Comparison of Fish Meal and Soybean Meal in the Prevention of Fatty Liver-Hemorrhagic Syndrome in Caged Layers

TWO experiments, of five weeks each, were designed to study the effect of protein source and level of dietary protein on hepatic and plasma lipids and incidence of liver hemorrhagein caged laying hens. Experiment 1 compared equicaloric (3.1 kcal/g) and isonitrogenous (12.5%) corn-fish meal and corn-soybean diets. An equicaloric 16.5% protein corn-soybean diet was included to assess the effect of dietary protein level. Fatty Iiver-hemorrhagic syndrome was induced under ad libitum feeding in birds fed the corn-soybean diet. The corn-fish meal diet reduced (P<.05) liver weight, hepatic and plasma lipids, and incidence of liver hemorrhage. Significant effects due to the level of dietary protein were not detected. No concomitant changes in egg production, egg weight, or body weight were observed. Plasma estrogen was lower (P<.01) in birds fed the corn-fish meal diet when compared to those fed the corn-soybean diet. Liver lipid was positively correlated (r = .83; P<.025) with plasma estrogen. Influence of dietary protein source was reevaluated in Experiment 2 and the effect of adding selenium (0.3 mg/kg as Na2 SeO3) or a combination of trace elements (As, Br, Cr, F, Mo, Ni, Sn, V) to the corn-soybean diet on liver lipid accumulation examined. Results with respect to dietary protein source were similar to the previous experiment. Neither selenium nor the combination of trace elements had a significant effect on hepatic and plasma lipids. Adding selenium to the corn-soybean diet reduced incidence of liver hemorrhage to the same level as that observed with the corn-fish meal diet.