Abstract

An experiment to evaluate the effect of concentration ratio (R:C) on milk secretion rate (g/h) in goats was carried out using a cross-over design in which each goat passed sequentially through all the treatments in random order. The treatments (R:C) were: A = 70:30; B = 50:50 and C = 30:70. In this experiment, 13 goats were fed at 5% body weight (DM basis) using fresh-cut elephant grass (Pennisetum purpureum) and a 16.44% crude protein concentrate ratio. The goats were milked from the 6th to 9th week of lactation once a day for one week per each treatment. Data was analyzed by using the treatments as main effect with live weight and week of lactation as covariates. The overall milk secretion rate was 6.86 g/h. It was found that the treatment had a high significant effect (P < 0.001) on milk secretion rate. Treatment C gave the highest mean value followed by Treatment B. Treatment A gave the least mean value. The week of lactation and live weight of doe at time of milking had a high significant effect (P < 0.001). Milk secretion data was adjusted to 5th week of lactation and 20 kg live weight of doe, and a predictive model based on quadratic function was developed. Y = 2.27836 + 0.16588X – 0.00135X²; R² = 0.94 where Y = milk secretion rate (g/h) and X = percent concentrate in feed ration. From the curve, the optimum roughage to concentrate ratio (R/C) was 40:60, which should yield a milk secretion rate of 7.37 g/h.

Key words: Pennisetum pupureum, concentrate, goats.