Review: Limit-Feeding with Altered Forage-to-Concentrate Levels in Dairy Heifer Diets1

Limit-feeding high-concentrate or high-digestibility diets for growing dairy heifers may offer an economical alternative to ad libitum consumption of the high-forage, low-digestibility diets that are traditionally fed to dairy heifers. Literature pertaining to economic, physiological, and nutritional responses to alterations in feeding level and dietary concentrate level are reviewed. From the available research, it was found that limit-feeding higher-concentrate diets did not affect growth or first-lactation milk production compared with feeding high-forage diets when equivalent levels of gain are obtained. Dairy heifers that are limit-fed often have greater diet digestibility, lower levels of environmental excretion and methane production, and greater feed efficiency. Although the digestibility was increased for heifers limit-fed high-concentrate diets, retention and excretion of N was not consistently affected. It was concluded that limit-feeding high-concentrate diets does not need to be excluded as a management option and may offer an opportunity for heifer growers to reduce feed costs and environmental output under the circumstances thus far investigated.