Influence of Growth Retardation of Heifers on the Development, Production, Duration and Efficiency of Productive Lifespan of Dairy Cows.

Abstract

It was established that the age at first calving of dairy cows, their milk production, reproductive traits, duration and efficiency of productive lifespan depend on the growth intensity of replacement heifers. Heifers with growth retardation in any period up to 1 year of age are characterized by an older age at first calving (by 4.7–7.9% depending on the age at which growth retardation was observed), lower live weight in the first year of life (by 4.1–24.4%), first lactation milk production (milk yield by 6.1–13.2%, milk fat yield by 7.4–13.1%, milk protein yield by 8.7–17.3%) and lifetime milk production (lifetime milk yield by 12.1–25.9%, milk fat + milk protein yields by 13.1–26.3%), as well as lower milk yield, milk fat and milk protein per one day of life, productive lifetime and lactation (by 8.6–21.1%) compared with animals without growth retardation.