Effects of feeding condensed barley distillers soluble on growth rate, ruminal fermentation, plasma metabolites, and myofiber properties of the longissimus thoracis muscle in Japanese Black calves

This study evaluated the effects of condensed barley distillers soluble (CBDS) on growth rate, rumen fermentation, plasma metabolite, and myofiber properties, and gene expression related to metabolism in the skeletal muscles of Japanese Black calves, compared with soybean meal and corn. Twenty-four calves were divided into four groups: fed 5% CBDS based on the hay dry matter weight (low CBDS) and fed soybean meal and corn at the same nutrition level (control); and fed 15% CBDS based on the hay dry matter weight (high CBDS) and fed soybean meal and corn at the same nutrition level (high soy). The daily gain was larger in the low (p = 0.08) and high (p < 0.05) CBDS groups compared with the control group. In the CBDS-fed groups, plasma β-hydroxybutyric acid concentrations were significantly higher at 6 months of age (p < 0.05), the percentage of type I myofibers was significantly lower and their diameters were significantly larger at 9 months of age (p < 0.05), and carnitine palmitoyltransferase 1b mRNA expression was significantly lower (p < 0.05) and citrate synthase mRNA expression tended to be lower (low; p = 0.06, high; p = 0.05) compared with control group. Thus, feeding CBDS promotes growth and leads to animals with more glycolytic and less oxidative muscle metabolism.

Effect of feeding rice whole crop silage on growth rate, levels of vitamin A, β-carotene, vitamin E and IGF-1 in plasma and skeletal muscle protein degradation in Japanese black calves

This study evaluated the effects of rice whole crop silage (RWCS) on growth, plasma levels of vitamin A, β-carotene, vitamin E and IGF-1, and expression of genes involved in muscle protein degradation and synthesis in Japanese Black calves. Eleven calves were divided into RWCS (fed RWCS ad libitum and concentrate, n = 5) and control groups (fed hay ad libitum and concentrate, n = 6). Final body weight and dairy gain were significantly larger in the RWCS group compared with the control group. Plasma β-carotene and vitamin E concentrations were significantly higher in the RWCS group compared with control group. Although plasma vitamin E concentration in the RWCS group significantly increased from 4 to 9 months of age, it did not increase in the control group. At 6 months of age in the RWCS group, ubiquitin B (p < 0.05) and calpain 1 (p = 0.097) mRNA expression were lower than control group, but they were not different between groups at 9 months of age. These results indicate that RWCS increases plasma β-carotene level and promotes muscle growth because of a decrease in the rate of protein degradation, but the effect is lost with the increase in plasma vitamin E level.