WET CAGE LAYER EXCRETA ADDED TO WHOLE PLANT CORN PRIOR TO ITS ENSILING AND EFFECT ON FOOD INTAKE AND UTILIZATION BY SHEEP

Abstract

Corn ensiled with wet cage layer excreta was compared with untreated corn silage supplemented at feeding either with excreta or with soybean meal, in an intake assay and balance study using 25-kg lambs. Comparisons were made at both 10 and 20% inclusion levels (wt/wt, as-is basis) for excreta and to equivalent levels of crude protein from soybean meal, providing six treatments in all. Voluntary intake of dry matter for excreta-silage (mean – 56.8 g/kg0.75 body wt) was lower (P < 0.05) than for corn silage supplemented with excreta (mean – 80.7 g/kg0.75 body wt) which was comparable to the value obtained for silage supplemented with soybean meal. Digestibilities of dry and organic matter were significantly lower (P < 0.05) for all diets containing cage layer excreta compared to soybean meal. Nitrogen retention was lower (P < 0.05) for sheep fed silage supplemented with excreta rather than soybean meal, but was not adversely affected for sheep fed corn ensiled with excreta. Relative to untreated silage, addition of excreta at ensiling caused extensive degradation of free amino acids to amines and ammonia but did not enhance proteolysis. Absolute levels of five amines were increased by 46% in 10% excreta-silage and by 64% in 20% excreta-silage compared to untreated silage (163 mg amine-N/100 g DM). Low intake of excreta-silage may be explained by the amine levels associated with them but it is quite probable that several other factors were involved. Key words: Animal waste, ruminant nutrition, nutritive value, ensiling, corn