The effect of litter size and birth weight on the pre-weaning survivability of Kalahari Red goats

Pre-weaning mortality is a challenge for goat production systems, especially under extensive management. The study investigated the effect of the litter size and birth weight on the pre-weaning survivability of Kalahari Red goat kids. A longitudinal dataset which comprised of the litter size, birth weight and mortality records that occurred over 15 years (2009-2024) was retrieved from the database. A two-way analysis of variance was used for analysis. The results indicated that the litter size had a significant impact (p < 0.05) on the pre-weaning survivability of kids and pre-weaning survival rates were shown to decrease with an increasing litter size, from a survival rate of 95% in singletons to one of 69% in quintuplets. The results showed that the birth weight, nor its interaction with litter size, were not significantly (p > 0.05) associated with the pre-weaning survivability of Kalahari Red kids, although a positive trend was identified where heavier kids exhibited higher survival rates with kids born under 2 kg having a pre-weaning survivability of 93% and those with a birth weight greater than 6 kg having a 100% having a pre-weaning survivability. In conclusion, this study suggests that litter sizes 1-4 make for the most viable pre-weaning survivability rates and that, although not significantly associated in the current study, higher birth weights are positively associated with better pre-weaning survivability rates. The results of the current study will inform selection efforts and guide farmers' breeding objectives to selecting for better litter size and birth weights whilst maintaining economically viable pre-weaning survivability rates.