The purpose of this study is to explore the carcass traits, meat quality, and nutritional attributes of local yellow cattle (Guangfeng, Ji’an, and Jinjiang) and buffalo (Poyanghu, Xiajiang, and Xinfeng mountain) in Jiangxi Province, and compare the differences among different breeds. The results showed that the dressing percentage, net meat percentage, and meat–bone ratio of Jinjiang cattle were highest, and that Jinjiang cattle had the best meat production performance. Regarding meat quality, the pH_24h value of all breeds was at normal level, and no dark-cutting beef was produced. Poyanghu buffalo and Xinfeng mountain buffalo had higher redness (a*) values, and Guangfeng cattle had the best water retention and tenderness. The intermuscular fat of yellow cattle breeds was higher than that of buffalo breeds; Poyanghu buffalo had the highest crude protein content. The composition of amino acids and fatty acids was different among breeds, and the composition of Jiangxi breeds was healthy. The muscle fibers of buffalo breeds are generally smaller and denser than those of yellow cattle breeds. The MyHC-Ⅰ, MyHC-Ⅱa, and MyHC-Ⅱx were the main types of muscle fibers of Jiangxi local breeds, and the proportion varied with different breeds. This work elucidated the carcass characteristics, meat quality, and nutritional attributes of Jiangxi breed cattle to provide a theoretical basis for optimizing the development of beef cattle industry.

Heat stress induced by high temperature and humidity in southern China during summer reduce goat production efficiency and meat quality. Taurine (TAU), one of the most abundant amino acids in animal tissues, plays a vital role in alleviating heat stress and regulating energy metabolism through its involvement in glucose uptake and glycogen turnover. This study aimed to investigate the effects of rumen-protected (RP)-TAU on the meat quality, hepatic gluconeogenesis, and muscle energy metabolism of heat-stressed goats. During summer, twenty-four male crossbred Gan-xi goats (20.45 ± 2.95 kg) aged 5 months were randomly allocated to two groups treated with or without 0.4% RP-TAU (on a diet weight basis). After feeding for 60 days, six goats per treatment were slaughtered. Compared with the control group, RP-TAU supplementation significantly improved the growth performance of goats, as evidenced by increased final body weight, average daily gain, and average daily feed intake (p < 0.05). The goats in the RP-TAU group showed a reduced splenic index (p < 0.05), lower serum cortisol levels (0.05 < p < 0.1), and decreased muscle crude fat content (p < 0.01). Crucially, meat quality was improved with reduced hardness, gumminess, and chewiness (p < 0.05), indicating better textural properties. Nutritionally, RP-TAU supplementation modulated the muscle fatty acid profile, significantly reducing the concentrations of palmitic (a saturated fatty acid), palmitoleic (a monounsaturated fatty acid), and nervonic acids (p < 0.05), while cystine content was reduced (p < 0.05). RP-TAU supplementation significantly enhanced the muscle contents of glucose and glycogen, glycolytic potential, phosphofructokinase activity, and ATP level, while decreasing the pyruvate level and AMP/ATP ratio (p < 0.05). Gene expression analysis revealed the upregulation of GLUT4 and PYGM and the downregulation of GSK3β in muscle (p < 0.05). These results indicated that dietary supplementation of RP-TAU might be beneficial to improve stress resistance and meat quality by increasing muscle energy supply and glucose uptake in Gan-xi goats.

Prolonged high temperature and humidity pose significant challenges to sheep health and productivity due to heat stress. This research assessed the physiological regulatory impact of supplementing heat-stressed Hu sheep with rumen-protected taurine. Forty-eight animals were assigned to four groups receiving different taurine doses over a 63-day period. A comprehensive evaluation was conducted on growth performance, nutrient digestibility, serum biochemical parameters, antioxidant and immune indices, transcriptomic profiles, and gut microbiota composition. Dietary supplementation with 0.4% RPT significantly enhanced feed intake, daily weight gain, and feed efficiency. Serum analysis revealed increased taurine and high-density lipoprotein levels, reduced cortisol and inflammatory cytokines, and elevated antioxidant enzyme activity. Transcriptomic analysis identified differentially expressed genes enriched in immune and antiviral pathways, including JAK-STAT signaling pathway being among those highlighted. Gut microbiota profiling showed increased diversity and improved composition, particularly Olsenella and its several species were positively correlated with anti-inflammatory responses. These findings demonstrate that rumen-protected taurine supplementation at 0.4% can effectively alleviate heat stress by improving physiological resilience, immune balance, and gut health in sheep. This research provides a scientific basis for developing nutritional strategies to enhance animal welfare and productivity under climate stress conditions.

Preslaughter nutritional strategies that preserve energy reserves in transported beef cattle may help maintain normal post-mortem muscle metabolism and meat quality. β-alanine, a carnosine precursor, enhances glucose metabolism and glycogen reserves. This study evaluated the effects of rumen-protected β-alanine (RP-β-Ala) on meat quality, hepatic gluconeogenesis-related indices, and muscle energy metabolism in long-distance transported cattle. Thirty-six healthy 18-month-old Simmental crossbred bulls (627 ± 41 kg) were randomly assigned diets containing 0 (control) or 96 g/head/d RP-β-Ala. After 28 days of feeding, serum was sampled from six bulls per group. Following a 2-day rest (RP-β-Ala supplementation continued), these twelve bulls were transported, slaughtered, and sampled. Transport significantly increased serum lactate dehydrogenase (LDH) and creatine kinase (CK). The transport × RP-β-Ala interaction significantly affected serum superoxide dismutase (SOD). Post-slaughter tissue indices were analyzed solely for the effect of RP-β-Ala supplementation, as all slaughtered bulls underwent transportation. Compared to controls, the RP-β-Ala group exhibited significantly higher muscle pH_{45 min} and an accelerated pH decline rate within 24 h post-mortem in both M. longissimus dorsi (LD) and M. semitendinosus (ST) muscles. In LD muscle, hardness, shear force, gumminess, and chewiness significantly decreased, while ATP content and HK, PFK, PK, and LDH activities significantly increased. In ST muscle, lactate content and GP, HK, PFK, and LDH activities significantly increased. In the liver, glucose, lactate, ATP, and ADP contents significantly increased, alongside enhanced G-6-Pase and pyruvate carboxylase (PC) activities. Dietary RP-β-Ala supplementation may regulate energy metabolism in transported cattle by enhancing muscle glycolytic activity and indices associated with hepatic gluconeogenic capacity, thereby improving selected meat-quality traits.