Reproductive performance of Purebred Boer, Grade Boer and Grade Nubian in Jamaica and thermoregulation of Purebred Boer goats (Capra aegagrus hircus, Linnaeus, 1758) at the Bodles Research Station

Abstract

Records of 94 does and 419 kids for the period 2004-2011from the Bodles Research Station, Jamaica West Indies were used in the study. Grade Boers (GB) had 75% Boer blood while grade Nubian (GN) had 75% Nubian blood. Thirteen purebred, non-pregnant F2 Boer does were used for the thermoregulation study. The traits: birth weight, weaning weight and pre-weaning growth weight of kids were analyzed. Reproductive traits: kidding interval, age at first kidding, prolificacy, and total number of parities for does were analyzed using GLM procedure. There were differences among breeds for age at first kidding (p=0.015) and kidding interval (p=0.001) but not for prolificacy (kids/doe) (p=0.832). Percentage kid mortality was significant (p=0.000) among breeds, ranging from 9.3 to 17.1%. There were no significant differences (P= 0.103) among breeds for birth weight (values were 3.01 kg for purebred Boer (PB), 3.05 kg for GB and 3.11 kg for GN. Birth weight was also not significantly affected (p=0.629) by season, however year of birth had a significant impact on birth weight (p=0.000). Sex and litter size affected (p=0.00) birth weights of kids for all three breeds. Birth weight decreased with litter size, with singles being 3.19 kg, twins 2.84 kg and triplets 2.70 kg. Average weaning weight differed significantly (p=0.000) among breeds; PB kids were the lightest (12.94 kg), followed by GB (13.97 kg) and the heaviest kids were GN (14.40 kg). Average daily weight gain to weaning age significantly differed among breeds (P= 0.00) where PB had the lowest mean daily gain of 117.20 g/d, GB was 165.80 g/d and GN had the highest at 171.30 g/d. Rectal temperatures for PB were not significantly different (P= 0.227) between the morning (38.4 ± 0.3 oC) and afternoon periods (38.8 ± 0.3 oC). The data showed that the imported animals (PB, GN and GB) being used to improve the island’s genetic stock are able to perform at an acceptable level and suggested that the continued use of these animals in the Jamaican environment would be desirable.