The effect of feeding plant vs. animal protein sources on growth performance, organ weights and selected physiological parameters in rats

摘要

Growth performance, relative weight of elements of the digestive tract, pH of caecal digesta and intestinal area covered by peyer's patches were studied in growing rats fed during four weeks diets containing animal (fish meal and casein) or plant protein (industrial soy concentrates HP-100, HP-300, Soycomil K, Provasoy 45, extruded full fat soybean, soybean oil meal and potato protein). Significant differences in many parameters (except thymus) were found both among groups fed animal vs. plant proteins and within each type of protein, including different soy products. Final body weight was the greatest in animals fed fish meal, Provasoy 45 and casein (185, 177 and 177 g. respectively), the smallest - potato protein and HP-300 (145 and 149 g). Theweight of small intestine was greater in rats given potato protein, than other protein sources (3.32 vs. 2.60 to 2.89 g). Weight of pancreas was not related to trypsin inhibitor activity and was greater in rats fed potato protein, casein and HP-100 (0.31-0.32 g) than other proteins (0.25 to 0.28 g). The greatest mass of caecal tissue and caecal digesta was in animals fed Provasoy 45 (0.45 and 1.33 g), the lowest in rats fed fish meal and casein (0.20, 0.76 and 0.29, 0.83 g. respectively). The total areaof Peyer's patches was significantly greater in rats fed HP-100 and Provasoy 45 than potato protein (171 and 163 vs. 141 mm~2).