| Abstrakt: |
The article presents results of evaluation of body type in primiparous cows of Ukrainian black-and-white dairy breed. The following linear body type traits were found to have a significant effect on average daily milk yield of the primiparous cows: stature (12.2%), chest width (7.8%), angularity (11.3%), rump width (7.5%), rear udder height (8.9%), udder depth (9.1%), p<0.01; central udder ligament (10.7%), p<0.001 and rear teat placement (5.5%), p<0.05. Average milk yield of primiparous cows significantly correlated with their stature (+0.325), body depth (+0.229), rump width (+0.260), rear udder height (+0.290), central ligament (+0.278), udder depth (-0.284). Average somatic cell count in primiparous cow milk had a significant negative correlation only with udder depth (-0.155), central ligament (-0.152) and rear teat placement (-0.168). Mastitis incidence rate in primiparous cows had a significant negative correlation with chest width (-0.150), body depth (-0.203), rump width (+0.128), central ligament (-0.176) and rear teat placement (-0.180). Based on the study results, a regression model for prediction of average daily milk yields in primiparous cows using linear cow body type trait scores was developed, which would allow to make decisions on further use of primiparous cows in the second month of their lactation. Models developed for prediction of milk fat and protein percentage are to be used as auxiliary ones for evaluation of primiparous cows. Based on the linear body type trait scores, models for prediction of mastitis incidence rate in primiparous cows and somatic cell count in milk were also developed. [ABSTRACT FROM AUTHOR] |
