Litters Of Piglets Research Articles

Impact of porcine epidemic diarrhea on herd and individual Berkshire sow productivity

Porcine epidemic diarrhea (PED) is an emerging disease of pigs in several countries. In the present study, individual sow productivity of Berkshire sows exposed to PED virus at different stages of production was compared. On a commercial farrow-to-finish farm in Kagoshima Prefecture, Japan, the clinical presence of PED was observed in the farrowing barn on January 6, 2014, and all gilts and sows were immunized on January 9, except those in the farrowing barn. The sows were categorized into six groups based on the period in which they were exposed to PED virus: between days 0–30 (G1), 31–60 (G2), 61–90 (G3), or after 91 days of pregnancy (G4), during lactation (L), and after weaning (W). The control group was not exposed to PED during the period of PED outbreak. The study was based on 574 production records. The sows of the G4 and L groups had the fewest piglets weaned (4.8±0.4, and 4.0±0.3 pigs, respectively; P<0.05) and the greatest pre-weaning mortality (33.1±4.8%, and 39.7±4.1%, respectively; P<0.05). The number of piglets weaned and pre-weaning mortality, however, did not differ among the G1, G2, G3, and uninfected groups. The G4 and W groups had slightly lesser farrowing rates than the uninfected group (P<0.05), however, similar subsequent piglet litter performance as the uninfected group. In conclusion, the effect of PED on individual sow productivity differed with the production stage in which sows were exposed to PED virus.

Increases in circulating amino acids with in-feed antibiotics correlated with gene expression of intestinal amino acid transporters in piglets.

In-feed antibiotics have been commonly used to promote the growth performance of piglets. The antibiotics can increase protein utilization, but the underlying mechanism is largely unknown. The present study investigated the effects of in-feed antibiotics on intestinal AA transporters and receptors to test the hypothesis that the alteration of circulating AA profiles may be concomitant with the change of intestinal AA transporters and receptors. Sixteen litters of piglets at day 7 started to receive creep feed with (Antibiotic) or without (Control) antibiotic. Piglets were weaned at day 23 after birth, and fed the same diets until day 42. In-feed antibiotics did not affect the BW of 23-day-old (P=0.248), or 42-day-old piglets (P=0.089), but increased the weight gain to feed ratio from day 23 to 42 (P=0.020). At day 42 after birth, antibiotic treatment increased the concentrations of most AAs in serum (P<0.05), and decreased the concentrations of most AAs in jejunal and ileal digesta. Antibiotics upregulated (P<0.05) the mRNA expression levels for jejunal AAs transporters (CAT1, EAAC1, ASCT2, y+LAT1), peptide transporters (PepT1), and Na+-K+-ATPase (ATP1A1), and ileal AA transporters (ASCT2, y+LAT1, b0,+AT, and B0AT1), and ATP1A1. The antibiotics also upregulated the mRNA expression of jejunal AAs receptors T1R3 and CaSR, and ileal T1R3. Protein expression levels for jejunal AA transporters (EAAC1, b0,+AT, and ASCT2) and PepT1 were also upregulated. Correlation analysis revealed that the alterations of AA profiles in serum after the in-feed antibiotics were correlated with the upregulations of mRNA expression levels for key AA transporters and receptors in the small intestine. In conclusion, the in-feed antibiotics increased serum level of most AAs and decreased most AAs in the small intestine. These changes correlated with the upregulations of mRNA expression levels for key AA transporters and receptors in the small intestine. The findings provide further insights into the mechanism of in-feed antibiotics, which may provide new framework for designing alternatives to antibiotics in animal feed in the future.

Analysis of Reproductive Characters in Hybrid Pig Combination (CLW x CL) x (D x Pn)

The aim of the experiment was to analyse reproductive characters in hybrid pig combination (CLW x CL) x (D x Pn). These reproductive traits of sows were studied: number of all, live born and weaned piglets, loses from live born piglets till weaning. These influences with an impact on reproductive characters were monitored: order of litter, number of piglets in a litter, birth weight of piglets, influences of sex and litter order on birth weight of piglets. An average number of all born piglets per sow and litter it was 13.25 piglets. From this an average number of live born piglets it was 12.48 piglets per sow and litter and from each litter there was 11.40 of weaned piglets. The highest number of live born piglets was reached in sows on the fourth litter – 14.50 piglets. On eighth and nineth litter fertility decreased to 11.60 and 11.00 piglets. Statistical conclusive difference (P ≤ 0.05) was found between fourth (14.50) and nineth (11.00) litter. Among birth weight in both sexes a statistical conclusive difference (P ≤ 0.05) was found. Higher birth weight (1.46 kg) was found in boars in comparison with gilts (1.40 kg). The highest birth weights in gilts were reached in litters of sows on the second and nineth litters – 1.49 kg and 1.48 kg. Birth weight decreased on tenth litter with average weight of 1.28 kg. The highest birth weight in boars was detected on the seventh litter but on the seventh litter piglets of only one sow were weightened so the result 1.67 kg is not objective. The second highest average birth weight was reached on the third litters – 1.53 kg. On the contrary the lowest average birth weight was on the fourth and tenth litters where boars reached weight of 1.28 and 1.25 kg. Statistical conclusive difference (P ≤ 0.05) was found between the second (1.53 kg) and tenth (1.25 kg) litter.

Differential effect of early antibiotic intervention on bacterial fermentation patterns and mucosal gene expression in the colon of pigs under diets with different protein levels.

The study aimed to evaluate the effects of early antibiotic intervention (EAI) on bacterial fermentation patterns and mucosal immune markers in the colon of pigs with different protein level diets. Eighteen litters of piglets at day (d) 7 were fed creep feed without or with growth promoting antibiotics until d 42. At d 42, pigs within each group were further randomly assigned to a normal- or low-crude protein (CP) diet. At d 77 and d120, five pigs per group were slaughtered for analyzing colonic bacteria, metabolites, and mucosal gene expressions. Results showed that low-CP diet increased propionate and butyrate concentrations at d 77 but reduced ammonia and phenol concentrations (P<0.05). EAI increased p-cresol and indole concentrations under normal-CP diet at d 77 (P<0.05). Low-CP diet significantly affected (P<0.05) some bacteria groups (Firmicutes, Clostridium cluster IV, Clostridium cluster XIVa, Escherichia coli, and Lactobacillus), but EAI showed limited effects. Low-CP diet down-regulated gene expressions of pro-inflammatory cytokines, toll-like receptor (TLR4), myeloid differentiating factor 88 (MyD88), and nuclear factor-κB p65 (NF-κB p65) (P<0.05). EAI up-regulated mRNA expressions of interleukin-8 (IL-8) and interferon-γ (IFN-γ) under normal-CP diet at d 77 (P<0.05). Furthermore, reductions of E. coli and ammonia under low-CP diet were positively correlated with down-regulated gene expressions of pro-inflammatory cytokines, which were positively correlated with the down-regulated TLR4-MyD88-NF-κB signaling pathway. In conclusion, EAI had short-term effects under normal-CP diet with increased aromatic amino acid fermentation and gene expressions of pro-inflammatory cytokines. Low-CP diet markedly reduced protein fermentation, modified microbial communities, and down-regulated gene expressions of pro-inflammatory cytokines possibly via down-regulating TLR4-MyD88-NF-κB signaling pathway.

Influences Which Affect Reproductive Characters of Sows in Studied Reproductive Breeding

The aim of the study was to evaluate influences which affect reproductive characters of sows in chosen reproductive breeding. These reproductive traits of sows were studied: number of all, live born and weaned piglets, losses from live born piglets till weaning. These influences which affect reproductive characters were studied: order of litter, number of piglets in litter, birth weight of piglets and influence of sex on birth weight of piglets. An average number of all born piglets per litter it was 11.74 animals. From that 11.33 live born piglets per sow and litter. 10.15 piglets were weaned from each litter in average. It represents 11.68 % of losses in live born piglets till weaning. An influence of litter order on number of live born piglets in litter was studied in an experiment. The first litters show 11.36 of live born piglets in average, the second litters 10.38 piglets, the third litters 10.43 piglets and the fourth litters 10.75 piglets. Maximum was reached on fifth litter with 13.33 of live born piglets. From the sixth litter number of live born piglets was decreasing. On the sixth litter it was 12.33 piglets, on the seventh only 9.40 of live born piglets. Between fifth litter (13.33 piglets) and seventh litter (9.40 piglets) statistical conclusive difference (P ≤ 0.05) was found. The sixth litters showed the highest number of weaned piglets – 11.00. On the contrary the lowest number of weaned piglets it was on the seventh litter – 8.40 piglets. Statistical conclusive difference among the numbers of weaned piglets according to litter order it was not proved. Higher average birth weight (1.50 kg) was found in boars in comparison to gilts (1.46 kg). Next birth weight of gilts and boars was studied in dep endence on litter order. The lowest birth weight in both sexes was found on the first litters – gilts (1.27 kg) and boars (1.36 kg). Gilts reached the highest birth weights on the seconds and the sixths litters (1.62 kg). Statistical conclusive difference (P ≤ 0.05) was found in gilts among litters one (1.27 kg) and two (1.62 kg) respectively six (1.62 kg). Boars reached the lowest birth weight (1.36 kg) on the first litter. The highest birth weight of boars (1.73 kg) was reached on the fourth litter. Statistical conclusive difference (P ≤ 0.05) was found among these litters. Next statistical conclusive difference (P ≤ 0.05) was found between the first (1.36) and sixth (1.70 kg) litter and statistical conclusive difference (P ≤ 0.01) between the first and the second litter (1.68 kg).

Dietary ractopamine supplementation during the first lactation affects milk composition, piglet growth and sow reproductive performance

Excessive mobilization of body reserves during lactation delays the return to reproductive function in weaned primiparous sows. This study tested the hypothesis that supplementing the lactation diets of first-parity sows with ractopamine hydrochloride would reduce maternal weight loss and improve subsequent reproductive performance. Gestating gilts were allocated to one of two treatment groups (n=30 sows/treatment), with one group fed a standard lactation diet (2.5g/Mcal LYS: DE) throughout lactation (CTRL), whereas the treatment group received the standard lactation diet supplemented with 10mg/kg ractopamine hydrochloride (RAC) from d 1 to 13 of lactation and 20mg/kg RAC from d 14 of lactation until artificial insemination (AI). Weaning occurred on d 21 of lactation, with AI occurring at the first post-weaning estrus. Compared to CTRL, RAC supplementation decreased (P<0.05) liveweight loss between d 13 and 20 of lactation (4.3±0.90 versus 1.3±0.96kg), and tended to increase (P=0.06) the number of second litter piglets born alive (9.5±0.52 versus 8.1±0.74). Treatment (RAC versus CTRL) reduced milk protein levels on d 13 and 20 of lactation (P<0.05), and piglet weight gain between d 13 and 20 of lactation (260±0.01 versus 310±0.01g/day, P<0.01). In conclusion, it is evident that dietary RAC altered milk composition and stimulated conservation of maternal body reserves during the third week of lactation, resulting in a beneficial effect on subsequent reproductive performance.

Survival Analysis of Hungarian Large White, Duroc and Pietrain Sows

The aim of the present study was to perform lifetime performance analysis in three pig breeds; Hungarian Large White (n=295), Duroc (n=76) and Pietrain (n=91) on a commercial farm using analysis of survival sows. We took into consideration the age of sows at the time of their inclusion into breeding, their age at the time of culling, time spent in production, number of mating and parities, parity percentage, intervals between litters, number and mean of piglets born alive and born dead, number of raised piglet litters, number and mean of 21 days old piglets, the weight and mean of raised litter and raise percentage.&#x0D; We carried out the analysis by SPSS 22.0. Single factor analysis of variants, Kaplan-Meier analysis and Cox PH model were used. The determination of the significance of risk rates differences was done by Wald chi square test.&#x0D; Our results showed that the average culling age were 1056 (±33.52) days for the Hungarian Large White, 735 (±73.56) days for Duroc and 818 (±71.98) days for the Pietrain.&#x0D; The log rank test of the survival analysis indicated a significant difference between the three tested genotypes (χ2=16.981, P&lt;0.001), which means that the survival percentage of the individual breeds varied significantly from one another. In comparison with the Hungarian Large White genotype the Duroc genotype has a 1.6 times higher (P&lt;0.001) culling risk while that of the genotype Pietrain was 1.36 times higher (P&lt;0.001).&#x0D; Our results can be used to compare the breeds kept under the same conditions and to compare the life span of one genotype under different farming conditions. Factors that increase survival and improve the profitability of pig farming can be determined by this method.

Does litter size affect emotionality, spatial learning and memory in piglets?

Average litter size has steadily increased over the past decades in the pig farming industry. Large litters are associated with an increase of piglets born with a lower birth weight and reduced overall piglet viability. The aim of our study was to investigate whether litter size affects emotionality, learning and memory in pigs. Ten piglets from large litters (≥18 piglets) were compared with ten piglets from small litters (≤13 piglets). Piglets from two different suppliers, using different breeds, (hereafter called: Source) were tested. Effects were determined of Litter size and Source on birth weights and growth rates, on emotionality of the piglets measured in an open field test (OFT) at 5 weeks of age, and on effects of OFT-induced stress as indicated by salivary cortisol. The effects of Litter size and Source on spatial learning and memory in a holeboard task were assessed between 9 and 14 weeks of age. Small litter piglets from Source 1 grew faster than large litter piglets from the same source. This effect of Litter size was not found in piglets from Source 2. In the OFT, no effects of Litter size on behaviours were found. However, piglets from Source 1 had lower baseline cortisol levels, made more escape attempts and showed higher locomotor activity during the OFT than piglets from Source 2. During the acquisition phase of the holeboard task, piglets from Source 2 learned the reference memory component faster and reached a higher overall working memory level in the reversal phase than piglets from Source 1. Our results show that Source (i.e. supplier and/or breed) influenced performance in behavioural tasks, and that the occurrence of litter size effects was supplier or breed dependent.

Non-Strongyloides rhabditida identified in fecal samples – two case reports: lessons learned from morphological and molecular diagnostic approaches

SUMMARYNematodes in the order Rhabditida, including species ofStrongyloidesandPelodera, may be parasites of domestic animals. In this paper, we describe two apparent cases of rhabditid infections, one in a dog and one in a litter of piglets. The dog infection was originally considered likely to be an infection withStrongyloides, based on superficial morphological examination and PCR results without sequencing. However, more careful morphological analysis and inclusion of several molecular analyses, including sequencing, revealed that an infection withPeloderasp. was more likely, probablyPelodera pseudoteres. Treatment with fenbendazole and selamectin was apparently successful. Similarly, based on both morphological and molecular analyses the apparent piglet infections were considered most likely to be withRhabditisspp., possiblyRhabditis axei. The detection of larvae of nematodes in the order Rhabditida in fecal samples, particularly from dogs, may easily be considered as being indicative ofStrongyloidesinfection. Given the zoonotic potential of canineStrongyloides, correct diagnosis is important. However, as illustrated by these two cases, careful morphological examination and measurement, supported by full molecular investigations, including sequencing, are essential in order to avoid this misdiagnosis.

Weaning Induced Hepatic Oxidative Stress, Apoptosis, and Aminotransferases through MAPK Signaling Pathways in Piglets.

This study investigated the effects of weaning on the hepatic redox status, apoptosis, function, and the mitogen-activated protein kinase (MAPK) signaling pathways during the first week after weaning in piglets. A total of 12 litters of piglets were weaned at d 21 and divided into the weaning group (WG) and the control group (CG). Six piglets from each group were slaughtered at d 0 (d 20, referred to weaning), d 1, d 4, and d 7 after weaning. Results showed that weaning significantly increased the concentrations of hepatic free radicals H2O2 and NO, malondialdehyde (MDA), and 8-hydroxy-2′-deoxyguanosine (8-OHdG), while significantly decreasing the inhibitory hydroxyl ability (IHA) and glutathione peroxidase (GSH-Px), and altered the level of superoxide dismutase (SOD). The apoptosis results showed that weaning increased the concentrations of caspase-3, caspase-8, caspase-9 and the ratio of Bax/Bcl-2. In addition, aspartate aminotransferase transaminase (AST) and alanine aminotransferase (ALT) in liver homogenates increased after weaning. The phosphorylated JNK and ERK1/2 increased, while the activated p38 initially decreased and then increased. Our results suggested that weaning increased the hepatic oxidative stress and aminotransferases and initiated apoptosis, which may be related to the activated MAPK pathways in postweaning piglets.

Piglets born after intrauterine laparoscopic embryo transfer.

The aim of the study was the preliminary development of laparoscopic transfer of embryos to the uterus in the pig, which can become the alternative for more invasive surgical methods. We proposed the original method of embryo transfer. Donors (n = 40) and recipients (n = 15) of embryos were sows of age of 6-8 months. The estrus cycle of both recipients and donors was routinely synchronized. The experimental animals were divided into two groups. In the first group (10 donors and 3 recipients) embryos were transplanted according to the method described earlier and in the second group (30 donors and 12 recipients) embryos were transplanted according to our own proposed method. As the control group, we used 16 sows after insemination (AI). In animals from both experimental groups pregnancy was diagnosed between 28-31 day after transplantation and in the control group between 28-31 day after insemination. All animals were observed during pregnancy and weaning period in pig farm. Embryos at the development stage of 2-4 cell were obtained surgically and cultured in vitro for 4 days. Obtained blastocysts were transferred to donors. The original set of catheters for blastocysts transfer to pig uterus was constructed. Three trocars were placed in abdominal cavity for inserting endoscope and 2 grasps for uterus stabilization. After uterus stabilization, the slide was inserted into abdomen which was used for putting the needle to puncture uterus. Through this needle catheter with embryos was inserted into the uterus cavity. Embryos were placed by injection into lumen of the one uterine horn. From 12 recipients pregnancy was diagnosed in 6 recipients. From 6 litters, 57 piglets were born. We weaned 41 piglets (71.9%). In our study we obtained 50% efficacy, with the mean number of 9.5 alive piglets in litter and 6.8 weaned piglets. The efficacy of developed method of laparoscopic transfer of porcine embryos allows it to be used in routine practice.

Influenza A Virus Surveillance Based on Pre-Weaning Piglet Oral Fluid Samples.

Influenza A virus (IAV) surveillance using pre-weaning oral fluid samples from litters of piglets was evaluated in four ˜12500 sow and IAV-vaccinated, breeding herds. Oral fluid samples were collected from 600litters and serum samples from their dams at weaning. Litter oral fluid samples were tested for IAV by virus isolation, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), RT-PCR subtyping and sequencing. Commercial nucleoprotein (NP) enzyme-linked immunosorbent assay (ELISA) kits and NP isotype-specific assays (IgM, IgA and IgG) were used to characterize NP antibody in litter oral fluid and sow serum. All litter oral fluid specimens (n=600) were negative by virus isolation. Twenty-five oral fluid samples (25/600=4.2%) were qRT-PCR positive based on screening (Laboratory 1) and confirmatory testing (Laboratory 2). No hemagglutinin (HA) and neuraminidase (NA) gene sequences were obtained, but matrix (M) gene sequences were obtained for all qRT-PCR-positive samples submitted for sequencing (n=18). Genetic analysis revealed that all M genes sequences were identical (GenBank accession no. KF487544) and belonged to the triple reassortant influenza A virus M gene (TRIG M) previously identified in swine. The proportion of IgM- and IgA-positive samples was significantly higher in sow serum and litter oral fluid samples, respectively (P<0.01). Consistent with the extensive use of IAV vaccine, no difference was detected in the proportion of IgG- and blocking ELISA-positive sow serum and litter oral fluids. This study supported the use of oral fluid sampling as a means of conducting IAV surveillance in pig populations and demonstrated the inapparent circulation of IAV in piglets. Future work on IAV oral fluid diagnostics should focus on improved procedures for virus isolation, subtyping and sequencing of HA and NA genes. The role of antibody in IAV surveillance remains to be elucidated, but longitudinal assessment of specific antibody has the potential to provide information regarding patterns of infection, vaccination status and herd immunity.

Early-life environmental variation affects intestinal microbiota and immune development in new-born piglets.

BackgroundEarly-life environmental variation affects gut microbial colonization and immune competence development; however, the timing and additional specifics of these processes are unknown. The impact of early-life environmental variations, as experienced under real life circumstances, on gut microbial colonization and immune development has not been studied extensively so far. We designed a study to investigate environmental variation, experienced early after birth, to gut microbial colonization and intestinal immune development.Methodology/Principal FindingsTo investigate effects of early-life environmental changes, the piglets of 16 piglet litters were divided into 3 groups per litter and experimentally treated on day 4 after birth. During the course of the experiment, the piglets were kept with their mother sow. Group 1 was not treated, group 2 was treated with an antibiotic, and group 3 was treated with an antibiotic and simultaneously exposed to several routine, but stressful management procedures, including docking, clipping and weighing. Thereafter, treatment effects were measured at day 8 after birth in 16 piglets per treatment group by community-scale analysis of gut microbiota and genome-wide intestinal transcriptome profiling. We observed that the applied antibiotic treatment affected the composition and diversity of gut microbiota and reduced the expression of a large number of immune-related processes. The effect of management procedures on top of the use of an antibiotic was limited.Conclusions/SignificanceWe provide direct evidence that different early-life conditions, specifically focusing on antibiotic treatment and exposure to stress, affect gut microbial colonization and intestinal immune development. This reinforces the notion that the early phase of life is critical for intestinal immune development, also under regular production circumstances.

Porcine reproductive and respiratory syndrome virus (PRRSV) surveillance using pre-weaning oral fluid samples detects circulation of wild-type PRRSV

Oral fluid samples collected from litters of piglets (n=600) one day prior to weaning were evaluated as a method to surveil for porcine reproductive and respiratory syndrome virus (PRRSV) infections in four sow herds of approximately 12,500 sow each. Serum samples from the litters’ dam (n=600) were included for comparison. All four herds were endemically infected with PRRSV and all sows had been vaccinated ≥2 times with PRRSV modified-live virus vaccines. After all specimens had been collected, samples were randomized and assayed by PRRSV real-time reverse transcription polymerase chain reaction (RT-qPCR) and four PRRSV antibody ELISA assays (IgM, IgA, IgG, and Commercial Kit). All sow serum samples were negative by PRRSV RT-qPCR, but 9 of 600 oral fluid samples tested positive at two laboratories. Open reading frame 5 (ORF5) sequencing of 2 of the 9 positive oral fluid samples identified wild-type viruses as the source of the infection. A comparison of antibody responses in RT-qPCR positive vs. negative oral fluid samples showed significantly higher IgG S/P ratios in RT-qPCR-positive oral fluid samples (mean S/P 3.46 vs. 2.36; p=0.02). Likewise, sow serum samples from RT-qPCR-positive litter oral fluid samples showed significantly higher serum IgG (mean S/P 1.73 vs. 0.98; p<0.001) and Commercial Kit (mean S/P 1.97 vs. 0.98; p<0.001) S/P ratios. Overall, the study showed that pre-weaning litter oral fluid samples could provide an efficient and sensitive approach to surveil for PRRSV in infected, vaccinated, or presumed-negative pig breeding herds.

Growth of suckling piglets in litters standardized by weight

This study examined the relationship between birth weight and growth performance when suckling piglets were reared in litters standardized by birth weight. Forty-four gilts (Landrace × Large White) due to farrow during the same week were selected. Piglets born to those gilts were individually weighed at birth and cross-fostered to obtain litters with 11 piglets and standardized birth weight (CV, lower than 5%). Based on average birth weight, 4 litter weight classes were established: class 1 (> 1.10 kg to ≤ 1.33 kg), class 2 (> 1.34 kg to ≤ 1.46 kg), class 3 (> 1.47 kg to ≤ 1.57 kg), and class 4 (> 1.58 kg to ≤ 1.88 kg). At 21 d of age, piglets were weighed to determine BW and calculate ADG and weight gain relative to birth weight. A completely randomized experimental design was used with birth weight classes as treatments. At 21 d of age, the average BW of piglets from the heaviest birth weight class (5.67 kg) was greater (P < 0.05) than the lightest class (5.06 kg); however, all classes had the same ADG (P < 0.05). There was a positive correlation (r = 0.184; P < 0.01) between birth weight and weight at 21 d of age, but birth weight was not correlated (r = -0.040; P = 0.37) with ADG during the suckling phase. Therefore, piglet birth weight did not influence weight gain when piglets were reared by sows in litters with standardized birth weight.

A Pig Model of the Preterm Neonate: Anthropometric and Physiological Characteristics

BackgroundLarge animal models are an essential tool in the development of rationally-based new clinical therapies for preterm infants. We provide a description of the newborn pig as a model of the preterm neonate in terms of growth parameters, physiology and the requirement for intensive care over a range of gestational ages.MethodsTwenty-nine litters of piglets (n = 298) were delivered by caesarean section at six timepoints during gestation from 91d to 113d (term = 115d). Two groups, at 91 and 97d gestation, also received maternal glucocorticoid treatment. At four of these timepoints, piglets (n = 79) were ventilated, sedated and monitored using standard neonatal intensive care techniques for up to 8 h in various experimental protocols.ResultsBody weight increased from mean 697 g (SD 193) at 91d gestation to 1331 g (SD 368) at 113d gestation. Piglets delivered at 97d gestation were able to be resuscitated and kept alive for at least 8 h on respiratory support after surfactant administration. Maternal glucocorticoid treatment 48 h and 24 h hours prior to delivery reduced the requirement for ventilator support and improved cardiovascular stability.ConclusionThe pig provides a relevant model for the study of human preterm physiology and for investigation of novel therapies to improve outcomes.

Postpartum deaths: Piglet, placental, and umbilical characteristics1

The fetal growth of the piglet is highly dependent on its placenta, and the newborn piglet birth weight is highly associated with postpartum death. However, there is little information available in the literature on the assessment of the placenta in relation to postpartum death in piglets. The aim of this study was to evaluate the impact of the placental area and placental weight, status of the umbilical cord, and piglet birth characteristics, such as blood parameters, vitality score, and birth weight on postpartum death. All live born piglets in litters from 26 Landrace-Yorkshire sows were monitored during farrowing and the status of each was recorded, including placental area and placental weight and blood variables obtained from the piglets and umbilical veins. Out of the 386 live-born piglets, 16.8% died before weaning at 5 wk. Among these, 78.5% died within the first 3 d of life. Mean blood concentration of lactate was increased in piglets that did not survive to weaning (P = 0.003). Concentrations of hemoglobin and hematocrit were decreased (P < 0.001) compared with survivors. Piglets born with a broken umbilical cord had a reduced vitality score vs. piglets born with an intact umbilical cord (P = 0.021), and they had an increased probability of dying before weaning (P = 0.050). Mean birth weight, body mass index, placental area (P < 0.001), and placental weight (P = 0.020) were reduced in piglets that died before weaning vs. those that survived. Birth weight and placental area were furthermore negatively associated with live litter size. Blood concentrations of IgG and albumin recorded at d 1 were decreased in piglets that died before weaning (P < 0.01), and blood concentration of albumin was positively associated with placental area (P < 0.001). We conclude that placental area and placental weight, status of the umbilical cord, birth weight, body mass index, blood concentrations of lactate, hemoglobin, and hematocrit recorded at birth, and blood concentrations of IgG and albumin recorded at d 1 were associated with postpartum death in this study. These results may indicate that there is an upper uterine limitation of litter size and that placental area and placental weight influence postpartum survival.

1117 A Pig Model of the Preterm Neonate: Anthropometric and Physiological Characteristics

Background and AimsLarge animal models are an essential research tool to investigate the physiology of the preterm infant, which remains poorly understood. We aim to describe the pig model of...

Heritability and connections of sow fertility traits

Purpose of this paper was to determine fertility traits heritability coefficients of the sows (number of live born, total number of born, stillborn and reared piglets in the litter) and interconnections between these traits. Heritability coefficients were low and averaged in interval from h2 = 0,056 for number of reared piglets in litter to h2 = 0,142 for total number of born piglets in litter, which is in accordance with heritability values for reproductive traits. Genetic interconnections of these traits had wide variation interval and averaged from r = - 0,221 between number of still born and reared piglets in litter to r = 0,947 between total number of born and number of live born piglets in litter. Coefficients of phenotype correlation varied in interval from r = -0,162 between number of still born and number of live born piglets in litter to r = 0,909 between total number of born and number of live born piglets in litter.

Biological Markers of Boar Fertility

The semen evaluation techniques used in most commercial artificial insemination centers, which includes sperm motility and morphology measurements, provides a very conservative estimate of the relative fertility of individual boars. As well, differences in relative boar fertility are masked by the widespread use of pooled semen for commercial artificial insemination (AI) in many countries. Furthermore, the relatively high sperm numbers used in commercial AI practice usually compensate for reduced fertility, as can be seen in some boars when lower numbers of sperm are used for AI. The increased efficiency of pork production should involve enhanced use of boars with strong reproductive efficiency and the highest genetic merit for important production traits. Given that the current measures of semen quality are not always indicative of fertility and reproductive performance in boars, accurate and predictive genetic and protein markers are still needed. Recently, significant efforts have been made to identify reliable markers that allow for the identification and exclusion of sires with reduced reproductive efficiency. This paper reviews the current status of proteomic and genomic markers of fertility in boars in relation to other livestock species.