Search

BackgroundThe fat tail of sheep is an adaptive trait that facilitates their adaptation to harsh natural environments. MicroRNAs (miRNAs) have been demonstrated to play crucial roles in the regulation of tail fat deposition.MethodsIn this study, miRNA-Seq was employed to investigate the expression profiles of miRNAs during different developmental stages of sheep fat tails and elucidate the functions of differentially expressed miRNAs (DE miRNAs).ResultsA total of 350 DE miRNAs were identified, among which 191, 60, 26, and 21 were significantly upregulated in tail fat tissues of fetal, lamb, hogget Altay sheep, and adult Xinjiang fine wool (XFW) sheep but downregulated in other stages. Furthermore, we predicted a set of candidate target genes (4,476) for the top 20 DE miRNAs. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that they involve in several adipogenesis-related pathways. Subsequent investigations indicated that four DE miRNAs, miR-433-3p, miR-485-3p, miR-409-3p, and miR-495-3p, could suppress the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and phosphoinositide-3-kinase regulatory subunit 3 (PIK3R3) and regulate the preadipocyte development in sheep. Meanwhile, the lipid metabolism-related genes, fatty acid-binding protein (FABP3), perilipin 1 (PLIN1), adiponectin C1Q and collagen domain containing (ADIPOQ), and lipoprotein lipase (LPL), were significantly downregulated (p < 0.01).ConclusionThe expression patterns of miRNAs exhibited significant fluctuations during different development periods of the fat tail, and some of them may participate in the regulation of tail fat deposition by modulating the proliferation and differentiation of preadipocytes.

Abstract Background Ruminant gut microbiota are critical in ecological adaptation, evolution, and nutrition utilization because it regulates energy metabolism, promotes nutrient absorption, and improves immune function. To study the functional roles of key gut microbiota in sheep and goats, it is essential to construct reference microbial gene catalogs and high-quality microbial genomes database. Results A total of 320 fecal samples were collected from 21 different sheep and goat breeds, originating from 32 distinct farms. Metagenomic deep sequencing and binning assembly were utilized to construct a comprehensive microbial genome information database for the gut microbiota. We successfully generated the largest reference gene catalogs for gut microbiota in sheep and goats, containing over 162 million and 82 million nonredundant predicted genes, respectively, with 49 million shared nonredundant predicted genes and 1138 shared species. We found that the rearing environment has a greater impact on microbial composition and function than the host’s species effect. Through subsequent assembly, we obtained 5810 medium- and high-quality metagenome-assembled genomes (MAGs), out of which 2661 were yet unidentified species. Among these MAGs, we identified 91 bacterial taxa that specifically colonize the sheep gut, which encode polysaccharide utilization loci for glycan and mucin degradation. Conclusions By shedding light on the co-symbiotic microbial communities in the gut of small ruminants, our study significantly enhances the understanding of their nutrient degradation and disease susceptibility. Our findings emphasize the vast potential of untapped resources in functional bacterial species within ruminants, further expanding our knowledge of how the ruminant gut microbiota recognizes and processes glycan and mucins. Video Abstract

The objective of current experiment was to study the potential influence of hydrolysable tannin supplementation on slaughter performance, meat quality, intestinal digestive enzyme activity, antioxidant ability and barrier function in fattening lambs. In total, 36 male Hu sheep lambs with similar body weight (15.83 ± 0.48 kg) and days in age (55 ± 2 d) were randomly assigned to one of three groups of 12 animals each: control without tannin (CON) and tannin supplementation groups (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). All the lambs were reared in individual hutches, and the experiment lasted for 60 d. On d 61, 8 lambs from each group were randomly selected to slaughter. Results showed that the serum diamine oxidase and lipopolysaccharide contents of TA2 group were higher (p

Grape seed extract (GSE) has a variety of biological functions. At present, there has been limited information on the utilization of GSE as a feed additive in weaned lambs. The aim of this experiment was to study the potential influence of dietary supplementation with GSE on the growth performance, rumen fermentation characteristics, apparent digestibility, blood parameters and immunity in weaned lambs. In total, 30 male Hu sheep lambs with similar body weight (15.43 ± 0.49 kg) and age (48 ± 2 days) were randomly divided into two treatments: control (CON, fed basal ration) and GSE [fed basal ration and 0.6 g/d GSE (main compositions: proanthocyanidin 50%, catechin 24%, gallic acid 16% and epicatechin 6%) per lamb]. The feeding experiment lasted for 60 d. Results showed that GSE supplementation significantly increased (p = 0.008) the average daily gain of lambs. Compared with CON group, the ruminal propionate and butyrate concentrations were significantly increased (p

Objective The aim of this research was to explore the effects of dietary substitution of alfalfa hay by amaranth hay on production performance, rumen fermentation, nutrient digestibility, serum biochemical parameters and antioxidant ability in dairy cows. Methods A total of 45 healthy Holstein cows with same parity and similar milk yield and body weight were randomly divided into 3 groups: control diet without amaranth hay (CON) or 50% and 100% alfalfa hay replaced by an equal amount of amaranth hay (dry matter basis, AH1 and AH2, respectively). All the cows were fed regularly 3 times a day at 06:30, 14:30, and 22:30 and had free access to water. The experiment lasted for 60 d. Results The dry matter intake of CON and AH1 groups was higher (p

The purpose of the current research was to evaluate the influence of lactic acid bacteria and cellulase supplementation on the chemical composition, fermentation parameters, aerobic stability, microbial count, and in vitro nutrients digestibility of silage prepared with Pennisetum giganteum and rice straw. This study consisted of four treatments: a control group with no additive supplementation (CON), a lactic acid bacteria supplementation group (LAB), a cellulase supplementation group (CEL), and a combined supplementation group (LAC). After ensiling for 60 d, the chemical composition, fermentation parameters, microbial count, and aerobic stability were determined. Additionally, ruminal fermentation characteristics were evaluated by an in vitro incubation technique. Compared with CON silage, the quality of LAB and CEL silages was enhanced to a certain degree. Combined supplementation with lactic acid bacteria and cellulase in mixed silage of Pennisetum giganteum and rice straw noticeably increased (p < 0.05) the dry matter, crude protein, and lactic acid contents, whereas it reduced (p < 0.05) the pH and ammonia nitrogen/total nitrogen as well as the neutral detergent fiber and acid detergent fiber concentrations. The lactic acid bacteria count in LAC silage was higher (p < 0.05) than that of CON silage, whereas an opposite trend of yeast, aerobic bacteria, and mold was observed between the two groups. The aerobic stability time, in vitro crude protein, and neutral detergent fiber digestibility in LAC silage were significantly increased (p < 0.05) compared with those in CON silage. Moreover, the in vitro ruminal ammonia nitrogen content was reduced (p < 0.05), and the microbial protein and propionic acid concentrations were increased (p < 0.05) in silage after combined inoculation with additives. Taken together, the quality of Pennisetum giganteum and rice straw mixed silage can be improved by inoculation with lactic acid bacteria and cellulase, and combined supplementation shows the greatest improvement in silage quality.

Castration is often employed in animal management for reproductive control. However, it is important to evaluate its impact on animal welfare. In this study, we developed rat models for both surgical (n = 6) and GnRH immunocastration (n = 6) to assess the effects of these castration methods on physiological and behavioral characteristics. The novel GnRH-based vaccine significantly increased serum GnRH antibody levels and drastically reduced testosterone, with the testes shrinking to one-fifth the size of those in the control group, thereby halting spermatogenesis at the secondary spermatocyte stage. Behavioral evaluations demonstrated that sexual behavior was significantly suppressed in both surgically and immunologically castrated groups compared to the control, confirming the effectiveness of both methods. However, psychological tests revealed significant signs of depression and social deficits in the surgically castrated group, whereas the behavior of the GnRH-immunocastrated group did not significantly differ from the control. Furthermore, no significant differences in learning and memory were observed among the three groups in the water maze test. Compared to surgical castration, GnRH immunocastration offers effective results and better animal welfare, providing a more humane alternative for livestock management.

This experiment aimed to study the effects of tannin supplementation on growth performance, rumen fermentation characteristics, apparent digestibility and serum biochemistry, and antioxidant and immune indexes in fattening lambs. A total of 36 male Hu sheep lambs (body weight = 15.83 ± 0.48 kg and days of age = 55 ± 2 d) were fed a high-concentrate diet and randomly divided into one of three groups of 12 animals each: control with no tannin (CON) and tannin treatments (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). The feeding experiment lasted for 60 d. The results showed that the average daily gain and ruminal propionate content of lambs in the TA1 group were higher (p < 0.05) than those in the CON group. Lambs fed tannin had significantly increased (p < 0.05) microbial protein and decreased (p < 0.05) ammonia nitrogen concentrations in the rumen. In addition, the crude protein and neutral detergent fiber digestibility of the TA2 group were significantly decreased (p < 0.05) as compared with the TA1 and CON groups, respectively. The serum concentrations of triglyceride, immunoglobulin A, and catalase and the total antioxidant capacity were higher (p < 0.05) in the TA1 group that those in the CON group, whereas an opposite trend of urea nitrogen, interleukin-1β, and malondialdehyde was found between the two groups. Also, tannin supplementation increased (p < 0.05) Lactobacillus and decreased (p < 0.05) Salmonella counts in the feces of lambs. Taken together, tannin supplementation can improve the growth performance, immunity, and antioxidant ability of fattening lambs fed a high-concentrate diet.

IntroductionThe purpose of this study was to explore the effects of tea polyphenols on growth performance, cytokine content, intestinal antioxidant status and intestinal barrier function of lambs, in order to provide reference for intestinal health of ruminants.MethodsThirty weaned lambs (average initial weight 9.32 ± 1.72 kg) were randomly divided into five groups with six lambs in each group. The control group did not add anything but the basic diet mainly composed of Pennisetum and Corn, and the other four groups added 2, 4, 6 g/kg tea polyphenols and 50 mg/kg chlortetracycline to the basic diet, respectively. The experiment lasted for 42 days.ResultsDietary tea polyphenols improved the growth and stress response and reduced intestinal permeability of lambs (p > 0.05), while CTC did not affect the final lamb weight (p > 0.05). Both tea phenols and CTC significantly reduced inflammatory factors and enhanced the immune system (p > 0.05). Dietary tea polyphenols increased villus height, villus height/crypt depth, secretory immunoglobulin A (p > 0.05), and antioxidant enzymes, while decreasing MDA and apoptosis in the intestine (p > 0.05). However, compared with other groups, the content of T-AOC in jejunum did not change significantly (p > 0.05). Tea polyphenols also increased claudin-1 levels in the duodenum, jejunum, and ileum more than CTC (p > 0.05). CTC had a limited effect on the mRNA expression of Occludin and ZO-1, while tea polyphenols increased these in both the duodenum and ileum (p > 0.05).ConclusionThis study demonstrated that tea polyphenols can effectively improve the intestinal barrier of weaned lambs, and that they have anti-inflammatory and antioxidant effects similar to those of antibiotics. Thus, tea polyphenols could be used to replace antibiotics in ensuring safety of livestock products and in achieving the sustainable development of modern animal husbandry.

AOS alleviates inflammatory responses; however, whether it exerts an effect on the rumen or regulates rumen inflammatory reaction remains unknown. In this study, firstly, the ovine ruminal epithelial cells (ORECs) were treated with 0, 200, 400, 600, and 800 µg/mL AOS, hoping to explore whether AOS hurt cell health. The results showed that compared with the AOS-0 group, the AOS-400 group could significantly increase (p < 0.05) cell viability, reduce (p < 0.05) reactive oxygen species (ROS) and interleukin (IL)-6 content, and have no adverse effect on cells. Secondly, we used LPS to construct an in vitro inflammatory model of rumen epithelial cells and then explored the protective role of AOS on rumen epithelial cells. The study was divided into three groups: the control group (CON), LPS, and LPS + AOS. The results demonstrated that the LPS + AOS group significantly increased the cell viability and reduced the ROS level in comparison with the LPS group (p < 0.05). Pretreatment with AOS also repressed (p < 0.05) the secretion of IL-1β, IL-6, IL-8, and immunoglobulin (Ig)A from ORECs in the culture medium following LPS. In terms of tight junction (TJ) proteins, AOS treatment also significantly increased (p < 0.05) the zonula occludens 1 (ZO-1) and Occludin expression. The apoptosis rate, Caspase3, Caspase9, BAD, and BCL-2/BAX were decreased (p < 0.05) after AOS treatment, and the expression of BCL-2 was increased (p < 0.05). In addition, the expressions of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and nuclear factor-κB (NF-κB) were inhibited (p < 0.05) with the addition of AOS. At the protein level, pretreatment of AOS decreased (p < 0.05) the expression of MyD88 and the phosphorylation level of inhibitor κB α (IκBα) after the LPS challenge. Taken together, our results indicated that AOS could alleviate the LPS-induced apoptosis and inflammatory response of rumen epithelial cells through the NF-κB signaling pathway, which may be a promising strategy for treating apoptosis and inflammation in sheep breeding.

The objective of this research was to investigate effects of different additives on the fermentation quality, aerobic stability and rumen degradation of mixed silage composed of amaranth and corn straw. The mixture ratio of amaranth to corn straw was 78%: 22%. Three additives were selected in this study and five groups were as follows: control group (CON, without additive), lactic acid bacteria group (LAB, 5 mg/kg, Lactobacillus plantarum ≥ 1.6×1010 CFU/g and L. buchneri ≥ 4.0×109 CFU/g), glucose group (GLU, 30 g/kg), cellulase group (CEL, 2 mg/kg) and lactic acid bacteria, glucose and cellulase group (LGC, added at the same levels as in individual group). The period of ensiling was 60 days. Fermentation quality, chemical composition and aerobic stability of mixed silage were analyzed. Four cows with permanent ruminal fistula were selected as experimental animals. Nylon bag technique was used to study rumen degradation characteristic of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of mixed silage. Compared with CON group, the addition of different silage additives could improve mixed silage quality of amaranth and corn straw to some extent. Combining three additives significantly increased (P < 0.05) the DM, CP and lactic acid contents, whereas decreased (P < 0.05) the ADF and NDF contents as well as pH and ammonia nitrogen/total nitrogen. Moreover, the aerobic stability and rumen degradation of DM, CP and NDF were significantly improved (P < 0.05) in LGC group when compared to other groups. In conclusion, the combined addition of lactic acid bacteria, glucose and cellulase increased DM, CP and lactic acid contents as well as lactic acid bacteria count, decreased NDF and ADF contents and aerobic bacteria and mold counts, improved aerobic stability and rumen degradation of amaranth and corn straw mixed silage.

The aim of this experiment is to investigate the effects of lactic acid bacteria and cellulase on the fermentation quality, chemical composition, aerobic stability and ruminal degradation characteristics of mixed silage prepared with amaranth and rice straw. Lactic acid bacteria and cellulase were used as silage additives, and the four treatments were as follows: control group (CON, no additive), lactic acid bacteria group (LAB, additive amount was 5 mg/kg fresh matter), cellulase group (CEL, 2 mg/kg) and lactic acid bacteria and cellulase group (LBC, additive amount was the same as in the individual treatments). All treatments were ensiled for 60 days. The dry-matter, crude-protein, neutral-detergent-fiber and acid-detergent-fiber ruminal degradability of silage were analyzed utilizing the nylon bag method. Compared with the CON group, the inoculation of lactic acid bacteria and cellulase individually promoted the fermentation of mixed silage to a certain degree. The combined inoculation of mixed silage significantly increased (p < 0.05) the concentrations of lactic acid and dry matter, while it reduced (p < 0.05) the pH and ammonia nitrogen/total nitrogen, harmful microorganism counts and contents of acetic acid, neutral detergent fiber and acid detergent fiber. In addition, the aerobic stability time of the LBC group was lower (p < 0.05) than that of the other groups. The ruminal degradation rate of dry matter, crude protein, neutral detergent fiber and acid detergent fiber in the LBC group was significantly increased (p < 0.05) compared to the CON group. Overall, the addition of the additives mentioned earlier improved the quality of mixed silage composed of amaranth and rice straw, and the best results were obtained by combining the inoculation of lactic acid bacteria and cellulase.

This paper explores the effects of fucoidan on the frequency of diarrhea, colon morphology, colon antioxidant status, cytokine content, short-chain fatty acids, and microflora of cecal contents in early weaned lambs in order to provide a reference for the intestinal health of young ruminants. Fucoidan is a natural active polysaccharide extracted from kelp and other large brown algae. It has many biological effects, such as improving immunity, nourishing the stomach and intestines, and anti-tumor properties. This study investigated the effects of fucoidan supplementation in milk replacer on the large intestine's ability to act as an intestinal barrier in weaned lambs. With six duplicate pens and one lamb per pen, a total of 24 weaned lambs (average starting body weight of 7.32 ± 0.37 kg) were randomly assigned to one of four milk replacer treatments. Four concentrations of fucoidan supplementation (0, 0.1, 0.3, and 0.6% dry matter intake) were employed to investigate the effects of fucoidan on cecal fermentation and colon microbial organization. The test period lasted 37 days (1 week before the test and 1 month after the test), and lamb cecal contents and colon organization were collected for examination. In addition, the fecal status of all lambs was observed and recorded daily, allowing us to calculate the incidence of diarrhea in weaned lambs. The findings demonstrated that fucoidan may significantly increase the concentration of short-chain fatty acids (propionic acid and butyric acid) in the cecal digesta of weaned lambs. In weaned lambs, 16S rDNA testing showed that fucoidan at 0.3–0.6% (dry matter intake) was beneficial for boosting the variety of the intestinal bacteria and modifying the relative abundance of a few bacterial strains. In addition, fucoidan enhanced colon antioxidant and immune functions and decreased the diarrhea rate to relieve weaning stress. This result demonstrates that milk replacer supplementation with fucoidan contributes to the improvement in the large intestinal health of weaned lambs.

The purpose of this research was to evaluate effects of grape seed extract (Gse) supplementation on the growth performance; ruminal fermentation; nutrient digestibility; and serum biochemical, antioxidative, and immune parameters of weaned beef calves. A total of 30 Simmental crossbred male calves with similar age and body weight were randomly allocated to two groups: a control group with no Gse (CON) and a Gse supplementation group (GSE) (4 g/d Gse per animal). The results show that, compared with the CON group, the average daily gain significantly increased (p = 0.043) in the GSE group. The ruminal contents of microbial protein and butyrate in GSE group were higher (p < 0.05) than those in the CON group. Additionally, calves fed Gse displayed increased (p < 0.05) dry matter and neutral detergent fiber digestibility. Moreover, the serum concentrations of triglyceride, catalase, superoxide dismutase, immunoglobulin G and immunoglobulin M were higher (p < 0.05) in the GSE group than those in the CON group. However, opposite tendencies of non-esterified fatty acid, malondialdehyde, tumor necrosis factor-α and interleukin-6 were found between the two groups. Overall, the supplementation of Gse can improve ruminal fermentation, nutrient digestibility, antioxidant ability, and immunity, as well as promoting the healthy growth of weaned cross-breed beef calves.

Intense artificial selection has been imposed to Luzhong mutton sheep population in the past years. Improvements on growth and reproductive performance are two breeding goals in the present herd. Although some progresses were phenotypically observed possibly due to inbreeding induced by strong selection in terms of these traits, the genomic evaluation was poorly understood. Therefore, a high-density SNP array was used to characterize the pattern of runs of homozygosity (ROH), estimate inbreeding and inbreeding depressions on early growth performance and litter size based upon ROH, and scan positive selection signatures of recent population. Consequently, a low inbreeding level was observed which had negative effects on litter size, but not on early growth performance. And 160 genes were under selection, of which some were reported to be linked to several traits of sheep including body weight, litter size, carcass and meat quality, milk yield and composition, fiber quality and health, and the top genes were associated with growth (growth hormone [GH]- growth hormone receptor [GHR]- Insulin-like growth factor 1 [IGF1] axis) and litter size (bone morphogenic proteins [BMPs]-associated). The effectiveness of previous breeding measures was highlighted, but purging selection was proposed to alleviate the inbreeding depression on litter size, providing some genomic insights to breeding management of Luzhong mutton sheep.

Abstract Background Long non-coding RNAs (lncRNAs) can play important roles in uterine and ovarian functions. However, little researches have been done on the role of lncRNAs in the adrenal gland of sheep. Herein, RNA sequencing was used to compare and analyze gene expressions in adrenal tissues between follicular phases and luteal phases in FecB BB (MM) and FecB ++ (WW) sheep, respectively, and differentially expressed lncRNAs and genes associated with reproduction were identified. Results In MM sheep, 38 lncRNAs and 545 mRNAs were differentially expressed in the adrenal gland between the luteal and follicular phases; In WW sheep, 513 differentially expressed lncRNAs and 2481 mRNAs were identified. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses indicated that differentially expressed lncRNAs and their target genes are mainly involved in the circadian rhythm, the mitogen activated protein kinase, thyroid, ovarian steroidogenesis and transforming growth factor beta signaling pathways. Differentially expressed lncRNAs can regulate reproduction by modulating genes involved in these signaling pathways and biological processes. Specifically, XLOC_254761, XLOC_357966, 105,614,839 and XLOC_212877 targeting CREB1, PER3, SMAD1 and TGFBR2, respectively, appear to play key regulatory roles. Conclusion These results broaden our understanding of lncRNAs in adrenal gland of sheep and provide new insights into the molecular mechanisms underlying sheep reproduction.

Fat tail in sheep presents a valuable energy reserve that has historically facilitated adaptation to harsh environments. However, in modern intensive and semi-intensive sheep industry systems, breeds with leaner tails are more desirable. In the present study, RNA sequencing (RNA-Seq) was applied to determine the transcriptome profiles of tail fat tissues in two Chinese sheep breeds, fat-rumped Altay sheep and thin-tailed Xinjiang fine wool (XFW) sheep, with extreme fat tail phenotype difference. Then the differentially expressed genes (DEGs) and their sequence variations were further analyzed. In total, 21,527 genes were detected, among which 3,965 displayed significant expression variations in tail fat tissues of the two sheep breeds (P < 0.05), including 707 upregulated and 3,258 downregulated genes. Gene Ontology (GO) analysis disclosed that 198 DEGs were related to fat metabolism. In Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, the majority of DEGs were significantly enriched in “adipocytokine signaling,” “PPAR signaling,” and “metabolic pathways” (P < 0.05); moreover, some genes were involved in multiple pathways. Among the 198 DEGs, 22 genes were markedly up- or downregulated in tail fat tissue of Altay sheep, indicating that these genes might be closely related to the fat tail trait of this breed. A total of 41,724 and 42,193 SNPs were detected in the transcriptomic data of tail fat tissues obtained from Altay and XFW sheep, respectively. The distribution of seven SNPs in the coding regions of the 22 candidate genes was further investigated in populations of three sheep breeds with distinct tail phenotypes. In particular, the g.18167532T/C (Oar_v3.1) mutation of the ATP-binding cassette transporter A1 (ABCA1) gene and g.57036072G/T (Oar_v3.1) mutation of the solute carrier family 27 member 2 (SLC27A2) gene showed significantly different distributions and were closely associated with tail phenotype (P < 0.05). The present study provides transcriptomic evidence explaining the differences in fat- and thin-tailed sheep breeds and reveals numerous DEGs and SNPs associated with tail phenotype. Our data provide a valuable theoretical basis for selection of lean-tailed sheep breeds.

The pituitary is a vital endocrine organ that regulates animal seasonal reproduction by controlling the synthesis and secretion of the hormone. The change of photoperiod is the key factor affecting the function of the pituitary in animals, but the mechanism is unclear. Here, we studied the transcriptomic variation in pars distalis (PD) of the pituitary between short photoperiod (SP) and long photoperiod (LP) using RNA sequencing based on the OVX+E2 sheep. 346 differentially expressed (DE) lncRNAs and 186 DE-mRNA were found in the PD. Moreover, function annotation analysis indicated that the reproductive hormones and photoperiod response-related pathways including aldosterone synthesis and secretion, insulin secretion, thyroid hormone synthesis, and circadian entrainment were enriched. The interaction analysis of mRNA-lncRNA suggested that MSTRG.240648, MSTRG.85500, MSTRG.32448, and MSTRG.304959 targeted CREB3L1 and DUSP6, which may be involved in the photoperiodic regulation of the PD. These findings provide resources for further study on the seasonal reproductive in ewes.

Circular RNAs (circRNAs) are highly enriched in the central nervous system and significantly involved in a range of brain-related physiological and pathological processes. Ischemic stroke is a complex disorder caused by multiple factors; however, whether brain-derived circRNAs participate in the complex regulatory networks involved in stroke pathogenesis remains unknown. Here, we successfully constructed a cerebral ischemia-injury model of middle cerebral artery occlusion (MCAO) in male Sprague-Dawley rats. Preliminary qualitative and quantitative analyses of poststroke cortical circRNAs were performed through deep sequencing, and RT-PCR and qRT-PCR were used for validation. Of the 24,858 circRNAs expressed in the rat cerebral cortex, 294 circRNAs were differentially expressed in the ipsilateral cerebral cortex between the MCAO and sham rat groups. Cluster, GO, and KEGG analyses showed enrichments of these circRNAs and their host genes in numerous biological processes and pathways closely related to stroke. We selected 106 of the 294 circRNAs and constructed a circRNA-miRNA-mRNA interaction network comprising 577 sponge miRNAs and 696 target mRNAs. In total, 15 key potential circRNAs were predicted to be involved in the posttranscriptional regulation of a series of downstream target genes, which are widely implicated in poststroke processes, such as oxidative stress, apoptosis, inflammatory response, and nerve regeneration, through the competing endogenous RNA mechanism. Thus, circRNAs appear to be involved in multilevel actions that regulate the vast network of multiple mechanisms and events that occur after a stroke. These results provide novel insights into the complex pathophysiological mechanisms of stroke.

Early studies have provided a wealth of information on the functions of microRNAs (miRNAs). However, less is known regarding their functions in the hypothalamus involved in sheep reproduction. To explore the potential roles of hypothalamic messenger RNAs (mRNAs) and miRNAs in sheep without FecB mutation, in total, 172 and 235 differentially expressed genes (DEGs) and 42 and 79 differentially expressed miRNAs (DE miRNAs) were identified in polytocous sheep in the follicular phase versus monotocous sheep in the follicular phase (PF vs. MF) and polytocous sheep in the luteal phase versus monotocous sheep in the luteal phase (PL vs. ML), respectively, using RNA sequencing. We also identified several key mRNAs (e.g., POMC, GNRH1, PRL, GH, TRH, and TTR) and mRNA–miRNAs pairs (e.g., TRH co-regulated by oar-miR-379-5p, oar-miR-30b, oar-miR-152, oar-miR-495-3p, oar-miR-143, oar-miR-106b, oar-miR-218a, oar-miR-148a, and PRL regulated by oar-miR-432) through functional enrichment analysis, and the identified mRNAs and miRNAs may function, conceivably, by influencing gonadotropin-releasing hormone (GnRH) activities and nerve cell survival associated with reproductive hormone release via direct and indirect ways. This study represents an integral analysis between mRNAs and miRNAs in sheep hypothalamus and provides a valuable resource for elucidating sheep prolificacy.

Bamei mutton sheep is a Chinese domestic sheep breed developed by crossing German Mutton Merino sheep and indigenous Mongolian sheep for meat production. Here, we focused on detecting candidate genes associated with the increasing of the litter size in this breeds under recent artificial selection to improve the efficiency of mutton production. We selected five high- and five low-fecundity Bamei mutton sheep for whole-genome resequencing to identify candidate genes for sheep prolificacy. We used the FST and XP-EHH statistical approach to detect the selective sweeps between these two groups. Combining the two selective sweep methods, the reproduction-related genes JUN, ITPR3, PLCB2, HERC5, and KDM4B were detected. JUN, ITPR3, and PLCB2 play vital roles in GnRH (gonadotropin-releasing hormone), oxytocin, and estrogen signaling pathway. Moreover, KDM4B, which had the highest FST value, exhibits demethylase activity. It can affect reproduction by binding the promoters of estrogen-regulated genes, such as FOXA1 (forkhead box A1) and ESR1 (estrogen receptor 1). Notably, one nonsynonymous mutation (p.S936A) specific to the high-prolificacy group was identified at the TUDOR domain of KDM4B. These observations provide a new opportunity to research the genetic variation influencing fecundity traits within a population evolving under artificial selection. The identified genomic regions that are responsible for litter size can in turn be used for further selection.

Rumen microbiota are essential for maintaining digestive and metabolic functions, producing methane as a byproduct. Dairy heifers produce large amounts of methane based on fermentation of digested organic matter, with adverse consequences for feed efficiency and the environment. It is therefore important to understand the influence of host age on the relationship between microbiota and methane production. This study explored the age effect on the relationship between microbial communities and enteric methane production in dairy cows and heifers using high-throughput sequencing. Methane production and volatile fatty acid concentrations were age-related. Heifers (9–10 months) had lower methane production but higher methane production per dry matter intake (DMI). The acetate:propionate ratio decreased significantly with increasing age. Age-related microbiota changes in the rumen were reflected by a significant shift in bacterial taxa, but relatively stable archaeal taxa. Prevotella, Ruminococcus, Flavonifractor, Succinivibrio, and Methanobrevibacter were affected by age. This study revealed different associations between predominant bacterial phylotypes and Methanobrevibacter with increasing age. Prevotella was strongly correlated with Methanobrevibacter in heifers; howerver, in older cows (96–120 months) this association was replaced by a correlation between Succinivibrio and Methanobrevibacter. This shift may account for the age-related difference in rumen fermentation and methane production per DMI.

Circular RNA (circRNA), as an emerging class of noncoding RNA, has been found to play key roles in many biological processes. However, its expression profile in the hypothalamus, a powerful organ initiating the reproductive process, has not yet been explored. Therefore, we used RNA sequencing to explore the expression of circRNAs in the hypothalamus of sheep with the FecB ++ genotype. We totally identified 41,863 circRNAs from sheep hypothalamus, in which 333 (162 were upregulated, while 171 were downregulated) were differentially expressed in polytocous sheep in the follicular phase versus monotocous sheep in the follicular phase (PF vs. MF), moreover, 340 circRNAs (163 were upregulated, while 177 were downregulated) were differentially expressed in polytocous sheep in the luteal phase versus monotocous sheep in the luteal sheep (PL vs. ML). We also identified several key circRNAs including oar_circ_0018794, oar_circ_0008291, oar_circ_0015119, oar_circ_0012801, oar_circ_0010234, and oar_circ_0013788 through functional enrichment analysis and oar_circ_0012110 through a competing endogenous RNA network, most of which may participate in reproduction by influencing gonadotropin-releasing hormone (GnRH) activities or affecting key gene expression, indirectly or directly. Our study explored the overall expression profile of circRNAs in sheep hypothalamus, which potentially provides an alternative insight into the mechanism of sheep prolificacy without the effects of FecB mutation.

The diverse functions of long noncoding RNAs (lncRNAs), which execute their functions mainly through modulating the activities of their target genes, have been have been widely studied for many years (including a number of studies involving lncRNAs in the ovary and uterus). Herein, for the first time, we detect lncRNAs in sheep hypothalami with FecB++ through RNA Sequencing (RNA-Seq) and identify a number of known and novel lncRNAs, with 622 and 809 found to be differentially expressed in polytocous sheep in the follicular phase (PF) vs. monotocous sheep in the follicular phase (MF) and polytocous sheep in the luteal phase (PL) vs. monotocous sheep in the luteal phase (ML), respectively. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed based on the predicted target genes. The most highly enriched GO terms (at the molecular function level) included carbonyl reductase (NADPH), 15-hydroxyprostaglandin dehydrogenase (NADP+), and prostaglandin-E2 9-reductase activity in PF vs. MF, and phosphatidylinositol-3,5-bisphosphate binding in PL vs. ML was associated with sheep fecundity. Interestingly, the phenomena of valine, leucine, and isoleucine degradation in PL vs. ML, and valine, leucine, and isoleucine biosynthesis in PF vs. MF, were present. In addition, the interactome of lncRNA and its targets showed that MSTRG.26777 and its cis-targets ENSOARG00000013744, ENSOARG00000013700, and ENSOARG00000013777, and MSTRG.105228 and its target WNT7A may participate in the sheep reproductive process at the hypothalamus level. Significantly, MSTRG.95128 and its cis-target Forkhead box L1 (FOXG1) were shown to be upregulated in PF vs. MF but downregulated in PL vs. ML. All of these results may be attributed to discoveries of new candidate genes and pathways related to sheep reproduction, and they may provide new views for understanding sheep reproduction without the effects of the FecB mutation.

MicroRNAs (miRNAs) are key regulators in miRNA-mediated gene regulatory networks and play important roles in many biological processes, such as growth and development of mammals. In this study, we used microarrays to detect 261 miRNAs that are expressed in sheep skeletal muscle. We found 22 miRNAs that showed high levels of expression and equated to 89% of the total miRNA. Genetic variations in these 22 pri-miRNAs were further investigated using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and sequencing. A total of 49 genetic variations, which included 41 single nucleotide polymorphisms (SNPs) and 8 deletions/insertions, were identified in four sheep breeds. Three variations were further researched in a larger sample set, including five sheep breeds with different meat production performances. We found that the genotype and allele frequencies of the CCC deletion/insertion in pri-miR-133a were significantly related to the sheep meat production trait. Finally, cell assays and quantitative reverse transcription PCR (qRT-PCR) were employed to investigate the effect of pri-miRNA genetic variation on the miRNA biogenesis process. The results confirmed that genetic variations can influence miRNA biogenesis and increase or decrease the levels of mature miRNAs, in accordance with the energy and stability change of hair-pin secondary structures. Our findings will help to further the understanding of the functions of genetic variations in sheep pri-miRNAs in skeletal muscle growth and development.

To elucidate the tissue expression levels of BMPR1B, BMP15, GDF9, Smad1, Smad5, and Smad9 genes in rams with different fecundity, quantitative real-time polymerase chain reaction was used to investigate the expression level of six genes in the brain, cerebellum, hypothalamus, pituitary, testis, epididymis, vas deferens, and adrenal gland in high fecundity (Small Tail Han sheep) and low fecundity (Sunite sheep) rams. The results were as follows: BMPR1B, GDF9, Smad1, Smad5 and Smad9 were expressed in all selected tissues, but BMP15 was specifically expressed in the epididymis. Further study indicated that the expression of BMPRIB in the brain, hypothalamus, pituitary, epididymis, and adrenal gland was significantly higher in Sunite sheep than in Small Tail Han sheep (p < 0.05, p < 0.01); the expression of BMP15 in the epididymis was significantly higher in Sunite sheep than in Small Tail Han sheep (p < 0.01); the expression of GDF9 in the cerebellum and vas deferens was significantly higher in Small Tail Han sheep than in Sunite sheep (p < 0.05); the expression of GDF9 in the adrenal gland was significantly higher in Sunite sheep than in Small Tail Han sheep (p < 0.01); the expression of Smad1 in the brain and adrenal gland was significantly higher in Small Tail Han sheep than in Sunite sheep (p < 0.05); the expression of Smad1 in vas deferens was significantly higher in Sunite sheep than in Small Tail Han sheep (p < 0.01); the expression of Smad5 in the adrenal gland was significantly higher in Small Tail Han sheep than in Sunite sheep (p < 0.05); the expression of Smad9 in the brain and epididymis was significantly higher in Sunite sheep than in Small Tail Han sheep (p < 0.05, p < 0.01); and the expression of Smad9 in the cerebellum and hypothalamus was significantly higher in Small Tail Han sheep than in Sunite sheep (p < 0.05). This is the first study to systematically analyze the BMPR1B, BMP15, GDF9, Smad1, Smad5, and Smad9 genes’ tissue expression pattern in rams. [ABSTRACT FROM AUTHOR]