Identification of functional circRNAs regulating ovarian follicle development in goats.

BARKGROUND: Circular RNAs (circRNAs) play important regulatory roles in a variety of biological processes in mammals. Multiple birth-traits in goats are affected by several factors, but the expression and function of circRNAs in follicular development of goats are not clear. In this study, we aimed to investigate the possible regulatory mechanisms of circRNA and collected five groups of large follicles (Follicle diameter > 6 mm) and small follicles (1 mm < Follicle diameter < 3 mm) from Leizhou goats in estrus for RNA sequencing. RESULTS: RNA sequencing showed that 152 circRNAs were differentially expressed in small and large follicles. Among them, 101 circRNAs were up-regulated in large follicles and 51 circRNAs were up-regulated in small follicles. GO and KEGG enrichment analyses showed that parental genes of the differential circRNAs were significantly enriched in important pathways, such as ovarian steroidogenesis, GnRH signaling pathway, animal autophagy and oxytocin signalling pathway. BioSignal analysis revealed that 152 differentially expressed circRNAs could target 91 differential miRNAs including miR-101 family (chi-miR-101-3p, chi-miR-101-5p), miR-202 family (chi-miR-202-5p, chi-miR-202-3p),60 circRNAs with translation potential. Based on the predicted sequencing results, the ceRNA networks chicirc_008762/chi-miR-338-3p/ARHGAP18 and chicirc_040444/chi-miR-338-3p/STAR were constructed in this study. Importantly, the new gene circCFAP20DC was first discovered in goats. The EDU assay and flow cytometry results indicated that circCFAP20DC enhanced the proliferation of follicular granulosa cells(GCs). Real-time quantitative PCR and western blotting assays showed that circCFAP20DC activated the Retinoblastoma(RB) pathway and promoted the progression of granulosa cells from G1 to S phase. CONCLUSION: Differential circRNAs in goat size follicles may have important biological functions for follicular development. The novel gene circCFAP20DC activates the RB pathway, promoting the progression of GCs from G1 to S phase. This, in turn, enhances the proliferation of follicular GCs in goats.

Selection and Regulatory Network Analysis of Differential CircRNAs in the Hypothalamus of Goats with High and Low Reproductive Capacity.

The objectives of this investigation were to identify differentially expressed circular RNAs (circRNAs) in the hypothalamus of goats with high and low prolificacy and construct a circRNA-mRNA regulatory network to uncover key potential circRNAs that influence goat prolificacy. Transcriptome analysis was performed on hypothalamus samples from low-prolificacy (n = 5) and high-prolificacy (n = 6) Chuanzhong black goats to identify circRNAs that influence prolificacy in these goats. Differential expression analysis identified a total of 205 differentially expressed circRNAs, comprising 100 upregulated and 105 downregulated circRNAs in the high-prolificacy group compared with the low-prolificacy group. Enrichment analysis of these differentially expressed circRNAs indicated significant enrichment in Gene Ontology terms associated with mammalian oogenesis, negative regulation of neurotransmitter secretion, reproductive developmental processes, hormone-mediated signaling pathways, and negative regulation of hormone secretion. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis highlighted significant enrichment in the oxytocin signaling pathway, GnRH signaling pathway, and hormone-mediated oocyte maturation. The hypothalamus of low- and high-prolificacy goats contains circular RNAs (circRNAs), including chicirc_063269, chicirc_097731, chicirc_017440, chicirc_049641, chicirc_008429, chicirc_145057, chicirc_030156, chicirc_109497, chicirc_030156, chicirc_176754, and chicirc_193363. Chuanzhong black goats have the potential to influence prolificacy by modulating the release of serum hormones from the hypothalamus. A circRNA-miRNA regulatory network was constructed, which determined that miR-135a, miR-188-3p, miR-101-3p, and miR-128-3p may interact with differentially expressed circRNAs, thereby regulating reproductive capacity through the hypothalamic-pituitary-gonadal axis. The results of this study enhance our knowledge of the molecular mechanisms that regulate prolificacy in Chuanzhong black goats at the hypothalamic level.

Identification and Functional Analysis of circRNAs during Goat Follicular Development.

Litter size is a crucial quantitative trait in animals, closely linked to follicular development. Circular RNA (circRNA), a type of single-stranded closed-loop endogenous RNA with stable expression, plays pivotal roles in various biological processes, yet its function in goat follicular development remains unclear. In this study, we collected large (follicle diameter > 3 mm) and small (1 mm < follicle diameter < 3 mm) follicles from black goats in the Chuanzhong region for circRNA sequencing, with the aim of elucidating the functional circRNAs that influence follicle development in goats. Differential analysis revealed that 17 circRNAs were upregulated in large follicles, and 28 circRNAs were upregulated in small follicles. Functional enrichment analysis revealed significant enrichment of pathways related to reproduction, including cellular response to follicle-stimulating hormone stimulus, the PI3K-Akt signaling pathway, the MAPK signaling pathway, and the Notch signaling pathway. Based on the ceRNA mechanism, 45 differentially expressed circRNAs were found to target and bind a total of 418 miRNAs, and an intercalation network including miR-324-3p (circRNA2497, circRNA5650), miR-202-5p (circRNA3333, circRNA5501), and miR-493-3p (circRNA4995, circRNA5508) was constructed. In addition, conservation analysis revealed that 2,239 circRNAs were conserved between goats and humans. Prediction of translation potential revealed that 154 circRNAs may potentially utilize both N6-methyladenosine (m6A) and internal ribosome entry site (IRES) translation mechanisms. Furthermore, the differential expression and circularization cleavage sites of five circRNAs were validated through RT-qPCR and DNA sequencing. Our study constructed a circRNA map in goat follicle development, offering a theoretical foundation for enhancing goat reproductive performance.

miR-128-3p Regulates Follicular Granulosa Cell Proliferation and Apoptosis by Targeting the Growth Hormone Secretagogue Receptor.

The proliferation and apoptosis of granulosa cells (GCs) affect follicle development and reproductive disorders, with microRNAs playing a crucial regulatory role. Previous studies have shown the differential expression of miR-128-3p at different stages of goat follicle development, which suggests its potential regulatory role in follicle development. In this study, through the Cell Counting Kit-8 assay, the EDU assay, flow cytometry, quantitative real-time polymerase chain reaction, Western blot, and the dual-luciferase reporter assay, we used immortal human ovarian granulosa tumor cell line (KGN) cells as materials to investigate the effects of miR-128-3p and its predicted target gene growth hormone secretagogue receptor (GHSR) on GC proliferation and apoptosis. The results show that overexpression of miR-128-3p inhibited the proliferation of KGN cells, promoted cell apoptosis, and suppressed the expression of proliferating cell nuclear antigen (PCNA) and B-cell lymphoma-2 (BCL2) while promoting that of Bcl-2 associated X protein (BAX). The dual-luciferase reporter assay revealed that miR-128-3p bound to the 3' untranslated region sequence of GHSR, which resulted in the inhibited expression of GHSR protein. Investigation of the effects of GHSR on GC proliferation and apoptosis revealed that GHSR overexpression promoted the expression of PCNA and BCL2, enhanced GC proliferation, and inhibited cell apoptosis, whereas the opposite effects were observed when GHSR expression was inhibited. In addition, miR-128-3p and GHSR can influence the expression of extracellular signal-regulated kinase 1/2 protein. In conclusion, miR-128-3p inhibits KGN cell proliferation and promotes cell apoptosis by downregulating the expression of the GHSR gene.

Expression profile and bioinformatics analysis of circRNA and its associated ceRNA networks in longissimus dorsi from Lufeng cattle and Leiqiong cattle.

This paper aims to explore the role of circRNA expression profiles and circRNA-associated ceRNA networks in the regulation of myogenesis in the longissimus dorsi of cattle breeds surviving under subtropical conditions in southern China by RNA sequencing and bioinformatics analysis. It also aims to provide comprehensive understanding of the differences in muscle fibers in subtropical cattle breeds and to expand the knowledge of the molecular networks that regulate myogenesis. With regard to meat quality indicators, results showed that the longissimus dorsi of LQC had lower pH (P < 0.0001), lower redness (P < 0.01), lower shear force (P < 0.05), and higher brightness (P < 0.05) than the longissimus dorsi of LFC. With regard to muscle fiber characteristics, the longissimus dorsi of LQC had a smaller diameter (P < 0.0001) and higher density of muscle fibers (P < 0.05). The analysis results show that the function of many circRNA-targeted mRNAs was related to myogenesis and metabolic regulation. Furthermore, in the analysis of the function of circRNA source genes, we hypothesized that btacirc_00497 and btacirc_034497 may regulate the function and type of myofibrils by affecting the expression of MYH6, MYH7, and NEB through competitive linear splicing.

Polymorphisms in BMPR-IB gene and their association with litter size trait in Chinese Hu sheep.

Identification and utilization of sheep major fecundity genes offer opportunities for the increase in litter size, as well as the improvement of production efficiency in livestock industry. BMPR-IB gene belongs to the TGF-ß superfamily, and is also considered as a regulator for sheep reproductive performance due to its involvement in the mammalian gametogenesis pathway. This study aimed to detect the variations of BMPR-IB gene in Hu sheep (N = 934) and to evaluate their effects on the litter size trait. qRT-PCR results showed that the mRNA expression level of BMPR-IB in kidney was the highest. And in the tissues of ovary and pituitary, the expression levels of prolific group were significantly higher than that of non-prolific group (p < 0.05). Through DNA sequencing and PCR-RFLP, three SNPs were identified in the genomic region of BMPR-IB gene; the individuals with CC in g.29362047T > C, AA in g.29427689G > A and GG in FecB had better fecundity characterization. Additionally, association analysis indicated that two diplotypes of Hap2/2 and Hap2/4 showed larger litter size. Overall, our results verified several useful markers which would contribute to further development of sheep breeding strategies.

miR-450-5p and miR-202-5p Synergistically Regulate Follicle Development in Black Goat.

Follicle maturation is a complex biological process governed by numerous factors, and researchers have observed follicle development by studying the proliferation and apoptosis of follicular granulosa cells (GCs). However, the regulatory mechanisms of GCs proliferation and death during follicle development are largely unknown. To investigate the regulatory mechanisms of lncRNAs, mRNAs, and microRNAs, RNA sequencing (RNA-seq) and small RNA-seq were performed on large (>10 mm) and small follicles (<3 mm) of Leizhou black goat during estrus. We discovered two microRNAs, miR-450-5p and miR-202-5p, which can target GCs in goats and may be involved in follicle maturation, and the effects of miR-450-5p and miR-202-5p on ovarian granulosa cell lines were investigated (KGN). Using cell counting kit-8 (CCK-8) assays, 5-Ethynyl-2'-deoxyuridine (EdU) assay and flow cytometry, miR-202-5p overexpression could suppress the proliferation and induce apoptosis of GCs, whereas miR-450-5p overexpression induced the opposite effects. The dual-luciferase reporter assay confirmed that miR-450-5p could directly target the BMF gene (a BCL2 modifying factor), and miR-202-5p targeted the BCL2 gene. A considerable rise in phosphorylated Akt (p-AKT) protein was observed following the downregulation of BMF by miR-450-5p mimics. After BMF gene RNAi therapy, a notable elevation in p-AKT was detected. Mimics of miR-202-5p inhibited BCL2 protein expression, significantly decreasing p-AMPK protein expression. These results imply that during the follicular development in black goats, the miR-450-5p-BMF axis favored GC proliferation on a wide scale, while the miR-202-5p-BCL2 axis triggered GC apoptosis.

Identification of genetic markers associated with milk production traits in Chinese Holstein cattle based on post genome-wide association studies.

With the rapid development of dairy industry, the breeding process of dairy cows has been accelerated. In previous genome-wide association studies (GWAS), a large number of genetic markers have been reported which may contribute to the selection of Holstein populations with superior milk-producing traits, but they remain to be further verified before practical application. In this study, 90 single nucleotide polymorphisms (SNPs) were selected, which were reported to be significantly associated with five milk production traits, including 305-day milk yield (305MY), 305-day milk fat percent (305FC), 305-day milk protein percent (305PC), 305-day milk fat yield (305FY) and 305-day milk protein yield (305PY). Effective 305-day data and fresh DNA samples were obtained from 295 healthy cows with gestational age of 1-4. Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) was used to perform precise genotyping of these loci, followed by site association and haplotype analysis. Results showed that 36 out of 90 loci were supported to be used as genetic markers. In particular, several novel and effective haplotypes were also presented. Overall, our results verified tens of useful markers and provided a basis for further development of breeding strategies.

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

BACKGROUND: Fertility 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. RESULTS: The 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. CONCLUSIONS: This 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.

Synthesis and Antiproliferative Activities of Novel Substituted 5-Anilino-α-Glucofuranose Derivatives.

In order to find novel antitumor candidate agents with high efficiency and low toxicity, 14 novel substituted 5-anilino-α-glucofuranose derivatives have been designed, synthesized and evaluated for antiproliferative activities in vitro. Their structures were characterized by NMR (1 H and 13 C) and HR-MS, and configuration (R/S) at C(5) was identified by two-dimensional 1 H,1 H-NOESY-NMR spectrum. Their antiproliferative activities against human tumor cells were investigated by MTT assay. The results demonstrated that most of the synthesized compounds had antiproliferative effects comparable to the reference drugs gefitinib and lapatinib. In particular, (5R)-5-O-(3-chloro-4-{[5-(4-fluorophenyl)thiophen-2-yl]methyl}anilino)-5-deoxy-1,2-O-(1-methylethylidene)-α-glucofuranose (9da) showed the most potent antiproliferative effects against SW480, A431 and A549 cells, with IC50 values of 8.57, 5.15 and 15.24 µm, respectively. This work suggested 5-anilino-α-glucofuranose as an antitumor core structure that may open a new way to develop more potent anti-cancer agents.

Role of mRNAs and long non-coding RNAs in regulating the litter size trait in Chuanzhong black goats.

Fecundity improvement is one of the most important objectives for goat breeders as it can considerably greatly increase production efficiency. The molecular mechanisms underlying fecundity in goats remain largely unknown. To explore the molecular and genetic mechanisms related to the fecundities and prolificacies in Chuanzhong black goats, we performed high-throughput RNA sequencing to identify differentially expressed long non-coding RNAs (lncRNAs) and mRNAs (DElncRNAs and DEmRNAs, respectively) the ovaries of high-fecundity and low-fecundity goats; furthermore, we conducted functional annotation analyses to identify pathways of interest. Overall, 1,353 DEmRNAs and 168 DElncRNAs were identified. Quantitative real-time PCR (qRT-PCR) was performed to validate some randomly selected DElncRNAs and DEmRNAs. We found that two DElncRNAs ENSCHIT00000005909 and ENSCHIT00000005910 might positively influence the expression of the corresponding gene IL1R2 (upregulated in high-fecundity group), exerting co-regulative effects on the ovarian function, through which litter size might show variations. KEGG pathway analysis indicated that the DEmRNAs SRD5A2, LOC102191297 and LOC102171967 were significantly enriched in steroid hormone biosynthesis-this pathway was related to animal reproduction. To summarize, our findings expand the understanding pertaining to the biological functions of lncRNAs and contribute to the annotation of the goat genome; moreover, they should be helpful for further studying the role of lncRNAs in ovulation and lambing.

Lycopene supplementation regulates the gene expression profile and fat metabolism of breeding hens.

This study investigated the effects of lycopene on the gene expression profile and expression of genes related to fat metabolism of Xinghua breeding hens. Seven hundred and twenty healthy breeding hens were randomly assigned to four treatments; each treatment was replicated six times with 30 hens each. Broken rice and soybean meal were adopted for the basal diet and added with 0 (control group), 20, 40 and 80 mg/kg lycopene respectively. Gene expression profile of the liver induced by lycopene and expression of genes related to fat metabolism in hens liver and intestine were analysed after 42-day feeding trial including 7-day pre-feeding period and 35-day formal period. The genes involved in fat metabolism were analysed, and we found that lycopene significantly increased the expression of PGC1α, PPARα, RXRα and RARα in the liver, PPARγ, RXRα and RXRγ in the jejunum, and RARα in the duodenum (p < .05); reduced the expression of FABP1 and FABP10 in the liver, and FATP4 in the jejunum (p < .05). By analysing gene expression profile, 158 differentially expressed genes (DEGs) including 69 up-regulated genes and 89 down-regulated genes were obtained between control group and 40 mg/kg group. KEGG pathway analysis was performed on all DEGs, and 5 pathways were obtained. In conclusion, lycopene can affect the expression of related genes, and this may be one of the reasons that lycopene can regulate fat metabolism.

Interactive Curve-Linear Relationship Between Alteration of Carbohydrate Macromolecular Structure Traits in Hulless Barley (Hordeum vulgare L.) Grain and Nutrient Utilization, Biodegradation and Bioavailability.

The aim of this study was to reveal an interactive curve-linear relationship between altered carbohydrate macromolecular structure traits of hulless barley cultivars and nutrient utilization, biodegradation, as well as bioavailability. The cultivars had different carbohydrate macromolecular traits, including amylose (A), amylopectin (AP), and ß-glucan contents, as well as their ratios (A:AP). The parameters assessed included: (1) chemical and nutrient profiles; (2) protein and carbohydrate sub-fractions partitioned by the Cornell Net Carbohydrate and Protein System (CNCPS); (3) total digestible nutrients (TDN) and energy values; and (4) in situ rumen degradation kinetics of nutrients and truly absorbed nutrient supply. The hulless barley samples were analyzed for starch (ST), crude protein (CP), total soluble crude protein (SCP), etc. The in situ incubation technique was performed to evaluate the degradation kinetics of the nutrients, as well as the effective degradability (ED) and bypass nutrient (B). Results showed that the carbohydrates (g/kg DM) had a cubic relationship (p < 0.05), with the A:AP ratio and ß-glucan level; while the starch level presented a quadratic relationship (p < 0.05), with the A:AP ratio and cubic relationship (p < 0.05), with ß-glucan level. The CP and SCP contents had a cubic relationship (p < 0.05) with the A:AP ratio and ß-glucan level. The altered carbohydrate macromolecular traits were observed to have strongly curve-linear correlations with protein and carbohydrate fractions partitioned by CNCPS. For the in situ protein degradation kinetics, there was a quadratic effect of A:AP ratio on the rumen undegraded protein (RUP, g/kg DM) and a linear effect of ß-glucan on the bypass protein (BCP, g/kg DM). The A:AP ratio and ß-glucan levels had quadratic effects (p < 0.05) on BCP and EDCP. For ST degradation kinetics, the ST degradation rate (Kd), BST and EDST showed cubic effects (p < 0.05) with A:AP ratio. The ß-glucan level showed a cubic effect on EDST (g/kg DM) and a quadratic effect on BST (g/kg ST or g/kg DM) and EDST (g/kg DM). In conclusion, alteration of carbohydrate macromolecular traits in hulless barley significantly impacted nutrient utilization, metabolic characteristics, biodegradation, and bioavailability. Altered carbohydrate macromolecular traits curve-linearly affected the nutrient profiles, protein and carbohydrate fractions, total digestible nutrient, energy values, and in situ degradation kinetics.

Evaluation of pigeon pea leaves (Cajanus cajan) replacing alfalfa meal on growth performance, carcass trait, nutrient digestibility, antioxidant capacity and biochemical parameters of rabbits.

A 30-day experiment was performed to determine the effect of pigeon pea leaves (PPL) on growth performance, carcass trait, meat quality, nutrient digestibility, antioxidant capacity and biochemical parameters of growing rabbits. In a completely randomized design, PPL replaced alfalfa meal at the level of 0%, 10%, 20% and 30%, which were named PPL0 (control), PPL10, PPL20 and PML30 respectively. Two hundred New Zealand white rabbits at 6 weeks with similar weight (870.23 ± 15.98 g) were allocated to four dietary groups with five replicates containing 10 rabbits/per replicate (male). The results showed that: (a) PPL powder contained 24.26% crude protein, 4.34% crude fat, 17.86% crude fibre, 7.05% ash, 1.35% calcium, 0.28% phosphorus, 1.09% lysine and 0.20% methionine, and the chemical compositions are on DM basis; (b) the ratio of feed to gain of rabbits fed diet PPL10 was significantly better (p < 0.05) than those fed other three diets; (c) the content of longissimus dorsi (LD) moisture in the rabbits fed diets without PPL (control group) was 12% lower than that in the PPL30 diets (60.1 vs. 72.1; p < 0.05). In PPL10, PPL20 and PPL30 diets, the leg muscle (LM) b*(yellowness) value was 33%, 30% and 22.6% higher than the control group respectively. The rabbits fed diets PPL0 had lower (p < 0.05) LM crude protein and ash and higher (p < 0.05) crude fat of LD and LM as compared with those fed other diets; (d) crude protein and energy digestibility of PPL0 and PPL10 diets were significantly higher (p < 0.05) than PPL30 diets; and (e) serum glutathione peroxidase (GSH-Px) activity of the rabbits fed PPL10 and PPL30 diets was significantly higher (p < 0.05) than that fed PPL20 diets. Liver total antioxidant capacity (T-AOC) activity of the PPL30 groups was 1.3% higher (p < 0.05) than the PPL10 group. Additionally, the control group (PPL0) had the highest (p < 0.05) blood urea nitrogen (BUN), total cholesterol (TCHO) and low-density lipoprotein cholesterol (LDLC) content compared with the groups supplemented with PPL. The PPL30 group had the highest (p < 0.05) triiodothyronine (T3 ) and tetraiodothyroxine (T4 ) value among the dietary groups.

Xanthophyll supplementation regulates carotenoid and retinoid metabolism in hens and chicks.

This study investigated the effects of xanthophylls (containing 40% lutein and 60% zeaxanthin; Juyuan Biochemical Co., Ltd., GuangZhou, China) on gene expression associated with carotenoid cleavage enzymes (ß-carotene 15, 15'-monooxygenase, BCMO1; and ß-carotene 9', 10'-dioxygenase, BCDO2) and retinoid metabolism (lecithin:retinol acyl transferase (LRAT) and STRA6) of breeding hens and chicks. In experiment 1, 432 hens were divided into 3 groups and fed diets supplemented with zero (as the control group), 20, or 40 mg/kg xanthophyll. The liver, duodenum, jejunum, and ileum were sampled at d 35 of the trial. Results showed that 40 mg/kg xanthophyll supplementation increased BCDO2 mRNA in the liver, duodenum, and jejunum; LRAT mRNA in the jejunum; and STRA6 mRNA in the liver, while it decreased LRAT mRNA in the liver. Experiment 2 was a 2 × 2 factorial design. Male chicks hatched from a zero or 40 mg/kg xanthophyll diet of hens were fed a diet containing either zero or 40 mg/kg xanthophylls. The liver, duodenum, jejunum, and ileum were sampled at zero, 7, 14, and 21 d after hatching. Results showed that in ovo xanthophyll modulated carotenoid and retinoid metabolism mainly within one wk after hatching. The maternal effects gradually vanished and dietary effects began to work one to 2 wk after hatching. Dietary xanthophyll regulated carotenoid and retinoid metabolism mainly from 2 wk onward. The xanthophyll regulation of carotenoid and retinoid metabolism also revealed strong tissue specificity. In conclusion, xanthophyll supplementation could modulate carotenoid and retinoid metabolism in different tissues of hens and chicks.

Effect of organic acids on fermentation quality and microbiota of horseshoe residue and corn protein powder.

This experiment aimed to investigate the impact of malic acid (MA) and citric acid (CA) on the nutritional composition, fermentation quality, rumen degradation rate, and microbial diversity of a mixture of apple pomace and corn protein powder during ensiling. The experiment used apple pomace and corn protein powder as raw materials, with four groups: control group (CON), malic acid treatment group (MA, 10 g/kg), citric acid treatment group (CA, 10 g/kg), and citric acid + malic acid treatment group (MA, 10 g/kg + CA, 10 g/kg). Each group has 3 replicates, with 2 repetitions in parallel, subjected to mixed ensiling for 60 days. The results indicated: (1) Compared to the CON group, the crude protein content significantly increased in the MA, CA, and MA + CA groups (p < 0.05), with the highest content observed in the MA + CA group. The addition of MA and CA effectively reduced the water-soluble carbohydrate (WSC) content (p < 0.05). Simultaneously, the CA group showed a decreasing trend in NDFom and hemicellulose content (p = 0.08; p = 0.09). (2) Compared to the CON group, the pH significantly decreased in the MA, CA, and MA + CA groups (p < 0.01), and the three treatment groups exhibited a significant increase in lactic acid and acetic acid content (p < 0.01). The quantity of lactic acid bacteria increased significantly (p < 0.01), with the MA + CA group showing a more significant increase than the MA and CA groups (p < 0.05). (3) Compared to the CON group, the in situ dry matter disappearance (ISDMD) significantly increased in the MA, CA, and MA + CA groups (p < 0.05). All three treatment groups showed highly significant differences in in situ crude protein disappearance (ISCPD) compared to the CON group (p < 0.01). (4) Good's Coverage for all experimental groups was greater than 0.99, meeting the conditions for subsequent sequencing. Compared to the CON group, the Shannon index significantly increased in the CA group (p < 0.01), and the Simpson index increased significantly in the MA group (p < 0.05). However, there was no significant difference in the Chao index among the three treatment groups and the CON group (p > 0.05). At the genus level, the abundance of Lentilactobacillus in the MA, CA, and MA + CA groups was significantly higher than in the control group (p < 0.05). PICRUSt prediction results indicated that the metabolic functional microbial groups in the CA and MA treatment groups were significantly higher than in the CON group (p < 0.05), suggesting that the addition of MA or CA could reduce the loss of nutritional components such as protein and carbohydrates in mixed ensilage. In conclusion, the addition of malic acid and citric acid to a mixture of apple pomace and corn protein powder during ensiling reduces nutritional losses, improves fermentation quality and rumen degradation rate, enhances the diversity of the microbial community in ensiled feed, and improves microbial structure. The combined addition of malic acid and citric acid demonstrates a superior effect.

Isolation and screening of high biofilm producing lactic acid bacteria, and exploration of its effects on the microbial hazard in corn straw silage.

Silage is a well-established method for preserving feed. However, the preparation process still poses several potential microbial hazards. Lactic acid bacteria exhibiting a biofilm phenotype are considered the most advanced 'fourth-generation probiotics' due to their significant potential in enhancing fermentation quality. In this study, a strain of high-biofilm-producing lactic acid bacteria (HBP-LAB) was successfully isolated from silage samples using the crystal violet method and designated as Lactiplantibacillus plantarum S23Y. This strain was subsequently used as an inoculant in corn straw for experimental purposes. The results indicated that it effectively reduced dry matter loss caused by microorganisms, thereby enhancing the retention of dry matter in silage. Following aerobic exposure, this strain was able to maintain the population of Lactobacillus and the concentration of lactic acid, which significantly decreased the likelihood of yeast-induced aerobic spoilage and improved the aerobic stability of the silage. However, it is important to note that this HBP-LAB did not have a significant impact on antibiotic resistance genes (ARGs) or mobile genetic elements (MGEs) in the silage. In conclusion, using S23Y as a representative strain, we have demonstrated that HBP-LAB can enhance the fermentation quality of silage to a certain extent and mitigate the detrimental effects of microorganisms. The findings of this study provide valuable insights for the application of lactic acid bacteria with a biofilm phenotype in silage fermentation.

Effects of different dietary energy levels on growth performance, meat quality and nutritional composition, rumen fermentation parameters, and rumen microbiota of fattening Angus steers.

This study investigates the effects of varying energy levels in diets on Black Angus steers, focusing on growth performance, muscle composition, rumen microbial community, and their interrelationships. Twenty-seven Black Angus steers, aged approximately 22 months and weighing 520 ± 40 kilograms, were randomly divided into three groups: low-energy (LE), medium-energy (ME), and high-energy (HE). Each group consisted of nine individuals. The steers were fed diets with energy levels of 6.657 MJ/kg (LE), 7.323 MJ/kg (ME), and 7.990 MJ/kg (HE) following a 14-day pre-feeding period, with a subsequent 90-day main experimental phase. After the 90-day feeding period, both the HE and ME groups exhibited significantly higher average daily weight gain (ADG) compared to the LE group (p < 0.05). The feed-to-weight ratios were lower in the HE and ME groups compared to the LE group (p < 0.05). The HE group showed significantly higher crude fat content in the longissimus dorsi muscle compared to the LE group (p < 0.05), with total fatty acid content in the muscle surpassing that in the ME and LE groups (p < 0.05). As dietary energy levels increased, the diversity of the rumen microbial community decreased (p < 0.05), and significant differences in bacterial community structure were observed between the LE and HE groups (p < 0.05). The results suggest that higher dietary energy levels enhance growth performance and alter muscle composition in Black Angus steers, while also influencing the rumen microbial community. This study contributes to understanding optimal dietary strategies for finishing Angus cattle to improve beef quality, economic returns, and the development of standardized production procedures.

Overview of Bovine Mastitis: Application of Metabolomics in Screening Its Predictive and Diagnostic Biomarkers.

Bovine mastitis is an inflammatory disease of the mammary glands, and its pathogenesis and diagnosis are complicated. Through qualitative and quantitative analysis of small-molecule metabolites, the metabolomics technique plays an important role in finding biomarkers and studying the metabolic mechanism of bovine mastitis. Therefore, this paper reviews the predictive and diagnostic biomarkers of bovine mastitis that have been identified using metabolomics techniques and that are present in samples such as milk, blood, urine, rumen fluid, feces, and mammary tissue. In addition, the metabolic pathways of mastitis-related biomarkers in milk and blood were analyzed; it was found that the tricarboxylic acid (TCA) cycle was the most significant (FDR = 0.0015767) pathway in milk fluid, and glyoxylate and dicarboxylate metabolism was the most significant (FDR = 0.0081994) pathway in blood. The purpose of this review is to provide useful information for the prediction and early diagnosis of bovine mastitis.

Whole-genome sequencing identified candidate genes associated with high and low litter size in Chuanzhong black goats.

The reproductive performance of goats significantly influences breeding efficiency and economic returns, with litter size serving as a comprehensive indicator. Despite this, research on the genetic control of litter size remains limited. Therefore, we aimed to explore the candidate genes affecting fecundity and compared the whole-genome sequences (WGS) of 15 high-litter (HL) and 15 low-litter (LL) size in Chuanzhong black goats. Then genetic diversity and genomic variation patterns were analyzed by phylogenetic, principal component and population genetic structure analysis, it was found that HL and LL subpopulations diverged. Population evolutionary selection elimination analysis was performed by Fst and θπ resulted in 506 genes were annotated in HL and 528 genes in LL. These genes were mainly related to Hippo signaling pathway, G protein-coupled signaling pathway, G protein-coupled receptor activity, cell surface receptor signaling pathway, gonadal and reproductive structure development. According to the significantly selected genomic regions and important pathways, we found that the g.89172108T > G variant locus in the exon of the AMH gene was significantly associated with litter size (P < 0.05), which could be used as an auxiliary selection gene for the high fertility of Chuanzhong black Goat.