Growth and lactation performance from dairy heifers raised in confinement or on pasture

Authors: CASMISA NOVA, CARLOS H.P. - University Of Wisconsin; Kalscheur, Kenneth; Jaramillo, David; Bleier, Jonathan; BETZOLD, NANCY - University Of Wisconsin; BRINK, GEOFF - Retired ARS Employee

Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/27/2026
Publication Date: 5/29/2026
Citation: Casmisa Nova, C., Kalscheur, K., Jaramillo, D.M., Bleier, J.S., Betzold, N.K., Brink, G. 2026. Growth and lactation performance from dairy heifers raised in confinement or on pasture. Journal of Dairy Science. https://doi.org/10.3168/jds.2025-28136.
DOI: https://doi.org/10.3168/jds.2025-28136

Interpretive Summary: Raising heifers on dairy farms presents a complex challenge, as producers must balance the need to reduce rearing cost while ensuring that heifers reach the recommended age and body weight at first calving to optimize future milk production. Heifers raised on pasture are often described as a cost-effective strategy. However, its long-term impact on future lactation performance remains unclear. The objective of this study was to evaluate the impact of raising dairy heifers on pasture or in confinement on their first lactation performance, as well as to conduct an economic evaluation of each system. Heifers raised on pasture resulted in similar body weight, body condition score and age at first calving compared to heifers raised in confinement. In addition, heifers raised on pasture resulted in lower feed cost for the heifer stage of production. During the first lactation, cows that were raised as heifers on pasture produced more milk and had greater dry matter intake than cows raised as heifers in confinement. This research will be of interest to dairy heifer growers, dairy producers, dairy cattle nutritionists, and researchers interested in understanding how raising dairy heifers impacts future milk production and the cost of raising future dairy replacements.

Technical Abstract: Raising heifers on pasture may be a strategy for reducing economic cost of heifer rearing. However, few studies have compared heifers raised in confinement versus on pasture and their long-term effects on first-lactation performance. Therefore, the objective of this study was to evaluate the impact of raising dairy heifers on pasture or in confinement on their first lactation performance, as well as to conduct an economic evaluation of each system. Thirty-six Holstein heifers were raised under two contrasting strategies (treatments): 1) 18 heifers were rotationally stocked on cool-season grass pastures during the grazing season, or 2) 18 heifers were housed and fed under confinement management. During winters, all heifers were housed in confinement and fed similar diets. Initial and final BW, BCS as well as ADG were recorded throughout the study. During the winter period, prepartum and lactation, animals were fed and managed under similar conditions. Milk yield and composition (i.e., total fat, and total protein), DMI, and body weight were recorded through lactation (at 50, 100, 150, and 200 DIM). Income over feed cost (IOFC) was calculated to evaluate potential economic differences between the two treatments. The ADG and final BW were both lower for heifers raised on pasture (-0.11 kg/d and -20 kg, respectively), compared to confinement heifers. In the winter, no differences in BCS, final BW and ADG were detected through the winter. In the second grazing season, BW, BCS, and ADG did not differ between treatments. On performance during the cow’s first lactation, pasture-raised heifers produced 3.40, 3.90, 4.10 and 6.30 kg/d of milk and 4.60, 4.30, 4.80 and 7.60 kg/d of ECM greater than confinement-raised heifers at 50, 100, 150, and 200 DIM, respectively. The greater milk production resulted in greater IOFC for pasture-raised heifers than in the confinement-raised heifers at 50, 100, 150, and 200 DIM (US$ +1.13, US$ +1.59, US$ +1.81, US$ +2.53, respectively). At the end of the first lactation, pasture-raised heifers produced 1,230 kg more milk and 79.3 kg more milk protein than confinement-raised heifers. Therefore, heifers raised on pasture and supplemented to support the recommended growth for dairy heifers demonstrated similar growth, lower feed cost, and improved performance during first lactation, compared to heifers raised in confinement, resulting in more milk production and greater DMI capacity.