Abstract
The main dairy breeds used in Barbados is the Holstein Friesian breed or cross breeds, like other areas in CARICOM with the exception of Jamaica, which has developed the Jamaica Hope. The Holstein breed is a non-adapted climate sensitive genotype not noted for its thermo-tolerance which becomes a main challenge that can alter the body temperature from its resting position and negatively impact on productivity under tropical conditions. This study evaluated the performance and thermoregulation of Holstein dairy cattle in a modern dairy cattle facility that modified the environment of the animal. Differences existed between AM and PM in rectal temperatures, respiratory rates and milk yield, (p<0.05). The mean rectal temperature and respiratory rates in the morning were 38.94(±0.05) and 62.52(±0.42) 0C, and afternoon were 39.25(±0.06) and 65.58(±0.44) br/ min, respectively. A significant difference was found between mean morning and evening milk yield, AM being 11.26(±0.31), and PM 10.3(±0.26) kg/day; a difference of 0.96 kg. There was no significant difference between lactation yields or peak yields for wet and dry seasons. There was however an increase in mean (305- day) milk yield from 6182.42 kg in 2008 to 7254.88 kg in 2010. Calving interval decreased from 497.80(±14.75) in the first parity to 440.83(±8.50) in the third parity. AI per conception ranged from 2.00 to 2.68 over the three years and 2.33 to 2.35 for dry and wet season, respectively. It was concluded that although the Holstein breed is not as well adapted to the tropical climatic region as other breeds, the housing and management employed in the study kept the Holsteins thermostable based on rectal temperature, respiratory rates and milk production levels that were comparable to results from some temperate areas.
