Reproductive Performance Of Sheep Research Articles

Body Condition in Small Ruminants—Effects of Nutrition on the Hypothalamic–Pituitary–Gonad Axis and Ovarian Activity That Controls Reproduction

Nutritional status plays a vital role in regulating ovary activity. This regulation is mediated by the hypothalamus–pituitary–gonad axis and by effects exerted directly on the ovary. Therefore, to achieve the best reproductive performance, it is essential to know how the nutritional status affects the secretion of GnRH, gonadotrophins, and sex steroid hormones. Adequate body reserves and energy balance are critical for optimal reproductive performance in sheep and goats. However, over- or under-conditioned animals experience issues like extended anestrus, irregular ovarian cycles, and reduced conception. Body condition scoring allows for the evaluation of the relationships between adiposity, nutritional status, and fertility. Acute feed deficits briefly stimulate processes, but chronic restrictions suppress pulsatile LH release, disrupting ovarian function. The process of follicle development is a very complex one which involves intricate interactions between the pituitary gonadotrophins and metabolic hormones as well as between the locally produced factors by the ovarian somatic and germ cells including the IGF system and the TGF-β superfamily members. Genotype and nutrition are factors that have an impact on follicular development, and seasonal factors are also involved. This review will give a brief overview on how the body condition can be evaluated and the effects of nutrition on the hypothalamus–pituitary–gonad axis and ovarian activity, which are responsible for reproductive regulation. This paper presents a clear and reasonable summary of the pathway that runs from the nutritional status of small ruminants to ovarian activity through the hypothalamic–pituitary–gonadal axis. This review summarizes methods for body condition evaluation in small ruminants and evidence regarding acute versus prolonged nutritional impacts on the hypothalamic–pituitary–gonadal axis and ovarian activity controlling reproduction.

Effects of melatonin implants on reproductive performance in sheep: a systematic review and meta-analysis

Context Sheep are seasonal breeding animals. Different reproduction systems exist to enhance productivity in non-breeding season. One of the methods used in enhancing reproductive performance in sheep breeding is melatonin administration. Aim This study aimed to evaluate the impact of melatonin application on reproductive performance in sheep by meta-analysis according to different factors. Methods To find eligible studies, PubMed and Web of Science databases were searched. Twenty studies published between 1991 and 2021 were included in the meta-analysis. The effect sizes of pregnancy rate, lambing rate and litter size were calculated according to breeds, production characteristics (dairy-meat breeds) and season (breeding–non-breeding). The study estimated the risk ratio for pregnancy and lambing rates, and standardized mean difference for litter size as effect size. Key results The melatonin hormone increases the pregnancy rate by 1.07 times and the lambing rate by 1.36 times. The effect size (risk ratio) of the Rasa Aragonesa breed (1.15) for pregnancy rate and the Merino breed (1.65) for lambing rate was higher than the Sarda breed. Conclusions The positive effect of melatonin was found to be higher in the non-breeding season than in the breeding season for the three reproductive performance traits examined. Implications This study is a comprehensive research study examining the effect of melatonin application in sheep according to different factors.

Rapid on-site genotyping of the ovine prolific FecBB mutation using a CRISPR/Cas12a-based detection system

BMPR1B is a pivotal gene that influences reproductive performance in sheep. The sheep populations that carry the FecBB mutation within this gene exhibit significantly higher lambing rates compared to wild-type populations. Therefore, screening for individuals carrying the FecBB mutation is crucial for effective sheep breeding programs. This study aims to establish a rapid, precise, and visualised on-site detection method for genotyping the prolific FecBB mutation in sheep. We combined the CRISPR/Cas12a system with the recombinase-polymerase amplification (RPA) technique. We introduced an additional nucleotide mismatch on the amplification primers to form a Cas12a-recognised protospacer adjacent motif (PAM) sequence. In addition, mismatches were introduced in CRISPR-derived RNA (crRNA) to enable naked-eye differentiation of the assay results. Subsequently, we validated the accuracy of the method by examining additional blood samples from 56 sheep representing four breeds. The results of using our developed system were highly consistent with the Sanger sequencing. Overall, the CRISPR/Cas12a-based detection provides a rapid and more versatitle method for FecBB genotyping. It holds promise in enhancing efficiency in livestock breeding programmes for any single nucleotide mutations.

Association analysis of polymorphisms in SLK, ARHGEF9, WWC2, GAB3, and FSHR genes with reproductive traits in different sheep breeds.

The aim was to investigate the relationship between polymorphisms of gene mutation loci and reproductive traits in local sheep breeds (Duolang Sheep) and introduced sheep breeds (Suffolk, Hu Sheep) in Xinjiang to provide new molecular markers for the selection and breeding of high fecundity sheep. The expression pattern of typing successful genes in sheep tissues was investigated by RT-qPCR technology, providing primary data for subsequent verification of gene function. The 26 mutation loci of WWC2, ARHGEF9, SLK, GAB3, and FSHR genes were typed using KASP. Association analyses were performed using SPSS 25.0, and the typing results showed that five genes with six loci, WWC2 (g.14962207 C>T), ARHGEF9 (g.48271079 C>A), SLK (g.27107842 T>C, g.27108855 G>A), GAB3 (g.86134602 G>A), and FSHR (g.80789180 T>G) were successfully typed. The results of the association analyses showed that WWC2 (g.14962207 C>T), SLK (g.27108855 G>A), ARHGEF9 (g.48271079 C>A), and FSHR (g.80789180 T>G) caused significant or extremely significant effects on the litter size in Duolang, Suffolk and Hu Sheep populations. The expression distribution pattern of the five genes in 12 sheep reproduction-related tissues was examined by RT-qPCR. The results showed that the expression of the SLK gene in the uterus, the FSHR gene in the ovary, and the ARHGEF9 gene in hypothalamic-pituitary-gonadal axis-related tissues were significantly higher than in the tissues of other parts of the sheep. WWC2 and GAB3 genes were highly expressed both in reproductive organs and visceral tissues. In summary, the WWC2 (g.14962207 C>T), SLK (g.27108855 G>A), ARHGEF9 (g.48271079 C>A), and FSHR (g.80789180 T>G) loci can be used as potential molecular markers for detecting differences in reproductive performance in sheep. Due to variations in typing results, the SLK (g.27107842 T>C) and GAB3 (g.86134602 G>A) loci need further validation.

Correlation between Sheep Body Condition Score and Lambing Interval in Langkat District of Indonesia

The Body Condition Score relates to livestock reproduction, such as estrus, pregnancy, the birth process, and the condition of lambs. If the lamb has a bodyweight exceeding the ideal body weight, the animal will experience reproductive disorders to metabolic diseases. However, if the mother sheep has a body weight less than ideal, it can disrupt the reproductive system, affecting the symbol interval. This research aims to find out the relationship between Body Condition Score and the reproductive performance of sheep in Langkat Regency, namely Service Per Conception and Lambing Interval. The study design is Deskriptif analysis. Research conducted in Langkat Regency, Indonesia, between November 2022 and January 2023.The method used in this research is a case study, namely by collecting primary and secondary data. The observed variables are Body Condition Score (BCS) and Lambing Interval. The results of the study are The value of the Body Condition Score with the Lambing Interval regression equation Y = 15.677-0.818X. (R2) 12.8%. (r) of 0.358. The relationship between Body Condition Score and Calving Interval is positive, with an R2 value of 12.8%. The conclusion of the research is The relationship between the lambs Body Condition Score (BCS) and the Lambing Interval had a good correlation with an average Calving Interval ranging from ≤8 to 9 months.

Association of Novel C319T Variant of PITX2 Gene 3'UTR Region With Reproductive Performance in Awassi Sheep.

Several genes influence sheep's reproductive performance, among them the paired-like homeodomain transcription factor 2 (PITX2) gene. Thus, this study aimed to examine whether the variability within the PITX2 gene is associated with the reproductive performance of Awassi ewes. A total of 123 single-progeny ewes and 109 twin ewes were used to extract genomic DNA. An amplicon of 4 sequence fragments from exons 2, 4, 5 (upstream portion), and 5 (downstream portion) of the PITX2 gene was generated by polymerase chain reaction (PCR), 228, 304, 381, and 382 bp, respectively. Three genotypes of 382 bp amplicons were identified: CC, CT, and TT. Sequence analysis revealed a novel mutation in the CT genotype 319C > T. Statistical analysis revealed that single-nucleotide polymorphism (SNP) 319C > T was associated with reproductive performance. Single-nucleotide polymorphism 319C > T-carrying ewes had significantly (P ⩽ .01) lower litter sizes, twinning rates, lambing rates, and more days to lambing than those carrying CT and CC genotypes. Based on a logistic regression analysis, it was confirmed that the 319C > T SNP decreased litter size. Ewes with TT genotype produced fewer lambs than ewes with CT and CC genotypes. According to these results, the variant 319C> T SNP negatively affects the reproductive performance of Awassi sheep. Ewes carrying the 319C > T SNP have a lower litter size and are less prolific than those without the SNP.

Impact of phyto-oestrogens on reproductive health of sheep

Phyto-oestrogens are plant compounds that mimic the effects of oestrogen. They are mainly found in legumes, especially red and subterranean clover and lucerne. Levels vary with cultivar, season, growing stage and stress to the plant. Consumption of oestrogenic pasture or conserved forage has been shown to have negative effects on reproductive performance of sheep — in particular, a decrease in fecundity and an increase in barren rate. Prolonged exposure may lead to irreversible changes to cervical structure and reproductive performance. Evidence for the impact of phyto-oestrogens on cattle is much weaker than for sheep. The many advantages of clover and lucerne should be exploited, but an understanding of phyto-oestrogenism is needed to avoid unwanted negative impacts on livestock reproductive performance.

Evaluation of the BMPR-1B gene functional polymorphisms and their association with litter size in Qinghai Tibetan sheep

The Bone morphogenetic protein receptor-1B (BMPR-1B) was one of the most major candidate gene for sheep follicular development and litter size trait. The BMPR-1B gene encoded a structural and functional highly conserved transmembrane protein related to sheep reproductive performance. To further validate its genetic effect, genotype-phenotype associations were performed in Tibetan sheep. Through DNA sequencing of the entire coding region of the BMPR-1B gene using DNA of 30 unrelated Tibetan ewes (10 Singletons Tibetan ewes, and 20 Twins Tibetan ewes). And genotyping the target SNPs loci using PCR-RFLP (or PCR-SSCP) combined with DNA sequencing and analyzing their association with lambing traits in 510 Tibetan ewes. One mutation in 3′UTR (A1354G) and three mutations in exons (G192A, A746G, T864C) were found to be strongly associated with lambing traits in Tibetan ewes in this study. χ2 suitability test showed that all of SNPs were Hardy-Weinberg equilibrium. After independence test, A746G, T864C and A1354G of BMPR-1B gene polymorphisms were significantly correlated with litter size in all-types of Tibetan sheep. These results indicate that the variations in the BMPR-1B genes and their corresponding genotypes may be considered as marker-assisted selection (MAS) for litter traits in Tibetan sheep breeding.

EVIDENCE OF ANTIBODIES AGAINST DIFFERENT Leptospira spp. SEROGROUPS AND FACTORS ASSOCIATED WITH ITS PRESENCE IN SHEEP FROM VERACRUZ, MEXICO

<p class="Default"><strong>Background</strong>. Leptospirosis is a bacterial zoonosis caused by pathogenic species of the genus <em>Leptospira</em> that affects mainly reproductive performance in sheep. <strong>Objective</strong>. To identify the seroprevalence of <em>Leptospira </em>spp., associated serogroups, and possible risk factors in the state of Veracruz, Mexico. <strong>Methodology</strong>. Blood samples were collected from 405 sheep in 55 farms located in 13 municipalities distributed along three ovine-producing regions in the state. Serological diagnosis was made by Microscopic Agglutination Technique (MAT). The prevalence and its confidence intervals (CI) were calculated using Vassarstats software, the Odds Ratio (OR) values were estimated with WinEpiscope. <strong>Results.</strong> An overall seroprevalence of 53.83% (<sub>95%</sub>CI:48.84-58.75), per municipality of 100% (<sub>95%</sub>CI :71.66-100) and per flock of 92.73% (<sub>95%</sub>CI: 81.58-97.65) were noted. The highest prevalence by region was 58.82% (<sub>95%</sub>CI<sub>:%</sub>:50.57-66.62) for Los Tuxtlas (p= 0.218) and per municipality 86.36% (<sub>95%</sub>CI:71.95-94.33) for Ángel R. Cabada. The predominant serogroup was Hardjo (45.93%; <sub>95%</sub>CI:41.02-50.92). By age, the highest values were 55.93% (<sub>95%</sub>CI:48.29-63.31) in the group of 19-36 months. The main recognized risk factors were region and municipality. Los Tuxtlas Region (OR =1.92; <sub>95%</sub>CI:1.08-3.43) and the municipalities of Ángel R. Cabada (OR=15.5; <sub>95%</sub>CI:5.1-47.2), Ayahualulco (OR=10.1; <sub>95%</sub>CI :3.6-28.7), and Coatzintla (OR=6.1; <sub>95%</sub>CI: 30.3 – 95.0).<strong> Implications. </strong>This study explores the presence of antibodies against <em>Leptospira</em> spp. in sheep, its associated serogroups and risk factors in the state of Veracruz, Mexico. This is this first report on the presence and relevance of this infection in sheep of this region. The role of sheep as a maintenance host for <em>Leptospira</em> spp. in endemic areas is stressed. <strong>Conclusions. </strong>The study concludes that <em>Leptospira</em> spp. in sheep has an overall seroprevalence of 53.83% in the state of Veracruz, Mexico and several serogroups present.</p>

A Review on Evaluation of Productive and Reproductive Performance and Major Constraints of Indigenous Sheep: An Ethiopian Perspective

The objective of this paper is to evaluate the productive and reproductive performance and major constraints of indigenous sheep in Ethiopian perspective. Ethiopia is home for at least 9 breeds and 14 traditional sheep populations. Sheep are the second most important species of livestock next to cattle in Ethiopia. The productivity of sheep mostly based on the reproductive performance of sheep. The age at first sexual maturity may be affected by weaning season and post weaning nutrition and thus through good management age at first sexual maturity could be substantially improved. Arsi Bale and Horro sheep have short lambing interval from other indigenous sheep. Litter size of Ethiopian sheep breeds like Menz and Afar sheep breeds is low (which is almost close to one lamb per lambing while breeds like Horro and Washera are more prolific with litter size of 1.35 and 1.2, respectively. Ethiopian indigenous sheep are characterized by slow growth, late maturity and low production performances. Feed shortages, both in quality and quantity, high prevalence of diseases and parasites, shortage of water; lacks of markets are the major constraints sheep production in Ethiopia. As the conclusion reproductive performances like litter size, age at first lambing and lambing interval are important traits of sheep production. Ethiopian indigenous sheep are characterized by slow growth, late maturity and low production performances. Therefore, on farm performance evaluation of sheep is required to understand effect of seasons and year on productive and reproductive of small ruminants. Keywords: Constraint; indigenous sheep; productive; reproductive; performance DOI: 10.7176/JNSR/13-13-02 Publication date: July 31 st 2022

Thyroid Transcriptomic Profiling Reveals the Follicular Phase Differential Regulation of lncRNA and mRNA Related to Prolificacy in Small Tail Han Sheep with Two FecB Genotypes.

Long non-coding RNA (lncRNA) accounts for a large proportion of RNA in animals. The thyroid gland has been established as an important gland involved in animal reproduction, however, little is known of its gene expression patterns and potential roles in the sheep. Herein, RNA-Seq was used to detect reproduction-related differentially expressed lncRNAs (DELs) and mRNAs (DEGs) in the follicular phase (FT) FecBBB (MM) and FecB++ (ww) genotypes of Small Tail Han (STH) sheep thyroids. Overall, 29 DELs and 448 DEGs in thyroid between MM and ww sheep were screened. Moreover, GO and KEGG enrichment analysis showed that targets of DELs and DEGs were annotated in biological transitions, such as cell cycle, oocyte meiosis and methylation, which in turn affect reproductive performance in sheep. In addition, we constructed co-expression and networks of lncRNAs-mRNAs. Specifically, XLOC_075176 targeted MYB, XLOC_014695 targeted VCAN, 106991527 targeted CASR, XLOC_075176 targeted KIFC1, XLOC_360232 targeted BRCA2. All these differential lncRNAs and mRNAs expression profiles in the thyroid provide a new resource for elucidating the regulatory mechanism underlying STH sheep prolificacy.

FecB mutation and litter size are associated with a 90-base pair deletion in BMPR1B in East Friesian and Hu crossbred sheep

Litter size is a critical economic trait in livestock, but only a few studies have focused on associated indel mutations in BMPR1B, a key regulator of ovulation and litter size in sheep. We evaluated the effects of BMPR1B mutations on the reproductive performance of sheep. We used Hu, East Friesian, and East Friesian/Hu crossbred sheep as experimental subjects and identified a novel 90 bp deletion in BMPR1B, which coincides with the c.746A > G (FecB mutation) genotype. The correlation between the two loci and litter size was then evaluated. We identified three genotypes for the Del-90bp locus, namely, II, ID, and DD, and three genotypes for the c.746A > G locus, namely ++, B+, and BB. Both Del-90bp and c.746A > G significantly affected the litter size of Hu and East Friesian/Hu crossbred sheep. Linkage disequilibrium analysis revealed a strong linkage disequilibrium between these loci in Hu sheep and the F1 population (r 2 > 0.33), which suggests that detecting this 90 bp deletion might be a simple method to identify the likely carriers of c.746A > G. However, the function of this 90-bp deletion still needs further exploration. We provide genetic data that can be used as a reference for the breeding of improved prolific traits in sheep.

Identifying the heat resistant genes by multi-tissue transcriptome sequencing analysis in Turpan Black sheep

Heat stress not only affects the physical condition but also affects reproductive performance in sheep. A thorough understanding of the molecular and physiological mechanisms underlying heat stress would certainly improve livestock productivity and provide genetic evaluation ways for heat resistant breeds selection. In this study, 85 Turpan Black sheep, a breed exhibited excellent heat resistance from long-term artificial selection, and 85 heat sensitive Kazakh sheep in Turpan basin were tested for physiological and reproductive performance from July to August in summer. The results showed that the estrus rate was significantly higher in Turpan Black sheep (P < 0.05), while the heart rate and respiratory rate of Turpan Black sheep are significantly lower than that of Kazakh sheep (P < 0.05). Furthermore, to clarify genes participated in heat stress response, the pituitary, ovarian and hepatic tissues from three Turpan Black sheep and three Kazakh sheep were subjected to RNA-seq. The results indicated that 32, 49 and 69 genes were up-regulated, and 39, 60 and 145 genes were down-regulated in pituitary, ovarian and hepatic tissues in Turpan Black sheep compared with that of the Kazakh sheep, respectively. KEGG and gene set enrichment analysis showed that the differentially expressed genes were mainly involved in signal transduction pathways. In particular, the differentially expressed genes in hepar were enriched in the energy metabolism pathway, while the differentially expressed genes in ovarian tissue were enriched in the ovarium steroidogenesis pathway. In conclusion, our results implied that the pituitary-ovary axis might include hepar as downstream targeted organism in heat resistant regulation. Under heat stress, the signals released from pituitary would impact steroidogenesis in ovary, and further alter energy metabolism in hepar. As we know, this is the first comparative study to investigate the gene expression in multi-tissue in sheep under heat stress.

Ewe Vaginal Microbiota: Associations With Pregnancy Outcome and Changes During Gestation.

Reproductive performance is paramount to the success of livestock production enterprises focused on lamb meat production. Reproductive success is influenced by various factors, possibly including the reproductive tract microbial communities present at the time of copulation and throughout pregnancy. There are few publications that identify the vaginal microbial communities of livestock, and even fewer exist for sheep. To compare ewe vaginal microbial communities, vaginal swabs were taken from 67 Hampshire and Hampshire X Suffolk crossbred ewes from the Iowa State University sheep farm at a pre-breeding time point (S1) and after pregnancy testing (S2). Animals that were determined pregnant were sampled again within a few days of expected parturition (S3). DNA was extracted from these swabs, and 16S rRNA gene Illumina MiSeq amplicon sequencing was conducted to fingerprint the bacterial communities found within this system. Pre-breeding time point samples showed no differences in community structure between animals later found to be pregnant or non-pregnant, but significant changes were detected in species richness (Chao; P < 0.001) and species diversity (Shannon; P < 0.001) at the second sampling time point. A higher microbial diversity within the S2 time point samples may suggest a more stable environment driven by pregnancy, as this increased diversity is maintained in pregnant animals from the S2 to the S3 time point. Additionally, several bacterial phylotypes, such as Mannheimia, Oscillospiraceae-like OTUs and Alistipes, were more abundant at either the S1 or S2 time points in animals that established pregnancy, suggesting a beneficial effect on pregnancy outcome. This study identifies changes within the microbial communities of the ewe vagina before and during gestation and offers inferences on how these changes may impact pregnancy outcome. Information presented herein offers new knowledge about sheep vaginal microbial communities and serves as a starting point to help guide researchers to improve sheep reproductive performance in the future.

Abortive diseases and their various associated risk factors in small ruminants in Algeria: a systematic review

Abortive infections are a major health challenge affecting productive and reproductive performance of sheep and goats. However, there is no comprehensive summary on the occurrence and distribution of these infections in Algeria. This systematic review provides a comprehensive summary on the prevalence of different abortive diseases and assesses potential risk factors in small ruminants in Algeria. Five databases were used to search epidemiological data on the prevalence of different abortive diseases (bacterial, parasitic, and viral). Data were collected from 25 papers published between 2003 and 2020. The total mean sample size was 53,080 small ruminants. The majority of the diseases/infections were diagnosed by serological and molecular tests. The overall prevalence of brucellosis was 0.39% in sheep and 5.31% in goats. Chlamydia and Q fever were observed in 32.72% and 20.62% of small ruminants, respectively. The prevalence of peste des petits ruminants was 15.76% and the overall prevalence of bluetongue in sheep and goats was, respectively, 13.41% and 44.50%. Border disease and bovine viral diarrhea were detected in 22.68% and 1.01% of sheep examined, respectively. Toxoplasma gondii infection prevalence among sheep and goats was 21.43% and 32.31% respectively. This study is a comprehensive epidemiological analysis of abortion diseases in small ruminants in Algeria and will therefore be a useful tool for researchers. Larger and more robust prevalence studies are needed to adequately support risk assessment and management of animal and public health threats.

Polymorphisms in BMPRIB gene affect litter size in Chinese indigenous sheep breed

The BMPRIB gene belongs to the TGF-β superfamily and is considered to be a regulator of sheep reproductive performance. Single nucleotide polymorphisms (SNPs) of BMPRIB gene in the Small Tail Han, Hu, Mongolian, Oula, Gansu Alpine Fine-wool, Dorper and Australian White sheep were detected by Sanger sequencing. Five SNPs (rs427897187 G > A, rs418841713 A > G, rs159952533 T > C, rs429416173 C > A and rs403555643 A > G) of BMPRIB gene were identified. For rs427897187 G > A, further analysis revealed that genotype GG and GA had 0.26 (p < 0.05) and 0.33 (p < 0.05) litter size less than those with genotype AA in Oula sheep. For rs403555643 A > G, further analysis revealed that genotype GG and AG had 0.65 (p < 0.05) and 0.38 (p < 0.05) litter size more than those with genotype AA in Oula sheep, and genotype GG had 0.56 (p < 0.05) litter size more than those with genotype AA in Mongolian sheep. The results showed that rs427897187 G > A and rs403555643 A > G are potential molecular markers wich could improve litter size of Chinese indigenous sheep and be used in Chinese indigenous sheep breeding.

Synergistic effect of royal jelly in combination with glycerol and dimethyl sulfoxide on cryoprotection of Romanov ram sperm

Sperm fertility decreases significantly after freezing. Providing a suitable and useful diluent compound for freezing ram sperm can increase the efficiency of artificial insemination and consequently, the reproductive performance of sheep. Various biological properties such as antibacterial, anti-cancer, immunosuppressive, antioxidant and reproductive properties of royal jelly (RJ) are well known. The aim of this study was to investigate the possible synergistic effect of royal jelly in combination with glycerol and dimethyl sulfoxide (DMSO) in sperm cryopreservation extender of Romanov ram. The pooled semen samples from 5 Romanov rams were allocated into 3 experiments. The effect of 6% DMSO, 6% glycerol and a combination of 3% DMSO +3% glycerol co-supplemented with 1, 2 and 3% RJ was evaluated in 3 experiments. Samples were frozen by conventional slow freezing method and post-thaw parameters of total motility, progressive motility, plasma membrane integrity, DNA damage, apoptosis, enzyme activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx), total antioxidant capacity (TAC) and malondialdehyde (MDA) were evaluated. The results showed that the percentage of motility, progressive motility, TAC, GPx, SOD and all sperm kinematic parameters except LIN in the group containing 2% RJ + 6% DMSO was higher than the control group (p < 0.05). Some parameters such as progressive motility, sperm membrane integrity, TAC, GPx, VAP, VCL, STR and SRT in the group containing 2% RJ + 6% DMSO were more than (p < 0.05) in the sperm group containing 1% RJ + 6% DMSO. MDA values in sperm groups containing 2% RJ + 6% DMSO were significantly (p < 0.05) lower than the sperm containing 1% royal jelly and the control group. In the sperm group containing 2% RJ + 6% glycerol, sperm membrane integrity, TAC, GPx, SOD, progressive motility and all sperm kinematic parameters except VAP were higher and MDA values and sperm abnormalities were lower than the control group (p < 0.05). The sperm group containing 1% RJ and 3% DMSO +3% glycerol had higher motility, progressive motility, membrane integrity, and all sperm kinematic parameters except VSL; and lower sperm abnormalities, DNA damage, apoptosis and MDA than the control group (p < 0.05). As a general conclusion of this study, the addition of 2% RJ + 3% DMSO and 3% glycerol to the freezing extender improved microscopic and biochemical ram sperm parameters after the freeze-thaw process. Hence, moderate concentrations of royal jelly (2%) are sufficient to protect sperm from freezing damage, and high (3%) and low (1%) concentrations do not have a good cryoprotective effect.

A 24-bp indel within the sheep AHR gene is associated with litter size

Aryl Hydrocarbon Receptor (AHR) is a member of the PER-ARNT-SIM (PAS) family, which could mediate various biological processes, for instance, the balance of the immune system, cell proliferation, differentiation, vascular tissue remodeling and reproduction ability regulation. A previous research showed that the AHR gene exerted important functions on the pig reproduction, implying that it could serve as a candidate gene related to animal reproductive traits. Here, the aim of this work was to identify potential insertion/deletion (indel) mutations of the AHR gene in three sheep breeds and analyze the associations between these mutations and reproductive traits. Results showed that a 24-bp indel was uncovered three genotypes (II, ID and DD) in the Australian White sheep (AuW) and Lanzhou fat-tail sheep (LZFT) population, while there were only two genotypes (ID and DD) in Luxi black-headed sheep (LXBH). Moreover, the Fisher's exact test showed that the 24-bp indel mutation was significantly associated with litter size and live litter size in AuW sheep (Fisher’s p < 0.05). Therefore, the 24-bp indel of sheep AHR gene can contribute to sheep marker-assisted selection breeding and further improve the sheep reproductive performance.

The relationship of hematological parameters with adaptation and reproduction in sheep; A review study

Sheep possess desirable characteristics for farmers such as resistance to disease, good acclimation to environmental fluctuations, and endurance to extreme weather. This may, in part, be due to hematology characteristics and various types of hemoglobin that interact differently to external changes; displaying various reproductive ability in certain environmental conditions. This review aims to investigate the effect of hematology parameters and hemoglobin types on the adaptation and reproductive performance of sheep. Hematological parameters are useful tools for the detection of adaptation and physiological traits of these animals. The reproduction of sheep has depended on the ability of each type and breed to acclimate to different environmental conditions. In addition, hemoglobin types have also been correlated with the environmental adaptability and physiological traits of sheep. Thus, the present review provides useful information on the association of hematology parameters and hemoglobin types in sheep with adaptation and reproductive performance, and could be used as vital tools that help in determining the species or breed of sheep that are more adapted to certain environments or have more reproductive potential.

Pineal gland transcriptomic profiling reveals the differential regulation of lncRNA and mRNA related to prolificacy in STH sheep with two FecB genotypes

BackgroundLong noncoding RNA (lncRNA) has been identified as important regulator in hypothalamic-pituitary-ovarian axis associated with sheep prolificacy. However, little is known of their expression pattern and potential roles in the pineal gland of sheep. Herein, RNA-Seq was used to detect transcriptome expression pattern in pineal gland between follicular phase (FP) and luteal phase (LP) in FecBBB (MM) and FecB++ (ww) STH sheep, respectively, and differentially expressed (DE) lncRNAs and mRNAs associated with reproduction were identified.ResultsOverall, 135 DE lncRNAs and 1360 DE mRNAs in pineal gland between MM and ww sheep were screened. Wherein, 39 DE lncRNAs and 764 DE mRNAs were identified (FP vs LP) in MM sheep, 96 DE lncRNAs and 596 DE mRNAs were identified (FP vs LP) in ww sheep. Moreover, GO and KEGG enrichment analysis indicated that the targets of DE lncRNAs and DE mRNAs were annotated to multiple biological processes such as phototransduction, circadian rhythm, melanogenesis, GSH metabolism and steroid biosynthesis, which directly or indirectly participate in hormone activities to affect sheep reproductive performance. Additionally, co-expression of lncRNAs-mRNAs and the network construction were performed based on correlation analysis, DE lncRNAs can modulate target genes involved in related pathways to affect sheep fecundity. Specifically, XLOC_466330, XLOC_532771, XLOC_028449 targeting RRM2B and GSTK1, XLOC_391199 targeting STMN1, XLOC_503926 targeting RAG2, XLOC_187711 targeting DLG4 were included.ConclusionAll of these differential lncRNAs and mRNAs expression profiles in pineal gland provide a novel resource for elucidating regulatory mechanism underlying STH sheep prolificacy.