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 Huber, J. T. Articles by Rosser, R. A. Search for Related Content PubMed Articles by Huber, J. T. Articles by Rosser, R. A.

Effect of Whey on Milk Composition and Rumen Volatile Fatty Acids in Restricted-Roughage Rations

Department of Dairy Science, Virginia Polytechnic Institute, Blacksburg

ABSTRACT

In two trials lactating Holstein cows were fed rations of 16% hay and 84% concentrate at 120% of the Morrison Standard for energy. Concentrates contained varying amounts of partially delactosed whey (PDW) and dried whole whey (DWW).

Per cent fat in milk was maintained at pretreatment levels when as little as 10% PDW was incorporated into the concentrate. At the 30% level, the DWW was not as effective in maintaining milk fat as was PDW. Neither milk SNF nor protein was consistently affected by addition of whey. Milk yields were depressed when the concentrate contained 60% of either whey, but not at 30%. All concentrates were readily consumed by the cows.

Molar per cent of rumen butyrate was increased by addition of both kinds of whey at all levels tested. These increases were probably due to the lactose in whey. Rumen propionate was decreased and acetate-to-propionate ratios increased by addition of PDW, but not by DWW. The increased rumen butyrate and acetate-to-propionate ratios, as well as the decrease in rumen propionate, were associated with maintenance of normal milk fat percentages in groups fed rations containing PDW.

¹ Present address: Department of Dairy, Michigan State University, East Lansing.