Ensiling characteristics of whole-crop small grains harvested at milk and dough stages.

Abstract

Dynamics of the ensiling process and final quality of whole-crop wheat, oats, and barley harvested at the milk and the dough stage of maturity were studied using 2.2-liter laboratory silos. An ensiling period of 64 d was used. Silage DM was higher (P less than .05) at the dough than at the milk stage on d 0 and 64. Silage total N content was not different (P greater than .05) among small grain species or stages of maturity either at harvest or 64 d after ensiling. Overall, buffering capacity (BC) on d 0 was greater (P less than .05) in oats and barley than in wheat silages. Small grains had a greater (P less than .05) BC when harvested in the milk stage than when harvested in the dough stage. In all silages, pH had declined (P less than .01) by d 64, when it ranged from 3.8 to 4.1. During the ensiling period, lactic acid concentrations increased (P less than .01) and ranged from 6 to 11% of DM by 64 d of ensiling. Water-soluble carbohydrate (WSC) content was greater (P less than .01) in milk- than in dough-stage silages for each small grain species and declined (P less than .05) during the ensiling period. The WSC decline during ensiling was greater (P less than .01) for milk-stage than for dough-stage harvested forage. Water-soluble N increased during ensiling (P less than .01) and increased 100 to 200% by d 64 for all silages. Ammonia N increased during the 64-d ensiling period but never exceeded .2% of DM.(ABSTRACT TRUNCATED AT 250 WORDS)