Abstract The definition of breeding objectives in meat rabbits’ breeding programs requires assigning economic weights to relevant traits. Our objective in this study was to estimate economic values for 12 key traits in meat rabbit production by calculating the first partial derivative of the profit function in a full-cycle production system. The model was parameterized to represent a semi-technified farm with 250 does managed in two triweekly groups, with natural mating occurring at 11 days postpartum. Economic data were expressed in U.S. dollars. Production costs were categorized into feed and non-feed costs associated with adult does, replacement does, bucks, replacement bucks, and growing rabbits. Revenues were derived from carcasses, pelts, and culled animals. Relative economic values (REV), expressed per doe per year, were obtained by multiplying the absolute economic value of each trait by its respective additive standard deviation. Feed costs accounted for 72.8% of the total. The REVs for litter size traits were $46.05 for the number of kits born alive, $42.83 for the total number of kits born, and $0.22 for the proportion of kits born alive. Efficiency traits’ REV were –$6.93 for feed conversion ratio, $0.08 for feed efficiency, $2.98 for daily weight gain during the fattening period, and $0.14 for carcass yield. The functional traits’ REV were $0.03 for female fertility, $0.002 for replacement doe fertility, and $0.57 for longevity. Health traits’ REV were $0.18 and $0.19 for survival during lactation and fattening, respectively. Sensitivity analyses showed that increasing feed costs by 50% and carcass rabbit sale price by 40% resulted in changes ≤ 4% for most traits in the relative proportion of economic values, compared to that of the number of kits born alive. The traits with higher changes were efficiency traits (1–16%) and mainly feed conversion ratio (15–136%). The estimated economic values provide a basis for defining breeding objectives under the given production and market conditions. The methodological framework allows adaptation of selection goals to market fluctuations and the incorporation of new traits as they become relevant. Although the economic weights were relatively stable under these variations, it is recommended that they be re-estimated periodically.

Background: Exfoliative vaginal cytology because of its simplicity, accessible equipment, and the possibility of getting rapid results could be used as a valuable technique to any reproductive diagnosis in she-dogs. The knowledge of the reproductive physiology of the estrous cycle is important for animal management and to determine the reproductive and productive potential of animals Aim: The present study aimed to determine the ovulation time in canines. Place and Duration of Study: Veterinary Clinical Complex, Krantisinh Nana Patil College of Veterinary Science, Shirwal, Satara. September 4th, 2024 to February 26th, 2025. Methodology: We studied 24 bitches through exfoliative vaginal cytology using Giemsa staining method. Results: In total 24 bitches were studied out of which, natural mating was carried out in 21 bitches whereas in three bitches, artificial insemination with fresh semen was done. Twenty out of 24 bitches were found pregnant upon transabdominal ultrasound one month after mating or artificial insemination. Ultrasonography was conducted one month after the final day of mating to identify early pregnancy through ultrasonographic assessment of the gestational sac, along with the body and head of the fetus in the pregnant bitches. Fetal heart activity was evaluated through ultrasonography, demonstrating the fetus's viability. Additionally, non-pregnancies were verified through ultrasonographic assessment. Conclusion: Vaginal cytology increases the conception rates in canine by giving an ideal time for mating.

The increasing livestock demand in developing countries raises concerns about endemic zoonotic diseases, such as bovine tuberculosis (bTB). Farmer behaviors and social contexts drive transmission, necessitating behavior change interventions. An epidemiological field survey was conducted to assess artificial insemination (AI) use and bTB incidence among dairy farmers in Madagascar, combined with socioeconomic interviews with 114 farmers in Malagasy from 2021 to 2022. A probit regression model analyzed farm-level bTB infection status as the dependent variable. AI was used by 14.1% (15 households), with 93.3% (14 households) employing natural bull mating. The herd-level bTB prevalence was 41.2% (50 cows), and 41.6% (47 households) owned at least one bTB-positive cow. AI use increased the risk of bTB, likely due to inadequate cleaning of AI equipment. Despite AI’s potential to improve productivity, improper implementation may increase the risk of bTB. These findings underscore the need for enhanced farmer education on bTB prevention and proper sanitation of AI equipment.

Conditioning ostrich males to routine semen collection does not compromise their reproductive performance in a natural mating system

Evaluating genomic breeding programs for a small dairy cattle population with widespread use of private bulls.

Disclosure: S.E. Khoury: None. E. Morales-Grahl: None. L. Thompson: None. A.C. Gore: None. N.Y. Eldiraoui: None.This study aims to evaluate how early life exposure of rats to endocrine-disrupting chemicals (EDCs) affects development and sexual differentiation of the brain through molecular and epigenetic programming. Our lab and others have shown that EDC exposure affects the hypothalamus in a sex, time, and exposure dependent manner. These effects lead to changes in gene expression related to gonadal steroid hormone signaling in the brain, shifts in pubertal timing, and altered DNA methylation patterns in hypothalamic regions. Current work is addressing effects of EDC exposure on mating behaviors in rats and whether epigenetic modification in brain regions involved in these behaviors underlie any observed physiological changes. In our lab we use NeuroMix, an EDC mixture containing 9 common industrial chemicals at environmentally relevant doses. We expose rats orally to NeuroMix in early postnatal life through feeding of rat dams, during hormone sensitive periods of brain development in the offspring. Brain tissues are collected at postnatal day 1, adolescence, and during early adulthood and bed nucleus of the stria terminalis and preoptic area of the hypothalamus are dissected for Tag-Seq to look at mRNA expression and whole genome bisulfite sequence (WGBS) to assess changes to gene expression and DNA methylation associated with sex differences at these time points. In adulthood, a subset of early adult males are observed in a natural mating environment and number of and latency to mounts, intromission, and ejaculation are counted. A subset of early adult females are tested and recorded in a paced mating paradigm to uncover differences in female typical sexual behaviors due to NeuroMix treatment. The results of these experiments will provide novel insights into the effects of NeuroMix treatment on sexually dimorphic behaviors and brain epigenetics. Supported by NIH R35 ES035024Presentation: Saturday, July 12, 2025

The purpose of this research is to identify the technical management of goat maintenance in Bikomi Utara District, North Central Timor Regency. This research was conducted from July to September 2024 in Banain A, Banain B, Banain C, Faenake, Sainoni, Tes, and Napan Villages, Bikomi Utara District, North Central Timor Regency. The research method used survey techniques and direct interviews with farmers based on the prepared questionnaire. The variables in this study are feed management, housing management, reproduction management, disease control management, and marketing management. The results of this study indicate that the technical management of goat maintenance includes feed management, with 90.9% providing feed 2 times/day, 84.8% frequency of providing drinking water is 1 time/day, the type of feed given is 56.6% grass + forage, the type of concentrate and frequency of providing concentrate is 71.7% never given, agricultural waste 50.5% is corn waste. The type of housing in this study is 84.8% dominated by group housing, the materials for making housing 85.9% come from local materials, with housing sizes of 0-10 m² being 28.3%, the frequency of cleaning the housing is 1 time/day 42.4%, the availability of feed and drinking water places 57.6% is not available, 100% no disinfectant spraying is available. Reproduction management 100% uses a natural mating system, handling of mothers giving birth and kids at birth is 97.0% handled by farmers, understanding of the signs of goats in heat 72.7% do not understand, understanding of the goat heat cycle 100% of farmers do not understand, 90.0% of farmers do not understand the duration of heat in goats. Disease control management 47.5% of livestock have never been affected by disease, livestock that are not treated amount to 55.6%, 64.6% of livestock are not given medicine, vitamin administration 88.9% of livestock are not given vitamins, the number of livestock that died due to illness 66.7% of livestock did not die due to illness. Marketing management 94.9% of livestock are sold in the market, with the purpose of selling livestock for household needs 41.4%, farmers sell their livestock only when needed, which is 96.0%.

The purpose of this study is to identify the technical management of goat livestock maintenance in North Insana District, North Central Timor Regency. This research was carried out in July-September 2024 in North Insana District, North Central Timor Regency. The method used is a survey method using quantitative descriptive analysis techniques to collect secondary data and primary data from respondents. In this study, purposive sampling techniques were used and the observed variables were feed management, cage management, reproductive management, health management, and marketing management The results of this study are the identification of technical management of goat livestock in North Insana District, North Central Timor Regency based on:1) Feed management with the frequency of feeding depends on nature 35.9%, the frequency of drinking water 1 time/day 53.5%, the type of feed in the form of grass and forage 39.4%, the type of concentrate in the form of sago 26.1%, never giving concentrate 70.4% and the utilization of agricultural waste in the form of corn 33.1%. 2) Cage management with cage type 100%, cage making from 100% local materials, cage size >10-20 m² 30.3%, never cleaning cage 30.3%, feed and drinking place not available 83.8% and never spraying disinfectant 84.5%. 3) Reproductive management with a 100% natural mating system, no handler for the mother at birth 94.4%, no handling of cempe at birth 92.3%, breeders who do not understand the characteristics of goat bite 84.5%, breeders who do not understand the goat bite cycle 97.9% and breeders who do not understand the length of goat bite 97.9%. 4) Health management which includes: complications that affect goats 33.8%, treatment by the breeder himself 51.4%, sick livestock not treated 37.3%, not given vitamins 95.8% and farmers whose livestock die 1-10 heads/year 55.6%. 5) Marketing management with a direct sales point in the barn 80.3%, sales destination for all needs 44.4% and time to sell livestock when there is a need 97.2%.

Abstract Due to the nature of traditional beef cattle production systems and the logistical need for natural mating schemes, genetic improvement is largely limited by geographic location. Through spermatogonial stem cell transplantation (SSCT) of germline ablated recipient males, generation of surrogate sire bulls that produce sperm containing the genetics of higher merit males would be possible and allow for improved dissemination of trait-driving genetics through natural breeding. Previously, we used CRISPR-Cas9 gene editing to generate male mice, pigs, and goats with inactivation of the evolutionarily conserved gene NANOS2 and found that the resulting sterility from the ablation of endogenous germ cells created an ideal host for donor-derived sperm production following SSCT. Here, two germline ablated Angus crossbred bulls were generated by CRISPR-Cas9 editing of the NANOS2 gene and transplanted during early pre-pubertal development with spermatogenic stem cells from a Holstein donor male. At maturity, one of the bulls was found to be producing ejaculates with sperm concentrations, motility, and morphology parameters in the range of normal bulls of similar breeds. Post-thaw survival of cryopreserved sperm was also in the normal range and use for in vitro fertilization resulted in embryo production. Genotyping analysis of the embryos indicated that the sperm were donor derived. In addition, pregnancies were generated following natural mating of the surrogate bull. Upon histological analysis of the testes, spermatogenesis was identified in the seminiferous tubules, further establishing the ability of the NANOS2 knockout male to harbor and maintain spermatogenesis following SSCT. In the second bull, limited sperm production occurred after SSCT and although fertility was not achieved, subsequent processing of the testes post-castration revealed sperm in the epididymis therefore suggesting some success in establishing donor-derived colonies of spermatogenesis in the seminiferous tubules. Together, these findings significantly advance surrogate sires’ development as a potential breeding tool for the beef cattle industry to achieve large scale and widespread dissemination of select genetics to accelerate trait improvements.

ABSTRACTNatural mating ability is a critical behavioral trait for the reproductive success of captive endangered mammals, and its loss often reflects declining adaptability and potential physiological dysfunctions. However, the underlying molecular regulatory mechanisms remain poorly understood. In this study, we integrated blood transcriptome and whole‐genome DNA methylation (whole‐genome bisulfite sequencing) data to systematically explore the molecular basis of natural mating ability differences in captive male giant pandas (Ailuropoda melanoleuca). A total of 21 male individuals, which were classified into either capable (with successful natural mating experience) or incapable (with repeated mating failure despite physical health) groups, were sampled from three breeding centers. RNA‐seq analysis identified key differentially expressed genes (DEGs) such as ZPBP2, enriched in functional pathways related to GnRH signaling, MAPK cascades, immune modulation, and olfactory perception. Whole‐genome bisulfite sequencing (WGBS) analysis revealed significant differences in CpG (CG) methylation density on the X chromosome, and identified promoter‐ and gene body‐associated differentially methylated regions (DMRs) that were inversely correlated with gene expression. Integrative analysis demonstrated a strong association between gene expression and DNA methylation, with the associated genes enriched in reproduction‐relevant pathways including axon guidance, cysteine and methionine metabolism, and apoptosis/autophagy. These findings suggest that DNA methylation may influence transcriptional activity involved in natural mating behavior. This multi‐omics approach provides valuable insights into the epigenetic regulation of complex reproductive phenotypes in endangered species and offers a theoretical basis for future applications in molecular marker–based individual selection and optimization of captive breeding programs, thereby contributing to wildlife conservation efforts.

Gene dysregulation impairs placental angiogenesis in allogeneic pig pregnancies.

Simple SummaryGiant pandas are conservation reliant. Natural mating is more successful than artificial insemination. Mate preference is a critical factor in the natural reproduction of giant pandas, but it is poorly understood. Given the importance of improving the reproductive efficiency of the giant panda, this study focused on the physiological and metabolic changes in female giant pandas during mate preference trials conducted at estrus. In this study, we collected environmental biomarkers from 19 female pandas during mate preference trials with 3 males and performed metabolomics analysis. We identified several differential metabolites, including prostaglandin G2, prostaglandin E2, and estrone, which are potentially associated with female mate preference. In addition, through KEGG pathway enrichment analysis, we found that female mate preference was related to steroid hormone biosynthesis, phenylalanine metabolism, and tropane, piperidine and pyridine alkaloid biosynthesis. These results reveal potential physiological markers related to female mate preference, providing insights for formulating effective conservation and breeding strategies for the giant panda.The giant panda (Ailuropoda melanoleuca) is a vulnerable animal in China, and it is crucial to improve the reproduction efficiency of the giant panda. Mate preference is an important part of natural mating. We hypothesized that AGS metabolites differ according to their mate preference. In this study, we determined estrus-associated hormone levels in the urine of 19 female giant pandas. After confirming estrus via hormone levels and behavioral observation, we collected environmental biomarkers for metabolomics analysis. A total of 19 samples were divided to two groups according to the mating preference of female giant pandas. Metabolomics analysis by LC-MS/MS showed that a total of 115 differentially expressed metabolites were identified, including 97 upregulated metabolites and 18 downregulated metabolites. We found that prostaglandin B2, palmitoylcarnitine, prostaglandin G2, and estrone may be the potential markers of female mate preference. Pathway enrichment analysis showed that steroid hormone biosynthesis, phenylalanine metabolism, and tropane, piperidine, and pyridine alkaloid biosynthesis were the top three pathways. These results revealed the physiological changes in female giant pandas during mate preference trials, providing a perspective for understanding their chemical communication system reliant on anal gland secretions and improving the success rate of natural mating of giant pandas.

Isolation of pathogen Leptospira sp. from preputial smegma of bull.

ABSTRACTMany threatened felid species, including the jaguar (Panthera onca), have low reproductive success in captivity. This may be partially attributed to a lack of knowledge on natural history parameters like courtship and mating behaviour in wild animal populations ‐ an essential aspect for fine‐tuning ex situ breeding programs. During a series of basin‐wide biodiversity inventories in the Brazilian Amazon, we captured videographic evidence of a mating event involving a melanistic jaguar. Such videographic evidence of natural jaguar mating behaviour remains rare, with prior behavioural descriptions being derived from artificial settings like zoos and wildlife parks. Our findings provide the first insights into the courtship and mating interactions between different jaguar colour morphs in the wild, and offer critical validation for behavioural data obtained from controlled environments. These insights enhance our understanding of jaguar reproductive biology and contribute valuable context for refining ex situ conservation strategies. More broadly, they highlight the role of natural history research in advancing conservation efforts for elusive species.

Cloacal feather trimming improves reproductive performance of layer breeder roosters☆

ABSTRACT In forest tree breeding, there is a growing trend towards using pedigree reconstruction after offspring are produced through natural random mating (open-pollination), as an alternative to traditional controlled crosses and full-sib genetic trials. Given that most forest tree species are predominantly outcrossing organisms, the accuracy of narrow-sense heritability (h 2) under natural mating conditions has not been thoroughly examined, particularly with regard to sample size. Our simulation study focuses on the genetic parameters specific to Norway spruce (Picea abies L.) in Norway. We used the stochastic model MoBPS to simulate a founder population with 100,000 SNP markers distributed across 12 haploid chromosomes, representative of many conifer species. Parental trees were selected from this population, followed by random mating and offspring evaluation. We focused on estimating the accuracy of h 2, with particular attention to its precision and bias. Our results suggest that the population sample sizes currently used in forest tree breeding are generally adequate for achieving precision. However, we identified two primary sources of bias: one due to dominance effects and the other from phenotypic parental selection. We discuss potential strategies to mitigate these biases in breeding programs.

Germline transmission of cryopreserved mouse spermatogonial stem cells maintained on the International Space Station

Complex intercellular interactions occur at the maternal-fetal interface during pregnancy. Human uterine decidual epithelial cells play a crucial role in maternal immune tolerance and placental development. Macrophages are major cells at the maternal-fetal interface regulating tissue remodeling and immune response. The role of F11 receptor (F11r) in regulating the biological functions of epithelial cells and immune cells is particularly prominent. Thus, this study was to determine the mechanism by which F11r mediates the interaction of decidual epithelial cells with macrophages. F11r knockout (KO) mice were obtained using CRISPR/Cas9 technology. On Day 12.5 of gestation, single-cell RNA sequencing (scRNA-seq) was performed and reproduction was recorded at the uterine implantation sites in the WT and the KO groups, respectively. F11r KO mice have increased embryo resorption after natural mating. Decidual epithelial cells were classified into three subtypes based on scRNA-seq data: Epi1, Epi2, and Epi3. In F11r KO mice, Epi2, located at an early stage of differentiation, prematurely differentiates to an immunoregulatory cell fate and participates in the regulation of the immune response. In addition, the interaction between epithelial cell subpopulations and macrophage subpopulations was disturbed in the KO group. Specifically, Csf1-Csf1r interactions between Epi1 and C1q+ macrophages were reduced in the F11r KO group. However, Spp1-cd44 interactions were enhanced between subclusters of decidual epithelial cells (Epi1, 2, and 3) and macrophage subclusters (C1q+, Cxcl10+, and Spp1+ macrophages). In conclusion, we elucidated the immunomodulatory mechanisms by which F11r mediates decidual epithelial-macrophage interactions at the maternal-fetal interface from cellular and molecular perspectives.

The yak (Bos grunniens) is a key species in high-altitude rangelands of Asia. Despite their ecological and economic importance, yak production faces persistent challenges, including low milk yields, vulnerability to climate changes, emerging diseases, and a lack of systematic breeding programs. This review presents the genomic, physiological, and environmental dimensions of yak biology and husbandry. Genes such as EPAS1, which encodes hypoxia-inducible transcription factors, underpin physiological adaptations, including enlarged cardiopulmonary structures, elevated erythrocyte concentrations, and specialized thermoregulatory mechanisms that enable their survival at elevations of 3000 m and above. Copy number variations (CNVs) and single nucleotide polymorphisms (SNPs) present promising markers for improving milk and meat production, disease resistance, and metabolic efficiency. F1 and F2 generations of yak-cattle hybrids show superior growth and milk yields, but reproductive barriers, such as natural mating or artificial insemination, and environmental factors limit the success of these hybrids beyond second generation. Infectious diseases, such as bovine viral diarrhea and antimicrobial-resistant and biofilm-forming Enterococcus and E. coli, pose risks to herd health and food safety. Rising ambient temperatures, declining forage biomass, and increased disease prevalence due to climate changes risk yak economic performance and welfare. Addressing these challenges by nutritional, environmental, and genetic interventions will safeguard yak pastoralism. This review describes the genes associated with different yak traits and provides an overview of the genetic adaptations of yaks (Bos grunniens) to environmental stresses at high altitudes and emphasizes the need for conservation and improvement strategies for sustainable husbandry of these yaks.

This study aims to refine sterile cesarean section techniques, in vitro fertilization (IVF) and foster mother selection strategies to enhance the efficiency of germ-free (GF) mouse production. We conducted the following analyses: (1) comparing different cesarean section methods, (2) evaluating the impact of natural mating versus in vitro fertilization (IVF) for obtaining donor mice, and (3) assessing maternal care among three inbred strains (C57BL/6J, BALB/c, NSG) and one outbred strain (KM) as GF foster mothers. The results showed that optimizing surgical methods which preserve the female reproductive tract during cesarean section (FRT-CS), significantly improved fetal survival rates while maintaining sterility. IVF enabled precise control over donor delivery dates, enhancing experimental reproducibility. Among GF foster strains, BALB/c and NSG mice exhibited superior nursing and weaning success, whereas C57BL/6J had the lowest weaning rate, in stark contrast to findings on maternal care in SPF C57BL/6J foster mothers. These findings offer practical guidance for optimizing GF mouse production, improving the efficiency of obtaining germ-free mice through cesarean derivation.