Sex/age of kid/lamb and dam age/parity and managing dam nutrition as determinants of mortality in small ruminants

Abstract

Mortality is one of the prime after effect on viability of commercial goat and sheep meat production efficiency, through its consequential compromised ewe/doe performance and economic losses in production. Several factors are potential determinants of kid/lamb mortality such as birth type, sex and age, birth weight, dam’s milk yield, parity order, dam age, dam weight and condition etc. However, the present review will focus on sex/age of kid/lamb, dam age and parity, and dam nutrition/season as determinants of kid/lamb mortality. Although results on the influence of sex on mortality has been inconsistent, several studies have reported a trend where mortality rates have been sex biased in goat and sheep. Male kids/lambs have lower survival rates and higher mortality hazard ratios as compared to female kids/lambs. Mortality is highest during the initial phase of kid/lamb life and have a propensity to decline as age progresses. Kids/lambs delivered to low parity order dams have low chances of survival due to poor maternal instinct. The advancement of maternal behavior gets better with parity order, as parity order progresses maternal instinct is consolidated. On the other hand, improvement in dam nutrition will enhance dam milking capacity which has been associated with high survivability of kids/lambs. This entails understanding of nutritional management of dams becomes an essential tool to curtail mortality in goats and sheep. Kidding/lambing season should coincide with seasonal availability of high quality forage to feed nursing dams hence high survivability of kids/lambs. The present discussion will give an insight on the influence of sex/age, dam parity and dam nutrition/season as determinants of mortality in goat and sheep meat production.