Effect of Dietary Protein and Tsaa Levels on Performance, Carcass Traits, Meat Composition and Some Blood Components of Egyptian Geese During the Rearing Period

SIMPLE SUMMARY: Egyptian geese were domesticated more than 4000 years ago; so this bird is among the first domesticated avian species. Therefore, it is necessary to determine the nutritional requirements and establish more precise feeding standards for this breed (Egyptian geese) to ensure its effective production. Dietary level of crude protein (CP) and total sulfur amino acids (TSAA) should closely meet the maintenance and production requirements, especially toward the middle and end of the grow-out period. Thus, this study focused on the effect of varying dietary crude protein and TSAA on growth, carcasses, biochemical blood parameters, and meat quality to determine the nutritional requirement of Egyptian geese. From our results, it can be concluded that the consumption of diets with high levels of protein or methionine and cystine (M + C) can improve the productive performance, carcass and meat quality of Egyptian geese during the rearing period. ABSTRACT: The present study was performed to investigate the effect of dietary levels of protein, total sulfur amino acids (TSAA), methionine and cystine (M + C) and their interaction on the performance, carcass characteristics, blood components and meat quality of Egyptian geese. A total number of 144 geese at twelve weeks of age were randomly divided into 9 groups (16 birds/each group), each group of birds was sub-divided into 4 replicates, each of 4 birds. There was a significant increase in the bodyweight of geese due to protein and M + C levels (p < 0.01). The studied levels of M + C affected significantly on weight gain of growing geese at the early period of 12–18 wk of age. Feed intake was increased with high dietary levels of CP % or M + C (p < 0.05). There was a significant (p < 0.01) increase in percentages of carcass, liver, dressing, breast and wing with high dietary protein level as compared to a moderate or low level. A high level of dietary protein led to increase in concentrations of total protein and albumin, while total lipids, cholesterol, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were decreased with increasing level of protein (p < 0.01). Fat percentage of breast muscle was significantly (p < 0.01) decreased with increasing M + C levels. Protein % of breast muscle was increased with increasing protein levels. Finally, it can be concluded that the consumption of diets with high levels of protein or M + C can improve the bodyweight, feed conversion ratio, carcass and meat composition of Egyptian geese during the rearing period (12–24 wk of age).