Influence of Reducing Dietary Crude Protein from 17 to 13.5 Percent on Early Lactation

Abstract

A total of 117 Holstein cows were in two trials to determine how reduction in concentration of dietary protein influences early lactation. Treatments were feeding 17% crude protein for 3 mo or reducing dietary crude protein from 17 to 13.5% after 1st or 2nd mo postpartum. Results were similar in both trials. Reducing concentration of dietary crude protein to 13.5% at 1 mo postpartum tended to decrease intake of dry matter during the 2nd and 3rd mo of lactation. Milk production of multiparous, but not primiparous cows, was decreased. Dry matter intake and milk production did not decrease following a drop in concentration of dietary protein at 2 mo postpartum. Returns over feed costs were reduced by feeding the diet with 17% crude protein to primiparous cows longer than 1 mo or to multiparous cows longer than 2 mo postpartum. Milk composition, body weight change, and reproductive performance were not affected by treatment. © 1983, American Dairy Science Association. All rights reserved.