Relationship Between Rate of Gain from Birth to Six Months of Age and Subsequent Yields of Dairy Cows

Abstract

Three breeds of experiment station cows (WSU Guernseys, Jerseys, and Holsteins, and WWES Holsteins) were used to determine if average daily gain (pounds) from birth to 6 mo. of age was related to later 305-day lactation yields of 4% fat-corrected milk (FCM). Feeding and management of the cows and calves was above average. The 200 calves gained an average of 1.34 lb. daily and they subsequently produced an average of 10,544 lb. FCM per lactation. Comparing FCM yield by (a) simple averages or as (b) mature equivalent (ME) with average daily gain, without regard to breed, gave correlations and regressions misleadingly high. When yields were expressed in terms of (c) FCM/1000 lb. of cow, (d) relative lactation capacity (Kleiber and Mead, J. Dairy Sci., 28:49. 1945), or (e) gross efficiency (Gaines, Science, 67:353. 1928), gain and subsequent yield were negatively correlated. The slower-gaining WSU Jerseys produced significantly better than the faster-gaining ones as judged by any of the 5 measures of producing ability mentioned above. In contrast, the faster-gaining WSU Holsteins produced the best (P < 0.05) for FCM and mature equivalent FCM. The WSU Jerseys and WSU Holsteins were significantly different with respect to gain and subsequent production for each of the 5 measures [(a)-(e)] of producing ability. Similarly, WSU Guernseys and WWES Holsteins showed no significant relationship between gain and subsequent yield. On an intra-herd and intra-breed basis the linear correlation and regression coefficients between gain and yield were significant only for FCM and MEFCM and these were of a low order ( r = 0.14 and 0.15, respectively). Judging from the results of this study, it is unlikely that gain can be used to predict producing ability.