title: Effects of vitamin A supplementation on growth performance, carcass characteristics and meat quality in Limosin×Luxi crossbreed steers fed a wheat straw-based diet.
abstract: Three experiments were conducted to examine the effects of dietary vitamin A supplementation on performance and carcass parameters in Limosin×Luxi crossbreed finishing steers fed a wheat straw-based diet. Sixteen 12-month old (301±22kg) steers, 16 12-month old (309±15kg) steers and 16 24-month old (411±20kg) steers were used in experiment 1 for 6 months feeding period, in experiment 2 for three months feeding period and in experiment 3 for three months feeding period, respectively. Sixteen steers of each experiment were randomly divided into the four groups of four animals. Treatments consisted of four vitamin A supplementation levels (0, 1100, 2200 and 4400IU/kg DM). The growth rate was affected by dietary vitamin A level in experiment 1 and 2, revealing that the suitable amount of vitamin A supplementation increased the growth rate; excessive vitamin A in the ration decreased the growth rate of 12-month-old finishing steers. The marbling deposition decreased with the increment of vitamin A supplementation level, but possibly associated with vitamin A supplementing duration. Furthermore, the suitable dietary vitamin A level probably decreased lipid and pigment oxidation, and increased the tenderness of beef meat. Vitamin A supplementation had no significant effect on chemical composition of gluteus medius muscle and longissimus dorsi muscle.
authors: Key Laboratory of Subtropical Agricultural Ecology, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha 410125, PR China; Graduate University of the Chinese Academy of Sciences, Beijing 100039, PR China.
authors: W J
authors: WJ
authors: Wang
authors: S P
authors: SP
authors: Wang
authors: Y S
authors: YS
authors: Gong
authors: J Q
authors: JQ
authors: Wang
authors: Z L
authors: ZL
authors: Tan