Wood molasses as a preservative for high moisture barley: 3. Feeding value for growing cattle

Abstract

In two experiments the feeding value for growing cattle of barley ensiled with wood molasses (55 % DM) was compared with dried barley (DB) and barley ensiled with AIV II solution (AIVB). Wood molasses was applied at levels of 8 (WMB8) or 16% (WMB16) of barley DM in Exp. 1 and 12 % (WMB12) of barley DM in Exp. 2. The AIV II solution was used at a level of 0.3 % v/w. In Exp. 1 DB and WMB8 were compared during period 1 and DB and WMB16 during period 2. AIVB and WMB12 were compared In Exp. 2. Experiment 1 was performed with 12 and Exp. 2 with 16 animals of Ayrshire and Friesian breed. The average ages of the animals at the beginning of the experiment were 126 and 100 days. The first period in Exp. 1 lasted 45 days and the second 53 days. Experiment 2 lasted 140 days. The feeding was based on barley, soybean meal and hay in Exp. 1 and on barley, rapeseed meal and grass silage in Exp. 2 and daily gain of 1200g/d was targeted. The average proportion of barley of total DM intake averaged 61 % during period 1 and 59 % during period 2 of Exp. 1 and 54 % in Exp. 2. The corresponding proportions of forage of DM intake were 27, 32 and 37 %. The average daily gains of 1107 and 1178g for DB and WMB8, 1182 and 1129 g for DB and WMB16 and 1248 and 1251 g for AIVB and WMB12 were not significantly different. Nor did the groups show any significant differences in feed conversion rate, carcass characteristics and rumen fermentation except the lower (P < 0.05) dressing percentage of the WMB16 group in Exp. 1. Plasma urea N was higher (P < 0.01) and cholesterol lower (P < 0.01) in the AIVB group than in the WMB12 group. Plasma concentrations of glucose, alanine aminotransferase, asparte aminotransferase and creatinine did not differ significantly in the different groups.