Utilization of raw or heat-treated starch fed in liquid diet to preruminants 2. Lambs

Abstract

Eighteen Assaf lambs, 10±2 days old, weighing 6.3±0.33 kg were fed during 14 days milk replacer (MR) or MR in which 20% was substituted by heat-treated corn starch-soy mixture (20ES) or 20% untreated corn starch-soy mixture (20US). During the following 8 days, the amount of starch-soy mixtures was increased to 40% (40ES and 40US), after which lambs were weaned gradually. During the first suckling period (14 days) total weight gain was 2.5±0.30, 3.0±0.22, and 2.3±0.28 kg for the MR, 20ES and 20US groups, respectively (NS). However, feed utilization in the 20US was inferior to the MR and 20ES groups by 20% ( P<0.05). When starch-soy mixture substituted 40% of the milk replacer, feed consumption (kg/7 days) and daily body weight gain (g) were significantly lower ( P<0.05) in the 40ES (1.54±0.07 and 102±5.8) than in the MR (1.70±0.05 and 156±6.0) or 40US (1.65±0.05 and 131±9.7) groups. Daily gains of 40US group were significantly lower than those of MR lambs. The apparent digestibility of dry matter, ash and protein of liquid diets was higher in the MR group than in the other groups by 2–6% when fed 20US and 20ES, and by 3–12% when fed 40US and 40ES ( P<0.05). the pH of rumen liquor after the meal was slightly lower (NS) in 20ES and 20US groups than in the MR group. The 40ES lambs were less active before meals compared with the other groups.