Abstract | A study was conducted to evaluate cull onions as a feed source for growing wethers. An additional objective was to assess toxicity of dietary onions. Fifty-six polypay x rambouillet wethers (average initial BW of 33 kg) were randomly assigned to one of four dietary treatments: (1) 50% whole sorghum grain (CON), (2) 33% sorghum: 17% onions (17%), (3) 17% sorghum: 33% onions (33%), and (4) 50% onions (50%). The remaining 50% of the diet (DM basis) was pelleted alfalfa (19% CP). All wethers were pen fed (7 wethers/pan) and treatments were replicated. Each diet was fed for 6 weeks following a 3-week adaptation period to the control diet. Serum was obtained at the end of weeks 0, 1, 3, and 6 to obtain a serum clinical profile (SMAC-25). Body weight did not differ (P > .05) among treatments during the trial. Average gaily gain tended (P = 0.057) to be lower for the 33 and 50% treatments during weeks 1 and 2 but did not differ (P > .05) from CON during the remainder of the trial (over all ADG are .13, .17, .14, and .11 kg/d for CON, 17, 33, and 50% treatments, respectively). Packed cell volume tended to be less (P = .057) for 33 and 50% groups during weeks 1 and 2 and was less (P < .0001) for the same groups during week 3 (34, 33, 29, and 29% for CON, 17, 33, and 50%, respectively). Differences in PCV among treatments were not detected (P > .05) for weeks 4, 5, or 6. Serum LDH was elevated (P < .05) for weeks 3 and 6 in sheep eating diets of 33 or 50% onions. We conclude that under the conditions of this study, onions can be fed safely to sheep and support weight gains similar to those from sorghum grain. |