Pre-weaning growth performance of crossbred lambs (Dorper × indigenous sheep breeds) under semi-intensive management in eastern Ethiopia

Abstract

A study was conducted to assess the effect of genetic and non-genetic factors (litter size, sex of lamb, and parity of dam) on pre-weaning growth performance of crossbred lambs (75% Dorper (DR) 25% indigenous lambs; and 50% Dorper 50% indigenous lambs) under semi-intensive husbandry practices in eastern Ethiopia. Data from a total of 275 Dorper sire breed × indigenous (Blackhead Ogaden [BHO] and Hararghe Highland [HH]) crossbred lambs with different genetic group of the parental breeds were collected for three consecutive years (2009 to 2011). Pre-weaning growth performance attributes of crossbred lambs studied were birth weight, weaning weight, and pre-weaning average daily gain. Data were analyzed using the GLM procedure of SAS (2003). Breed group and non-genetic factors significantly affected pre-weaning growth performance. Lambs with 75% Dorper and 25% indigenous had higher (P < 0.01) birth weight than 50% DR and 50% HH but similar to 50% DR and 50% BHO. Weaning weight and pre-weaning live weight gain were higher (P < 0.01) for ¾DR¼BHO and ¾DR¼HH than 50% Dorper inheritance. Single-born lambs had higher weight at birth, weaning weight, and pre-weaning average daily gain as compared to twins. Sex comparison is significant (P < 0.05) and male lambs recorded highest pre-weaning growth performance compared to female counterparts. Parity, season, and lambing year significantly (P < 0.01) influenced the pre-weaning growth of crossbred lambs. Therefore, it could be concluded that 50-75% Dorper inheritance improved pre-weaning growth performance of indigenous breeds of Hararghe Highland and Blackhead Ogaden sheep. The result also suggested culling of ewes older than fourth parity to improve the pre-weaning growth performance of lambs.

Early growth and survival rates of crossbred lambs (Dorper x indigenous) under semi-intensive management at Areka, Southern Ethiopia: Effects of non-genetic factors

“…Generally, higher birth weight and subsequent weights found in our study, during the heavy rainy season, concurs with the previous reports (Taye et al, 2010;Teklebrhan et al, 2014). Except preweaning growth rate, there was a general faster postweaning and overall ADG during the light and heavy rain season mainly due to feed availability both in quality and quantity.…”

“…This could be associated with seasonal nutrient fluctuations (Legesse, 2008) and feed selection behaviour of sheep (Deribe et al, 2014). The reported higher body weights and ADG of lambs during the heavy rain and part of light rain seasons is consistent with other reports (Teklebrhan et al, 2014). On the other hand, the higher body weight and faster preweaning gain during early dry season at some ages is partly due to better body reserves of dams at the end of heavy rain season, and the associated higher milk yield.…”

“…That could be a reason for decreased body weights and ADG as litter size increased. The overall ADG (0 to 180 days of age) and lamb output found in our study is comparable with previous reports of crossbred lambs under similar management condition (Teklebrhan et al, 2014). Generally, single births attained higher body weights (0 to 180 days) and ADG (pre, post and overall) than twin and triplets.…”

“…The influence of season of birth on birth weight, weight at various ages and ADG has been well documented at station (Gootwine et al, 2008;Teklebrhan et al, 2014) and under smallholder management systems (Hassen et al, 2002;Deribe et al, 2014). Generally, higher birth weight and subsequent weights found in our study, during the heavy rainy season, concurs with the previous reports (Taye et al, 2010;Teklebrhan et al, 2014).…”

“…It plays a significant role in creating employment opportunities, income generation, capital reserve, and improving household nutrition (Kocho et al, 2011;Teklebrhan et al, 2014). Ethiopia's sheep population is estimated at 24 million heads categorized into 18 to 19 sheep breeds or populations (Gizaw et al, 2011).…”