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 Nastis, A. S. Articles by Malechek, J. C. Search for Related Content PubMed Articles by Nastis, A. S. Articles by Malechek, J. C.

Digestion and Utilization of Nutrients in Oak Browse by Goats¹

Utah State University, Logan 84322

Abstract

Gambel oak (Quercus gambelii) browse harvested in June, when immature, and in August, when mature, was mixed with alfalfa to form two diets containing 40 and 80% mature browse and one containing 80% immature browse. These three diets were compared with an alfalfa control diet in digestion-balance trials with goats. Dry matter digestibility of the pure, mature browse was estimated by difference. Special attention was given to the effects of tannin on digestion and utilization of nutrients. All oak-containing diets were less digestible than alfalfa, even though they contained higher concentrations of cellular constituents. Tannin seemingly reduced the apparent digestibility of cellular constituents and led to an increase in the excretion of fecal N. The apparent digestibility of mature oak browse was 46.7%. Voluntary intake was also depressed with diets high in oak content. Animals retained less total N while eating oak diets than when eating alfalfa, particularly when they ate immature oak. Large fecal N losses may be associated with tannin-protein complexes occurring in the digestive tract. None of the four blood factors monitored (hemoglobin, plasma urea nitrogen, serum glutamate oxalacetate transaminase and packed cell volume) indicated toxicological reactions, even though the 80% immature oak diet contained almost 9% tannin. Mature oak browse, when consumed in a mixed diet with equally nutritious forages, can contribute effectively to the nutrition of growing and lactating goats. Immature oak, however, is low in utilizable energy and contains high levels of tannin.

¹ Published with the approval of the Director, Utah Agr. Exp. Sta., as Journal Paper No. 2359.

² We gratefully acknowledge the technical advice and physical facilities provided by Dr. L. F. James and his staff at the USDA-SEA Poisonous Plants Research Laboratory, Logan, UT, and the consultation of Dr. J. C. Street, Dept. of Anim., Dairy and Vet. Sci., Utah State Univ.

³ Dept. of Range Sci., Utah State Univ. (UMC 52).