Environmental effects on productive and reproductive performance of Pelibuey ewes in Southeastern México

Abstract

The objective of this study was to determine the effect of some environmental factors on reproductive and productive performance traits and to estimate their repeatability in Pelibuey ewes in Yucatan, Mexico. Information of 956 Pelibuey ewes lambing from 2007 to 2013 in three farms were used (n = 2215 lambing). The assessed traits were age at first lambing (AFL), lambing interval (LI), litter size at birth (LSB), litter size at weaning (LSW), litter weight at birth (LWB) and litter weight at weaning adjusted to 60 days (LWWA). Mixed models were used to determine the effects of farm, lambing season or birth, year of lambing or birth and parity number on above traits. Repeatability were calculated using the between and within ewe components of variance. Overall means and standard deviations for AFL, LI, LSB, LWB, LSW and LWWA were 526.7 ± 107.1d, 259.4 ± 70.3d, 1.5 ± 0.6, 4.3 ± 1.6 kg, 1.4 ± 0.7 and 19.1 ± 10.1 kg, respectively. Repeatability for LI, LSB, LSW, LWB and LWWA were 0.06 ± 0.20, 0.12 ± 0.04, 0.00 ± 0.04, 0.13 ± 0.04 and 0.01 ± 0.04, respectively. AFL was not affected by any of the environmental factors. However, the other traits were influenced (p < .05) by farm, lambing year, lambing season, parity and LSB (for LI and LSW). In conclusion, productive and reproductive performance traits of Pelibuey ewes were influenced by environmental factors, and repeatability were lows. To improve the performance of Pelibuey ewes adjustments to management schemes should be made as well as to base the selection on more than one productive and reproductive indicator. ARTICLE HISTORY

Evaluation of some reproductive traits of Pelibuey ewes under humid tropical conditions of Mexico

“…In addition, the difference between mean values of AFL could be attributed to differences between regions and animal management strategies. The lack of influence of season of lambing on AFL in the present study agree with previous results for Pelibuey sheep under tropical conditions (Magaña-Monforte et al, 2013;Tec-Canché et al, 2016). These data suggest that better management and nutrition are needed to improve the reproduction of first-parity ewes.…”

“…The LCI least squares mean found (145.4 days) in this study is higher than those means reported by other authors (subtracting 150 days from lambing interval mean). Lowest overall lambing interval means of 254, 274, 255.9, and 259.4 days were obtained by Galina et al (1996), González-Garduño et al (2001), Magaña-Monforte et al (2013), and Tec-Canché et al (2016 in Pelibuey ewes in the tropics of Mexico, corresponding to LCI of 104, 124.0, 105.9, and 109.4 days, respectively. However, they are similar to the value of 295.7 days of lambing interval notified by Andrade-Montoya et al (2015).…”

“…Therefore, a good practice to implement to improve reproduction in the flock is the energy supplementation of first-parity ewes during the months of food scarcity and the culling of those ewes kept in the flock without reproducing or lasting more than 120 days to conceive. The effect of parity has been reported as an important factor on LCI (López-Leyva et al, 2017) and lambing interval of Pelibuey sheep (Tec-Canché et al, 2016).…”

“…Therefore, their effects must be determined to apply sound management practices. Some authors have reported the effects of year, season, lambing, and nutritional management on the reproductive and productive performance of hair sheep breeds in the tropics (Galina et al, 1996;González-Garduño et al, 2001;Magaña-Monforte et al, 2013;Tec-Canché et al, 2016). However, those authors evaluated Pelibuey performance mainly under subtropical condition and used general linear models to test non-genetic factors.…”

Factors affecting the productivity and the efficiency at weaning of hair ewes in a dry tropical environment

“…The effect of lambing season (<0.05; Table 2) is basically due to nutritional aspects associated to tropical conditions (Duguma et al, 2002;Magaña-Monforte et al, 2013;Hinojosa-Cuellar et al, 2015;Tec-Canche et al, 2016).…”