Relationship between growth and milk production in dairy cattle

Relationships between growth and milk production in dairy cows were reviewed. Some studies revealed a negative relationship between increased prepubertal growth intensity and subsequent milk production. Other studies did not confirm that relation. Growth intensity is highly variable, lowly heritable, and a poor indicator of milk production. First lactation milk yield is related to body weight, age, and body condition score at the first calving. Generally recommended optimal body weight and age at the first calving are 570 kg (i.e. 85% of mature weight) and less than 24 months, respectively. The costs of dairy replacement heifer rearing can be reduced by altering feeding programmes, accelerated growth intensity, and early breeding. Genetic variability in the shape of the growth curve can be used for improvement of an individual ability to mature at the early age. In selection for early maturity, decreasing mature size would be expected. Investigation of biological fundaments of growth and particularly its hormonal control is an opportunity for further studies of the relationship between growth and milk production in dairy cattle.