Weaning age/time based model influencing performance in goats and sheep meat production

Abstract

Weaning is an essential animal husbandry intervention which has been associated with nutritional stress that interferes with both animal’s behavioral and physiological responses consequently influencing post weaning growth performance in goats and sheep production. The timing of weaning and/or weaning age of kids/lambs becomes critical in determination of flock performance with the intention of maximizing meat productivity and improving profitability. There are two possibilities that exist in deciding on weaning age of kids/lambs, thus early and late weaning, however, the decision on when to wean is dependent mainly on the production environment and purpose, as well as the dam welfare.   Age at weaning differ greatly in sheep and goats, therefrom 14 days to natural weaning, and exceeding four months of age. In sheep production effective early weaning has been practiced untimely at 14 days; in goats’ kids have been weaned early successfully at 28 days. Early weaning is considered traditionally weaning ahead of the 90 days of age; 60 days is most widely used; age thereafter qualifies for late weaning. The age at weaning greatly influences post weaning animal performance, however if not timed properly it would impact negatively also on weaner survival rates. Weaning itself is a very stressful procedure and subjecting kids/lambs to further stress which directly impinge on the kid/lamb’s immunity consequently increasing their susceptibility to diseases and reduced weight gain. There is need for age of weaning to balance the potential positive impacts on the ewes/does to rebreed, with potential negative impacts on the kid/lamb growth performance and survivability. Early weaning has become an effective husbandry practice especially in advanced goat and sheep production systems, which focuses on shortened female breeding reproductive cycle, while enhancing meat productivity through increased frequency of kidding/lambing. It is important to consider weaning age in relation to nutritional strategies which provide adequate time for diet transition which is intended not to compromise feed utilization and feed conversion efficiency in kids/lambs consequently reducing growth performance. The effectiveness of weaning age and anticipated live weight gains post-weaning is dependent on nutritional management especially concentrate supplementation which may promote performance and productivity in pastured based systems. Late weaning is probably convenient for less prolific goat and sheep breeds and genotypes not selected for their growth potential. It should be acknowledged that there is interaction between weaning age with other factors such as nutrition, sex and weight of animal. Some of the goat and sheep producers worldwide have shifted to use of weight based weaning model, similar age but with different weights, heavier lambs have superior development efficiency during lactation. The present review gives an insight on the consequences of early and late weaning on animal’s post weaning performance in small ruminants.