Mahmoudzadeh H, Fazaeli H, Kordnejad I, Mirzaei H R
Department of Animal and Poultry Health and Nutrition, Faculty of Veterinary Medicine, University of Tehran, P.O. Box 14155-6453, Tehran, Iran.
Pak J Biol Sci. 2007 May 1;10(9):1398-405. doi: 10.3923/pjbs.2007.1398.1405.
A factorial experiment with completely randomised design was conducted, using 27 heads of 15 month buffalo male calves with initial live weight of 287 +/- 15 kg. The animals were individually housed and randomly allocated into 9 treatment groups of three animals each. Three levels of energy (E1, E2, E3) with three levels of crude protein (P1, P2, P3) were formulated to provide 90, 100 and 110% requirement equivalents for 900 g, expected body weight gain of steers derived from NRC beef cattle requirements (1976). Live weight changes were obtained by direct weighing of the animals every month and ended by slaughtering the calves for carcass index measurements. Results indicated that Dry Matter Intake (DMI) was not significantly different between treatments. Average Daily Gain (ADG) ranged from 503 to 951 g/animal that was significantly varied among the diets (p < 0.05). The significantly higher daily gain was obtained (p < 0.05) when animals received medium energy diets that was similar to 100% beef cattle steer requirements. In addition the feed conversion ratio was significantly lower, when the animals received medium energy diets (p < 0.05). The dressing yield as well as the meat % age was not affected by the type of the diet, but abdominal fat was significantly higher in medium energy diets (p < 0.05). It can be concluded that the optimum fattening performance of 15 month old buffalo male calves may be obtained by providing around 10.42 MJ/kg of dietary metabolisable energy and about 10.22% of crude protein.
进行了一项完全随机设计的析因试验，使用了27头15月龄的雄性水牛犊牛，初始体重为287±15千克。这些动物单独饲养，并随机分为9个处理组，每组3只动物。配制了三种能量水平（E1、E2、E3）和三种粗蛋白水平（P1、P2、P3），以提供相当于美国国家研究委员会（NRC）肉牛营养需要量（1976年）中900克育肥牛预期体重增加量的90%、100%和110%的营养需要量。通过每月直接称量动物体重来获取体重变化情况，试验结束时宰杀犊牛以测量胴体指标。结果表明，各处理间的干物质采食量（DMI）无显著差异。平均日增重（ADG）范围为503至951克/动物，不同日粮间差异显著（p<0.05）。当动物采食与100%肉牛育肥营养需要量相似的中等能量日粮时，日增重显著更高（p<0.05）。此外，当动物采食中等能量日粮时，饲料转化率显著更低（p<0.05）。日粮类型对屠宰率和肉的比例没有影响，但中等能量日粮的腹部脂肪显著更高（p<0.05）。可以得出结论，通过提供约10.42兆焦/千克的日粮代谢能和约10.22%的粗蛋白，可使15月龄雄性水牛犊牛获得最佳育肥性能。
