Environmental and genetic effects on preweaning growth performance of hair sheep in Mexico

Abstract

Data on 4,754 lambs born from Pelibuey (PB) and Barbados Blackbelly (BB) ewes collected over 9 years at the Mococha Experimental Centre in Yucatan, Mexico, were used to determine environmental, dam-breed and sire-breed effects on birth weight (BW), weaning weight (WW) and average daily gain (ADG). Effects of year and season of birth, sex of the lamb, type of birth, breed of dam, breed of sire, their interaction and ewe body weight were included. Heritabilities were estimated for each breed. Season of lambing was a significant source of variation on WW and ADG. Male lambs weighed more than female lambs at birth and weaning. Single born lambs were heavier than twins and triplets. Lambs born from PB dams were heavier and grew faster than those born from BB dams. Heritabilities of BW, WW and ADG for the PB breed were 0.16 +/- 0.04, 0.12 +/- 0.03 and 0.11 +/- 0.03, respectively and 0.04 +/- 0.07, 0.17 +/- 0.09 and 0.15 +/- 0.08 for the BB breed. Heterosis values were close to zero.

Effect of some factors on growth of lambs from crossing between the Improved Wallachian and East Friesian

“…This is in agreement with the results by Carrillo and Segura (1993), Analla et al (1998), Goetsh (1998), and Fernandes et al (2001). On the other hand, as far as daily gains were concerned, it was found that this factor was a relatively significant source of variation because the highest values of DG 1, DG 2 and DG 5 were found in singles, twins and triplets, resp.…”

“…This is in agreement with the results by Carrillo and Segura (1993). Higher DG 1 and DG 5 were found out in lambs born in February whereas higher DG 2 and DG 6 were found out in lambs born in January.…”

The estimation of variance components for prolificacy and growth traits of Sakız sheep

“…The estimate of direct heritability for weaning weights was also in general agreement with the estimated weight of 0.10 to 0.147 for different sheep breeds reported by Hanford et al (2006), Reale et al (1999); Notter and Hough (1997); Ozcan et al (2005), Carrillo and Segura (1993) and Babar et al (2003). The estimate of direct heritability for weaning weight was also lower with the estimated weight of 0.25 to 0.35 for different sheep breeds reported by Tosh and Kemp (1994), Hanford et al (2003) and Hanford et al (2006).…”

“…The estimate of direct heritability for weaning weight was also in general agreement with the estimated weight of 0.10 to 0.17 for different sheep breeds reported by Ligda et al (2000), Tosh and Kemp (1994), Nakagawa et al (2005), Reale et al (1999), Hanford et al (2006), Ligda et al (2000), Wyk et al (2003), Carrillo and Segura (1993); Babar et al (2003);and Bahereini et al (2007). The estimate of direct heritability for weaning weights was also in general agreement with the estimated weight of 0.10 to 0.147 for different sheep breeds reported by Hanford et al (2006), Reale et al (1999); Notter and Hough (1997); Ozcan et al (2005), Carrillo and Segura (1993) and Babar et al (2003).…”

“…Reported estimates direct heritability for different sheep breeds range from 0.00 to 0.38 for lamb birth weight, 0.025 to 0.49, for weaning weight (Babar et al, 2003;Bahreini et al, 2007;Duru and Koyuncu, 2005;Hanford et al, 2006;Ligda et al, 2000;Maria et al, 1993;Carrillo and Segura, 1993;Hanford et al, 2003;Nakagawa et al, 2005;Noter and Hough, 1997;Ozcan et al, 2005;Reale et al, 1999;Sawalha et al, 2005;Szwaczkowski et al, 2006;Tosh and Kemp, 1994;Wuliji et al, 2001;Wyk et al, 2003) and 0.12 to 0.25 for yearling weights (Reale et al, 1999;Ozcan et al, 2005), and 0.11 to 0.33 for average daily gain (Carrillo and Segura, 1993;Maria et al, 1993;Noter and Hough, 1997;Ozcan et al, 2005).…”