Preweaning milk replacer intake and effects on long-term productivity of dairy calves.

摘要: The preweaning management of dairy calves over the last 30 yr has focused on mortality, early weaning, and rumen development. Recent studies suggest that nutrient intake from milk or replacer during period alters phenotypic expression for yield. objective this study was to investigate relationship between pre- postweaning growth rate with lactation performance in Cornell herd a commercial farm. analysis conducted using traditional 305-d first-lactation yield residual estimates test-day model (TDM) analyze records multiple lactations. overall calf nutrition program both herds double birth weight by weaning through increased starter intake. First-lactation residuals TDM were generated 1,244 624 heifers farm, respectively. used generate after accounting effects test day, calving season, days milk, pregnant, number, year. In addition, cattle lactations determine if effect could be associated lifetime Factors such as average daily gain (ADG), energy maintenance, other outcomes variables regressed data. herd, ADG, ranged 0.10 1.58 kg, significantly correlated yield; every 1 kg heifers, average, produced 850 more their first 235 Mcal metabolizable above maintenance. 1,113 further, prepubertal ADG 3,281 increase Among 2 herds, accounted 22% variation analyzed TDM. These results indicate before some form epigenetic programming is yet understood, but positive This identifies preweaned major environmental factors influencing genetic capacity animal