Effects of feed refreshing frequency on growth and carcass characteristics of Awassi lambs

Abstract

Sixty, two-month old male Awassi lambs were used in this study to investigate the effects of feed refreshing (FR) frequencies on their growth and carcass characteristics over a period of 65 days. Treatments were: Feed refreshing at 2 h (FR2), 4 h (FR4), 8 h (FR8), 12 h (FR12) and 24 h (FR24) intervals. The lambs were fed individually. At the onset of each refreshing period the lambs were offered fresh feed ad libitum. Daily feed intakes, weekly live weights and carcass characteristics were recorded. Daily feed intakes per lamb per treatment were: 1.13 kg, 1.05 kg, 1.00 kg, 0.98 kg and 0.95 kg; daily gains were 193.6 g, 180.6 g, 148.6 g, 169.3 g and 146.4 g; feed conversion ratios (kg feed/kg gain) were 6.1, 6.7, 7.2, 7.2 and 7.5; hot carcass weights were 13.0 kg, 13.1 kg, 12.1 kg, 13.3 kg and 13.1 kg; dressing percentages were 42.3%, 42.4%, 39.9%, 40.2% and 41.2%; the proportion of muscle in the carcass was 52.0%, 55.2%, 55.6%, 55.8% and 54.8%; bone ratio was 20.4%, 20.3%, 21.9%, 21.1% and 20.9%; subcutaneous fat ratio was 16.9%, 14.2%, 12.9%, 12.7% and 14.0% and intramuscular fat ratio was 8.8%, 7.1%, 6.8%, 8.7% and 7.7% in FR2, FR4, FR8, FR12 and FR24 treatments, respectively. Results showed that frequent feed refreshing stimulated feed intake and daily gain without affecting carcass characteristics.

Keywords: Lamb, feeding system, daily gain, body components

South African Journal of Animal Science Vol. 37 (4) 2007: pp. 248-255