Confinement of lactating sows in crates for 4 days after farrowing reduces piglet mortality

To reduce mortality among suckling piglets, lactating sows are traditionally housed in farrowing crates. Alternatively, lactating sows can be housed in farrowing pens where the sow is loose to ensure more behavioural freedom and consequently a better welfare for the sow, although under commercial conditions, farrowing pens have been associated with increased piglet mortality. Most suckling piglets that die do so within the first week of life, so potentially lactating sows do not have to be restrained during the entire lactation period. Therefore, the aim of the current study was to investigate whether confinement of the sow for a limited number of days after farrowing would affect piglet mortality. A total of 210 sows (Danish Landrace × Danish Yorkshire) were farrowed in specially designed swing-aside combination farrowing pens measuring 2.6 m × 1.8 m (combi-pen), where the sows could be kept loose or in a crate. The sows were either: (a) loose during the entire experimental period, (b) crated from days 0 to 4 postpartum, (c) crated from days 0 to 7 postpartum or (d) crated from introduction to the farrowing pen to day 7 postpartum. The sows and their subsequent litters were studied from introduction to the combi-pen ∼1 week before expected farrowing and until 10 days postpartum. Confinement period of the sow failed to affect the number of stillborn piglets; however, sows that were crated after farrowing had fewer live-born mortality deaths (P < 0.001) compared with the sows that were loose during the experimental period. The increased piglet mortality among the loose sows was because of higher mortality in the first 4 days after farrowing. In conclusion, the current study demonstrated that crating the sow for 4 days postpartum was sufficient to reduce piglet mortality.     

Effect of Hyperoxia on Cortical Neuronal Nuclear Function and Programmed Cell Death Mechanisms

There is growing concern over detrimental neurologic effects to human newborns caused by increased inspired oxygen concentrations. We hypothesize that hyperoxia (FiO₂ > 0.95) results in increased high-affinity Ca²⁺-ATPase activity, Ca²⁺-influx, and proapoptotic protein expression in cortical neuronal nuclei of newborn piglets. Neuronal cerebral energy metabolism was documented by determining ATP and phosphocreatine levels. Neuronal nuclear conjugated dienes and fluorescent compounds were measured as indices of lipid peroxidation. High-affinity Ca²⁺-ATPase activity and ATP-dependent Ca²⁺-influx were determined to document neuronal nuclear membrane function. Hyperoxia resulted in increases in lipid peroxidation, high-affinity Ca²⁺-ATPase activity, ATP-dependent Ca²⁺-influx, and Bax/Bcl-2 ratio in the cortical neuronal nuclei of newborn piglets. We conclude that hyperoxia results in modification of neuronal nuclear membrane function leading to increased nuclear Ca²⁺-influx, and propose that hyperoxia-induced increases in intranuclear Ca²⁺ activates the Ca²⁺/calmodulin-dependent protein kinase pathway, triggering increased CREB protein-mediated apoptotic protein expression in hyperoxic neurons.     

Effects of different iron supply to pregnant sows (Sus scrofa domestica L.) on reproductive performance as well as iron status of new-born piglets

The present study aimed to investigate the effects of different iron (Fe) supply to sows during gestation on their reproductive performance and placental Fe load. Additionally, the Fe status of the corresponding offspring was assessed. Twenty multiparous sows were fed from insemination to farrowing with isoenergetic and isonitrogenic balanced diets differing in Fe content. The diet low in Fe (Group ?Fe) was mainly composed of soybean meal and maize meal and had a Fe content of 114 mg/kg DM. For the diet high in Fe (Group +Fe), the diet was supplemented with Fe(II)SO₄ · 7H₂O to a total Fe content of 256 mg/kg. Blood characteristics (haemoglobin, haematocrit, mean corpuscular haem concentration, total Fe-binding capacity, transferrin saturation) of all sows were measured at the beginning and at the end of gestation. Daily Fe retention was calculated at the day of farrowing. After birth, reproductive performance (litter size, piglet weight, litter weight), placental Fe content and Fe blood characteristics of the piglets were determined. Apparent daily Fe retention tended to be greater in Group +Fe (p < 0.1). Blood parameters of the sows did not show any variations between feeding groups, neither at the beginning nor at the end of pregnancy, whereas placental Fe content was lower in Group ?Fe (p < 0.05). In addition, Fe supply during gestation improved litter size (p < 0.01) and litter weight (p < 0.05). Although all sows were supplied according to the current Fe recommendations, a significant decline in reproductive performance of Group ?Fe was recognised. Therefore, it was concluded that the re-evaluation of the gross Fe requirements of pregnant sows is inevitable to accommodate the current feeding recommendations.     

代表性差异分析比较两株来自不同地区的猪源Lactobacillus菌株

[目的]对分离自猪肠道的乳酸杆菌S1菌株进行鉴定,并比较该菌株与同种的001T菌株的基因差异.[方法]对S1菌株进行16S rRNA基因序列分析和种特异PCR检测,并且对S1菌株和Lactobacillus sobrius 001T进行代表性差异分析(Representational difference analysis,RDA).[结果]16S rRNA基因序列分析表明,与S1菌株最相似的已知菌为L.sobrius.变性梯度凝胶电泳分析显示,仔猪空、回肠细菌图谱中有一与S1菌株有相同迁移位置的优势条带,克隆、测序鉴定表明,与该条带相匹配的16S rRNA基因克隆(Clone S)的最相似已知菌也为L.sobrius.16S rRNA基因系统进化分析表明,S1菌株与Clone S和L.sobrius 16S rRNA基因序列同源性分别为99.8%和99.6%.L.sobrius特异性引物也可以扩增S1株菌的16S rRNA基因的特定片段.因此S1菌株可被确定为Lsobrius.RDA对菌株S1和同种的猪源L.sobrius 001T菌株的基因差异进行分析,未发现这两株菌的基因组差异.[结论]猪肠道乳杆酸菌S1菌株属于L.sobrius,其与猪源L sobrius 001T菌株为相似菌株.     

Pain behaviour after castration of piglets; effect of pain relief with lidocaine and/or meloxicam

Behavioural responses and the effect of lidocaine and meloxicam on behaviour of piglets after castration were studied. A total of 144 piglets of 2 to 5 days of age were allocated to one of six treatments: castration (CAST), castration with lidocaine (LIDO), castration with meloxicam (MELO), castration with lidocaine and meloxicam (L + M), handling (SHAM) and no handling (NONE). Behaviour was observed for 5 days after the procedure, growth until weaning was recorded and characteristics of the castration wound noted. MELO piglets showed significantly (P < 0.05) more no pain-related behaviour than CAST and LIDO at the afternoon after castration, and were not significantly different from SHAM and NONE. LIDO piglets showed an increase (P < 0.001) in tail wagging, lasting for 3 days. This increase was not seen in L + M piglets. The occurrence of several behaviours changed with age, independent of treatment. A treatment effect on growth was not found. Wound healing was rapid in all treatments, but thickening of the heal was observed in several piglets, suggesting perturbation in the cicatrization process. Our study showed a pain-relieving effect of meloxicam after castration. Local anaesthesia resulted in piglets performing more tail wagging during the first few days after castration, which was prevented by administering meloxicam in combination with local anaesthesia.     

Sow level risk factors for early piglet mortality and crushing in organic outdoor production

Piglet mortality is a major problem in organic pig production affecting both farm economy and animal welfare. Knowledge is scarce on the risk factors of piglet mortality in Danish commercial organic pig production. The objectives of this study were to evaluate season, litter size, parity, sow body condition and stillborn littermates as risk factors for early piglet mortality and crushing of liveborn piglets from parturition until castration at day 3 to 5 postpartum (pp). The study was conducted over a 1-year period in nine commercial Danish organic pig herds practicing outdoor farrowing all year round. Data included recordings on 3393 farrowings with 50 284 liveborn piglets of which 14.8% died before castration. A subset of the dead piglets were collected and necropsied to identify crushed piglets. The average number of liveborn piglets per litter was 14.8 (SD=3.7) and the average time from parturition until castration was 4.1 (SD=1.7) days. A negative binomial regression analysis was used to model the effect of the predictive variables on the early piglet mortality accounting for different time periods from parturition to castration. An increase in maternal body condition score (BCS) and parity significantly increased the risk of dying between parturition and castration. Early mortality was found to be lowest during spring (March to May) and highest during summer (June to August). Being born into a litter with one or more stillborn littermates increased the risk of early mortality. The risk factors for crushing of piglets were evaluated using a logistic analysis. A significant effect of parity and litter size was found where the odds of at least one piglet in a litter with mortality was diagnosed as crushed increased with increasing parity and litter size. In conclusion, being born during summer (June to August), high parity and maternal BCS and stillborn littermates were found to be risk factors for piglet mortality between parturition and castration. In addition, parity and increasing litter size were found to be risk factors for crushing of piglets in litters with mortality.     

An improved multi-element measurement of mineral absorption in the piglet utilizing the fecal monitoring technique

The fecal monitoring technique for measuring the absorption of Zn, Mn, Se, and Fe was studied in eight male piglets (mean±SEM birthweight (bw)=1695±50 g) using high resolution gamma spectrometry. Four d old piglets were fed a complete liquid milk diet for five d prior to the orogastric administration of an isotope dose (⁷⁵Se,⁵⁴Mn,⁵⁹Fe, and⁶⁵Zn) equilibrated with the liquid milk diet.⁵¹CrCl₃ was used as a fecal marker but was found to be partially absorbed. Stool samples were collected daily for 15 d, counted, and then the daily fecal excretion was calculated. Results indicate that endogenous excretion for each of the isotopes was not constant but decreased exponentially with time. The pattern of endogenous excretion varied between elements. An improved method for calculating the endogenous excretion was therefore developed. This method is based on the pattern of endogenous excretion in three-four d old male piglets (mean±SEM bw=2060±75 g) injected intravenously with the same isotopes and on the level of endogenous excretion in orally fed animals in the postabsorptive phase of excretion. These findings have important implications for the estimation of endogenous excretion in future fecal monitoring absorption studies in order to minimize underestimation of true absorption.     

Invited review: Piglet survival: benefits of the immunocompetence

Piglet mortality has a negative impact on animal welfare and public acceptance. Moreover, the number of weaned piglets per sow mainly determines the profitability of piglet production. Increased litter sizes are associated with lower birth weights and piglet survival. Decreased survival rates and performance of piglets make the control of diseases and infections within pig production even more crucial. Consequently, selection for immunocompetence becomes an important key aspect within modern breeding programmes. However, the phenotypic recording of immune traits is difficult and expensive to realize within farm routines. Even though immune traits show genetic variability, only few examples exist on their respective suitability within a breeding programme and their relationships to economically important production traits. The analysis of immune traits for an evaluation of immunocompetence to gain a generally improved immune response is promising. Generally, in-depth knowledge of the genetic background of the immune system is needed to gain helpful insights about its possible incorporation into breeding programmes. Possible physiological drawbacks for enhanced immunocompetence must be considered with regards to the allocation theory and possible trade-offs between the immune system and performance. This review aims to discuss the relationships between the immunocompetence of the pig, piglet survival as well as the potential of these traits to be included into a breeding strategy for improved robustness.     

Effect of swine leukocyte antigen‐DQA gene variation on diarrhea in Large White,Landrace, and Duroc piglets

Piglet diarrhea is one of the most common factors that affects the benefits of the swine industry. Although recent studies have shown that exon 2 of SLA‐DQA is associated with piglet resistance to diarrhea, contributions of genetic variation in the additional exon coding regions of this gene remain unclear. Here, we investigated variation in exons 1, 3 and 4 of the SLA‐DQA gene and evaluated their effects on diarrheal infection in 425 suckling piglets. No variation was identified in exon 1. In exon 3, there were eight alleles detected, generated by 14 single nucleotide polymorphisms (SNPs) and three nucleotide deletions, eight SNPs being newly identified. Four allele sequences and three SNPs were identified in exon 4, only one SNP being newly identified. Statistical analysis showed that the genotypes of exon 3 are significantly associated with piglet diarrhea; indeed, genotypes DQA*wb01/wb02 and wb04/wb05 are clearly associated with resistance to piglet diarrhea, as they have the lowest probabilities of infection (P < 0.05). However, no significant association was found between the genotypes of exon 4 and diarrhea (P > 0.05). These results provide important new information concerning the level of genetic diversity at the SLA‐DQA locus and suggest that further genetic association studies of piglet diarrhea resistance should include analyses of both exons 2 and 3 of this locus.