The value of crude protein content and in vitro pepsin digestibility of abattoir by-product meals in the prediction of their available protein content.
Amino acid composition of meat-and-bone meals, poultry by-product meals, blood meals, bone meals and feather meals showed characteristic differences. Meat-and-bone meals and blood meals had surplus in lysine, whereas poultry by-product meals and feather meals were relatively rich in cystine. Blood meals had high levels of branched-chain amino acids as compared to isoleucine. In vitro pepsin digestibility of meat-and-bone meals (79.9 +/- 17.7%; n = 24) and blood meals (95.8 +/- 4.2%; n = 11) was found to be higher than that of poultry by-product meals (65.3 +/- 7.7%; n = 14) or feather meals (44.7 +/- 9.2%; n = 16). Pepsin digestibility of poultry by-product meals showed a significant negative correlation with crude protein content (r = -0.73; P less than 0.05; n = 14). However, in vitro pepsin digestibility of poultry by-product meals as well as meat-and-bone meals, blood meals and feather meals, showed insignificant correlations with NPU indices as well as with available crude protein contents of the meals. The NPU values of meat-and-bone meals for rats (29.9 +/- 11.7; n = 100) were lower than those of poultry by-product meals (52.1 +/- 7.1; n = 14). The NPU values of blood meals (6.4 +/- 5.6; n = 11) and feather meals (23.5 +/- 10.0; n = 16), determined as sole sources of protein, were low and they did not elicit weight gain in rats. The available crude protein content of poultry by-product meals (34.3 g/100 g +/- 3.6; n = 14) was higher than that of meat-and-bone meals (17.0 g/100 g +/- 7.3; n = 100).(ABSTRACT TRUNCATED AT 250 WORDS)
Hegedüs
M
M
Bokori
J
J
Andrásofszky
E
E
D000003:Abattoirs; D000596:Amino Acids / Q000032:analysis*; D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004044:Dietary Proteins / Q000032:analysis* / Q000378:metabolism; D004063:Digestion; D010434:Pepsin A / Q000378:metabolism*
D000596:Amino Acids; D004044:Dietary Proteins; D010434:Pepsin A