Effects of Dietary Cobalt Supplemental Level on Growth Performance, Slaughter Performance, Muscle Quality and Fur Quality of Weaned to 3-Month-Old Rex Rabbits
This experiment was conducted to study the effects of dietary cobalt supplemental level on growth performance, slaughter performance, muscle quality and fur quality of weaned to 3?month?old Rex rabbits. Two hundred weaned Rex rabbits were randomly assigned into 5 groups with 40 replicates in each group and each replicate contained 1 rabbit. Rabbits in 5 groups were fed experimental diets which supplemented with 0, 0.1, 0.4, 1.6 and 6.4 mg/kg cobalt ( in the form of cobalt sulfate) on the basis of a basal diet, respectively. The trial lasted for 7 days for adaptation and 60 days for test. The results showed that dietary cobalt supplemen?tal level had significant influences on final body weight ( FBW) ( P<0.05) and average daily feed intake ( AD?FI) ( P<0.01) , but had no significant influences on average daily gain ( ADG) and feed/gain ( F/G) ( P>0.05). With the increase of dietary cobalt supplemental level, the FBW and ADFI tended to be increased firstly and then decreased, and the highest values appeared when dietary cobalt supplemental level was 0. 4 mg/kg. Dietary cobalt supplemental level had no significant influences on eviscerated ratio, half eviscerated ratio and muscle quality indices including pH, drip loss ratio, shear force and meat color ( L?, a?and b?values) ( P>0.05). However, with the increase of dietary cobalt supplemental level, the eviscerated ratio and half eviscera?ted ratio tended to be increased firstly and then decreased. Dietary cobalt supplemental level had no significant influences on fur area, fur weight and fur thickness ( P>0.05) . With the increase of dietary cobalt supplemen?tal level, the fur weight tended to be increased firstly and then decreased, and the highest value appeared when dietary cobalt supplemental level was 0. 4 mg/kg. Dietary cobalt supplemental level had no significant influ?ences on thymus index, spleen index and liver index ( P>0.05) . With the increase of dietary cobalt supplemen?tal level, the thymus index tended to be increased firstly and then decreased, and the highest value appeared when dietary cobalt supplemental level was 0.4 mg/kg. Considering all indices of this experiment, the appro?priate dietary cobalt supplemental level is 0.4 mg/kg for weaned to 3?month?old growing Rex rabbits ( the basal diet cobalt content is 0.27 mg/kg).
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万方数据
维普
