PRE-WEANING PERFORMZANCES OF CROSSBREEDING BETWEEN LOCAL SUMATERA SHEEP AND HAIR SHEEP

Abstract

Crossbreeding among Surnatera thin tail sheep and the tropical hair sheep breeds (St Croix and Barbados Blackbelly) have been conducted at the Sungai Putih Research Station, since 1986, in order to create composite brwds with genotype composition of 25% St. Crobg 25% Barbados Blackbelly, 50% Srmatera Results of the study show that the mean of birth weight of composite genotype (2.45 kg) is higher (P<.05) than that of St. Croix cross (2.23 kg), Barbados cross (2.15 kg)
and Sumatera sheep (1.68 kg). The differences in birth weight are continued imtil weaning. Weaning weight of composite genotype (13.14 kg) is higher than that of Barbados Blackbelly cross (11.73 kg), St. Croix cross (11.67 kg) and Surnatera sheep (8.67 kg). Composite genotype has improved weaning weight around 36.51% as compared to Surnatera sheep. From the analyses of the pre-weaning weight show that breed of ewes, sex of lambs and type of birth influence
significantly to the pre~weaning weight Composite genotype has survival rates (93.l2%) higher than that of other parental breeds (85%). Multiple birth tends to have low survival rates. Multiple birth tends to have survival rates similar to twinbom lambs of Surnatera sheep (85%). Growth rates of composite genotype (101.5 g/d) and Barbados cross (108.2 yd) higher than that of St. Croix cross (97.4 g/d) and Sumatra sheep (81.5 g/d). The higher weight of composite genotype and the St Croix and Barbados Blackbelly cross indicate that these sheep have adapted to the local environment.