Replacing Twenty Percent of Concentrate with Ground Hay in an Alfalfa-Based Diet for Cows in Early Lactation

Abstract

The objective was to observe performance of cows in early lactation when high quality ground alfalfa hay replaced part of dietary concentrate. Multiparous Holsteins were in two groups of 10 based on previous production and lactation number. Rations consisted of alfalfa-grass hay, alfalfa haylage, and concentrate based on corn, oats, and soymeal. Ground alfalfa replaced 20% of ingredients of the concentrate fed the experimental group. Individuals were fed to extent of appetite with restriction that concentrate dry matter did not exceed 65% of intake (52% if ground hay was considered as forage). Cows were on trial for 109 days, beginning 3 days postpartum.Daily intakes of dry matter averaged 26.0 and 25.1kg by the control and experimental groups; that of protein was 4.4 and 4.1kg. Dry matter digestibilities, determined by the acid insoluble ash procedure, were similar. Milk yields were 36.9 and 33.5kg per cow daily by control and experimental animals. Fat percentages averaged 3.2 and 3.7 making yields of fat-corrected milk similar. Both groups averaged 3.2% milk protein. Changes of body weight were similar.