Comparison of lamb production from indigenous and exotic x indigenous ewes in Indonesia

Lamb production in relation to total feed consumption was recorded in Javanese thin tail (JTT) ewes and in first cross Suffolk x JTT (SX), Wiltshire Horn x JTT (WX) and Poll Dorset x JTT (DX) ewes over three successive lambings or for 21/2 years after joining with rams of the same genotypes in a continuous mating system. For the JTT, SX, WX and DX genotypes respectively, total numbers of lambs weaned per ewe joined were 3.77, 2.50, 2.08 and 1.33, mean lamb body weights at weaning were 12.8, 18.8, 18.6 and 20.9 kg, total weights of lamb weaned per ewe joined were 48.4, 46.9, 38.8 and 27.9 kg, and average weights of feed consumed by the whole production system per kg of lamb weaned were 16.4, 21.9, 23.5 and 32.8 kg. Thus cross-bred ewes required more feed to produce fewer though heavier lambs without any real increase in total productivity.