Modelling Japanese quail responses to methionine + cystine, threonine and tryptophan intake

• Autor(a) principal: Sarcinelli, M. F. [UNESP]
• Data de Publicação: 2020
• Outros Autores: Sakomura, N. K. [UNESP], Dorigam, J. C.P. [UNESP], Silva, E. P. [UNESP], Venturini, K. S. [UNESP], Lima, M. B. [UNESP], Gonçalves, C. A. [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.anifeedsci.2020.114486; http://hdl.handle.net/11449/200290
• topic: Egg output; Factorial approach; Maintenance; Quail hens

The objective of this study was to evaluate the responses of Japanese quails to threonine (Thr), methionine + cystine (Met + Cys) and tryptophan (Trp) intakes, and develop factorial models to estimate the requirements of these amino acids (AA) based on maintenance and egg output coefficients determined by mathematical models. Thus, three trials (one for each AA) were conducted and a completely random design was used, which consisted of seven levels of each AA test, seven replicates and seven birds per experimental unit. The trials began at 16 weeks of age, quail at peak egg production, and lasted after seven weeks (three weeks of adaptation and four weeks for data collection). The variables analyzed were feed intake (FI), amino acid intake (I), body weight (BW), egg production (EP), egg weight (EW) and egg output (EO). The responses of quails to Thr, Met + Cys and Trp intake were evaluated using broken line analysis and to determine the AA requirements for maintenance (m) it was used monomolecular function. Thus, a coefficient (the requirement for EO) was adjusted in function of I and the maintenance was calculated when EO = 0. To determine the AA requirement for EO (a) it was used the broken-line with two slopes. The maximum egg output (EOmax) responses obtained were 9.49; 9.31 and 10.37 g per day for Met + Cys, Thr and Trp, respectively. The m values determined were 176, 64 and 47 mg per BW kg 0.75 per day and the values determined were 15, 17 and 4 mg g for Met + Cys, Thr and Trp, respectively. The recommendation for AA intake for EOmax were 176, 191 and 55 mg per day for Thr, Met + Cys, and Trp, respectively, considering the same feed intake (25 g/day) and body weight (180 g/bird).