Efeito do rácio triptofano:lisina em regimes de baixa proteína no crescimento de suínos entre os 20-40 kg de peso vivo
2014
Roxo, Alexandre Manuel Delgado | Freire, João Pedro Bengala
Mestrado em Engenharia Zootécnica - Produção Animal - Instituto Superior de Agronomia / Faculdade de Medicina Veterinária
显示更多 [+] 显示较少 [-]The effect of different standardized ileal digestible tryptophan:lysine ratios, in diets with low crude protein on the zootechnical performances of pigs between 20 and 40 kg, was studied using 120 pigs in a five week trial. The 120 pigs were allotted to four experimental diets, 30 animals per diet and placed in cages in groups of 3 pigs per cage. Diet 1 was the control diet, with a level of 16,5% crude protein and standardized ileal digestible tryptophan:lysine ratio of 20,7%; diets 2, 3 and 4 were diets with a low crude protein level (14,5%) and the standardized ileal digestible tryptophan:lysine ratios were 17,4%, 20,5% and 23,5%, respectively. The average daily feed intake and the average daily gain decreased in pigs fed diet 2 compared to pigs fed diet 1 (P=0,0432; P=0,0187, respectively). The average daily feed intake, average daily gain and feed conversion ratio were not significantly different between diets 1 and 3 and between diets 3 and 4. These results suggest that it is possible to reduce the level of crude protein in two percentage points, as long as balance is maintained in the standardized ileal digestible tryptophan:lysine ratio at 20,5%
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