Influence of Growth and Maintenance Regime of Romanian Black and White Heifers on the Milk Yield at their First Lactation

Abstract

The goal of this paper is to estimate if the growth regime, expressed by the daily gain of dairy heifers from the birth to their first pregnancy, has any effect on the milk yield in the first 305 days of their first lactation. The daily gain of the heifers was put in relation with the birth year of heifers and with the month of birth, doesn’t matter the year. Significance of differences of indices both for years and months were considered. Farther the effect of differences concerning the heifers’ daily gain upon the body weight and the age at the first successful insemination was discussed as possible factors correcting the influence of growth regime upon the milk yield in the first 305 days of the first heifers’ first lactation.

Keywords

• dairy heifers
• body growth
• sexual maturity