Application of Enzymatic Analysis with Glucoamylase, Pronase and Cellulase to Various Feeds for Cattle

Summary

Successive enzymatic analyses with glucoamylase, pronase and cellulase were applied to various feeds for cattle. Organic matter (OM) was divided into two fractions, organic cellular contents (OCC) and organic cell wall (OCW), using glucoamylase and pronase. Isolated cell wall separately was subjected to cellulase digestion; thus OCW was divided into two fractions, organic a (Oa) which was hydrolysed by cellulase, and organic b (Ob) which was resistant to cellulase treatment. Therefore, OM was expressed as follows- OM = OCC + Oa + Ob; OCW = Oa + Ob. In vivo digestibilities of OCC were higher than those of OCW in grass hays and mixed hays.

In vivo digestibilities of Oa of grass hays and mixed hays averaged 94.7 ± 2.7%, whereas, the average digestibility of Ob was 40.4 ± 2.9%. There was a high correlation (r = .992, P<.01) between the total amounts of “OCC plus Oa” and its digestible portions with 23 feeds which included grass hays, mixed hays, corn silages and rice straw. High correlation (P<.01) was obtained between in vivo digestible OM (DOM) and levels of "OCC plus Oa" in hays. The proportion of digestible “OCC plus Oa” in DOM was higher in early cut than late cut grass hays, mixed hays and legume hays.

© American Society of Animal Science 1979