Evaluation of sheep breeds for early growth in tropical north-east Brazil

Abstract

Three breeds of sheep, Brazilian Somali, Morada Nova and Santa Inês which are indigenous to hot tropical semi-arid north-east Brazil were studied for their early growth. There were large breed differences in size at birth, at the 86th day and at 6 months. The Santa Inês was the largest and the Brazilian Somali the smallest. The type of birth (single vs. multiple) had a profound effect on weight at virtually all stages of growth which was similar for male and female lambs. Sex effects tended to become significant at around the 86th day, female lambs slightly outweighing males but marked sex differences appeared around 6 months when males outweighed females. The 7-day variation in age of lambs when the weights were taken around the 15th day had a marked effect on weight and correction for age would be necessary in future studies. However, the 7-day variation in age around the 86th day and thereafter did not affect the weights. The birth weight and weights at the 15th, 86th and 112 days and at 6 months were significantly correlated.

Performance of three tropical hair sheep breeds

“…Also, part of the type of birth differences a t postpartum ages might be due to the carryover of the heavier weight of singles at birth. Reports from a wide range of production conditions and other breeds (Brown et al, 1961;Sidwell et al, 1970;Gala1 and Awgichew, 19811, as well as from northeastern Brazil using Morada Nova (Figueiredo et al, 1982;Fernandes, 1985;Figueiredo, 19861, indicate similar effects of type of birth on lamb growth traits. The gradual decrease of maternal effect as indicated by birth type and dam age on size as the lamb increases in age (Figure 1) can be explained, at least in part, by the stage of development at which the young are born (Hammond, 1961).…”

Seasonal variation in seminal and testicular characteristics of Brazilian Somali rams in the hot semi-arid climate of tropical northeast Brazil

“…Hairy breeds constitute a sizeable proportion of sheep population of Brazil and are being studied for their potential in the hot tropical climate (Figueiredo, Simplicio & Pant, 1982). The Brazilian Somali breed (Mason, 1980;Shelton & Figueiredo, 1981) is a much modified and locally adapted version of the original import.…”