Effect of plane of nutrition on body weight and birth weight of pregnant Gwembe Valley goats in Zambia

Abstract

Pregnant Gwembe Valley goats, aged 18–24 months, with an average BW of 23.2±0.82 kg were used. In addition to hay, they were fed concentrate mixtures for 12 weeks that contained 12.2, 13.3 or 13.7 MJ GE/kg and 14.3, 13.4 and 12.2% CP. Three dietary treatments were high protein-low energy (HL), medium protein-medium energy (MM) and low protein-energy (LH). Voluntary daily intake of concentrate before kidding was 0.53±0.08, 0.62±0.10 and 0.48±0.08 kg/doe for HL, MM and LH, respectively; and intake was more ( P < 0.05) in MM. Average daily live weight gains were 25 ± 0.08, 43 ± 0.53 and 24 ± 0.08 g/doe for HL, MM and LH groups. Intakes of concentrates after kidding were not significantly different ( P > 0.05); however, hay intakes differed ( P < 0.05) between groups. Mean birth weights of kids were 1.24±0.41, 1.60±0.13 and 1.63±0.09 kg for HL, MM and LH groups. Birth weights of kids were not different ( P > 0.05) between MM and LH, but they differed slightly from the HL group. Apparent digestibility coefficients were significantly influenced ( P < 0.05) by levels of protein and energy. From these results, the estimated optimal protein and energy requirements in concentrate supplements for pregnant Gwembe Valley goats is 13.4% CP and 13.3 MJ GE/kg, since body weight and birth weight were best at that level.