The development of dairy replacement heifers — from birth through first calving at approximately 22-24 months — is a critical period that shapes the animal's lifelong welfare and productivity. Investment in heifer welfare and health during this period pays dividends in reduced disease, improved longevity, and better welfare throughout the adult career.
The first weeks of life are the highest mortality risk period. Colostrum management, housing hygiene, and disease prevention (particularly BRD and scour) are welfare priorities. Group housing of calves from an early age — replacing traditional individual hutches — improves cognitive development, reduces stress, and better prepares heifers for the social complexity of adult dairy life.
Weaning stress can be minimized through gradual weaning methods and group housing continuity. Target growth rates (approximately 0.8-0.9 kg/day for Holstein-Friesian) ensure heifers reach target body weight (85-90% of mature weight) at first calving — neither too light (metabolic disease risk) nor too heavy (over-conditioned, with reduced feed intake post-calving).
Heifers reared in socially complex environments — with access to same-age peers, appropriate space for play behavior, and varied social experiences — are more socially competent as adults. Play behavior in young calves is a reliable positive welfare indicator. Farms that provide play opportunities and social enrichment during rearing produce better-adapted adult cows.
Moving heifers to the calving pen at least 2-3 weeks before expected calving date allows acclimation to new environments and social groups before the additional stress of parturition. Integration with dry cows enables social learning about calving pen resources.
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