Climate-influenced performance and offspring development of merino sheep in a dry temperate-cold valley

Abstract

This study aims to explore the effects of climate on the performance and offspring development of aged Merinosheep relocated from an arid, cold environment with harsh grazing conditions to a dry, temperate-cold valleywith irrigated pasture production. We utilized time series data from merino sheep in a dry temperate-coldclimate in southern Argentina to characterize their growth curves, assess the impact of climate on performance,and compare offspring growth with maternal growth. Our approach involved developing a dynamicmodel, a non-autonomous differential equation growth curve based on the widely used Brody model. The modelconsidered variables such as local temperature, age, sex, origin, and pregnancy status to determine the optimalcombination of parameters for sheep growth in our dataset. The results have shown that moving the old sheepfrom the steppe to the valley resulted in an increase of an average of 1 kg in weight, but their offspring had anasymptotic weight of 65 kg, 17 kg more than their mothers. The optimum temperature for the growth rate was15.7+/-0.56 C and 8.7+/-6.3C for the asymptotic weight.