Search Results (34)

This study was conducted through in vivo and in vitro experiments and aimed to reveal the regulatory effect of water extract of Artemisia annua L. (WEAA) on the antioxidant function of mutton sheep and the underlying mechanism. In the in vivo experiment, 32 Dorper × Han female sheep (3 months old; avg. body weight: 24 ± 0.09 kg) were allocated to four groups (eight lambs/group) and fed a diet containing 0, 500, 1000, and 1500 mg/kg WEAA, respectively. In the in vitro experiments, peripheral blood lymphocytes (PBLs) were cultured with different doses of WEAA (0, 25, 50, 100, 200, 400 µg/mL) to determine the optimal concentration, followed by a 2 × 2 factorial experiment with four treatment groups (six replicates per treatment group): the ML385(−)/WEAA(−) group, the ML385(−)/WEAA(+) group, the ML385(+)/WEAA(−) group, and the ML385(+)/WEAA(+) group. The results showed that WEAA supplementation dose-dependently increased serum, liver and spleen tissue total antioxidant capacity, glutathione peroxidase (GSH-Px), and catalase (CAT) activity while reducing malondialdehyde level (p < 0.05). Moreover, WEAA supplementation significantly upregulated the liver and spleen expression of nuclear factor erythroid 2-related factor 2, superoxide dismutase 2, GSH-Px, CAT and NAD(P)H quinone dehydrogenase 1 (p < 0.05) while significantly downregulating the kelch-like ECH associated protein 1 expression in a dose-dependent manner (p < 0.05), thereby activating the Keap1/Nrf2 pathway with the peak effect observed in the 1000 mg/kg WEAA group. Additionally, supplementation with 100 µg/mL of WEAA had significant antioxidation activity in the culture medium of PBLs. Its action mechanism involved the Keap1/Nrf2 pathway; specifically, WEAA exerted its antioxidant effect by upregulating the gene expression related to the Keap1/Nrf2 pathway. In conclusion, WEAA enhances sheep’s antioxidant capacity by up-regulating Keap1/Nrf2 pathway genes and boosting antioxidant enzyme activity. The results provided experimental support for the potential application of WEAA in intensive mutton sheep farming. Full article

Tan sheep outperform Dorper sheep in meat-quality traits, including muscle fiber characteristics and fatty acid composition, while Dorper sheep excel in carcass weight. However, the molecular mechanisms underlying these breed-specific traits, especially gut microbiota–bile acid (BA) interactions, remain poorly understood. As host–microbiota co-metabolites, BAs are converted by colonic microbiota via bile salt hydrolase (BSH) and dehydroxylases into secondary BAs, which activate BA receptors to regulate host lipid and glucose metabolism. This study analyzed colonic BA profiles in 8-month-old Tan and Dorper sheep, integrating microbiome and longissimus dorsi muscle transcriptome data to investigate the gut–muscle axis in meat-quality and carcass trait regulation. Results showed that Tan sheep had 1.6-fold higher secondary BA deoxycholic acid (DHCA) levels than Dorper sheep (p < 0.05), whereas Dorper sheep accumulated conjugated primary BAs glycocholic acid (GCA) and tauro-α-muricholic acid (p < 0.05). Tan sheep exhibited downregulated hepatic BA synthesis genes, including cholesterol 7α-hydroxylase (CYP7A1) and 27-hydroxylase (CYP27A1), alongside upregulated transport genes such as bile salt export pump (BSEP), sodium taurocholate cotransporting polypeptide (NTCP), and ATP-binding cassette subfamily B member 4 (ABCB4), with elevated gut BSH activity (p < 0.05). DHCA was strongly correlated with g_Ruminococcaceae_UCG-014, ENSOARG00000001393, and ENSOARG00000016726, muscle fiber density, diameter, and linoleic acid (C18:2n6t) (|r| > 0.5, p < 0.05). In contrast, GCA was significantly associated with g_Lachnoclostridium_10, g_Rikenellaceae_RC9_gut_group, ENSOARG0000001232, carcass weight, and net meat weight (|r| > 0.5, p < 0.05). In conclusion, breed-specific colonic BA profiles were shaped by host–microbiota interactions, with DHCA potentially promoting meat quality in Tan sheep via regulation of muscle fiber development and fatty acid deposition, and GCA influencing carcass traits in Dorper sheep. This study provides novel insights into the gut microbiota–bile acid axis in modulating ruminant phenotypic traits. Full article

This study evaluated the effects of dietary Rhodotorula yeast culture (RYC) supplementation on carcass traits, meat quality, antioxidant capacity, shelf life, and flavor substance in fattening lambs. Twenty-four three-month-old male Dorper × Han crossbred sheep (body weight: 36 ± 4 kg) were randomly assigned to four groups: R0 (basal diet), R10 (basal diet + 10 g RYC/day), R20 (basal diet + 20 g RYC/day), and R40 (basal diet + 40 g RYC/day). The experiment lasted 75 days. Compared to the control group, the R10, R20, and R40 groups exhibited significant reductions in shear force (p < 0.01), malondialdehyde levels (p < 0.01), and day-15 total volatile basic nitrogen values (p < 0.05), along with significant increases in glutathione peroxidase activity (p < 0.05) and total umami-taste amino acid content (p < 0.01). The R20 group also demonstrated significant increases in backfat thickness, muscle crude protein content, and total antioxidant capacity (p < 0.05). These results indicate that dietary supplementation with 20 g RYC improves physicochemical properties, antioxidant capacity, shelf life, and flavor compounds in fattening lambs. Full article

Background: Quantifying and controlling the inbreeding level in livestock populations is crucial for the long-term sustainability of animal husbandry. However, the extent of inbreeding has not been fully understood in sheep populations on a global scale. Methods: Here, we analyzed high-depth genomes of 210 sheep from 20 worldwide breeds to identify the pattern and distribution of genome-wide runs of homozygosity (ROH) and detect candidate selected genes in ROH islands for agronomic and phenotypic traits. Results: Leveraging whole-genome sequencing data, we found a large number of short ROH (e.g., <1.0 Mb) in all breeds and observed the overall higher values of ROH statistics and inbreeding coefficient in European breeds than in Asian breeds and Dorper sheep. We identified some well-known candidate genes (e.g., CAMK4, HOXA gene family, ALOX12, FGF11, and MTOR) and 40 novel genes (e.g., KLHL1, FGFRL1, WDR62, GDF6, KHDRBS2, and PAX1) that are functionally associated with fecundity, body size, and wool-related traits in sheep. Based on the candidate genes, we revealed different genetic bases for the fecundity traits of European and Asian sheep. Conclusions: This study improves the resolution of ROH detection and provides new insights into genomic inbreeding and trait architecture in sheep as well as useful markers for future breeding practice. Full article

The use of escape protein, which is absorbed in the small intestine, can improve the production of ruminant animals because it meets their protein requirements better. This study hypothesized that wax lipid matrices are effective encapsulants for escape lysine in ruminants and tested tannin extract as an adjuvant. Forty intact male Santa Ines × Dorper sheep (~4 months old, BW 23 ± 1.2 kg) were allocated, in a randomized block design, to four treatments: control group (no lysine addition), supplementation with free lysine, escape lysine, and escape lysine + tannin extract. The ether extract intake was higher in the sheep fed escape lysine + tannin compared to the control and free lysine group. The sheep fed escape lysine presented higher DM and aNDF eating efficiency (p ≤ 0.05) compared to the free lysine and control groups. Escape lysine with and without tannin presented greater TDN compared to free lysine and control. The NFCs were lower in the free lysine diet, and the crude protein digestibility was higher in the sheep fed lysine + tannin and the control group compared to the escape and free lysine groups. The lysine treatments did not affect (p > 0.05) the performance, ingestive behavior, and blood parameters. The rectal temperature was higher in the sheep fed lysine escape compared to those fed free lysine. The sheep fed escape lysine + tannin exhibited reduced (p ≤ 0.05) large particles and improved peNDF 12 h after feeding. The escape lysine diet, regardless of the addition of tannin, improved the total digestible nutrients and eating efficiency, without affecting the performance, feed conversion, and blood variables of the sheep. Full article

Background: Cannabis sativa is a high-value crop that can be cultivated for ruminant’s feed and medicinal purposes. The demand for Cannabis and Cannabis products has increased since the beginning of 21st century. Objectives: The increase in the production cost of high-protein feeds such as lucerne has led to an urgent need to investigate alternative high-protein sources. Methods: Cannabis has been identified as an alternative to lucerne due to its high protein content. Results: However, the cultivation and uses of Cannabis and its by-products in South Africa is limited due to the strict legislation. The metabolites and nutritional value of Cannabis are influenced by growing conditions and soil type. Furthermore, the available literature has shown that Cannabis contains anti-nutritional factors that may affect feed intake or bioavailability and digestibility. Conclusions: Therefore, it is crucial to employ a processing method that can reduce anti-nutritional factors to promote the feed intake and growth rate of sheep. Fermentation, as a processing method, can reduce anti-nutritional factors found in Cannabis, which will make it a palatable alternative feed supplement for ruminants such as Dorper sheep. Overall, this review paper aimed to examine the available literature on the use of Cannabis as an alternative high-protein feed supplement for Dorper sheep in South Africa. Full article

Fibroblast growth factor 5 (FGF5) plays key roles in promoting the transition from the anagen to catagen during the hair follicle cycle. The sheep serves as an excellent model for studying hair growth and is frequently utilized in various research processes related to human skin diseases. We used the CRISPR/Cas9 system to generate four FGF5-edited Dorper sheep and only low levels of FGF5 were detected in the edited sheep. The density of fine wool in GE sheep was markedly increased, and the proportion of fine wool with a diameter of 14.4–20.0 μm was significantly higher. The proliferation signal in the skin of gene-edited (GE) sheep was stronger than in wild-type (WT) sheep. FGF5 editing decreased cortisol concentration in the skin, further activated the activity of antioxidant enzymes such as Glutathione peroxidase (GSH-Px), and regulated the expression of Wnt signaling pathways containing Wnt agonists (Rspondins, Rspos) and antagonists (Notum) in hair regeneration. We suggest that FGF5 not only mediates the activation of antioxidant pathways by cortisol, which constitutes a highly coordinated microenvironment in hair follicle cells, but also influences key signals of the Wnt pathway to regulate secondary hair follicle (SHF) development. Overall, our findings here demonstrate that FGF5 plays a significant role in regulating SHF growth in sheep and potentially serves as a molecular marker of fine wool growth in sheep breeding. Full article

This experiment was conducted to investigate the effect of three–way hybrid sheep and Hu sheep on serum indicators, rumen fermentation, rumen enzyme activity, and microorganisms in sheep. Healthy and similar birth weights from three groups (Hu, n = 11; Charolais × Australian White × Hu, CAH, n = 11; Charolais × Dorper × Hu, CDH, n = 11) were selected to be fed by the ewes until 45 days of age. Subsequently, they were weaned intensively and underwent short–term fattening for 3 months along with selected male lambs fed intensively. During this period, they were fed and watered ad libitum. Blood and rumen fluid were collected and analyzed for serum indicators and rumen fluid microorganisms, enzyme activity, and VFA, respectively, at the end of the fattening period. Compared with Hu lamb, the offspring of the three–way hybrid lamb showed significant improvements in body weight, serum lactate dehydrogenase, and creatinine content. However, there was no significant effect on serum immunity and antioxidant indices. In addition, the rumen fluid volatile fatty acid (VFA) molar concentration and microcrystalline cellulose and lipase content were significantly lower in the three–way hybrid lamb compared to Hu lamb, but β–glucosidase, amylase, pepsin, and VFA molar ratio were not significantly affected. Subsequently, 16S rRNA sequencing diversity analysis revealed that three–way hybrid lamb significantly increased rumen microbial ACE and Chao1 indices compared to Hu lamb. Meanwhile, the abundance of Verrucomicrobiota and Synergistota significantly increased at the phylum level. Correlation analysis showed that Prevotella had the highest proportion, while Rikenellaceae_RC9_gut_group correlated most closely with others genus. The microbial communities isovaleric acid molar concentration and proportion were strongly correlated. In addition, there were significant differences in correlations between microbial communities and isobutyric acid, butyric acid and valeric acid content, and their molar proportion, but they were not significantly correlated with digestive enzymes. From the functional enrichment analysis, it was found that hybrid progeny were mainly enriched in the pyruvate metabolism, microbial metabolism in diverse environments, carbon metabolism, and quorum sensing pathways. In contrast, the Hu sheep were primarily enriched in the cysteine and methionine, amino sugar and nucleotide sugar, and biosynthesis of secondary metabolite pathways. These results suggest that hybridization can play a role in regulating organismal metabolism and improve animal production performance by influencing the structure and characteristics of microbial communities. Full article

Transport is a high-risk time for sheep, especially if the distances are long and sheep are fasted for a long time beforehand. Two experiments were conducted to compare transport durations of 1 hour (1 h) and 3 hours (3 h) and the effects of feeding before transport using Dorper × Mongolian sheep, which are typical of the region and may be tolerant of the high temperatures in the Inner Mongolian summer. Thirty 4-month-old male sheep were randomly divided into two treatment groups, with 15 sheep/treatment in each experiment, to evaluate the effects on blood biochemical indicators, stress hormone levels, rectal temperatures, and antioxidant status of lambs in summer. In Experiment 1, the levels of triglycerides and free fatty acids after 3 h transport were significantly lower than after 1 h transport (p < 0.05). The levels of thyroxine and malondialdehyde in blood were greater after 3 h transport than 1 h transport (p < 0.05). Creatine kinase levels after 3 h transport tended to be lower than after 1 h transport (p = 0.051). In Experiment 2, the levels of urea and superoxide dismutase in the group fasted pre-transport was significantly lower than those of the group fed pre-transport (p < 0.05). The serum cortisol level in the pre-transport fed group was higher compared to the group fed pre-transport (p = 0.04). Total antioxidant capacity in the pre-transport fasted group tended to be lower compared to that in the pre-transport fed group (p < 0.0001). We conclude that the reduction in nutritional status of sheep transported for longer and without feed pre-transport suggests that transporting sheep in hot conditions in northern China after fasting for a long period should be restricted. However, a decrease in the stress induced by transport following fasting is worthy of further study. Full article

Sheep have historically been bred globally as a vital food source. To explore the transcriptome of adipose tissue and investigate key genes regulating adipose metabolism in sheep, adipose tissue samples were obtained from F1 Dorper × Hu sheep. High-throughput sequencing libraries for second- and third-generation sequencing were constructed using extracted total RNA. Functional annotation of differentially expressed genes and isoforms facilitated the identification of key regulatory genes and isoforms associated with sheep fat metabolism. SMRT-seq generated 919,259 high-accuracy cDNA sequences after filtering. Full-length sequences were corrected using RNA-seq sequences, and 699,680 high-quality full-length non-chimeric (FLNC) reads were obtained. Upon evaluating the ratio of total lengths based on FLNC sequencing, it was determined that 36,909 out of 56,316 multiple-exon isoforms met the criteria for full-length status. This indicates the identification of 330,375 full-length FLNC transcripts among the 370,114 multiple-exon FLNC transcripts. By comparing the reference genomes, 60,276 loci and 111,302 isoforms were identified. In addition, 43,423 new genes and 44,563 new isoforms were identified. The results identified 185 (3198), 394 (3592), and 83 (3286) differentially expressed genes (transcripts) between tail and subcutaneous, tail and visceral, and subcutaneous and visceral adipose tissues, respectively. Functional annotation and pathway analysis revealed the following observations. (1) Among the differentially expressed genes (DEGs) of TF and SF tissues, the downregulation of ACADL, ACSL6, and NC_056060.1.2536 was observed in SF, while FFAR4 exhibited upregulation. (2) Among the DEGs of TF and VF tissues, expressions of ACADL, ACSL6, COL1A1, COL1A2, and SCD were downregulated in VF, with upregulation of FFAR4. (3) Among SF and VF expressions of COL1A1, COL1A2, and NC_056060.1.2536 were downregulated in VF. Specific differentially expressed genes (ACADL, ACSL6, COL1A1, COL1A2, FFAR4, NC_056060.1.2536, and SCD) and transcripts (NC_056066.1.1866.16 and NC_056066.1.1866.22) were identified as relevant to fat metabolism. These results provide a dataset for further verification of the regulatory pathway associated with fat metabolism in sheep. Full article

Physiological and blood measurement changes due to high heat load, restricted feed intake, and limited drinking water availability in 135 animals of three hair sheep breeds (Dorper, Katahdin, and St. Croix) were subjected to multivariate analysis techniques. The objective of this analysis was to evaluate the ability of these variables to separate individual hair sheep into groups based on adaptation characteristics in response to three physiological stressors and identify variables with greater discriminatory power. There were 16, 8, and 13 physiological and blood variables obtained from high heat load, restricted feed consumption, and water intake studies, respectively, for multivariate analysis. Physiological variables such as respiration rate, rectal and skin temperature, and panting score were measured only in the heat stress study. The results of the cluster and canonical discriminant analyses showed the presence of wide divergence (p < 0.05) between St. Croix and other breeds in their responses to high heat loads and restricted-feed- and -water-intake conditions. Dorper and Katahdin were grouped (p > 0.05) together based on the changes in physiological variables, which were separated (p < 0.05) from those of St. Croix as a resilient group. The stepwise discriminant analysis indicated that skin temperature, panting score, rectal temperature, respiration rate, and blood urea nitrogen and oxygen concentrations were the significant (p < 0.05) discriminating variables in clustering individual sheep into groups based on their responses to the high-heat-stress condition. Under the limited feed intake condition, the significant (p < 0.05) traits responsible for the separation of St. Croix from Dorper and Katahdin were blood triglyceride and cholesterol concentrations, whereas blood hemoglobin, osmolality, protein, and albumin were most important discriminating variables under the limited water intake condition. In conclusion, the results of the present study suggest that the stress responses of Dorper and Katahdin are similar and different from that of St. Croix. This finding can be useful information for future decisions in developing climate-resilient sheep through selective breeding. Full article

The anthelmintic resistance of gastrointestinal nematodes (GINs) poses a significant threat to sheep worldwide, but genomic selection can serve as an alternative to the use of chemical treatment as a solution for parasitic infection. The objective of this study is to conduct genome-wide association studies (GWASs) to identify single nucleotide polymorphisms (SNPs) in Rambouillet (RA) and Dorper × White Dorper (DWD) lambs associated with the biological response to a GIN infection. All lambs were genotyped with a medium-density genomic panel with 40,598 markers used for analysis. Separate GWASs were conducted using fecal egg counts (FECs) from lambs (<1 year of age) that acquired their artificial infections via an oral inoculation of 10,000 Haemonchus contortus larvae (n = 145) or naturally while grazing on pasture (n = 184). A GWAS was also performed for packed cell volume (PCV) in artificially GIN-challenged lambs. A total of 26 SNPs exceeded significance and 21 SNPs were in or within 20 kb of genes such as SCUBE1, GALNT6, IGF1R, CAPZB and PTK2B. The ontology analysis of candidate genes signifies the importance of immune cell development, mucin production and cellular signaling for coagulation and wound healing following epithelial damage in the abomasal gastric pits via H. contortus during GIN infection in lambs. These results add to a growing body of the literature that promotes the use of genomic selection for increased sheep resistance to GINs. Full article

Sheep growth performance, mainly skeletal muscle growth, provides direct economic benefits to the animal husbandry industry. However, the underlying genetic mechanisms of different breeds remain unclear. We found that the cross-sectional area (CSA) of skeletal muscle in Dorper (D) and binary cross-breeding (HD) was higher than that in Hu sheep (H) from 3 months to 12 months after birth. The transcriptomic analysis of 42 quadriceps femoris samples showed that a total of 5053 differential expression genes (DEGs) were identified. The differences in the global gene expression patterns, the dynamic transcriptome of skeletal muscle development, and the transcriptome of the transformation of fast and slow muscles were explored using weighted correlation network analysis (WGCNA) and allele-specific expression analysis. Moreover, the gene expression patterns of HD were more similar to D rather than H from 3 months to 12 months, which might be the reason for the difference in muscle growth in the three breeds. Additionally, several genes (GNB2L1, RPL15, DVL1, FBXO31, etc.) were identified as candidates related to skeletal muscle growth. These results should serve as an important resource revealing the molecular basis of muscle growth and development in sheep. Full article

Prolificacy is a crucial characteristic of livestock, particularly for species such as sheep that have many births. The objectives of this study were as follows: (1) to investigate the genetic diversity of the 13 new and 7 known variants in the BMPRIB, GDF9, BMP15, LEPR, and B4GALNT2 genes in Ujimqin (UM), the F1 population of Dorper × Ujimqin crossbred (DPU), the F1 population of Suffolk × Ujimqin crossbred (SFKU), Sonid sheep (SN), Tan sheep (Tan), Hu sheep (Hu), and Small-tailed Han sheep (STH) sheep breeds/populations; (2) to perform an association analysis of the above 20 variants with litter size in 325 UM, 304 DPU, and 66 SFKU sheep populations; (3) to compare the frequencies of the litter-size-related alleles of these 20 variants among 8 sheep breeds/populations (the above seven sheep breeds + Mongolia sheep breed). With the use of the Sequenom MassARRAY^®SNP assay technology, these 20 mutations were genotyped. The association analysis results showed that the c.746A>G (FecB) mutation in BMPR1B was significantly associated with the litter size of UM and DPU, the c.994A>G (FecG^A) in GDF9 was significantly associated with the litter size of SFKU, and the c.31_33CTTinsdel (B1) in BMP15 was significantly associated with the litter size of UM. Our findings might provide valuable genetic markers for expanding sheep litter sizes. Full article

The purpose of this study was to analyze the effects of corn substitution on the rumen functions and fatty acid profile of Dorper lambs fed a diet based on palm kernel cake (PKC). Corn was replaced with PKC basal diet at the following levels: C0% = (0% corn + 75.3% PKC), C1% = (5% corn + 70.3% PKC) and C2% = (10% corn + 65.3% PKC) of diet. The rumen fermentation was carried out in vitro, and feeding trials were in vivo. Twenty-seven lambs were used to determine gastrointestinal tract content and rumen fluid fatty acid. Rumen liquor was obtained from four fistulae Dorper sheep and incubated with 200 mg of each treatment for 24 and 72 h. In vitro organic matter digestibility (IVOMD), in vitro dry matter digestibility (IVDMD), volatile fatty acids (VFA), methane estimation (CH₄), rumen microbial population and fatty acid biohydrogenation were determined. The results of the in vitro study showed there were no significant differences in IVDMD, IVOMD, NH₃-N, pH and VFA at 72 h. Higher significant CH₄ production was observed in C0% when compared with C1% and C2%. Microbial population did not differ significantly between treatment groups. The rates of biohydrogenation were not affected by corn substitution, although a significant difference was observed in C18:1n9 (in vitro) and C18:1 t-11 (in vivo). In conclusion, the present study indicated that the corn substitution in the PKC diets maintained fermentation characteristics with an increase in unsaturated fatty acids in the rumen. Full article