Effects of dietary vitamin E supplementation on growth performance, slaughter performance, antioxidant capacity and meat quality characteristics of finishing bulls.

This study was conducted to investigate the effects of dietary supplementation of vitamin E (VE) on growth performance, slaughter performance, antioxidant capacity and meat quality characteristics of finishing bulls. Twenty Yanbian cattle (bulls) with initial body weight (BW) 485 ± 42 kg were randomly divided into two groups (control and treatment groups) and participated in a100-day finishing trial. The control group (CON) was fed a basal diet (total mixed ration, TMR). The treatment group was fed a basal diet supplemented with VE (provided as α-tocopherol acetate, 700 IU/bull/day). VE supplementation significantly increased the average daily gain (ADG) of finishing bulls, the beef marbling score, meat color parameters (a* [redness]), intramuscular fat content, the concentration of catalase, superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), VE and matrix metalloproteinases (MMP-13) in the serum and muscle tissue (P < 0.05). VE supplementation significantly decreased drip loss and cooking loss of the beef, the concentration of nitric oxide (NO) in the serum and muscle tissue, the concentration of malondialdehyde in the muscle tissue (P < 0.05), and tended to decrease the feed: gain (P = 0.077) and shear force (P = 0.062) of the beef. In conclusion, VE supplementation can improve the meat quality parameters of finishing bulls, especially the improvement of beef tenderness. The improvement of beef tenderness by VE supplementation may be related to the increase of MMPs concentration, and a potential mechanism for the secretion of MMPs by VE supplementation may be related to its antioxidant capacity.

Correlations between circulating leptin concentrations and growth performance, carcass traits, and meat quality indexes in finishing Simmental × Luxi bulls fed high-concentrate diets.

Circulating leptin concentrations could potentially be used as a predictor of production traits in cattle. This study aimed to clarify the correlations between circulating leptin concentrations and growth performance, carcass traits, and meat quality indexes in finishing bulls fed high-concentrate diets (concentrate-to-forage ratio 70:30). Fifty-seven Simmental × Luxi F1 crossbred bulls were used for 112-day finishing experiment. Circulating leptin concentrations and relevant indexes of growth performance, and carcass traits and meat quality were measured during or after finishing trail. The results indicated that the leptin concentrations tended to be negatively correlated with dry matter intake (DMI) (r = -.233, p = .081), and were positively correlated with 12th-rib fat thickness (r = .330, p = .012), marbling score (r = .336, p = .011), and intramuscular fat content (r = .368, p = .021). Moreover, the leptin concentrations were negatively correlated with cholesterol content (r = -.339, p = .037) and were not correlated with sensory indexes including tenderness, juiciness, and like flavor (p > .05). In conclusion, circulating leptin concentrations may potentially be used as a predictor of carcass traits related to content of fat and beef quality traits related to content of cholesterol in finishing bulls fed high-concentrate diets.