sow, presence of piglet protection bars and year of data collection did not significantly influence total piglet losses, losses due to crushing and losses due to reasons other than crushing. With greater litter size at birth, significantly more losses occurred due to all reasons (total, crushed, others). Total piglet mortality and losses for reasons other than crushing were significantly higher in older sows. Losses were therefore mainly attributable to sow-related characteristics rather than to the design of the farrowing pen.     

Can outdoor rearing and increased weaning age compensate for the removal of in-feed antibiotic growth promoters and zinc oxide?

This experiment determined whether delayed weaning and outdoor rearing could compensate for the removal of antimicrobials from piglet diets. One hundred and sixty litters of Large White (75%) × Landrace (25%) pigs on the same unit were reared either indoors (In) or outdoors (Out) and weaned at either 4 or 6 weeks of age into flat deck accommodation onto diets supplemented with either no antibiotic growth promoters and no zinc oxide (Un) or 40 mg avilamycin and 3.1 g zinc oxide/kg diet (S). Piglet performance was monitored to 8 weeks of age. A proportion of litters (25%) were sampled to investigate the effect of the different treatments on gut development. Mortality was higher in the first 24 h of life for Out piglets which subsequently grew faster to weaning. This was not simply due to smaller litter size as total litter gain was higher in outdoor litters. All piglets responded positively to antimicrobial supplementation post weaning regardless of rearing environment and weaning age and this was the biggest influence on post weaning performance. Outdoor piglets grew faster than indoor piglets post weaning (295 versus 242 ± 8.6 g/pig/day for the first 2 weeks post weaning, P < 0.001) and over the same period 6 week weaned piglets grew faster than 4 week weaned (324 versus 213 ± 8.6 g/pig/day, P < 0.001), however, when compared at similar age, 6 week weaning was detrimental to piglet growth with average daily gain (adg) from 4 to 8 weeks of age 310 g/pig/day versus 329 for 4 week weaned piglets (P = 0.001). At 8 weeks of age the outdoor 6 week weaned unsupplemented piglets had similar average weight to the indoor 4 week weaned supplemented piglets indicating the potential of this combination to counteract the need for antimicrobials, however the benefit was due to enhanced weaning weight not to improved post weaning performance.     

Colostrum yield and litter performance in multiparous sows subjected to farrowing induction

The consumption of colostrum at a low level can compromise the survival and growth of piglets. Therefore, this study aimed to evaluate the effect of farrowing induction on colostrum yield, IgG concentration and the survival and performance of piglets until the weaning. Sows of parity 3 to 7 were assigned into two groups: Control (n = 48), sows with spontaneous farrowing; and induction (n = 48), sows induced to farrow on day 114 of gestation with a PGF₂ analogue. Colostrum and blood samples were collected from the sows, at farrowing and 24 hr later. Blood samples from the piglets were collected at 24 hr after birth. The performance of the piglets was evaluated in a subsample of 28 litters from each group. All piglets were weighed at 7, 14 and 20 days of age. The farrowing length, the number of piglets born alive, stillborn piglets, weight at birth, litter weight at birth and colostrum yield were not significantly affected (p > .05) by farrowing induction. There was no difference between the groups (p > .05) in the percentage of sows with obstetric interventions. Serum IgG concentration, in both sows and piglets, and colostrum IgG concentration were similar between the groups (p > .05). Furthermore, survival rate, piglet weight and litter weight at 7, 14 and 20 days of age were also similar between the groups (p > .05). Therefore, it can be concluded that the farrowing induction performed on day 114 of gestation does not affect the colostrum yield, the IgG concentration in colostrum and serum of piglets, and the litter performance until the weaning.     

Leptin in sow: Influence on the resumption of cycle activity after weaning and on the piglet gain

In sows, a strong relationship exists between body condition and reproductive efficiency and milk yield. Leptin may act as a metabolic gate which permits the activation of reproductive axis: in the sow, serum concentration of leptin was positively correlated with adiposity at farrowing. An interesting aspect useful to clarify the biology of leptin, was the discovery that the placenta expresses the ob gene, the ob receptor gene and it is a site of leptin production, suggesting a possible role of the hormone in fetal growth; after birth, the placenta functions were taken over from milk, especially to the delivery of maternal hormones and growth factors to the neonate. The exact role of maternal leptin in the physiology of neonatal piglets remains to be determined. Our aim was to evaluate if maternal leptin levels at the beginning of lactation and at weaning could predict the resumption of cycle activity and/or the piglet gain. Thirty-eight Large White × Landrace pregnant sows (16 nulliparous and 22 pluriparous) were used. Blood samples were taken from sows and piglets at d 5 and d 21 after farrowing; in the same days, milk samples were taken after oxytocin injection by means of complete manual milking of all mammary glands of one side. On the basis of the blood leptin at d 5, sows were divided into 3 groups (Low: < 2.3 ng/ml; Medium: 2.3 to 2.6 ng/ml; High: > 2.6 ng/ml). Our results show a correlation at d 5 between backfat thickness and blood leptin (r = 0.342; P < 0.05). The resumption of the cyclic activity was faster in sows with a leptin level at d 5 greater than 2.3 ng/ml (P < 0.01). Milk composition at d 5 and 21 was not affected by parity and leptin. Piglet ADG was significantly (P < 0.05) influenced by sow leptin groups (0.180 kg day^− 1 for piglets from Low group and 0.224 for High group). Piglets weaned by High group sows have shown a greater blood leptin content at weaning (P < 0.01) than other groups. In conclusion we have found a significant correlation between leptin and productive and reproductive performances of pigs. This paper underlines the pleiotropic actions exerted by leptin in the productive sow.     

Influence of birth order,birth weight,colostrum and serum immunoglobulin G on neonatal piglet survival

Background

Intake of colostrum after birth is essential to stimulate intestinal growth and function, and to provide systemic immunological protection via absorption of Immunoglobulin G (IgG). The birth order and weight of 745 piglets (from 75 litters) were recorded during a one-week period of farrowing. Only pigs weighing greater than 0.68 kg birth weight were chosen for the trial. Sow colostrum was collected during parturition, and piglets were bled between 48 and 72 hours post-birth. Piglet serum IgG and colostral IgG concentrations were determined by radial immunodiffusion.

Results

Sow parity had a significant (P < 0.001) effect on sow colostral IgG concentration, being 5% higher in multiparous females. Sow colostral IgG concentration explained 6% and piglet birth order accounted for another 4% of the variation observed in piglet serum IgG concentration (P < 0.05); however, birth weight had no detectable effect. Piglet serum IgG concentration had both a linear (P < 0.05) and quadratic effect (P < 0.05) on % survival. Piglets with 1,000 mg/dl serum IgG or less (n=24) had a 67% survival; whereas, piglets with IgG concentrations between 2250 to 2500 mg/dl (n=247) had a 91% survival. Birth order had no detectable effect on survival, but birth weight had a positive linear effect (P < 0.05). Piglets weighing 0.9 kg (n = 107) at birth had a 68% survival rate, and those weighing 1.6 kg (n = 158) had an 89% survival.

Conclusion

We found that the combination of sow colostrum IgG concentration and birth order can account for 10% of the variation of piglet serum IgG concentration and that piglets with less than 1,000 mg/dl IgG serum concentration and weight of 0.9 kg at birth had low survival rate when compared to their larger siblings. The effective management of colostrum uptake in neonatal piglets in the first 24 hrs post-birth may potentially improve survival from birth to weaning.     

The welfare of finishing pigs in two contrasting housing systems: Fully-slatted versus straw-bedded accommodation

Four consecutive studies were carried out over a 3-year period to assess the health and welfare implications of housing finishing pigs in either fully-slatted or straw-bedded accommodation. In each study, 1024 (Large White × Landrace) × Large White pigs, housed in pen groups of 32, were fed ad libitum from 34 kg to slaughter at 104 kg live weight. Eight batches of pigs were received in each study and allocated alternately to fill one room of four pens in each house. Data were collected on a range of welfare parameters. Lameness (P < 0.001) and bitten tails (P < 0.001) were more prevalent health problems in the fully-slatted system, whilst in the straw-bedded system pigs showed more respiratory (P < 0.01) and PMWS-type symptoms (P < 0.01). Acute phase protein titres at slaughter were higher in pigs from the fully-slatted system (P < 0.001). Skin lesion score did not differ between systems; however, bursitis was more severe in pigs in the fully-slatted system (P < 0.001). Pigs in the straw-bedded system had poorer hygiene scores (P < 0.001), but the magnitude of this difference varied between studies depending on season. Pigs with straw were more active (P < 0.001), spending a large proportion of time manipulating straw. In the absence of straw, pigs spent more time in behaviour directed at other pigs (P < 0.001) and the pen components (P < 0.001). Post-slaughter assessment showed no system differences in lung lesions and cardiac scores, or osteochondrosis. Pigs with straw had more severe toe erosions on the foot (P < 0.001), whilst pigs without straw had more severe sole (P < 0.001) and heel erosions (P < 0.001). Gastric lesion scores were lower in the fully-slatted system (P < 0.001). The results show both advantages and disadvantages to each of the housing systems for pig welfare.     

Piglet Birthweights and the Order of Farrowing

The relationship between birthweight and order of farrowing was determined from the records of 202 attended farrowings. Statistical analysis of all individual birthweights showed the first-born piglet to be heavier (P<0.05) than the last-born. The order of farrowing might not be entirely random, as further evidenced by a delayed expulsion of stillborn piglets; 70 per cent of these births occurred during the last third of the farrowing period.     

Influence of sow dietary fatty acid composition on the behaviour of the piglets

Polyunsaturated fatty acids (PUFA) are essential for the development of the nervous system in animals, and increased concentration of n−3 PUFA in maternal diet improves the cognitive development of mammalian foetuses. In this study the effect of maternal diet fatty acid composition in pigs on the development of the central nervous system, monitored as behaviour of piglets, was investigated using three behavioural tests: recognition of the mother's faeces, back test, and hidden door test.Twenty-seven multiparous Yorkshire sows were split into four groups and fed diets with different content of fat and PUFA throughout pregnancy and lactation. LF (n = 6) was fed a standard diet, HFS (n = 4) a high fat and low PUFA diet, HFO (n = 7) a high n−6 PUFA diet, and HFL (n = 10) a high n−3 PUFA diet.Three behavioural tests were performed on 5–7 randomly chosen piglets per litter (n = 167). Recognition of the mother's faeces was tested in a maze two days after birth. Back test was performed twice (2–4 d and 4 w) and a hidden door test was performed at 4 w. In addition, the brain content of docosahexaenoic acid (22:6 n−3, DHA) of the newborn piglets was determined in treatment groups. Data from the tests were analysed with linear mixed models for each of the tests.Piglets from HFL treatment had significantly higher content of DHA (P < 0.001) and the ratio of n−6/n−3 PUFA was significantly lower in brain tissue (P < 0.001), compared to piglets from the other treatments. In parity 3, means for recognition for mother's faeces were for diets LF, HFS, HFO and HFL; 22.2, 37.0, 26.4 and 18.0%, respectively (P < 0.05), but no other significant effect of diet was found. Piglets in HFS treatment had the shortest latency to make escape attempts and HFO piglets the longest latency in the back test (P = 0.030). No significant effect of sow diet was found on piglet performance in the hidden door test, but intermediate piglets weighing 1410–1619 g had a lower probability of success in hidden door test than piglets weighing < 1410 g (P = 0.028), and ≥ 1875 g (P = 0.027), respectively.It was found that sow diet influenced the DHA content in the piglet brains, but there was no clear effect of sow diet on piglet behaviour. In order to draw any conclusions about possible enhancements of the behavioural development of the piglet more studies need to be performed.     

Welfare and production implications of teeth clipping and iron injection of piglets in outdoor systems in Scotland

To assess the merits of implementing piglet husbandry tasks in outdoor systems, 550 piglets in 49 litters were used in a split-plot experiment to determine the effects of (a) leaving piglet teeth intact or clipping them at birth in alternate litters, and (b) injecting alternate piglets within each litter with 200 mg of iron (as dextran) at 2–4 days after farrowing or leaving piglets untreated. Leaving teeth intact increased facial lesion scores at 7 days, 14 days and weaning (22 days) but had no effect on survival or daily liveweight gain. No udder damage was recorded on sows and no behavioural differences in time spent away from the farrowing hut or willingness to be suckled were observed. Administration of iron resulted in a small but significant elevation in piglet blood haemoglobin level at weaning, but had no significant effect on piglet performance. All piglets had blood haemoglobin levels in excess of 6 g 100ml⁻¹. A survey of 90 other untreated piglets from nine different herds in northeastern Scotland failed to detect any anaemic piglets. There was no overall correlation between herd mean haemoglobin level and soil iron content, although the lowest levels of both occurred in the same herd. Implementation of these husbandry tasks is seldom likely to be justified in outdoor systems in northeastern Scotland.     

Dynamics of vanishing of maternally derived antibodies of Ungulate protoparvovirus 1 suggests an optimal age for gilts vaccination

The prevention of Ungulate protoparvovirus 1 (UPV1) infection and consequently the reproductive losses is based on vaccination of all pigs intended for breeding. As maternally derived antibodies (MDA) can interfere with the development of immunity following vaccination, it is important to know the duration of anti-UPV1 MDA to determine the optimal age for the best vaccination efficacy. To elucidate the association between dam and piglet antibody levels against UPV1 and to estimate the decrease rate of MDA, sera and colostrum of 127 gilts (before the first vaccination against UPV1; 15 days after the second vaccine dose; at farrowing; and during the second pregnancy) and sera of 276 piglets (prior to initial colostrum intake; at 7, 21, 57, 87, and 128 days-old) were tested by ELISA. Most gilts (85.8%) had anti-UPV1 antibodies before vaccination and after vaccination all were positive. At 7 days old, the majority of the piglets had anti-UPV1 antibodies, but around 57 days old, only 35.3% were positive and at 87 days old, all were negative. The estimated average half-life of MDA was 29.8 (28.8–30.9) days. A strong correlation was determined between piglet serum at 7 days old with gilt serum at farrowing time (r = 0.77, n = 248, P < 0.001) and with piglet serum at 7 days old with colostrum (r = 0.73, n = 248, P < 0.001). The MDA decreased earlier and the antibody half-life was a little longer than previously reported. Based on these findings, UPV1 vaccination can be performed earlier than usual.

     

Effects of different gestation housing types on reproductive performance of sows

This study evaluated the effects of different gestation housing types on reproductive performance of sows. A total of 60 sows (218 ± 24 kg body weight) with mixed parity were used. During gestation, 28 sows were housed in groups with electronic sow feeders (space allowance = 1.26 m²/sow) and 32 sows were housed in individual stalls (space allowance = 1.20 m²/sow). Sows from both housing types were moved to farrowing crates on day 109 of gestation and stayed until weaning (18 days post‐farrowing). Typical corn‐soybean meal diets were provided to sows during gestation and lactation. Measurements were reproductive performance of sows at farrowing as well as performance of sows and their litter during lactation. Similar total numbers of piglets born at farrowing were observed for sows gestated in both housing types. However, group‐housed gestation sows had more mummies (0.321 vs. 0.064; P < 0.05) and stillbirths (0.893 vs. 0.469; P = 0.073) at farrowing than individual‐housed gestation sows. Consequently, individual‐housing type had higher percentage of piglets born alive (95.5 vs. 90.4%; P < 0.05) than the group‐housing type. Therefore, improved reproductive performance of sows from individual gestating housing was confirmed in this study.     

Effects of L‐citrulline supplementation on heat stress physiology,lactation performance and subsequent reproductive performance of sows in summer

Lactating sows are susceptible to heat stress (HS). Part of the thermoregulatory response to HS is to increase peripheral blood flow, which is mediated in part by the vasodilator, nitric oxide (NO). Therefore, the aim of this experiment was to determine the effect of supplementation of L‐citrulline, a NO precursor, on symptoms of HS, lactation performance and subsequent reproductive performance of sows in summer. A total of 221 summer farrowing mixed parity sows were fed either a control diet or supplemented with 1% L‐citrulline upon entry to the farrowing house (6 ± 1.8 days for mean ± standard deviation [SD] before farrowing) until weaning (26 ± 1.5 days). The average daily minimum and maximum temperature in the farrowing house was 21.0 ± 1.88 and 29.2 ± 3.82°C (mean ± SD). Rectal temperature, respiration rate, and plasma and urinary nitrite and nitrate (NOx) of sows were measured on the 19th day post‐farrowing. Supplemental L‐citrulline in the diet did not affect the number of piglets born alive, feed intake of sows, body weight or backfat thickness of sows at weaning, or litter weight gain. L‐citrulline tended to reduce piglet pre‐weaning mortality rate from 18.6% to 15.6% (p = 0.058). L‐citrulline reduced the respiration rate of sows compared to the control diet at 17:00 hr (Time × Diet, p < 0.001); however, rectal temperature was not affected. L‐citrulline tended to increase urinary NOx concentrations (127 vs. 224 µM, p = 0.057) but not plasma NOx concentrations. L‐citrulline did not affect farrowing rate or number of piglets born alive in the subsequent parity. In conclusion, L‐citrulline supplementation reduced respiration rate of lactating sows and reduced piglet pre‐weaning mortality rate in summer. Whether the effects were due to a NO‐dependent mechanism requires further validation.     

Influence of dietary fat source on sow and litter performance,colostrum and milk fatty acid profile in late gestation and lactation

The objective of this study was to investigate the effects of dietary supplementation with various fat sources (3.8–3.9% of diet) during late pregnancy and lactation on the reproductive performance, fatty acids profile in colostrum, milk and serum of sow progeny. A total of 80 multiparous sows were randomly fed a control (adding no oil), palm oil (PO), fish oil (FO) or soybean oil (SO) supplemented diet from 90 days of pregnancy to weaning. Supplementation of FO increased litter size of weak piglets, compared with the control‐fed sows (P < 0.05). Dietary FO and SO supplementation, enhanced the weaning survival rate, litter weaning weight, litter weight gain and fat content in milk (P < 0.05). The highest immunoglobulin (Ig)G and IgM levels in colostrum and milk were observed in the FO group (P < 0.05). Meanwhile, the highest concentration of C22:5 (n‐3) and C22:6 (n‐3) in colostrum, milk and piglet serum was observed in the FO group (P < 0.05). Taken together, dietary inclusion of FO or SO improved growth performance of nursing piglets by increasing milk fat output, and FO consumption by sows might benefit the piglets via increasing n‐3 polyunsaturated fatty acid availability and immunoglobulins (IgG and IgM) secretion.     

Effect of dietary supplementation of fish oil for lactating sows and weaned piglets on piglet Th polarization

The present study was designed to investigate the effect of dietary fish oil supplementation on piglet T helper cells (Th) polarization in relation to its impact on piglet serum interferon γ (IFN-γ) and interleukin 10 (IL-10) concentrations and splenic expression of Th1/Th2 characteristic genes. The diets of 18 gestating sows were supplemented with 7% lard (C) (n = 10) or 7% fish oil (T) (n = 8) from 10 d before parturition to weaning. At weaning, a split plot experiment was designed, 56 piglets, 28 each from sows fed with fish oil diet or lard diet, were divided into four groups of 7 replicates (one female and one castrated male per replicate) based on both sow diet during lactation and post-weaning piglet diet (C had 7% lard and T had 7% fish oil): CC, CT, TC, TT, and were fed the 7% fish oil or lard diet from day 35 to day 70. Serum concentrations of IFN-γ and IL-10, and Th1/Th2 related genes expression levels in spleen were measured and analyzed. The results showed that piglets fed with fish oil diet during post-weaning tended to have higher serum IFN-γ/IL-10 ratio (P = 0.09) than lard diet fed piglets. Lactation fish oil feeding increased splenic IL-12b, IL-12 receptor β2 (IL-12Rβ2), IL-2 and IFN-γ genes expression (P < 0.05 or P < 0.01) and post-weaning fish oil feeding increased splenic IL-12b (P = 0.06), IL-2 (P < 0.01) and IFN-γ (P = 0.08) mRNA expression than that in lard diet fed piglets at the end of this experiment. On the other hand, IL-4 gene expression (P = 0.01) in spleen was lower in weaned piglet from fish oil diet fed sows than that from lard diet fed sows. However, post-weaning piglets fed fish oil diet had higher splenic IL-4 (P = 0.06), IL-6 (P < 0.01) and IL-10 (P = 0.05) mRNA abundances than that fed with lard diet. These results indicated that dietary fish oil during lactation could increase Th1 polarization and accelerate immune maturation; while 7% fish oil in weaned piglets' diet was likely to increase Th2 cytokines expression.     

The interaction between dietary crude protein and fermentable carbohydrate source on piglet post weaning performance, diet digestibility and selected faecal microbial populations and volatile fatty acid concentration

A 2 × 2 × 2 factorial arrangement was used to investigate a 21 day study on the interaction between dietary crude protein (CP) (160 versus 200 g/kg), lactose level (50 versus 230 g/kg), and inulin supplementation (0 versus 15 g/kg) on piglet performance, diet digestibility, faecal volatile fatty acid (VFAs) concentration and selected microbial populations post weaning. Two hundred and fifty six weaned piglets (24 days old, 7.4 kg live weight, S.D. = 1.5 kg) were blocked on the basis of live weight and were assigned to one of 8 dietary treatments (n = 8) for 21 days. There was an interaction between CP and lactose concentration on average daily gain (ADG) during the overall experimental period. Pigs offered high CP diets containing 230 g/kg lactose increased ADG compared to those pigs offered high CP diets containing 50 g/kg lactose. However, there was no effect of lactose concentration in the low CP diets. There was a significant interaction (P < 0.05) between lactose level and inulin supplementation on Lactobacilli spp., Enterobacteria spp. and branched chain VFAs. Pigs offered inulin supplemented 230 g/kg lactose diets increased Lactobacilli spp. (P < 0.05) and decreased Enterobacteria spp. (P < 0.05) and branched chain VFAs (P < 0.05) compared to those offered the inulin supplemented 50 g/kg lactose diets. However there was no effect of lactose concentration in the non inulin supplemented diets. In conclusion, high CP diets and high inclusion levels of lactose improved piglet performance post weaning. Inulin supplementation had an additional effect in the 230 g/kg lactose diets through increased Lactobacilli spp. and decreased Enterobacteria spp. and branched chain VFAs.     

Dietary supplementation with Acanthopanax senticosus extract enhances gut health in weanling piglets

The present study was conducted to investigate the effects of Acanthopanax senticosus extract (ASE) as a dietary additive on gut health in weanling piglets by examining diarrhea frequency, intestinal microbiota and morphology. A total of 96 Duroc× (Landrace × Yorkshire) piglets weaned at 21 days of age with an average initial body weight (BW) of 5.6 ± 0.4 kg were randomly assigned to 3 treatment groups with 4 duplicates of 8 piglets each. The piglets were fed basal diet to which had been added 0 or 1 g/kg of ASE, or 0.7 g/kg antibiotics, respectively. Fecal consistence was monitored twice daily and the frequency of diarrhea was calculated. On day 21 after the initiation of supplementation, 8 piglets were randomly selected from each treatment group (2 piglets per pen) and slaughtered. The jejunum, ileum, colon and cecum were then excised and fixed in 10% neutral formalin solution to determine villus height and crypt depth, after their contents were collected to determine microbiota. The results showed that dietary supplementation with ASE increased (P < 0.05) the density of bacterial populations that co-migrated with Lactobacillus amylovorus, Lactobacillus salivarius, Bacillus subtilis, and Clostridium lituseburens, but decreased (P < 0.05) those co-migrating with Staphylococcus aureus, Salmonella typhimurium, Ruminococcus forques, and E. coli O157:H7 in the PCR-DGGE profiling analysis when compared with the control group. The villus height of the duodenum, jejunum and ileum increased (P < 0.05) by 14.8, 13.7 and 10.0%, while the crypt depth decreased (P < 0.05) by 17.9, 9.1 and 12.1%, respectively, in response to dietary ASE supplementation. Additionally dietary supplementation with ASE or an antibiotic decreased (P < 0.05) the frequency of diarrhea by 55.6 and 52.2%, respectively, compared with the control group. In conclusion, these findings suggest that dietary supplementation with ASE could regulate the microbiota composition and maintain a normal morphology of gut mucosa in weanling piglets, thereby decreasing diarrhea that resulted from weaning stress.     

Impacts of a freedom farrowing pen design on sow behaviours and performance

The limited space in farrowing crate imposes many challenges, such as prolonged farrowing duration and high piglet stillbirth rate. Although the features of farrowing pens compensate for the drawbacks of farrowing crates, they are associated with high piglet crushing mortality caused by the greater space afforded to sows and their rolling-over behaviour. Therefore, a freedom farrowing pen was designed to overcome the drawbacks of both farrowing crates and farrowing pens. The main features of the freedom farrowing pen are its left anti-crushing bar and detachable right anti-crushing bar on the sides of the sow lying area. It also has a 10 cm-high anti-crushing bar in the non-lying area. Eighteen healthy, multiparous Yorkshire sows (3-7 parity) were averaged and randomly assigned to farrowing crates, farrowing pens, and freedom farrowing pens to compare the effects of the farrowing systems on sow behaviour and performance. Results showed that the farrowing duration and the mean piglet birth intervals were longer for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P<0.05), but there was no difference between the sows in farrowing pens and those in freedom farrowing pens (P>0.05). The piglet stillbirth rate was higher for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P<0.001). Crushing mortality was higher among piglets in farrowing pens (P<0.001), but there was no difference between piglets in freedom farrowing pens and those in farrowing crates (P>0.05). The freedom farrowing pen and the farrowing pen allowed sows to turn around and move freely, but because of the different structures of their anti-crushing bars, the increase in sow movement did not cause higher piglet crushing mortality (P>0.05). Sows in freedom farrowing pens were found to be more protective of their piglets.