Abstract

Body measurements, milk production, and body weight data were collected on 1898 lactations of 771 Holstein dairy cows from 1968 to 1986. Body weight and the body measurements of heart girth, paunch girth, wither height, chest depth, pelvic length, pelvic width, and body length were used. Milk production variables were milk yield, fat yield, 4% FCM, fat percentage, and SNF percentage. Estimated feed efficiency was expressed as ratio of milk energy content to net energy feed intake. Phenotypic correlations indicated a high positive relation between estimated feed efficiency and milk (.61), fat (.62), and 4% FCM (.63) yields. Uniformly negative correlations were found between estimated feed efficiency and all seven body measurements and body weight; range was from −.18 for wither height to −.33 for body weight. Multiple regression analyses were conducted on a first, second, and overall parity basis, showing that cows with smaller heart girth and larger paunch girth had significantly higher yields. Taller cows produced more milk than shorter cows. Cows lighter in body weight yielded greater FCM as first-calf heifers and through all lactations.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call