Abstract
Four sorghums, ranging widely in tannin content, and yellow corn were evaluated in two 5x5 Latin square digestion trials and a growth trial. All grains were grown in the same field under similar conditions. The sor-gums and their tannin contents (milligrams of catechin/100 mg of dry matter, as determined by a modified vanillin-HCl method) were: Ga615, 3.40; NK300, 3.17; TAM680, .83, and G766-W, .88. Diets were supplemented with casein to provide .70 and .60% lysine in digestion trials 1 and 2, respectively. In trial 1, conducted with noncannulated, 25-kg pigs, digestibilities of dry matter, gross energy and N averaged for the low tannin sorghums (TAM680 and G766-W) were higher (P<.01) than the corresponding digestibilities averaged for the high tannin sorghums (Ga615 and NK300). N balance data indicated that utilization of absorbed N was not reduced in pigs fed the high tannin sorghums. Corn and the low tannin sorghums had similar digestibilities. In trial 2, conducted with 50-kg pigs fitted with T-cannulas at the terminal ileum, digestibilities of dry matter, gross energy, N and all amino acids again averaged higher (P<.01) for the low tannin sorghums than for the high tannin sorghums, whether measured at the end of the small intestine or over the total digestive tract. The one exception was methionine digestibilities at the terminal ileum, which did not differ between the high and low tannin sorghums. Among the amino acids, digestibilities of glycine, proline and histidine appeared to be the most depressed in the high tannin sorghums, as compared to the low tannin sorghums. Digestibilities of most nutrients were higher for NK300 than Ga615, suggesting a difference in type of tannin, or other compound, between the grains. Corn and the low tannin sorghums, averaged together, had similar digestibilities for most nutrients. In the growth trial, 10 pigs, individually fed from 20 to 94 kg, received grain-soybean meal diets based on each grain except NK300. Gains were not affected by diet, but feed consumption was 9% higher (P<.05) and feed efficiency 10% (P<.01) poorer for pigs fed Ga615 than for those fed low tannin sorghums. Performance was similar (P>.10) for animals fed the low tannin sorghums and those fed corn. Copyright © 1982. American Society of Animal Science. Copyright 1982 by American Society of Animal Science