Reproduction In Goats Research Articles

Rhythmic Changes in Serum Progesterone and Estradiol-17β in Surti Goats under Different Synchronization Protocols

Background: Success of any estrous synchronization protocol to optimize production and reproduction in goats requires deeper insight of dynamic regulation of hormones progesterone and estradiol-17β. Surti goats reared mostly by marginal livestock owners are native to Gujarat. Present study was conducted to study rhythmic changes in serum progesterone and estradiol-17β in Surti goats under different synchronization protocols.Methods: 18 Surti goats were divided equally (n=6) in 3 groups viz. G1, G2 and G3 (control). G1 and G2 groups were injected with GnRH analogue (day 0 and 11) and PGF2α analogue (day 9). Progestogen sponge was kept intravaginal in G1 group (day 0) and removed (day 11) before GnRH analogue injection. G3 group (control) received placebo of 2 ml normal saline simultaneous to treatment groups.Result: Levels were higher at estrus and lower at day 30 for Estradiol-17β and vice versa for progesterone. Coefficient of variation for estradiol-17β at estrus and for progesterone at day 30 was lower for G1 and higher in control. It was concluded that GPG synchronization protocol with intravaginal progestogen was better to synchronize estrus and establish reproductive cyclicity in Surti goats as it effectively minimized variability of progesterone during pregnancy and estradiol-17β at estrus.

Growth and reproduction trade‐offs can estimate previous reproductive history in alpine ungulates

Abstract Life‐history theory predicts energy allocation trade‐offs between traits when resources are limited. If females reduce allocation to growth when they reproduce, annual growth could reveal past reproductive effort, which would be useful to assess population dynamics and harvest sustainability. The potential and accuracy of growth measures for predicting reproductive success have rarely been evaluated with individuals with known reproductive history. We used long‐term monitoring of annual growth and reproduction of marked female bighorn sheep and mountain goats, two species in which primiparity normally occurs well before growth completion, to evaluate growth versus reproduction trade‐offs and their potential for predicting reproductive history of young females using mixed models and 10‐fold block cross‐validation. We documented a significant reduction in mass gain and horn growth in young reproducing females of both species. This trade‐off was affected by individual differences in energy acquisition and allocation because population density and previous allocation to growth affected the trade‐off. We then parameterized models to predict individual reproductive history of young females based on the growth traits subjected to a reproductive trade‐off. The accuracy of predictive models ranged from 85.2% to 91.0% across species and traits, indicating that growth is a good predictor of reproductive history. This method is especially useful for population management of species with traits that form permanent visible yearly annuli because they retain a record of annual growth that allows retrospective estimation of reproductive history over multiple years. Synthesis and applications. We show that because growth significantly decreased in years of allocation to reproduction, annual growth increments provide insights on reproductive history of young females. Population or temporal differences in reproduction of young females affect demographic rates and sustainable harvest. Growth measures of traits that form yearly annuli, such as teeth and horns, could be easily obtained at a low cost from animals harvested or found dead in multiple species. Thus, predictive models of reproductive history based on annual growth could assist conservation and management in a broad range of species.

Eif2s3y Promotes the Proliferation of Spermatogonial Stem Cells by Activating ERK Signaling.

The future fertility of males with cancer may be irreversibly compromised by chemotherapy and/or radiotherapy. Spermatogonial stem cell transplantation is believed to be a way to restore fertility in men. However, the survival efficiency of transplanted cells is still low. Eukaryotic translation initiation factor 2 subunit 3 and structural gene Y-linked (Eif2s3y) located on the Y chromosome of male animals is a coding gene of eIF2γ which mainly functions in translation initiation. Recently, the emerging role of Eif2s3y in spermatogenesis has been emphasized in several studies. However, the underlying mechanism is still unclear. In addition, how Eif2s3y functions in large animals remains largely unknown. In this study, we obtained the CDS sequence of the Eif2s3y gene from the testis of dairy goats and found that this gene was highly expressed in the testis and was evolutionarily conserved among different species. Interestingly, overexpression of Eif2s3y promoted the proliferation of spermatogonial stem cells of dairy goats by activating the ERK signaling pathway. In animal experiments, overexpressing Eif2s3y promoted transplanted goat spermatogonial stem cells and produced more colonies after microinjection into the seminiferous tubules of infertile mice. In conclusion, our study highlights an undiscovered role of Eif2s3y in dairy goat reproduction. This finding may provide an important basis for future works regarding male spermatogenic cell restoration and represent a major advance toward surrogate sires becoming a tool for disseminating and regenerating germplasm in all mammals.

ОСОБЕННОСТИ РЕПРОДУКТИВНОЙ ФУНКЦИИ КАРАЧАЕВСКИХ КОЗ В ЗАВИСИМОСТИ ОТ РАЗНЫХ ГЕОГРАФИЧЕСКИХ РАЙОНОВ РАЗВЕДЕНИЯ

In recent years, goat breeds with a dairy-meat-wool or combined productivity type, represented by local breeds that are bred mainly in the foothills and mountainous regions of the North Caucasus, Altai, Tyva and Khakassia, have become increasingly widespread in Russia. The Karachay goat population is the most interesting for research, since in their breeding was aimed at obtaining animals with a number of unique productive characteristics and capable of producing the required outputs under the harsh conditions of the mountain and foothill zones of the Caucasus. In view of the limited research on these animals, in particular their reproductive functions, the aim of this study was to investigate the natural implementation of the reproductive function of the Karachay goats in different geographical areas of breeding. There are slight differences in some parameters of Karachay goat reproduction in high mountain zone (from 2000 m a.s.l.) and middle mountain zone (1000–1500 m a.s.l.). An important conclusion is that the recognized low fertility of the Karachay goats is not genetically determined. Analyzing the number of ovulations and fresh yellow bodies in the ovaries by laparoscopy using Karl Storz (Germany) endoscopic equipment, the authors found a potential fecundity of 3.1 (2.8 to 3.4).

Nutritional supplementation improves the sexual response of bucks exposed to long days in semi-extensive management and their ability to stimulate reproduction in goats

In confined management systems, well-nourished bucks rendered sexually active by exposure to long days are efficient in fertilizing out-of-season goats. However, underfeeding is common in semi-extensive management systems and may reduce the reproductive efficiency of bucks. The objective of the present study was to determine whether nutritional supplementation improved the sexual activity of bucks submitted to long days in semi-extensive management systems and their ability to stimulate the reproduction of goats in semi-extensive or confined conditions. In experiment 1, three groups of bucks were placed in different flocks and grazed daily with females for 7 h. Each day after grazing, males were separated from females and moved into open pens. One group did not receive any treatment (control group; n = 6). Two other groups were submitted to artificially long days from 15 November to 15 January. From 16 January, one group did not receive nutritional supplementation (long-day group; n = 5), whereas bucks from the other group each received 600 g of a commercial concentrate (long-day+supplementation group; n = 5). The fourth group was kept in confined conditions, exposed to long days and fed alfalfa hay (long-day confined group; n = 6). On 26 March, anovulatory goats from other flocks were assigned to four groups (n = 27 each) and confined separately in open pens. Three bucks of each group were housed with the females. Pregnancy rates were greater in the goats housed with the long-day group than those housed with the control group (P < 0.01). However, pregnancy rates did not differ between the long-day confined group (89%) and long-day+supplementation group (70%; P = 0.09), but these rates were greater than those from the long-day (37%) and control groups (0%; P < 0.05). In experiment 2, two groups of males (n = 3 each) were incorporated into two flocks under semi-extensive management and grazed daily with females for 7 h. One group of males did not receive any treatment (control group). The other group was submitted to long days and nutritional supplementation as in experiment 1 (long-day+supplementation group). Males remained with females during the whole study. The pregnancy rate was greater in the goats joined by males of the long-day+supplementation group (78%) than in those from the control group (0%; P < 0.001). We conclude that long days and nutritional supplementation improve the ability of bucks kept in semi-extensive management to stimulate reproduction of out-of-season goats in confined or semi-extensive management systems.

Analysis and Screening of Reproductive Long Non-coding RNAs Through Genome-Wide Analyses of Goat Endometrium During the Pre-attachment Phase.

Reproduction in goat is highly impeded by implantation failure. Of concern, the underlying mechanism leading to embryo implantation remains unclear. In this study, deep sequencing was employed through strand-specific Ribo-Zero RNA-Seq to characterize transcriptome changes in the endometrium during the maternal recognition of pregnancy. A total of 996 differential transcripts (115 lncRNAs and 881 mRNAs) existing between the pregnant and non-pregnant endometrium were revealed through bioinformatics analysis. The screening was performed on lncRNAs (XR_001918173.1, LNC_002760, and LNC_000599) and LNC_009053, to determine their potential role in regulating the synthesis of retinol and endometrium remolding through the proteasome pathway, respectively. The hypothesis of whether certain lncRNAs, namely, LNC_007223, LNC_005256, and LNC_010092 could play important roles in embryo implantation was tested. These novel findings are of paramount relevance to further elucidate the molecular mechanisms of embryo implantation and uncover new targets to improve goat reproduction.

Identification and characterization of putative ovarian lincRNAs in dairy goats treated for repeated estrous synchronization

The goal of this study was to identify and characterize effects of repeated estrous synchronization (ES) treatments on the regulation of ovarian intergenic long non-coding RNAs (lincRNAs) in dairy goats. Six does were randomly assigned to a group administered three ES treatment regimens separated by 2 weeks or to a group administered only one ES treatment regimen (control) at the same time as the third ES treatment in the does administered the three hormonal regimens for ES. The paired-end RNA Sequencing procedures were used to evaluate lincRNAs of ovarian tissues. A total of 134 lincRNAs were differentially abundant between the two treatment groups. Several target genes were annotated and were related to hormone activity, cellular response to hormone stimulus, response to hormone, female pregnancy, as well as regulation of hormone secretion. These genes were noticeably enriched in MAPK, Hippo, estrogen signaling pathways, oocyte meiosis, progesterone-mediated oocyte maturation, ovarian steroidogenesis as well as GnRH signaling pathways. According to the enriched GO terms and KEGG pathways of regulated genes, 13 differentially abundant lincRNAs could be promising candidates for regulating reproductive functions of female goats. Current results indicate that repeated treatments with gonadotropins affected hormone sensitivity, estrogen synthesis, and ovarian function. The results also indicated that when there was imposing of the three hormonal treatment regimens for ES, there were several lincRNAs that could contribute to dysregulation of several genes that are important for reproduction in dairy goats. Findings provide novel insights for further investigation of lncRNAs biological functions in goats.

Incidence of reproductive disorders of goat in Dinajpur district of Bangladesh

The study was conducted at Upazila Livestock Office, Sadar, Dinajpur of Bangladesh from January 2018 to December 2018 to investigate the incidence of reproductive disorders in goat. Data on reproductive disorders were collected on the basis of owner’s complain and observed clinical signs. Age and season wise occurrences of reproductive disorders were also recorded. Descriptive statistical analysis was done. Out of 2484 clinical cases, a total of 107 reproductive disorders of goat were recorded. Incidence of abortion (38.3%) was higher and pyometra (0.9%) was lower among reproductive disorder in goat. The incidence of reproductive disorders of goat was higher in group-2 (above 1-2 years) (36.4%) followed by group-1 (upto 1 year) (21.6%), group-3 (above 23 years) (21.5%), group-5 (above 4 years) (15.3%) and group-4 (above 3-4 years) (3.6%). Among reproductive disorders, the incidence of abortion was higher in group-2 (58.9%) followed by retained placenta (50%) in group-4, metritis (47%) and dystocia (23.5%) in group-5, repeat breeding (17.4%) and anestrus (4.3%) in group-3, and pyometra (2.5%) in group-2. Slight seasonal variation among individual case of reproductive disorders were recorded, highest in winter (34.5%) than summer (32.4%) and rainy season (31.7%). The incidence rate of abortion was high in each season (summer 25%, rainy 32.3% and winter 56.7%). In case of retained placenta and dystocia, the incidence was high in summer season (22.2%). But in case of metritis and repeat breeding, the incidence was high in rainy season (32.3% and 14.7% respectively). For treatment of reproductive disorders in goat, antibiotics drugs (35%) were used most commonly and hormonal drugs (3%) used in lower percentages. It was concluded that the most pressing constraint on goat reproduction in Bangladesh is abortion, retained placenta, dystocia and metritis. Strategies should be taken to minimize their occurrence.&#x0D; Asian J. Med. Biol. Res. June 2020, 6(2): 212-221

Genetic analysis of reproduction, body weight and mohair production in South African Angora goats

Abstract Genetic parameters for South African Angora goats were estimated from body weight, mohair production and reproduction data collected from birth on ram and ewe kids, as well as on the adult ewes in three herds from 2000 to 2015. Medium heritabilities were estimated for body weight from birth until 12-month of age and adult body weight, while a high heritability was estimated for 16-month body weight. Heritability for fibre diameter and spinning fineness was high, while a low heritability was estimated for standard deviation of fibre diameter along the length of the staple and for staple length. Medium heritabilities were estimated for fleece weight and the remainder of the fibre traits. Low heritabilities were estimated for all reproductive traits. Heritability estimates of lifetime number of kids born and weaned were higher than the heritability estimated on the individual records. Expressing lifetime number of kids weaned per kidding opportunity further increased the heritability. There were favourable significant genetic correlations of total weight of kids weaned (TWW) with adult body weight and fibre diameter, but significant unfavourable genetic correlations of TWW with adult fleece weight. Fleece weight was, however, unfavourably correlated with fibre diameter. Early fleece weights were genetically favourably correlated with all the adult traits, except with adult fibre diameter. The opposite is true for early fibre diameter, which were genetically unfavourably correlated with all the adult traits, except with adult fibre diameter. Early body weights were also genetically favourably correlated with all the adult traits, except with adult fibre diameter. Maiden ewe reproductive performance at the first parity was favourable genetically correlated with lifetime reproductive performance. Different selection strategies are proposed for ram and ewe selection, where ewe selection should focus on improving reproduction, while the fleece traits should be accommodated under ram selection. Selection of young ewes should be based on early body weight and TWW at the first parity. Too much selection pressure on early fleece weight and fibre diameter should be avoided in the selection of young ewes.

Effect of Social Rank upon Estrus Induction and Some Reproductive Outcomes in Anestrus Goats Treated With Progesterone + eCG.

Simple SummaryThe potential effect of social rank [R] (high—HSR; medium—MSR; low—LSR) in anestrus goats subjected to an estrus induction protocol (EIP) primed with progesterone (P4) and receiving a differential equine chorionic gonadotropin (eCG) dose [D] (D100 vs D350) upon some reproductive outcomes in crossbred dairy goats under intensive stall-fed conditions was evaluated. Response variables included estrus induction (EI, %), latency to estrus (LAT, h), duration of estrus (DUR, h), ovulation (OVU, %), ovulation rate (OR, n), corpus luteum size (CLS, cm), pregnancy (PREG, %), kidding (KIDD, %), and litter size (LS, n). Most of the response variables were positively affected by social rank, favoring to the HSR goats (i.e., EI %, DUR h, OVU %, OR n, and CLS cm). In addition, increased OR and PREG occurred in the HSR + D350 group, while D350 increased LS, irrespective of R. Interestingly, since no differences regarding LAT, DUR, OVU, CLS, PREG, and KIDD occurred between D350 and D100, the obtained values support the use of a reduced level of exogenous hormones to induce and generate out-of-season reproductive efficiency.We evaluated the possible role of the social rank [R] (i.e., low—LSR, middle—MSR, or high—HSR) in anestrus goats exposed to a P4 + eCG [D] (i.e., 100 or 350 IU) estrus induction protocol (EIP). Adult, multiparous (two to three lactations), multiracial, dairy-type goats (Alpine–Saanen–Nubian x Criollo goats (n = 70; 25°51′ North) managed under stall-fed conditions were all ultrasound evaluated to confirm anestrus status while the R was determined 30 d prior to the EIP. The variables of estrus induction (EI, %), estrus latency (LAT, h), estrus duration (DUR, h), ovulation (OVU, %), ovulation rate (OR, n), corpus luteum size (CLS, cm), pregnancy (PREG, %), kidding (KIDD, %), and litter size (LS, n) as affected by R, D, and the R × D interaction, were evaluated. While OVU and CLS favored (p < 0.05) HSR (96% and + 1.04 ± 0.07 cm), an increased (p < 0.05) LS occurred in D350 vs. D100 (2.06 ± 0.2 vs. 1.36 ± 0.2); neither R nor D affected (p > 0.05; 38.5%) KIDD. However, EI, LAT, DUR, OR, and PREG were affected by the R × D interaction. The HSR group had the largest (p < 0.05) EI % and DUR h, irrespective of D. The shortest (p < 0.05) LAT occurred in D350, irrespective of R. While the largest (p < 0.05) OR occurred in HSR and MSR within D350, the HSR + D350 group had the largest PREG (p < 0.05). These research outcomes are central to defining out-of-season reproductive strategies designed to attenuate seasonal reproduction in goats.

Comprehensive analysis of mRNAs and miRNAs in the ovarian follicles of uniparous and multiple goats at estrus phase

BackgroundFertility is an important economic trait in the production of meat goat, and follicular development plays an important role in fertility. Although many mRNAs and microRNAs (miRNAs) have been found to play critical roles in ovarian biological processes, the interaction between mRNAs and miRNAs in follicular development is not yet completely understood. In addition, less attention has been given to the study of single follicle (dominant or atretic follicle) in goats. This study aimed to identify mRNAs, miRNAs, and signaling pathways as well as their interaction networks in the ovarian follicles (large follicles and small follicles) of uniparous and multiple Chuanzhong black goats at estrus phase using RNA-sequencing (RNA-seq) technique.ResultsThe results showed that there was a significant difference in the number of large follicles between uniparous and multiple goats (P < 0.05), but no difference in the number of small follicles was observed (P > 0.05). For the small follicles of uniparous and multiple goats at estrus phase, 289 differentially expressed mRNAs (DEmRNAs) and 16 DEmiRNAs were identified; and for the large follicles, 195 DEmRNAs and 7 DEmiRNAs were identified. The functional enrichment analysis showed that DE genes in small follicles were significantly enriched in ovarian steroidogenesis and steroid hormone biosynthesis, while in large follicles were significantly enriched in ABC transporters and steroid hormone biosynthesis. The results of quantitative real-time polymerase chain reaction were consistent with those of RNA-seq. Analysis of the mRNA-miRNA interaction network suggested that CD36 (miR-122, miR-200a, miR-141), TNFAIP6 (miR-141, miR-200a, miR-182), CYP11A1 (miR-122), SERPINA5 (miR-1, miR-206, miR-133a-3p, miR-133b), and PTGFR (miR-182, miR-122) might be related to fertility, but requires further research on follicular somatic cells.ConclusionsThis study was used for the first time to reveal the DEmRNAs and DEmiRNAs as well as their interaction in the follicles of uniparous and multiple goats at estrus phase using RNA-seq technology. Our findings provide new clues to uncover the molecular mechanisms and signaling networks of goat reproduction that could be potentially used to increase ovulation rate and kidding rate in goat.

Application of reproduction and production technology of goat livestock to improve living standards of the people of Dayow Village, Pinolosian Timur Subdistrict, Bolaang Mongondow Selatan Regency

Dayow Village has abundant and potential local resources (such as livestock and agricultural plantations) but has not sufficiently increased the income and welfare of the community due to the isolation of the region which has implications for the limited variety of accessibility of community life. A Community Service Program, The Application of Appropriate Technology Program (PPTTG) scheme has been held in Dayow Village with the aim to 1) increase community knowledge and skills in mastering the technology of reproduction and production of goat livestock, and in processing livestock waste into solid and liquid organic fertilizer; and 2) increase community economic income. The method used as a form of community empowerment in Dayow Village is a combination of methods of application of sciences and appropriate technology of superovulation to improve the reproduction of goats. The results of this activity show that the superovulation technology products, which are the results of research and development of the implementation team, can be applied to meet the needs of the people of Dayow Village. This activity can increase regional potential and community participation.

Predation risk and mountain goat reproduction: Evidence for stress‐induced breeding suppression in a wild ungulate

Abstract Non‐consumptive effects of predation can strongly impact reproduction and demography of prey species. Still, the underlying mechanisms that drive non‐consumptive effects are not fully understood, and the circumstances under which chronic physiological stress may mediate these effects remain unclear. Benefiting from over 23 years of environmental, physiological and demographic data, we tested the hypothesis that predation risk may impair reproduction of mountain goats through chronic elevation of physiological stress. We conducted path analyses to assess the relationships between predation risk, faecal glucocorticoid metabolites and hair cortisol concentration, and reproduction, while taking into account the potential effects of age class, sex, body mass, season and within individual variation in glucocorticoid concentration. Predation risk had a direct positive effect on the average annual faecal glucocorticoid concentration in the population, which, in turn, negatively affected the proportion of reproductive females. The same pattern was observed with hair cortisol concentration, but these results were inconclusive potentially due to methodological challenges in estimating annual average of hair cortisol at the population level. Our study presents one of the first robust evidence that stress‐mediated breeding suppression can occur in a wild ungulate following increased predation risk, thereby providing a major insight on the mechanisms underlying non‐consumptive effects of predation in wild mammals. A free Plain Language Summary can be found within the Supporting Information of this article.

Polymorphisms within the Boule Gene Detected by Tetra-Primer Amplification Refractory Mutation System PCR (T-ARMS-PCR) are Significantly Associated with Goat Litter Size.

Simple SummaryMutations of the Boule gene, a gene that contributes to spermatogenesis, are a main cause of mammal infertility in reproduction. As a conserved gene, only some single nucleotide polymorphisms (SNPs) in the introns within it have been reported in humans with meiosis block, but not in goats, and especially its fundamental roles in female reproduction are still unknown. Therefore, this study detected the potential polymorphisms of the Boule gene in goats via the tetra-primer amplification refractory mutation system PCR (T-ARMS-PCR). Herein, one predicted SNP locus (rs661484476: g.7254T>C) of the Boule gene was first detected and displayed moderate polymorphism among all the studied groups. Notably, the polymorphisms of the goat Boule gene were significantly associated with the goat litter size in different groups, and female goats with the heterozygous genotype (CT) had more possibilities to produce multiple lambs than others, indicating that the Boule gene might underlie female reproductive capacities and that g.7254T>C could be a potential marker in the marker-assisted selection process for litter size in goats.As a gene contributing to spermatogenesis, the Boule gene (also called Boll), whose mutations result in azoospermia and sterility of flies and mice, was conserved in reductional maturation divisions. However, in goats, the polymorphisms of Boule, especially with regard to their fundamental roles in female reproduction traits, are still unknown. Therefore, the aims of this study were to detect a potential mutation (rs661484476: g.7254T>C) located in intron 2 of the Boule gene by tetra-primer amplification refractory mutation system PCR (T-ARMS-PCR) and to explore its potential association with the litter size of Shaanbei White-Cashmere goats (SBWGs). In this study, g.7254T>C was firstly detected. The TT genotype was the dominant genotype in the single-lamb group, and T was also the dominant allele in all tested groups. Additionally, the detected locus displayed moderate polymorphism with polymorphism information content (PIC) values among all studied goats ranging from 0.303 to 0.344. Notably, according to the χ2 test, the distribution differences for the genotypic frequencies between the single- and multi-lamb groups was significant (p = 0.014). Furthermore, the polymorphisms of the goat Boule gene were significantly associated with the goat litter size in SBWGs (p < 0.05), which indicated that g.7254T>C could be a potential marker in the marker-assisted selection process for potential litter size in goats. These results also indicated that the Boule gene might exercise important functions in female goat reproduction, which provided new insight for female goat breeding and could accelerate the process of goat breeding.

A 14-bp functional deletion within the CMTM2 gene is significantly associated with litter size in goat

CKLF-like MARVEL transmembrane domain-containing 2 (CMTM2) plays an important role in animal reproduction, and abnormal CMTM2 expression leads to spermatogenesis disorders. This study was conducted to assess the role of CMTM2 in goat reproduction by investigating an insertion/deletion (indel) variation and its effect on litter size, and to reveal its functional mechanism. A 14-base pair (bp) indel was found at position −861 to −848 nt of the CMTM2 promoter in 1131 female Shaanbei white cashmere goats. Association analyses revealed that the 14-bp indel in dams was significantly correlated with the size of the first litter (P = 0.013), with the 14-bp deletion significantly decreasing litter size. Moreover, litter size at first kidding was significantly correlated with genotype frequencies (P = 0.019). Expression of the goat CMTM2 gene was detected in testes and ovaries. In male, CMTM2 was increased after the initiation of meiosis in the developing testis. In female, CMTM2 expression was higher in ovary from multiple prolific goats at first kidding compared to non-prolific goats. Moreover, both in testis after initiation of meiosis and in ovary, the homozygous 14-bp inserted genotype II was associated with increased CMTM2 expression compared to the heterozygous genotype ID (P < 0.05). To further explore whether the 14-bp indel was located in the core promoter activity region of the CMTM2 promoter, the five recombinant plasmids pGL3-pro1 (−1756 to +83), pGL3-pro2 (−1200 to +83), pGL3-pro3 (−763 to +83), pGL3-pro4 (−496 to +83), and pGL3-pro5 (−205 to +83) were co-transfected with pRL-TK into HEK293T and GC-1 cells. A luciferase reporter assay showed that the pGL3-pro2 and pGL3-pro5 vectors produced significantly stronger luminescence than the other vectors. Interestingly, the 14-bp indel locus was included in the pGL3-pro2 plasmid, suggesting that the indel was functional. Subsequently, the two recombinant plasmids pGL3-pro2-inserted-allele and pGL3-pro2-deleted-allele were co-transfected with pRL-TK into HEK293T and GC-1 cells, respectively. The luciferase reporter assay demonstrated that the deleted allele of CMTM2 showed significantly lower luminescence activity than the inserted allele (P < 0.05), which corresponded to a decrease in litter size in the deletion-deletion genotype. Therefore, our results suggest that a 14-bp deletion in the promoter region of CMTM2 is significantly correlated with litter size in goats; this marker seems promising for breeding selection for improving economically important traits in goats.

Research advances in reproduction for dairy goats.

Considerable progress in reproduction of dairy goats has been made, with advances in reproductive technology accelerating dairy goat production since the 1980s. Reproduction in goats is described as seasonal. The onset and length of the breeding season is dependent on various factors such as breed, climate, physiological stage, male effect, breeding system, and photoperiod. The reproductive physiology of goats was investigated extensively, including hypothalamic and pituitary control of the ovary related to estrus behavior and cyclicity etc. Photoperiodic treatments coupled with the male effect allow hormone-free synchronization of ovulation, but the kidding rate is still less than for hormonal treatments. Different protocols have been developed to meet the needs and expectations of producers; dairy industries are subject to growing demands for year round production. Hormonal treatments for synchronization of estrus and ovulation in combination with artificial insemination (AI) or natural mating facilitate out-of-season breeding and the grouping of the kidding period. The AI with fresh or frozen semen has been increasingly adopted in the intensive production system, this is perhaps the most powerful tool that reproductive physiologists and geneticists have provided the dairy goat industry with for improving reproductive efficiency, genetic progress and genetic materials transportation. One of the most exciting developments in the reproduction of dairy animals is embryo transfer (ET), the so-called second generation reproductive biotechnology following AI. Multiple ovulation and ET (MOET) program in dairy goats combining with estrus synchronization (ES) and AI significantly increase annual genetic improvement by decreasing the generation interval. Based on the advances in reproduction technologies that have been utilized through experiments and investigation, this review will focus on the application of these technologies and how they can be used to promote the dairy goat research and industry development in the future.

Detection of polled intersex syndrome (PIS) and its effect on phenotypic traits in goats

Polled intersex syndrome (PIS), a physiological defect associates polledness and intersexuality, will directly affect the reproduction and other phenotypic traits of goats, thus, it is a hazard to the development of the goat industry. Recent studies have revealed that goat PIS was caused by an 11.7-kb deletion located in chromosome 1q43, but its DNA detection method was little reported. Herein, a total of 503 goats from three goat breeds were used to successfully establish a simple, rapid, accurate and effective method for the detection of goat PIS mutation. Furthermore, based on this assay, the associations between the PIS mutation and growth traits were analyzed in Guanzhong dairy goats. These findings would provide the potential practical application for molecular breeding to accelerate the development of the goat industry.

Nature Inspires Estrus Synchronization in Murciano-Granadina Goats under Extremely Hot Climate

Despite the seasonal nature of reproduction in goats, creating a capacity that enables getting goats pregnant throughout the year is of economical importance in commercial settings. The objective was to compare natural and artificial (hormonal) methods of estrus synchronization on pregnancy rate of Murciano-Granadina goats under extremely hot climate of southern Iran. To synchronize estrus, experimental goats received one of three treatments. The first group (n = 123) was treated with CIDR (intravaginal progesterone release) on day-0 and which was later removed on day-19 plus eCG injection followed by introduction to bucks on day-21. The second group (n = 157) was treated with CIDR on day-0 and with eCG injection on day-17, then CIDR removed on day-19 followed by introduction to bucks on day-21. The third group (n = 257) did not receive any hormonal treatments and were only synchronized naturally via introduction to bucks (natural mating). Findings revealed that natural synchronization (male effect) resulted in significantly greater pregnancy rates compared to the second group (69 vs. 53%, P < 0.05). The first group tended to have greater pregnancy than did the first group (63 vs. 53%, P < 0.10). Improved reproductive performance of dairy goats under hot stressful climate signifies the economical importance and practicality of natural mating as an effective method of estrus synchronization in commercial goat production.

Comparative analysis of differentially expressed genes between the ovaries from pregnant and nonpregnant goats using RNA-Seq

BackgroundA multitude of genes tightly regulate ovarian follicular development and hormone secretion. These complex and coordinated biological processes are altered during pregnancy. In order to further understand the regulatory role of these genes during pregnancy, it is important to screen the differentially expressed genes (DEGs) in the ovaries of pregnant and nonpregnant mammals. To detect the genes associated with the development of pregnancy in goats, DEGs from the ovaries from pregnant and nonpregnant Anhui white goats (pAWGs and nAWGs, respectively) were analyzed using RNA sequencing technology (RNA-Seq).ResultsIn this study, 13,676,394 and 13,549,560 clean reads were generated from pAWGs and nAWGs, respectively, and 1724 DEGs were identified between the two libraries. Compared with nAWGs, 1033 genes were upregulated and 691 genes were downregulated in pAWGs, including PGR, PRLR, STAR and CYP19A1, which play important roles in goat reproduction. Gene Ontology analysis showed that the DEGs were enriched for 49 functional GO terms. Kyoto Encyclopedia of Genes and Genomes analysis revealed that 397 DEGs were significantly enriched in 13 pathways, including “cell cycle”, “cytokine–cytokine receptor interaction” and “steroid biosynthesis”, suggesting that the genes may be associated with cell cycle regulation, follicular development and hormone secretion to regulate the reproduction process. Additionally, quantitative real-time PCR was used to verify the reliability of the RNA-Seq data.ConclusionsThe data obtained in this work enrich the genetic resources of goat and provide a further understanding of the complex molecular regulatory mechanisms occurring during the development of pregnancy and reproduction in goats. The DEGs screened in this study may play an important role in follicular development and hormone secretion and they would provide scientific basis for related research in the future.

Associations between genetic variants of the POU1F1 gene and production traits in Saanen goats.

This study was conducted to determine the polymorphisms of the POU1F1 gene and their relationships with milk yield and components, litter size, birth weight, and weaning weight in goats. For this purpose, a total of 108 Saanen goats from two different farms (Bornova and Manisa) were used as animal materials. Polymorphisms at the exon 6 and the 3 flanking region of the POU1F1 gene were determined by using PCR-RFLP with PstI and AluI restriction enzymes and DNA sequencing analyses. Two alleles and three genotypes were identified by AluI or PstI digestions of the POU1F1 gene. The genotypes frequencies of TT, TC, and CC were 64.8 %, 31.5 % and 3.7 % for the PstI locus; 54.6 %, 31.5 % and 13.9 % for the AluI locus, respectively. T allele frequencies (0.56 and 0.88 for the AluI locus, 0.80 and 0.81 for the PstI locus, respectively) were predominant in both loci at the Bornova and Manisa farms. In terms of POU1F1-AluI and POU1F1-PstI loci, two populations were found to be in Hardy–Weinberg equilibrium. In the POU1F1-AluI locus, significant associations were found between genotypes and lactation milk yield and litter size. Similarly, a significant relationship between genotypes and birth weight in the POU1F1-PstI locus () was determined. The TC and CC genotypes were observed to be higher than the TT genotype for lactation milk yield and litter size at the POU1F1-AluI locus. Birth weight was found to be higher in animals that have the CC genotype at the POU1F1-PstI locus. In conclusion, the POU1F1 gene can be used as a molecular marker for economic features like reproduction, growth, milk content and yield in Saanen goats.