Effects of sugarcane silage on feed intake and growth rate of Japanese Black steers during rearing period

Abstract

This experiment evaluated the effects of 3 levels of sugarcane silage (0, 50 and 100% of forage) on feed intake and growth rate of Japanese Black steers (5 months of age, average BW : 174kg) during rearing period. Five steers were given oats hay (0% group), five steers were given a mixture of equal amount of oats hay and sugarcane silage on a fresh matter basis (50% group), and four steers were given sugarcane silage (100% group) for 5 months. Each steer fed ad libitum on the forage and the concentrate intake was gradually restricted from 2.1% to 1.5% of BW during rearing period. The average pH and V2-SCORE of sugarcane silage were 3.8 and 97, respectively. The NDF and ADF contents were 55 and 30% for oats hay and 73 and 45% for sugarcane silage, respectively. The dry matter (linear P < 0.10), forage (linear P < 0.05, quadratic P < 0.10), TDN (linear P < 0.05) and CP (linear P < 0.10) intake (kg/day) tended to show a high value in the 0% group or 50% group, and the lowest value in the 100% group. The dry matter (linear, P < 0.05 ; quadratic P < 0.05), forage (dry matter basis, linear, P < 0.01 ; quadratic P < 0.05) and TDN (linear, P < 0.01 ; quadratic P < 0.05) intake per body weight exhibited a high value in the 50% group and the lowest value in the 100% group. The CP intake per body weight (linear, P < 0.05 ; quadratic P < 0.10) tended to show a high value in the 0% group and in the 50% group, and the lowest value in the 100% group. Concentrate (dry matter basis, kg/day, %BW), NDF and ADF intake (kg/day, %BW) were not significantly different among treatments. The DG in the 0%, 50%, and 100% group was 1.10, 1.03 and 0.96 kg/day, respectively, which tended to show a linear decline as the proportion of sugarcane silage in the forage increased. The NDF and ADF intake(%BW) were 0.92 and 0.47% for the 0% group, 0.99 and 0.53% for the 50% group, and 0.88 and 0.50% for the 100% group, respectively. Therefore, the higher fiber content could be one factor responsible for the decline in forage intake. These results suggested that sugarcane silage was efficient for rearing Japanese Black steers when given in adequate amount of concentrate considering the latter's fiber content.