EFFECTS OF SODIUM BARBITAL ADMINISTRATION ON PERFORMANCE AND RATION DIGESTIBILITY OF YOUNG RUMINANTS

Abstract

In a first experiment, nine lambs and nine kids newly born were used to study the effect of oral administration of sodium barbital (SB) on performance during weaning. All animals received three doses of SB (0,30 and 60 mg d−1) during weaning and 3 wk postweaning. During the 7-day weaning period, total dry matter intake (TDMI), in terms of percentage of body weight, was higher for animals receiving 30 or 60 mg of SB as compared to controls (P < 0.01). Average daily gain (ADG) of animals receiving SB was twice that of controls (P < 0.01), lambs performing better than kids (228 vs. 119 g, respectively, P < 0.01). Average feed conversion (FC) was also better for lambs than for kids (0.98 vs. 1.54 respectively, P < 0.01). After weaning, TDMI was higher in animals receiving SB (P < 0.03), with no differences observed between doses and species; however, treatment effects were apparent mainly during the first week and disappeared gradually afterwards. During the first week postweaning, ADG and FC were superior for animals receiving SB (P < 0.01 and P < 0.05, respectively). During this period, ADG of lambs was 78% higher than that of kids (P < 0.01). Apparent digestibilities of dry matter, crude protein and lipids were similar for all treatments and species. In a second experiment, eight lambs and eight kids were used to determine if oral administration of SB stimulates feed intake of growing ruminants. Lambs (30–45 kg) received 0, 120 or 160 mg of SB and kids (20–28 kg) were given 0, 80 or 100 mg of SB daily. Feed intake of lambs was not affected by administration of SB. Kids, however, ingested higher amounts of concentrate during the first 3 h after administration of 80 mg of SB. Daily feed intake was not affected. It appears that polyphagic-type drugs can be used effectively as feed additives during weaning to improve animal performance. The effect seems to be by a direct stimulation of feed intake without affecting ration digestibility. Key words: Barbiturate feeding, lambs, kids, polyphagia.