Increased Litter Size Research Articles

Oligoasthenozoospermia is alleviated in a mouse model by [Gly14]-humanin-mediated attenuation of oxidative stress and ferroptosis.

Oligoasthenozoospermia is a common cause of male infertility, for which effective treatments are urgently needed. Humanin (HN) is a peptide associated with this condition. To investigate the ameliorative effect of [Gly14]-Humanin (HNG) on oligoasthenozoospermia and the mechanisms. Mice were treated with cyclophosphamide (CP) to construct a mice model of oligoasthenozoospermia. The resulting model mice were treated with saline or HNG. Subsequently, the testis weights, organ indices, testicular structure, sperm counts and motilities, litter sizes, and serum testosterone concentrations of the mice were determined. Differential gene expression in testicular tissues was determined by RNA sequencing. TM3, TM4, GC1, and GC2 cells were exposed to erastin to induce ferroptosis, followed by treatment with HNG or HNG + ML385 (a nuclear factor erythroid 2-related factor 2 inhibitor). Levels of reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), and ferrous ions (Fe2+) were determined and their expression of ferroptosis-related proteins was determined by immunofluorescence and western blot. The HNG treatment improved testis and sperm parameters and increased litter size and serum testosterone concentrations in model mice. Kyoto Encyclopaedia of Genes and Genomes pathway enrichment analysis revealed significant differential expression of ferroptosis-related genes. The expression of ferroptosis-related proteins increased in testicular tissues after the HNG treatment. The concentrations of ROS, MDA, and Fe2+ decreased and the concentrations of GSH increased in testicular tissues and in TM3 and TM4 cells after HNG treatment. In vitro experiments confirmed that HNG activated the nuclear factor erythroid 2-related factor 2/glutathione peroxidase 4 (Nrf2/GPX4) pathway. However, these effects of HNG were blocked by ML385 treatment. HNG demonstrated a therapeutic effect on oligoasthenozoospermia in a mouse model by reducing oxidative stress and ferroptosis. In TM3 and TM4 cells, HNG attenuated cellular oxidative stress and inhibited ferroptosis via the Nrf2/GPX4 pathway.

464 Awardee Talk: Gastrointestinal tract physiology in young pigs

Abstract It is indeed a great privilege to have been awarded the 2024 American Feed Industry Association Award in Nonruminant Nutrition Research. I am honored to follow in the footsteps of many great non-ruminant nutritionists in the industry. I commenced my career in the pork industry with a PhD in digestive nutritional physiology focusing on the newly weaned piglet that, some 35 yr later, is still the subject of significant interest amongst researchers, veterinarians and practitioners, and producers alike. My research was amongst the first to demonstrate direct relationships between voluntary feed intake after weaning and structure and function of the small intestine, corresponding to production consequences. To circumvent intestinal tract disturbances after weaning, antibiotic growth promotors (AGPs)/prophylactic levels of antibiotics and mineral compounds (e.g., ZnO) were routinely included in diets. With the withdrawal of AGPs and in some jurisdictions, in-feed medications and ZnO, the commercial importance of maximizing feed intake in the post-weaning period, with appropriate inclusion of fiber and selected feed additives, has become even more apparent. Some of the more recent work I have been involved in, still involving the gastrointestinal tract, has explored the interrelationships as to why progeny born to first-litter sows perform worse than progeny born to multiparous sows. This is a global issue for the pork industry, especially in view of increasing litter size, yet remains one that has been relatively underexplored. A series of Australian studies using primiparous and multiparous sows, and their progeny conducted on commercial farms confirmed these findings, and reported some significant physiological, immunological, and anatomical differences between piglets born to different parity mothers. Piglets born to first-litter sows are born and weaned lighter than their counterparts born to older sows, suggesting they suffer poorer acquisition of maternal immunity and delays in intestinal tract development and skeletal muscle both in utero and soon after birth, and around weaning. Piglets born to first-litter sows enter weaning with reduced intestinal tract integrity and show some signs of reduced immunocompetence, which taken together, may impede their ability to cope with the stressors of weaning. Weaned piglets are typically treated collectively and are not managed by parity, but lifelong consequences of being born to a first-litter sow suggests further work needs to be done in this field. Gastrointestinal tract structure and function in piglets, and indeed in all neonates, is intricately associated with ‘gut health’, which was a term not even in the lexicon of the pork industry when I began my career. It is pleasing to see that the study of the gastrointestinal tract continues today, stronger than ever, as advances in science and methodologies allow for greater introspection of this organ and its multi-directional influences on the biology of the pig.

Effects of Supplemental Diet during Breeding on Fertility, Litter Size, Survival Rate, and Weaning Weight in Mice (Mus musculus).

The addition of supplemental diets to laboratory animals, specifically rodents, is a common practice for the provision of additional nutritional support. We set out to investigate whether the use of commercially available supplemental diets during breeding affected fertility rate, litter size, pup health, and pup survival. Genetically modified female breeding mice with a C57BL/6 background were divided into 3 groups (n = 16 per group) that received standard rodent chow alone or standard rodent chow with one of 2 commercially available supplemental diets: Love Mash (Bio-Serv) extruded pellet or Nutra-Gel (Bio-Serv) diet gel. Male and female mice began receiving the supplemental diet 1 wk before being paired with a partner of the same supplemental group. The mice were allowed to breed for 1 wk before separation from the male. The dams were continued on the diet until all pups were weaned. Overall, breeding dams supplemented with the Love Mash diet experienced significantly greater reproductive success rates and pup survivability compared with the standard diet control group. Dams supplemented with either of the 2 supplemental diets supported significantly larger litters compared with the standard diet control group. Furthermore, Love Mash supplemented diet groups produced significantly larger pups compared with the Nutra-Gel supplemented groups. This study demonstrates that supplemental diets given 1 wk before breeding and continued throughout gestation, parturition, and weaning significantly improved reproductive success, increased litter sizes, and supported pup health and survival.

Novel single nucleotide polymorphism G216A of hormone-sensitive lipase gene associated with Awassi sheep reproduction

BackgroundLitter size plays a crucial role in determining profitability in the sheep industry. Breeding sheep with high litter sizes could be enhanced by selecting candidate genes. One gene affecting sheep's reproductive performance is the hormone-sensitive lipase (HSL) gene. As a result, this study investigated whether the HSL gene variation influenced the fertility of Awassi ewes. The genomic DNA was extracted from 52 singleton ewes and 48 twin ewes. The HSL gene exon 9 (278 bp) was amplified using polymerase chain reaction (PCR).ResultsStudy results revealed two genotypes identified in the 278-bp amplicons: GG and GA. Molecular sequence analysis identified a novel mutation in the GA genotype 216G > A. The statistical analysis revealed a significant association between the single nucleotide polymorphism (SNP) 216A > G and reproductive performance. Ewes with the SNP 216G > A genotype exhibited significantly increased litter sizes, twinning rates, lambing rates, and fewer days to lambing compared to ewes with GG genotypes (P ≤ 0.05). The logistic regression analysis results provided strong evidence that the 216G > A mutation significantly increased litter sizes.ConclusionsThis study concluded that variant 216G > A SNP positively impacts Awassi sheep reproduction. There is a higher litter size and more prolificacy in ewes with the 216G > A SNP than in those without the SNP.

Effects of parity, season of birth, and sex on within-litter variation and pre-weaning performance of F1 Large White × Landrace pigs.

A piglet's pre-weaning performance significantly influences both animal welfare and profitability in pig production. Understanding piglet pre-weaning performance influencing factors is key to enhancing animal welfare, reducing losses, and boosting profitability. The study aimed to evaluate the impact of parity, season of birth, and sex on within-litter variation and pre-weaning performance of F1 Large White × Landrace pigs. Information regarding total litter size, number of born alive, number of stillbirths, piglet weight at birth, mortality, and count of weaned F1 Large White × Landrace piglets was acquired from the farm database (April 2022-February 2023). 2602 females and 2882 males, a total of 5484 piglets were utilized, with records from 360 sows. The coefficient of variation (CV) of birth weights among piglets within a litter was calculated. The general linear model analysis in MiniTab 17 was used to evaluate the data, with Fisher's least significant difference test (p < 0.05) used for mean separation and Pearson's moment correlation coefficient calculated to assess relationships between survival rates, mortality rates, litter size, birth weight, and birth weight CV. Parity had a statistically significant impact on litter size, birth weight, and survival rate (p < 0.05). The sow's parity did not significantly (p > 0.05) impact the number of piglets born alive or weaned. Multiparous sows had a significantly larger litter size (p < 0.05) than primiparous sows at birth. The litter weights for parities 2, 4, and 5 did not significantly differ (p > 0.05), with averages of 20.95, 20.74, and 20.03 kg, respectively. About 91.29% was the highest survival rate recorded in parity 2 (p < 0.05). The 1st week of life recorded an 8.02% mortality rate. The mortality rate in parity 3-5 group was significantly (p < 0.05) higher (11.90%) in week 1 than in the other groups (parity 1: 6.79%, parity 2: 5.74%, parity 3-5: 8.54 and 9.21%). The litter sizes in autumn (17.34) and spring (17.72) were significantly larger (p < 0.05) than those in summer (16.47) and winter (16.83). In autumn and spring, the survival rate (83.15 and 85.84%, respectively) was significantly lower (p < 0.05) compared to summer (88.40%) and winter (89.07%). In all seasons, the litter weights did not significantly differ (p > 0.05). The birth weight CV was significantly (p < 0.05) lower during summer (20.11%) than during spring (22.43%), autumn (23.71%), and winter (21.69%). The season of birth had no significant effect (p > 0.05) on the number of live piglets. Males (1.34 kg) were heavier (p < 0.05) than females (1.30 kg) at birth. Notably, the birth weight CV was similar between males (22.43%) and females (22.52%). Litter size was positively correlated with average litter weight (rp = 0.576, p < 0.001), birth weight CV (rp = 0.244, p < 0.001), and mortality rate (rp = 0.378, p < 0.001). An insignificant relationship was observed between average litter weight and birth weight CV (rp = -0.028, p > 0.05) and survival rate (rp = -0.032, p > 0.05). In F1 Large White × Landrace pigs, birth uniformity among piglets declines as litter size grows larger. In parity 3-5, multiparous sows yield litters with reduced uniformity. With an increase in litter size, uniformity among piglets at birth worsens. A larger litter size and greater piglet birth weight variation are linked to a higher pre-weaning mortality rate. Producers need a balanced selection approach to boost litter size and must cull aging sows carefully to introduce younger, more productive females.

Variation in the AA-NAT gene G203A is associated with Awassi and Hamdani sheep fertility

Arylalkylamine-N-acetyl-transferase (AA-NAT) is one of several genes that influence sheep reproduction. Thus, the objective of this study was to investigate whether genetic variability within the AA-NAT gene influenced the reproductive performance of Awassi and Hamdani ewes. A total of 99 twin and 101 single-progeny ewes were analyzed for genomic DNA. Polymerase chain reaction (PCR) was used to produce amplicons of 300, 313, and 287 bp from exons 1, 2, and 3 of the AA-NAT gene. A 300-bp amplicon was genotyped, resulting in two genotypes: GG and GA. Through sequence analysis, a mutation 203 G > A was identified in the GA genotype. The statistical analysis revealed a strong correlation between the single nucleotide polymorphism (SNP) 203 G > A and reproductive performance. Ewes carrying this mutation showed significantly increased litter sizes, twinning rates, lambing rates, and fewer days to lambing compared to those carrying GG. These findings demonstrate that the presence of the 203 G > A SNP variant has a significant positive impact on litter sizes and enhances the fertility of Awassi and Hamdani sheep.

289 Evaluation of fecal microbiota transplantation in primiparous sows

Abstract Fifty primiparous (parity 3+) and 25 multiparous sows (DNA 241, DNA, Columbus, NE) were used to evaluate the impacts of fecal microbiota transplantation (FMT) from sows to gilts on piglet scours prevalence, mortality, and fecal microbial diversity. Fresh fecal samples were collected from the primiparous and multiparous sows on approximately d 69 and 89 of gestation. The sows selected for sampling were from the same breed week as the gilts and had a historical record of low piglet mortality with increased litter size and no medical treatment during the current gestation period. The fecal samples from the sows were pooled on an equal weight basis and used for FMT solution preparation. The gilts were randomly assigned to one of two treatments: FMT or placebo (PBO). The FMT solution was administered orally to the 25 FMT gilts on approximately d 70 through 76 and 90 through 96 of gestation, while saline was administered to the 25 PBO gilts on the same days. Fecal samples were collected from all gilts and sows at the time of farrowing and at weaning. Piglets were individually weighed at birth and 5 wk post-weaning to calculate average daily gain (ADG). Scours prevalence was recorded daily from d 0 to 6 of lactation. Fecal samples were collected from two piglets per litter at weaning and 5 wk post-weaning. Pre-wean and nursery piglet mortality and morbidity were recorded. Total DNA from fecal samples and FMT solution from each timepoint were submitted for amplicon sequencing (Illumina MiSeq, Illumina Inc., San Diego, CA) at the Iowa State University DNA Facility (Ames, IA) to evaluate differences in microbial diversity and relative abundances across treatments groups. Data were analyzed using R version 4.3.1 (R Core Team, 2023). The sow and her litter were the experimental unit and results were considered significant if P ≤ 0.05 and a tendency if 0.05 &amp;lt; P ≤ 0.10. The number of piglets after cross-fostering and weaned were similar across treatments (P ≥ 0.721). There was no effect of treatment group on piglet birth weight or ADG (P ≥ 0.198). Scours prevalence was less in sow litters compared with PBO litters (16.7 vs. 52.0%; P = 0.039), while FMT scours prevalence was intermediate. There was no effect of FMT on pre-wean or nursery mortality (P ≥ 0.890). In conclusion, FMT did not impact gilt litter scours prevalence, growth rate, or mortality through the nursery.

Superovulation with an anti-inhibin monoclonal antibody improves the reproductive performance of rat strains by increasing the pregnancy rate and the litter size

Rats are multiparous rodents that have been used extensively in research; however, the low reproductive performance of some rat strains hampers the broader use of rats as a biomedical model. In this study, the possibility of increasing the litter size after natural mating in rats through superovulation using an anti-inhibin monoclonal antibody (AIMA) was examined. In outbred Wistar rats, AIMA increased the number of ovulated oocytes by 1.3-fold. AIMA did not affect fertilization and subsequent embryonic development, resulting in a 1.4-fold increase in litter size and a high pregnancy rate (86%). In contrast, conventional superovulation by eCG/hCG administration decreased the pregnancy rate to 6–40% and did not increase the litter size. In inbred Brown Norway rats, AIMA increased the litter size by 1.2-fold, and the pregnancy rate increased more than twice (86% versus 38% in controls). AIMA also increased the litter size by 1.5-fold in inbred Tokai High Avoiders and Fischer 344 rats. AIMA increased the efficiency of offspring production by 1.5-, 2.7-, 1.4-, and 1.4-fold, respectively, in the four rat strains. Thus, AIMA may consistently improve the reproductive performance through natural mating in rats, which could promote the use of AIMA in biomedical research.

Astragalus root increases Treg and Th17 involvement in embryo implantation and pregnancy maintenance by decreasing CTLA-4+ Tregs.

Maintenance of pregnancy is highly dependent on the maternal immune system. High levels of regulatory T cells (Tregs) accumulate in the maternal placenta to suppress immunoreactivity against fetal antigens. We assessed whether Astragalus root (AsR) and AsR-containing Kampo medicines modulate immunoreactivity and thereby increase mouse litter size. AsR-exposed murine splenocytes exhibited significantly increased IL-2 secretion. In AsR-exposed mice, total Tregs were significantly increased, whereas cytotoxic T lymphocyte antigen 4 (CTLA-4)-positive Tregs were decreased in AsR-exposed mice. Tregs express IL-2 receptor subunit alpha and are activated by IL-2. CTLA-4 interacts with B7 expressed in antigen-presenting cells (APCs) with high affinity, and CTLA-4/B7 signaling plays a critical role in inhibiting APC activity, thereby suppressing CD4+ T cell proliferation and activation. The decrease in CTLA-4+ Tregs in AsR-exposed mice is thought to induce an increase in CD4+ T cells, leading to increased IL-2 secretion from CD4+ T cells followed by Treg activation. Th17 cells prevent trophoblast apoptosis, resulting in trophoblast invasion into the decidua. AsR increases Th17 cells, thereby inducing dose-dependent increases in litter size. Although Keishikaogito (KO)- and Ogikenchuto (OK)-exposed mice exhibited increased IL-2 secretion and splenic Tregs, KO also increased CTLA-4+ Tregs. Therefore, KO promoted immunosuppression by increasing CTLA-4+ Tregs, which induced a decrease in Th17 and exerted little effect on litter size. Therefore, an increase in both Tregs and Th17 cells can be considered necessary for embryo implantation and pregnancy maintenance.

The novel C268A variant of BMP2 is linked to the reproductive performance of Awassi and Hamdani sheep.

Prolificacy-associated genetic markers can be utilized to enhance litter size in the sheep breeding industry. Sheep reproduction is influenced by a multitude of genes, including bone morphogenetic protein 2 (BMP2). This study aimed to explore the potential relationship between variability in the BMP2 gene and reproductive performance in Awassi and Hamdani ewes. The genomic DNA was extracted from 99 single-progeny ewes and 101 twin ewes. Polymerase chain reaction (PCR) was employed to produce an amplicon consisting of four sequence fragments: 277bp, 251bp, 331bp, and 340bp, from exons 1, 2, 3, and 4 of the BMP2 gene, respectively. Three genotypes were identified for amplicons in exon 4 with 340-bp lengths: CC, CA, and AA. Upon analyzing the sequence of the CA genotype 382C > A, a novel mutation was discovered in this genotype. A robust association was identified between the single nucleotide polymorphisms (SNP) 382C > A and reproductive performance through statistical analysis. An important distinction was discovered between ewes carrying SNP 382C > A and those carrying CC in terms of litter sizes, twinning rates, lambing rates, and days to lambing. An analysis of logistic regression revealed a significant association between litter size and the 382C > A SNP. There was a decrease in lamb production among ewes with the CC genotype compared to those with the CA and AA genotypes. These results indicate that the SNP variant 382C > A has a positive influence on the reproductive performance of Awassi and Hamdani sheep. Sheep carrying the 382C > A SNP exhibit increased litter size and overall productivity compared to those without the SNP.

Detection of polymorphisms in six genes and their association analysis with litter size in sheep

Litter size in sheep is a complex trait controlled by micro-effective polygenes. APAF1, CLSTN2, CTH, PLCB1, PLCB4, and CHST11 are all involved in mammalian reproduction. However, the effects of these genes on litter size in sheep are still unclear. Therefore, in this study, we used Sequenom MassARRAY® SNP assay technology to type the single nucleotide polymorphisms (SNPs) loci of six genes in five sheep breeds. The results showed that most sheep breeds contain three genotypes at each locus. Then, we conducted population genetic analysis on the SNPs of six genes and found that the polymorphic information content in all sheep breeds ranged from 0 to 0.37, and most sheep breeds were in Hardy-Weinberg equilibrium (p > 0.05). In addition, association analysis in Small Tail Han sheep indicated that the rs399534524 locus in CLSTN2 was highly associated with first parity litter size, and litter size in ewes with CT genotype was higher than that in ewes with CC genotype or TT genotype. Furthermore, the rs407142552 locus in CTH was highly associated with second parity litter size in Small Tail Han sheep, and litter size in ewes with CT genotype was higher than that in ewes with TT genotype. Finally, we predicted the CTH and CLSTN2 protein interaction network and found that HTR1E, NOM1, CCDC174 and ALPK3 interact with CLSTN2 and have been reported as candidate genes related to litter size in sheep. These results suggest that they may be useful genetic markers for increasing litter size in sheep.

Artificially reared ewes cannot be distinguished from natural reared ewes based on observed maternal behavior or lamb weaning weights.

Artificially rearing lambs is an important component of United States sheep production as some flocks select for increasing litter size to boost productivity. However, there is a conception among shepherds that artificially reared ewe lambs will ultimately result in poor mothers since they were not naturally raised. The objective of this study was to determine if differences in maternal behavior could be detected between ewes raised artificially and those raised naturally and if dam rearing type had an impact on lamb growth performance. Forty-eight ewes were enrolled comprised of 4 equal sized groups: artificially reared primiparous, naturally reared primiparous, artificially reared multi-parous, and naturally reared multi-parous. Ewes were observed using remote cameras to record maternal behaviors toward the lambs during and shortly after parturition. Behavior of 29 ewes during the first hour after parturition was analyzed. Independent multivariable regression models were evaluated for: proportion of time spent grooming, proportion of time spent helping the lambs nurse, number of helpful bouts, and the number of negative bouts. No statistically significant difference (P < 0.05) was detected between artificially reared and naturally reared ewes for the proportion of time spent grooming and the proportion of time spent helping the lambs nurse. Historical flock data were utilized to evaluate lamb growth between artificially and naturally reared ewes. No detrimental associations between artificially reared ewes and lamb weaning weights were observed. This study shows that artificially reared ewes are no different in terms of mothering behaviors and may be used as potential replacement candidates.

The Novel PTX3 Variant g.22645332G>T Is Strongly Related to Awassi and Hamdani Sheep Litter Size.

The detection of polymorphisms in genes that control livestock reproduction could be highly beneficial for identifying and enhancing economic traits. One of these genes is pentraxin 3 (PTX3), which affects the reproduction of sheep. Therefore, this study investigated whether the variability of the PTX3 gene was related to the litter size of Awassi and Hamdani ewes. A total of 200 ewes (130 Awassi and 70 Hamdani) were used for genomic DNA extraction. Polymerase chain reaction was used to amplify the sequence fragments of exons 1, 2, 3, and 4 from the PTX3 gene (Oar_v4.0; Chr 1, NC_056054.1), resulting in products of 254, 312, 302, and 253, respectively. Two genotypes, GG and GT, were identified for 302 bp amplicon. A novel mutation was discovered through sequence analysis in the GT genotype at position g.22645332G>T. The statistical analysis revealed a significant association between single nucleotide polymorphism (SNP g.22645332G>T; Oar_v4.0; Chr 1, NC_056054.1) and litter size. The presence of the SNP g.22645332G>T (Oar_v4.0; Chr 1, NC_056054.1) genotype in ewes resulted in a significant difference compared to ewes with GG genotypes. The discrepancy became apparent in several aspects, including litter sizes, twinning rates, lambing rates, litter weight at birth, and days to lambing. There were fewer lambs born to ewes with the GG genotype than to ewes with the GT genotype. The variant SNP g.22645332G>T (Oar_v4.0; Chr 1, NC_056054.1) has positive effects on the litter size of Awassi and Hamdani sheep. The SNP g.22645332G>T (Oar_v4.0; Chr 1, NC_056054.1 has been associated with an increase in litter size and higher prolificacy in ewes.

Reproduction of Awassi and Hamdani Sheep Is Associated With a Novel Missense SNP (p.24Ile>Thr) of the GnIH Gene.

Litter size is a crucial economic factor in the sheep industry. Several factors and genes influence litter size, making the identification of genes or loci involved a genetic challenge. Gonadotropin-inhibitory hormone (GnIH) is one of several genes that influence sheep's reproductive traits. Thus, this study aimed to investigate whether variations in the GnIH gene affect the reproductive performance of Awassi and Hamdani ewes. DNA was extracted from 99 single-progeny ewes and 101 twin ewes. The polymerase chain reaction (PCR) produced amplicons of 262 bp, 275 bp, and 284 bp from exons 1, 2, and 3 of the GnIH gene. Single-strand conformational polymorphism (SSCP) technique was used for genotyping experiments. Sequencing and in silico analysis were performed on each set of SSCP-resolved bands. Two genotypes of 262 bp amplicons were found: TT and TC. Sequence analysis revealed a novel missense mutation in the TC genotype at position c.122T>C. Five in silico tools were used to assess the impact of this mutation on GnIH protein structure, function, and stability, all of them demonstrated a deleterious effect. An analysis of statistical data revealed a strong correlation between the c.122T>C single-nucleotide polymorphism (SNP) and reproductive performance. Ewes with the SNP 122T>C exhibited a significant increase in litter size, twinning rates, lambing rates, and days to lambing when compared with ewes with the TT genotype. A lower number of lambs were born to ewes with the TT genotype than those with the TC genotype. These results concluded that the c.122T>C SNP variant positively influences the reproductive performance of Awassi and Hamdani sheep. Sheep that carry the c.122T>C SNP show higher litter size and increased productivity.

Pırlak Koyun Irkında Bir Batında Doğan Yavru Sayısı ile Ilişkili PRL ve BHR Genlerindeki inDel Varyasyonlar

Numerous molecular genotyping methods are available to analyse local livestock populations at molecular level in which traditional Polymerase Chain Reaction (PCR) guided by specific oligonucleotides is a fast and cost-effective method to investigate single genes. Until today, many genes which are of major effects on litter size have been reported in sheep. Genetic variations in these genes shaping the expression profile at DNA level may lead to differences in litter size among the sheep breeds. This is the first attempt to investigate insertion/deletion (inDel) variations in Prolactin (PRL) intron 2 and Growth Hormone Receptor (GHR) intron 3 and intron 4 genes in Pirlak sheep breed via traditional PCR technique. A total of 100 unrelated animals sampled from representative herds reared in Antalya were genotyped based on absence/presence of 23 base pairs (bp) length inDel in which three genotypes (II, ID, and DD) were detected in all loci. I and D allele frequency were 0.421 and 0.579, respectively in terms of PRL-intron 2 locus. I / D allele frequencies were found as 0.599 / 0.401 and 0.372 / 0.628 in GHR intron 3 and intron 4, respectively. The lowest II (0.181) and DD (0.177) genotype frequencies were detected in GHR-intron 4 and GHR-intron 3 loci, respectively. The lowest (0.177 for DD) and highest (0.448 for ID) genotype frequencies were detected in GHR intron 3 locus across the population. Significant deviation from Hardy-Weinberg Equilibrium (HWE) was detected only in PRL-intron 2 locus. The results of the present study confirm that Pirlak breed conserves sufficient genetic variation in PRL and GHR gene regions which could be utilized in selection strategies in order to increase litter size in the future.

Effect of Selenomethionine or Yeast Enriched with Selenium on Reproductive Performance, Progesterone and Estrogen Hormones in Iraqi Ewes

This study was conducted at the animal farm affiliated with the college of agriculture, university of anbar, ramadi, iraq, to investigate the effects of selenomethionine or selenium-enriched yeast on the reproductive performance and hormone levels (progesterone and estrogen) in Iraqi ewes. the study was carried out from July 26, 2022, to january 27, 2023. eighteen ewes with an average age of 2-3 years and an average body weight of 43 ± 2.5 kg were used. the ewes were randomly divided into three equal groups, with six ewes in each group. all ewes were fed the same ration. group 1 served as the control group and received no treatment, while group 2 was treated with selenomethionine at a dose of 0.03 g/kg/bw. group 3 was treated with selenium-enriched yeast (saccharomyces cerevisiae-selenium) at the same dose, following the guidelines of the national research council (nrc, 1980). the treatments were administered orally for 45 days by dissolving the samples in 30 ml of distilled water. blood samples were collected from the jugular vein to assess changes in hormone concentrations. the results showed a significant increase in progesterone levels during the second period for groups 1 and 2 compared to group 3 (p ≤ 0.01). group 1 exhibited a significant increase in the time of the first appearance of estrus and the average time for estrus compared to group 2. group 2 showed a significant increase in estrus rate compared to group 1 and group 3. both group 2 and group 3 exhibited a significant increase in fertility rate, fertilization rate, pregnancy rate, and lambing rate. group 2 and group 3 also showed a significant increase in fecundity, twinning rate, and litter size compared to group 1. In conclusion, the supplementation of Selenomethionine and Selenium-enriched yeast positively affected reproductive performance in Iraqi ewes, as evidenced by improved hormone levels, estrus characteristics, fertility rates, and lambing outcomes.

Reproductive Efficiencies and Productive Potentials of Female Nigerian Indigenous Goat Breeds

Purpose: The overall objective of this study was to examine the reproductive and productive abilities of three Nigerian indigenous goat breeds.&#x0D; Methodology: The study covered 108 primiparous does and nine bucks from Sahel (SH), Red Sokoto (RS), and West African dwarf (WAD) goat breeds. In different pens, the animals were bred in various combinations: RS x RS, WAD x WAD, SH x SH, RS x SH, RS x WAD, SH x RS, and SH x WAD. WAD x SH, WAD x RS. Estrus synchronization was done using prostaglandins. Mating occurred naturally when animals were on heat. Dams were given special care throughout pregnancy. The study measured dams' weights, litter size, and pre-weaning mortality rates in kids. The total kid crop and sexes were also assessed. We measured dam lactation weight loss, birth weight, and weaning weight. SPSS, ANOVA, and the Turkey statistical test were used for data analysis.&#x0D; Findings: The result showed that there was a significant (P&lt;0.05) difference in the weight of does at kidding. The weight of does at weaning varied significantly (P&lt;0.05). Litter size significantly (P&lt;0.05) affected the birth weight and weaning weight of kids. An increase in litter size per birth resulted in a significant (P&lt;0.05) rise in kid mortality rates. Breed type significantly (P&lt;0.05) affected doe production efficiency and weaning weight ratio. Although WAD x WAD goats had lower birth and weaning weights, hybrid vigour (birth and weaning weights) improved significantly (P&lt;0.05) when cross-bred with SH or RS breeds. When crossed with SH or WAD goat breeds, RS breeds had the greatest positive effect on hybrid vigour (heterosis), followed by SH breeds. Both SH x RS and RS x SH progenies recorded higher hybrid vigour than the other nine bred line progenies.&#x0D; Unique contribution to theory, practice and policy: This study found that Nigerian indigenous goat breeds had great reproductive efficiency and breeding potential if properly managed. Genetic variations observed in the study could improve Kids crop, birth weight, litter size, hybrid vigour, and pre-weaning survivorship due to their broad variety. This study recommends a careful selection and crossbreeding of Nigerian indigenous goat breeds with suitable pedigree in order to increase their productivity.

Genome-wide single nucleotide polymorphism (SNP) data reveal potential candidate genes for litter traits in a Yorkshire pig population.

The litter trait is one of the most important economic traits, and increasing litter size is of great economic value in the pig industry. However, the molecular mechanisms underlying pig litter traits remain elusive. To identify molecular markers and candidate genes for pig litter traits, a genome-wide association study (GWAS) and selection signature analysis were conducted in a Yorkshire pig population. A total of 518 producing sows were genotyped with Illumina Porcine SNP 50 BeadChip, and 1969 farrowing records for the total number born (TNB), the number born alive (NBA), piglets born dead (PBD), and litter weight born alive (LWB) were collected. Then, a GWAS was performed for the four litter traits using a repeatability model. Based on the estimated breeding values (EBVs) of TNB, 15 high- and 15 low-prolificacy individuals were selected from the 518 sows to implement selection signature analysis. Subsequently, the selection signatures affecting the litter traits of sows were detected by using two methods including the fixation index (FST) and . Combining the results of the GWAS and selection signature analysis, 20 promising candidate genes (NKAIN2, IGF1R, KISS1R, TYRO3, SPINT1, ADGRF5, APC2, PTBP1, CLCN3, CBR4, HPF1, FAM174A, SCP2, CLIC1, ZFYVE9, SPATA33, KIF5C, EPC2, GABRA2, and GABRA4) were identified. These findings provide novel insights into the genetic basis of pig litter traits and will be helpful for improving the reproductive performances of sows in pig breeding.

180 Effect of Providing Liquid Milk Replacer During Lactation to Litters of Different Size on Piglet Pre-Weaning Performance

Abstract Larger litter sizes in commercial sows are generally associated with greater pre-weaning mortality (PWM) and lower piglet weaning weight (WW). Providing liquid milk replacer (MR) to piglets during lactation has been advocated for reducing PWM and increasing WW. The objective was to evaluate the effect of providing MR (using an automated feeder) to litters of different size on PWM and WW. A split-plot design with a 2 x 2 factorial arrangement of treatments was used: 1) MR [main plot; No Supplement (NS) vs. Supplement (SU)]; 2) Litter Size [LS; sub-plot; LOW (4 piglets less than functional teat number) vs. HIGH (2 piglets greater than functional teat number)]. Each MR feeder was available to 2 litters, one on the LOW and one on the HIGH LS treatment. There were 26 sows and litters per MR and LS treatment. Cross-fostering was carried out 24 hours after birth to create LS treatment litters which had similar gender ratio, proportion of cross-fostered piglets, and average and CV of piglet birth weight. Milk replacer was available from 24 hours after birth (day 1; start of study) to weaning (day 20; end of study). Piglets were weighed at the start and end; all PWM was recorded. Piglet weight data were analyzed using PROC MIXED of SAS; PWM data were analyzed using PROC GLIMMIX. Models accounted for the fixed effects of MR, LS, and the interaction, and random effects of replicate and replicate by MR interaction. There was a MR by LS treatment interaction (P ≤ 0.05) for total litter WW and PWM (Table 1). The MR treatment had no effect (P &amp;gt; 0.05) on total litter WW for the LOW LS treatment; however, for the HIGH LS treatment total litter WW was greater (P ≤ 0.05) for the SU than the NS treatment. For the NS treatment, PWM was greater (P ≤ 0.05) for the HIGH than the LOW treatment; however, PWM did not differ (P &amp;gt; 0.05) between the LS treatments for litters that had access to MR. There was no effect (P ≤ 0.05) of MR treatment on litter size or average piglet weight at the start and end of the study. The HIGH LS treatment had greater (P ≤ 0.05) litter size at the start and end of the study, but less (P ≤ 0.05) average piglet WW. In conclusion, increasing litter size above sow functional teat number had negative effects on piglet WW. In addition, providing MR to litters during lactation increased total litter WW in the HIGH but not LOW LS treatment. These results also suggest that providing MR reduced the negative effect of the larger litter size on PWM; however, further research is needed to validate this finding.

Relationship between piglets’ survivability and farrowing kinetics in hyper-prolific sows

BackgroundProlonged farrowing and more piglets born with low birth weight are undesirable consequences of genetic selection for increased litter size. The objective of the present observational study was to evaluate the relationship between piglets’ survivability and farrowing kinetics in hyperprolific sows. A total of 58 sows of different parities and 1190 piglets were included. The entire farrowing process was monitored and the following parameters were recorded: inter-piglet birth interval, birth order, total born, live born, dead born, and mummified piglets, obstetric intervention, weight at birth and 24h, colostrum yield and intake.ResultsThe sows included in this study had on average 20.6 ± 0.6 total piglets born, of which 16.4 ± 0.6 were live born, 3.3 ± 0.4 were stillborn and 0.9 ± 0.2 were mummified piglets. The average farrowing duration and average birth interval were 411.3 ± 31.6 and 20.6 ± 1.7 min, respectively. Farrowing duration was positively associated (p < 0.05) with parity, number of stillborn and mummified piglets. Piglet mortality 24h after birth was negatively affected (p < 0.01) by birth weight and positively affected (p < 0.01) by cumulative birth interval. The last tercile of piglets born (birth order ≥ 17) had the highest (p < 0.01) inter-piglet birth interval (IPBI) (43.4 ± 4.17 min) compared to piglets born in the first (birth order between 2 and 7) (26.5 ± 3.8 min) and second (birth order between 8 and 16) terciles (21.9 ± 3.8 min). Cumulative birth interval, birth weight, occurrence of stillborn piglets and manual intervention were positively associated (p < 0.05) with IPBI. Piglet birth weight was also positively associated (p < 0.01) to individual colostrum intake. Piglets ingesting more colostrum had lower (p < 0.01) mortality from 24h after birth until weaning. Sow’s parity and cumulative birth interval were positively associated with the presence of stillborn piglets (p = 0.02 and p < 0.01, respectively).ConclusionReducing farrowing duration may be crucial to decrease stillbirth rate and neonatal mortality in hyperprolific sows. Moreover, special care must be provided to the lighter piglets within a litter to increase their colostrum intake and minimize piglet’s mortality throughout lactation.