Litter size is a considerable quality that determines the production efficiency of mutton sheep. Therefore, revealing the molecular regulation of high and low fertility may aid the breeding process to develop new varieties of mutton sheep. CircRNAs are the important factors regulating follicular development, but their mechanism role in the regulation of litter size in Hanper sheep is not clear. In the present study, ovarian tissues from the follicular (F) or luteal phase (L) of Hanper sheep that were either consecutive monotocous (M) or polytocous were collected. Then, we performed transcriptome sequencing to screen for differentially expressed circRNAs (DE-circRNAs) and elucidate their function. In total, 4256 circRNA derived from 2184 host genes were identified in which 183 (146 were upregulated, while 37 were downregulated) were differentially expressed in monotocous sheep in the follicular phase versus polytocous sheep in the follicular phase (MF vs. PF). Moreover, 34 circRNAs (14 were upregulated, while 20 were downregulated) were differentially expressed in monotocous sheep in the luteal phase versus polytocous sheep in the luteal sheep (ML vs. PL). This was achieved through DE-circRNAs function enrichment annotation analysis by GESA, GO, and KEGG, which function through the EGF-EGFR-RAS-JNK, TGF-β and thyroid hormone signaling pathway to affect the litter size of Hanper sheep in MF vs. PF and ML vs. PL. STEM results showed that MAPK signaling pathways play a key role in MF vs. PF and ML vs. PL. Through WGCNA analysis, AKT3 was a core gene in MF vs. PF and ML vs. PL. Moreover, competitive endogenous RNA (ceRNA) network analysis revealed the target binding sites for miRNA such as oar-miR-27a, oar-miR-16b, oar-miR-200a/b/c, oar-miR-181a, oar-miR-10a/b, and oar-miR-432 in the identified DE-cirRNAs.

As the byproduct of finger millet, millet straw is a new forage resource of ruminants. The effect of the combined utilization of millet straw with corn straw on fattening lamb production is seldom reported. The purpose of this study was to investigate the effect of different proportions of millet straw instead of corn straw on the growth performance, blood metabolites, immune response, meat yield, and quality of fattening lamb. Sixty-three-month-old healthy Small-Tailed Han sheep crossbred rams with an average initial weight of 19.28 ± 2.95 kg were randomly divided into four groups, with three replicates in each group and five lambs in each replicate. The replacement ratio of millet straw of each group (Group I, II, III, IV) was 0%, 25%, 35%, 50% at the first stage (the first two months) and 0%, 20%, 28%, 40% in the second period (final two months), respectively. The experiment lasted 4 months 10 days of the pre-feeding period. The results indicated that the body weight gain and average daily gain of group Ⅱ were significantly higher than those of group Ⅰ and group Ⅳ (p < 0.05). The concentration of total protein in group Ⅳ was significantly increased compared to those of the other three groups at the second stage (p < 0.05), which proved that the protein synthesis metabolism capacity was improved with the addition of millet straw. The concentration of the plasma glutamic-oxalacetic transaminase and lactic dehydrogenase of lambs was significantly decreased in group Ⅱ (p < 0.05). The combination of millet straw and corn straw had no impact on the glucose, total cholesterol, and triglycerides metabolism (p > 0.05). There was no significant difference in the pre-slaughter weight, carcass weight, dressing percentage, loin-eye area, and GR value among the four groups (p > 0.05). Furthermore, the immune response and meat quality were not impacted by the different proportions of millet and corn forage diets. The results showed that the combined utilization of millet straw with corn straw could improve the blood biochemistry metabolism capability of fattening lambs. The replacement of 50% of corn straw with millet straw could improve the growth performance and be an application in fattening lamb production.

Sheep litter size is a critical trait in mutton production. While litter size regulation in relation to DNA transcription have been rigorously investigated, the function of RNA editing remains less explored. To elucidate the mechanisms controlling sheep fecundity at the RNA editing level and identify pivotal RNA editing sites, this study scrutinised RNA editing sites (RESs) in follicular and luteal phases of ovaries from sheep with high and low fecundity, and the functions of population-specific RESs were subsequently analysed. A total of 2 182 475 RESs, 74.61% of which were A-to-I and C-to-U sites, were identified. These RESs were fairly evenly dispersed over the chromosomes, with 46.8% showing close clustering (inter-site distance < 300 bp). Notably, 93% were primarily situated in intronic and intergenic regions. In the follicular phase, pivotal RESs were found in the introns of genes including LPS responsive beige-like anchor, MCC regulator of Wnt signalling, and RWD domain containing 3, among others, and in the exon region of EvC ciliary complex subunit 2. In the luteal phase, RESs were observed in the introns of genes such as H/ACA ribonucleoprotein assembly factor and SDA1 domain-containing 1, and the exon and 3'UTR regions of polypeptide N-acetylgalactosaminyltransferase 15 and ilvB acetolactate synthase-like, respectively. High-fecundity sheep showed RESs in the follicular phase in genes such as fibrillin 1, cyclin-dependent kinase 6, and roundabout 1, and in genes such as autophagy-related 2B and versican in the luteal phase. Thirteen RESs specific to the follicular phase and eight specific to the luteal phase were identified in high-fecundity sheep ovaries. These RESs offer promising molecular targets and enhance understanding of multiple births in sheep from the perspective of posttranscriptional alterations.

Serving as a mineral-derived dietary buffer, the alkaline mineral complex (AMC) has the potential to influence the physiological functions of animals. Nonetheless, there is a notable scarcity of research in the field of ruminant science regarding its effects on fattening lambs. Therefore, the purpose of the present study was to investigate the effects of AMC supplementation on the growth performance, meat quality, serum biochemical parameters, and digestive function of fattening lambs. A total of 96 six-month-old male Small-Tailed Han lambs with an average body weight of 48 ± 3.85 kg were randomly assigned to four groups: the control group (CON, 0 g/d per lamb of AMC), test group 1 (LAMC, 2 g/d per lamb of AMC), test group 2 (MAMC, 3 g/d per lamb of AMC), and test group 3 (HAMC, 4 g/d per lamb of AMC). Each group contained 24 lambs, with 3 pens per group and 8 lambs per pen. The trial lasted for 45 days, and the results showed that, compared with the CON group, the MAMC group demonstrated a significantly enhanced average daily gain (ADG) with a reduced feed conversion ratio (FCR) (p < 0.05). The redness (a*) of the meat in the AMC-treated groups was significantly greater than that of the CON group (p < 0.05). The intramuscular fat (IMF) content in the longissimus dorsi (LD) of the MAMC group was significantly increased compared to the CON group (p < 0.05). The low-density lipoprotein (LDL) and total cholesterol (TC) levels in the HAMC group were greater than those of other groups (p < 0.01), and the superoxide dismutase (SOD) content was higher in the AMC-treated groups compared to the CON group (p < 0.05). In addition, the duodenum lipase content in the HAMC group was significantly lower than that in the CON group (p < 0.05), and the amylase content in the MAMC group was significantly higher than that of the CON group (p < 0.05). The HAMC group had a significantly lower jejunum lipase content than those in the other groups (p < 0.05). The LEfSe analysis showed that the MAMC group possessed significantly increased g_Prevotellaceae_Ga6A1_group levels. Furthermore, SOD and catalase (CAT) were both positively correlated with meat redness (a*) but were not significantly associated with ADG. In contrast, malondialdehyde (MDA) was negatively correlated with ADG, while no significant relationship was observed for meat redness (a*). In conclusion, an appropriate supplementation of AMC (3 g/d per lamb) can improve growth performance and meat quality by enhancing the antioxidant capacity and modulating the composition of beneficial rumen bacteria.