The effects of heat, water, acid, and alkali treatment of tomato cannery wastes on growth, metabolizable energy value, and nitrogen utilization of broiler chicks

Two experiments were conducted to determine the effects of heat, water, acid, and alkali treatment of tomato pomace on gain, feed to gain ratio, nitrogen utilization, and ME of diets for broiler chicks. In Experiment 1, both treated and untreated tomato pomace was included in broiler diets at a 10 or 20% level. Results indicated that the level or antinutritional factors present in untreated tomato cannery waste did not appreciably depress any measured production parameter. Hence, it appeared that untreated tomato cannery wastes might be used as a feed ingredient in low-energy poultry diets (broiler breeder and laying hen recycling rations), ruminant diets, and as a protein source in regions of the world where such feed ingredients are scarce. The second experiment was designed to test the effect of alkali concentration and treatment time of tomato pomace on the performance of broiler chicks. Alkali treatment of tomato cannery wastes increased gain and decreased feed to gain ratios of broiler chicks over those of untreated tomato waste controls. Results indicated that the increased gain and decreased feed to gain ratios of the chicks were due in part to the acid neutralization phase of the alkali treatment. Alkali treatment apparently affects the tomato cannery wastes almost instantaneously, as differences among actual treatment times and concentrations were small. However, only the highest alkali treatment increased the pH of the tomato cannery waste above 7, suggesting that a true alkali treatment might cause additional improvements in gain and feed to gain ratio when fed to broiler chicks.