Hair Coat Color Influenced the Longevity of Holsteins in the Sub-Tropics

More than a decade of observations of dairy operations in Hawai‘i suggested that there were more black cows in the local dairy herds than white cows. Hence, the objective of the study was to investigate if hair coat color affected productive life of Holstein cows in the sub-tropics. Two large herds within 2,000 meters of each other in the Waianae Coast district were used. Lactating cows were classified into the following groups: 1) white (W, >90 percent of the body hair coat was white); 2) black:white (BW, the percentages of black and white hair coat on the cows were close to 50:50), and 3) black (B, >90 percent of the body hair coat was black). In Farm A, 211 out of 970 lactating cows were identified for study. In Farm B, 690 of the 1,350 lactating cows met the above criteria. Regression analyses with hair coat color on the y-axis and number of lactations in the respective herd on the x-axis suggest that the proportion of B cows increased in both farms with increasing lactation numbers while the proportion of W cows decreased. There was no change in the proportion of BW cows within a herd. Hair coat characteristics and milk yield are discussed in this paper.