Studies on Some Productive and Reproductive Traits of Sudan Nubian Goats under Village and Small Holder System

Abstract

This experiment was conducted on a flock of Nubian goats at Albutana area, to study tile effect of grazing supplementation, year/season of kidding, and parity order on some productive and reproductive traits of Sudan Nubian goats. The experiment lasted for three years extending from January 1998 to December 2000. The overall birth weight of kids was 2.344 ±0.557 kg. Sex of kid, type of birth and year/season of kidding had a significant effect on birth weight. However, parity order and nutritional supplementation had no significant influence on birth weight. The pre-weaning weight gain was 0.91 kg/15 days. Nutritional supplementation had an effect on growth rate. The results indicated that the poorest performing kids were those born in winter compared to those born in the wet and dry summer seasons. Male kids grew at a faster rate than male kids. Type of birth also had an effect on pre-weaning weight gain. The post weaning weight gain was 0.51 kg/15 days. Male kids grew at a faster rate than female kids. Birth weight was positively correlated with subsequent weights up to 6 months of age, after that the correlations became negative up to sexual maturity at 9 month. Abortions, still births, Neonatal, prenatal, pre-weaning and overall kid mortality rates were 25%, 2.13%, 7.61%, 9.74%, 25.85% and 48.98%, respectively. Type of birth, sex of kid, weight of kid, parity order, and season of kidding and age of the kid influenced kid mortality. The average age at puberty of female kids was 9.15±0.17 months, while their average weight at puberty was 12.74±1.37 kg. Nutritional supplementation did not significantly affect both traits, neither did age or weight at puberty. The average age at first conception was 10.86 ±2.41 months with an average body weight of 15.10 ±1.62 kg. The nutritional supplementation exerted non-significant effect on both traits. The overall results indicated the occurrence of services all year round. Gestation Length averaged 148.57 ±3.60 days. Nutritional supplementation, sex of kid, litter size and parity order had non- significant effect on gestation length. However, year/season of kidding had a significant effect on gestation length. The average age at 1st kidding was 16.5 ±2.67 months. Nutritional supplementation had non-significant effect on age at 1st kidding. The service period average age was 148.29 ±62.38 days. Nutritional supplementation and year/season of kidding exerted a significant effect on service period. However, the parity order had non-significant effect on service period. The average kidding interval was 278.05±75.19 days. Nutritional supplementation, year/season of kidding and parity order had non-significant effect on kidding interval. Litter size was 1.12± 0.36 kids. Nutritional supplementation, year/season of kidding and parity order had non-significant effect on litter size. Linear regression of litter size on post partum weight was not significant. The average lactation milk yield was 89.18 ±38.60 kg. Nutritional supplementation had a highly significant effect on average lactation milk yield. However, year/season of kidding, parity order and litter size had non-significant effect on average total lactation milk yield. Lactation milk yield was highly correlated with the first month yield ( r = 0.599). The overall mean of lactation length was 181.12 ±51.36 days. Nutritional supplementation and parity order had non-significant effect on lactation length. However, year'/season of kidding had a significant effect on lactation length. The linear regression of the lactation milk yield on lactation length was highly significant. However, the linear regression of the lactation milk yield on post-partum weight was not significant. The lactation curve was affected by nutritional supplementation, year/season of kidding and parity order.