Effect of Milk Fat Levels on Growth and Efficiency of Energy Utilization for Weight Gain in Dairy Calves Fed Ad Libitum

Abstract

Jersey calves were fed ad libitum on milk diets containing 3, 6 and 9% fat. Each diet was fed undiluted and diluted with 1.5 parts of water to three calves 2 through 22 days of age. As dietary energy levels decreased energy intakes diminished but fluid intakes increased. Weight gains on the 3, 6 and 9% undiluted milks averaged 21.3, 16.4 and 16.9 kg, respectively, and 10.3, 13.4 and 13.2 kg, respectively, for the diluted diets. For rapid weight gain the undiluted 3% fat diet was most satisfactory with the undiluted 6 and 9% fat diets acceptable under conditions where health problems are minimal. Calves on the undiluted 6 and 9% fat diets appeared to be less resistant to digestive disturbance and this was reflected in lowered weight gains. Metabolizable energy intakes per gram gain were significantly lower (5.8, 5.8, 5.9 kcal) on the undiluted 3, diluted 3 and 6% milks than on the undiluted 6 and 9 and diluted 9% fat milks (7.4, 8.3, 7.9 kcal). Metabolizable energy intakes above resting metabolism per gram gain ranged from 2.5 on the 3% diluted to 6.2 on the undiluted 9% milk. When the values for the different diets were adjusted for differences in energy intake and the data for the undiluted and diluted diets was pooled, the adjusted means of 3.6, 4.5 and 5.2 kcal per gram gain, respectively, for the 3, 6 and 9% fat diets differed significantly (P<0.05).