Thermoregulation and performance of British Anglo-Nubian and Saanen goats reared in an intensive system in Trinidad

Anglo-Nubian and Saanen goats were imported into Trinidad and Tobago to form the nucleus of the goat expansion and improvement programme. Thermoregulation and performance of the parent stock and the F1 were evaluated under intensive housing and management. Rectal temperature in the a.m. irrespective of breed or season ranged from 38.5°C to 38.7°C and p.m. ranged from 38.8°C to 39.0°C. After 2 h of exposure outdoors without shade, Saanen parent stock (SAPS) respiration rate (105 br/min) was significantly higher (p < 0.001) than Saanen F1 (SAF1, 76 br/min), Anglo-Nubian parent stock (ANSP, 65 br/min) and Anglo-Nubian F1 (ANF1, 51 br/min). Rectal temperature over the same period showed significant differences (p < 0.042) between SAF1 (39.8°C) and SAPS (39.4°C), and ANF1 (39.4°C); the value for ANSP was 39.7°C. Age at first kidding showed no significant difference (p > 0.05) between breeds or between the parent stock and the F1 generations, ranging from 638 to 686 days. The ANPS were the most prolific of all groups (p < 0.05); the mean for this group was 1.86 ± 0.07 kids/kidding. Saanen F1 was the least prolific among the group, with mean number of kids at 1.23 (±0.11) kids/kidding. Kidding interval showed no significant (p > 0.05) difference between the groups, ranging from 319 to 521 days. It was concluded that the Anglo-Nubian appears to be more suitable than the Saanen for the tropical humid environment in Trinidad as indicated by their thermoregulation, prolificacy and kidding interval.