HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ward, G. M. Articles by Kelley, P. L. Search for Related Content PubMed Articles by Ward, G. M. Articles by Kelley, P. L.

Influence of Roughage-to-Concentrate Ratios on ad Libitum Consumption by Lactating Cows¹

Departments of Dairy and Poultry Science, and Agricultural Economics, Kansas State University, Manhattan 66502

ABSTRACT

Ad libitum consumptions of all-hay, 5.5:1, 2.2:1, and 1:1 weight ratios of alfalfa hay and concentrate mixture fed 84 days were compared with consumption of a 7:4 ratio (control) of hay and concentrate fed for 50 days before and 24 days following the experimental period. Eight Holstein cows were used for three treatments and nine for the fourth. Control ratio hay consumption varied from 2.01 to 2.43 kg per 100 kg body weight (P < .01) over 33 lactations during five years. Variation among cows was indicated by coefficients of variation between 10 and 15%. Within year correlation between body weight and bay consumption was 0.38 (P < .05) and within treatment correlation between hay consumption in the control and experimental periods was 0.83 (P < .01). Nearly linear replacement of hay by concentrate occurred in the ratio of 0.44 kg hay per kilogram concentrate with the net effect of doubling estimated net energy consumption of the all-hay ration by feeding the 1:1 ratio.

¹ Contribution no. 713, Department of Dairy and Poultry Science, and no. 435, Department of Agricultural Economics, Kansas Agricultural Experiment Station.