Litter Size Research Articles

Polymorphisms of the BMPR1B, BMP15 and GDF9 fecundity genes in four Chinese sheep breeds

Abstract. Numerous studies on prolific sheep breeds have shown that the transforming growth factor beta (TGF-β) superfamily members, including bone morphogenetic protein receptor type 1B (BMPR1B), bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9), are the essential regulators of ovulation rate and litter size. In total, 11 known mutations (1 in BMPR1B, 6 in BMP15 and 4 in GDF9) are able to increase the ovulation rate and litter size, respectively. In this study, the genomic DNA was isolated from 512 high-prolificacy sheep (including the Small-tailed Han, Hu and Wadi sheep breeds) and 164 low-prolificacy sheep (Tan sheep), and genotyping of the specific mutations of the three fecundity-related genes was carried out by sequencing. The results showed that the FecB mutation in BMPR1B was detected in all four sheep breeds, and the frequency of B allele was significantly higher in the high-prolificacy breeds than that in the low-prolificacy breed (P<0.001). A novel mutation, c.T755C (named S1), was found in BMP15 from the four sheep breeds. However, known mutations such as FecXI, FecXH, FecXB, FecXG, FecXL and FecXR were not detected in these breeds. Three known loci (G1, G3 and G4) and a new mutation, c.A1515G (named S2), were found in GDF9, and the other three known mutations (FecGH (G8), FecGE and FecTT) were not detected in all four sheep breeds. The genotype distribution at the G1 and G4 loci had significant differences between the low-prolificacy sheep breed and the other three high-prolificacy sheep breeds. There was no difference in the genotype distribution at the G1 and G4 loci between the three high-prolificacy sheep breeds. Haplotype analysis of the four polymorphic loci in GDF9 suggested that H4 (GGAA) was the preponderant haplotype in the three high-prolificacy sheep breeds, but H1 (GGGG) was in the low-prolificacy sheep breed. These results preliminarily showed that the BMPR1B and GDF9 might be major genes influencing the prolificacy of Chinese sheep breeds.

Effects of Nesting Material Provision and High-Dose Vitamin C Supplementation during the Peripartum Period on Prepartum Nest-Building Behavior, Farrowing Process, Oxidative Stress Status, Cortisol Levels, and Preovulatory Follicle Development in Hyperprolific Sows.

Hyperprolific sows often experience increased oxidative stress during late gestation and lactation periods, which can adversely affect the farrowing process and overall lactation performance. This study examines the influence of providing a coconut coir mat (CCM; 1 × 1 m) as nesting material, supplementing high-dose vit-C (HVC; 20% vit-C, 10 g/kg feed) as an antioxidant, or both on maternal behavior, the farrowing process, oxidative status, cortisol levels, and preovulatory follicle developments in sows with large litters. In total, 35 sows (Landrace × Yorkshire; litter size 15.43 ± 0.27) were allocated to the following four treatment groups: control (n = 9, basal diet), vit-C (n = 8, basal diet + HVC), mat (n = 10, basal diet + CCM), and mat + vit-C (n = 8, basal diet + HVC + CCM). A post-hoc analysis showed that compared with sows that were not provided CCM, mat and mat + vit-C groups demonstrated increased durations of nest-building behavior during the period from 24 h to 12 h before parturition (p < 0.05 for both), reduced farrowing durations, and decreased intervals from birth to first udder contact (p < 0.01 for both). The mat group exhibited lower advanced oxidation protein product (AOPP) levels during late gestation and lactation periods than the control group (p < 0.05). Sows with HVC supplementation showed longer farrowing durations than those without HVC supplementation (p < 0.0001). The vit-C group had higher salivary cortisol levels on day 1 after farrowing than the other treatment groups (p < 0.05). Furthermore, the follicle diameters on day 3 after weaning in the vit-C group tended to be smaller than those in the control group (p = 0.077). HVC supplementation prolonged farrowing and increased the physiological stress on postpartum, and no advantageous effects on maternal behavior and developmental progression of preovulatory follicles were observed. Hence, alternative solutions beyond nutritional approaches are required to address increased oxidative stress in hyperprolific sows and secure their welfare and reproductive performance. The present results substantiated the positive impact of providing CCM as nesting material for sows with large litters on nest-building behavior and the farrowing process, which could mitigate the deleterious consequences induced by peripartum physiological and oxidative stress.

Progestin and adipoQ receptor 7 (PAQR7) mediate the anti-apoptotic effect of P4 on human granulosa cells and its deficiency reduces ovarian function in female mice

PurposePAQR7 plays a key role in cell apoptosis as a progesterone membrane receptor. The physiological mechanism of PAQR7 in ovarian function and its anti-apoptotic action in mammals remain poorly understood.MethodsWe first added 0.2 µM aminoglutethimide (AG), an inhibitor of endogenous progesterone (P4) secretion, and transfected siPAQR7 co-incubated with P4 in human KGN cells to identify granulosa cell apoptosis, respectively. Additionally, we used Paqr7 knockout (PAQR7 KO) mice to assess the role of PAQR7 in the ovary.ResultsThe PAQR7 deficiency significantly increased apoptosis of KGN cells, and this significant difference disappeared following P4 supplementation. The Paqr7−/− female mice showed a prolonged estrous cycle, reduced follicular growth, increased the number of atresia follicles, and decreased the concentrations of E2 and AMH. The litters, litter sizes, and spontaneous ovulation in the Paqr7−/− mice were significantly decreased compared with the Paqr7+/+ mice. In addition, we also found low expression of PAQR7 in GCs from human follicular fluids of patients diagnosed with decreased ovarian reserve (DOR) and ovaries of mice with a DOR-like phenotype, respectively.ConclusionsThe present study has identified that PAQR7 is involved in mouse ovarian function and fertilization potential. One possible mechanism is mediating the anti-apoptotic effect of P4 on GC apoptosis via the BCL-2/BAX/CASPASE-3 signaling pathway. The mechanism underlying the effect of PAQR7 on ovarian development and aging remains to be identified.

EVALUATION LITER SIZE OF DIFFERENT AGE MALES WITH DIFFERENT PARITY PARENTS ON SMALLHOLDER PIG FARMING IN BUAHAN VILLAGE-PAYANGAN

&#x0D; &#x0D; &#x0D; This study aims to evaluate litter size of different ages males with different parent parity in smallholder pig far- ming, used 3 males of different ages (P1, P2, P3) and 18 sows of parity 1 – 4 (I1, I2, I3 and I4) with a 3 x 4 factorial RAL experimental design and unequal number of replications. The variables observed were litter size, weaning litter size, mortality and percentage of weaning litter size. Data were analyzed using a analyse of variant with the general linear model procedure. The results showed that the average litter size based on males P1, P2, P3 was 8.38; 9.13 and 10.38 (P&gt;0.05) and based on parental parity I1, I2, I3 and I4 respectively 8.00; 8.83; 9.66 and 10.66 (P&lt;0.05). For weaning litter size, respectively 5.75; 7.50 and 8.87 (P&lt;0.05) and from parent parity was 6.17; 6.67; 8.17 and 8.50 (P&lt;0.05), while the mortality respectively was 31.82%; 17.62% and 12.39% (P&gt;0.05) and from parent parity respec- tively 23.54%; 23.21%; 15.74%; and 19.94% (P&gt;0.05). Weaning litter size percentage of each male was 68.17; 82.50; 87.61 (P&gt;0.05) and from parental parity 76.63; 76.78; 84.26 and 80.05 (P&gt;0.05). Older males and fourth parity of parent produced better litter size, weaning litter size and weaning litter percentage with lower mortality. There was no interaction between the use of males of different ages and parents of different parity on the observed variables.&#x0D; &#x0D; &#x0D;

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.

Sestrin1, 2, and 3 are dispensable for female fertility in mice

BackgroundSestrins have been implicated in regulating aging in various organs through multiple pathways. However, their roles in ovarian aging remain unrevealed.MethodsFemale Sestrin1−/−, Sestrin2−/−, and Sestrin3−/− mice were generated using the CRISPR-Cas9 system. Body weights, little sizes, ovarian weights, estrous cyclicity, and follicle number in female mice were observed. ELISA was utilized to measure serum anti-Müllerian hormone (AMH) levels. Real time PCR, western blot, immunofluorescence, and Masson trichrome staining were employed for assessment of aging-related change.ResultsThe deletion of Sestrin 1, 2, or 3 had no discernible impact on body weights,or serum AMH levels in female mice at the age of 12 months. And there were no discernible differences in litter sizes or estrous cyclicity which were assessed at the age of 8 months. At the age of 12 months, no significant differences were observed in ovarian weights or follicle numbers among the knockout mice. Consistently, the extent of fibrosis within the ovaries remained comparable across all experimental groups at this age. Additionally, autophagy, apoptosis, DNA damage, and inflammation within the ovaries were also found to be comparable to those in wild-type mice of the same age.ConclusionsThe loss of Sestrin 1, 2, or 3 does not exert a noticeable influence on ovarian function during the aging process. Sestrin1, 2, and 3 are not essential for female fertility in mice.

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.

Association of melatonin receptor 1 A with litter size in sheep: A review.

Sheep are a valuable livestock species worldwide, providing meat, milk, and various dairy products. This article aims to review the latest literature on the melatonin receptor 1A (MTNR1A) gene as a potential candidate gene associated with reproductive traits, particularly the litter size trait in sheep, by searching various databases for available literature. Studies have shown that different parts of the MTNR1A gene play various roles in sheep. By identifying marker genes associated with reproductive traits in MTNR1A polymorphisms linked to the litter size trait, breeders can achieve a faster selection response in sheep breeding by recognizing the genomic region where these genes are located and understanding their physiological functions. Therefore, highlighting the literature on these functions and their association with reproductive traits may contribute to improving the genetic makeup during sheep breeding.

Reproductive aspects of female Andean bears (Tremarctos ornatus) in the Chingaza massif, eastern range of the Colombian Andes

Abstract Knowledge of reproduction in wild Andean bears (Tremarctos ornatus) is scarce. Here we provide novel information about litter size, birth timings, courtship and multi-generational groups in a population in the Chingaza massif in Colombia. Pregnant females, mothers with cubs, estimated birth times, and litter size were registered through camera trapping of a population at the Chingaza massif (Colombia) between 2011 and 2016. A total of 34 independent records of reproductive female bears were obtained. Twenty-eight (28) different reproductive females were recognized by external key features. Six different females were recorded only pregnant, two others were recorded pregnant and later with cubs, and 20 others were recorded only with cubs. In total, 29 cubs were recorded in 22 litters, with a mean litter size of 1.27 (SD = 0.45): 16 litters with one cub, 5 with 2 cubs, and 1 with 2 cubs + a big cub from a previous litter (&gt;1 year). The highest records of mothers with little cubs were obtained for the low rain season in December, January, and February, full of dry-season-fruiting Ericaceae shrubs. Likewise, the highest estimated births were obtained during the rainy time in June. Multi-generational groups and the courtship behaviors are reported for the first time in Colombia.

Reproductive biology of two small-bodied sharks, Carcharhinus coatesi and Rhizoprionodon acutus, in the Northern Territory, Australia

Sharks and rays are widely perceived to have slow reproductive rates and, thus, are often considered highly susceptible to population declines from commercial fishing. However, the reproductive biology of sharks is highly diverse, and some species can sustainably support significant commercial harvest. Small sharks are commonly caught and discarded as bycatch in several Australian and international fisheries. This represents either a wasted resource that could potentially be sustainably utilised, or a potential conservation issue if overharvesting occurs. This study examines the reproductive biology of two small-bodied sharks in the Northern Territory, Australia. Carcharhinus coatesi (n = 726) and Rhizoprionodon acutus (n = 179) were collected between May 2018 and November 2019 from commercial trawl fisheries. Maximum lengths in both species were higher in females than males (C. coatesi: F = 862 mm, M = 822 mm; R. acutus: F = 862 mm, M = 835 mm). Size at 50% maturation size C. coatesi: F = 655 mm, M = 664 mm; R. acutus: F = 682 mm. Size-at-maturity that the logistic model predicted for male R. acutus (715 mm) appears to represent size at full maturation and this study could not determine 50% maturation size. Litter sizes were small in both species, with C. coatesi producing 1–2 pups (mean 1.9) and R. acutus producing 1–4 pups (mean 2.8). Both species gave birth to large pups when compared to other shark species (C. coatesi: 370 - 450 mm; R. acutus: 315 – 400 mm), with C. coatesi size-at-birth being 47.6% of maximum female total length, while R. acutus size-at-birth was 41.5% of maximum female total length). Both species reproduced throughout the year, complicating estimation of the gestation period. The reproductive biology of C. coatesi and R. acutus showed considerable spatial and temporal variability when compared to studies from other regions and a past study from the Northern Territory in 1991. Although C. coatesi and R. acutus are currently abundant in the Northern Territory, the low fecundity of both species compared to other small-bodied sharks may limit their potential to sustain high levels of commercial harvest. Any expansion of commercial fishing for these species should be based on detailed consideration of their reproductive biology—in particular their low fecundity—to avoid the declines experienced by other formerly abundant elasmobranchs globally.

Impact of spatial and temporal resource distribution on rabies dynamics in the Arctic

In the Arctic, rabies is endemic in the Arctic fox (Vulpes lagopus), posing a significant and ongoing health risk for people and domestic animals. The mechanisms by which rabies is maintained within the low-density fox populations in the Arctic remain unclear. In this study, we developed a spatially explicit individual-based stochastic epidemiological model and performed an uncertainty analysis to better understand Arctic fox rabies dynamics. Rabies persisted in 25.68% of model simulations, with several variables having significant impact on rabies persistence: probability of rabies transmission, spatial and temporal distribution food resources, mean litter size and variability of rabies incubation periods. Where rabies is endemic, we identified 5 key parameters for rabies dynamics: spatiotemporal resource distribution, probability of birth for adult females, mean and standard deviation of litter size, and incubation period of rabies. Our study demonstrates that Arctic rabies can persist in its primary host under conditions consistent with existing empirical data in the literature and showed the important role played by the spatial and temporal distribution of resources. Finally, our results suggest that the ecological impacts of rapid climate warming could decrease the overall persistence of rabies in the Arctic and the associated health risk in Arctic communities.

Reproductive effort of Plestiodon copei (Squamata, Scincidae), a highland viviparous lizard from Central Mexico

Female reproductive effort is defined as the proportion of total energy or resources devoted to reproduction. In reptiles, there is frequently high inter- and intra-population variation related to several factors, such as food availability, climatic conditions, age and size, all of which, in turn, also influence survival and future reproduction. The present study is the first reproductive effort analysis of a population of the high-mountain scincid lizard Plestiodon copei in central Mexico, focusing on relative litter mass (RLM), investment per capita (INV) and productivity (PROD). We also compared the reproductive efficacy of P. copei to those of other Mexican congeners. We collected 24 gravid females of P. copei over a 4-year period and recorded a total of 90 neonates born in captivity. We found significant variation in neonatal mass amongst individual females and across years. We recorded an average litter size of 3.75 and an average litter mass of 1.25 g, which were positively correlated with both the size and total mass of the reproductive females. The RLM, INV and PROD values (0.301, 0.428 g and 1.236 g × year-1, respectively) for P. copei were greater than those for other Mexican species in the P. brevirostris group (0.290, 0.412 g and 1.135 g × year-1), revealing that females of P. copei from Tenango invest a comparatively high amount of their resources in reproduction.

Effects of negative dietary cation-anion difference and calcidiol supplementation in transition diets fed to sows on piglet survival, piglet weight, and sow metabolism.

Diets that provide a negative dietary anion cation difference (DCAD) and supplement with a vitamin D metabolite 25-OH-D3 (calcidiol) may increase calcium availability at parturition, and enhance piglet survival and performance. This factorial study assessed the effects of DCAD, calcidiol (50 µg/kg), and parity (parity 1 or >1) and their interactions. Large White and Landrace sows (n = 328), parity 1 to 8 were randomly allocated in blocks to treatment diets from day 103 of gestation until day 3 postfarrow: 1) negative DCAD without calcidiol (negative DCAD + no CA), n = 84, 2) negative DCAD with calcidiol (negative DCAD + CA) n = 84, 3) positive DCAD without calcidiol (negative DCAD + no CA), n = 81, and 4) positive DCAD with calcidiol (positive DCAD + CA), n = 79. Negative DCAD diets were acidified with an anionic feed (2kg/t) and magnesium sulfate (2kg/t). All treatment diets contained cholecalciferol at 1,000 IU/kg. Dry sow diets contained 14.8% crude protein (CP), 5.4% crude fiber (CF), 0.8% Ca, and 83 mEq/kg DCAD. Treatment diets 1 and 2 contained 17.5% CP, 7.3% CF, 0.8% Ca, and -2 mEq/kg DCAD. Treatment diets 3 and 4 contained 17.4% CP, 7.4% CF, 0.8% Ca, and 68 mEq/kg DCAD. Before farrowing, all negative DCAD sows had lower urine pH than all sows fed a positive DCAD (5.66 ± 0.05 and 6.29 ± 0.05, respectively; P < 0.01); urinary pH was acidified for both DCAD treatments indicating metabolic acidification. The percentage of sows with stillborn piglets was not affected by DCAD, calcidiol, or parity alone but sows fed the negative DCAD + CA diet had a 28% reduction in odds of stillbirth compared to the negative DCAD + no CA diet and even lesser odds to the positive DCAD + CA diet. At day 1 after farrowing, blood gas, and mineral and metabolite concentrations were consistent with feeding a negative DCAD diet and that negative DCAD diets influence energy metabolism, as indicated by increased glucose, cholesterol, and osteocalcin concentrations and reduced nonesterified free fatty acids and 3-hydroxybutyrate concentrations. In the subsequent litter, total piglets born and born alive (14.7 ± 0.3 and 13.8 ± 0.3 piglets, respectively; P = 0.029) was greater for positive DCAD diets compared to negative DCAD diets; and there was an interaction between DCAD, calcidiol, and parity (P = 0.002). Feeding a negative DCAD diet influenced stillbirth, subsequent litter size, and metabolic responses at farrowing. More studies are needed to define optimal diets prefarrowing for sows.

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.

The relationship between G1 (c.260 G>A) and G4 (c.721 G>A) polymorphisms in the GDF9 gene and the litter size of sheep: A meta-analysis study.

The results of G1 and G4 polymorphisms as litter-size (LS) markers of ewes remain contradictory. The aim was to evaluate the impact of G1 (c.260 G>A) and G4 (c.721 G>A) polymorphisms on the LS of sheep by synthesizing data from multiple previous studies. Data were extracted from 14 eligible articles. The genotypes of G1 and G4 polymorphisms were homozygous wild-type (WW), heterozygous (WM), and homozygous mutant-type (MM). The standardized mean difference (SMD) method using random effect models was employed to determine the effect size of G1 and G4 polymorphisms on LS under dominant, recessive, additive, and co-dominant genetic models. Heterogeneity was analyzed with the I2 statistic index. Publication bias was depicted with funnel plots and tested by Egger's and Begg's tests. The study showed that the correlation between G1 polymorphism and LS in sheep was not significant (p > 0.05) under all genetic models. The influence of G4 polymorphism on the LS of sheep was found significantly (p < 0.05) under dominant [SMD = 0.28, I2 = 0% (no heterogeneity)] and co-dominant [SMD = -0.14, I2 = 36% (moderate heterogeneity)] genetic models. The WM genotype of G4 polymorphism increased LS, while the MM genotype reduced LS in sheep. Publication bias among G1 and G4 polymorphism studies was absent in all genetic models. Thus, the study revealed that G4 polymorphism could be a potential genetic marker for LS in ewes. On the contrary, G1 polymorphism has no association with the LS of ewes.

Whole-genome sequencing identified candidate genes associated with high and low litter size in Chuanzhong black goats.

The reproductive performance of goats significantly influences breeding efficiency and economic returns, with litter size serving as a comprehensive indicator. Despite this, research on the genetic control of litter size remains limited. Therefore, we aimed to explore the candidate genes affecting fecundity and compared the whole-genome sequences (WGS) of 15 high-litter (HL) and 15 low-litter (LL) size in Chuanzhong black goats. Then genetic diversity and genomic variation patterns were analyzed by phylogenetic, principal component and population genetic structure analysis, it was found that HL and LL subpopulations diverged. Population evolutionary selection elimination analysis was performed by Fst and θπ resulted in 506 genes were annotated in HL and 528 genes in LL. These genes were mainly related to Hippo signaling pathway, G protein-coupled signaling pathway, G protein-coupled receptor activity, cell surface receptor signaling pathway, gonadal and reproductive structure development. According to the significantly selected genomic regions and important pathways, we found that the g.89172108T > G variant locus in the exon of the AMH gene was significantly associated with litter size (P < 0.05), which could be used as an auxiliary selection gene for the high fertility of Chuanzhong black Goat.

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.

Reproductive performance of female rabbit (Oryctolagus cuniculus) at the smallholder farmer in Karanganyar Regency, Central Java Province, Indonesia

The aims of this study was to find out the reproductive performance of female rabbits in small holder farmer in Karanganyar Regency, Central Java Province, Indonesia. This research was conducted in July-Desember 2022 in Colomadu, Gondangrejo, Kebakkramat, Karanganyar, Matesih, Jumantono, Jumapolo, Karangpandan, and Tawangmangu. The methode used in this research was a survey with a purposive sampling method. The number of respondents used was 30 New Zealand White rabbit farmers. Data collection was carried out through interviews and observation. Research parameters used in reproduction were the age of first birth, gestation period, litter size, kitten interval, and service per conception (S/C). The results showed that average age of first bith, gestation lenght, litter size, kindling interval, service per conception (S/C) were 6.1±0.8 month, 30±0.7 days, 6.0±1.0 kits, 75.8±9.9 days, 1.6±0.7 times. It can be concluded that the reproductive performance of female rabbit in Karanganyar Regency were classified as in a good condition and have a potential to be developed in the future.

Multi-omics analysis reveals the dominant intestinal microbial strains and metabolites related to the reproductive performance in pregnant sows

Abstract Gut microbiome changed dramatically during pregnancy and played important roles in metabolic status and reproductive endocrinology in mammals. However, investigating the functional microbiota and metabolites to improve the reproductive performance and understanding the host–microbiota interaction are still arduous tasks. This study aims to reveal the dominant strains and metabolites that improve the reproductive performance. We analyzed the fecal microbiota composition and metabolic status of higher yield Chinese pig breed Meishan (MS) sows and lower yield but widespread raised hybrid pig breed Landrace × Yorkshire (L × Y) sows on days 28 and 100 of gestation. Results showed that MS sows had higher litter sizes and steroid hormone level but lower short-chain fatty acid level in feces. Fecal metabolomic analysis revealed that MS sows showed a different metabolic status compared with L × Y sows both at early and late pregnancy, which enriched with phenylpropanoid biosynthesis, bile secretion, steroid hormone biosynthesis, and plant secondary metabolite biosynthesis. In addition, 16S rDNA and internal transcribed spacer sequencing indicated that MS sows showed different structures of microbiota community and exhibited an increased bacterial α-diversity but non-differential fungal α-diversity than L × Y sows. Moreover, we found that the litter sizes and bacteria including Sphaerochaeta, Solibacillus, Oscillospira, Escherichia–Shigella, Prevotellaceae_UCG-001, dgA-11_gut_group, and Bacteroides, as well as fungi including Penicillium, Fusarium, Microascus, Elutherascus, and Heydenia both have positive association to the significant metabolites at the early pregnancy. Our findings revealed significant correlation between reproductive performance and gut microbiome and provided microbial and metabolic perspective to improve litter sizes and steroid hormones of sows.