Teores de glicina+ serina total em dietas de baixa proteína bruta para de frangos de corte de 22 a 35 dias de idade

Supplementation of L‐glycine and L‐glutamate to Japanese quails from 01 to 36 days of age using the ideal protein concept

“…By analyzing the performance of quails fed diets T 1‐1 versus T 1‐2 , it was observed that the protein reduction and the supplementation of limiting essential amino acids (T 1‐2 ) did not significantly alter the feed intake of quails in relation to the control diet (T 1‐1 ), in which there was no reduction of crude protein. These data corroborate with Applegate et al (), Darsi et al (), Hernandez et al (), Vasconcellos et al () and Vasconcellos et al (), who did not verify a reduction in feed intake in broilers and/or laying hens by reducing the dietary crude protein level and supplementing with only the limiting amino acids.…”

“…No significant change was observed in feed conversion (Table ) of quails fed the control diet (T 1‐1 ) in relation to those fed the diet supplemented only with limiting essential amino acids (T 1‐2 ), corroborating evidence from Applegate et al (), Darsi et al (), Hernandez et al () and Vasconcellos et al (). These authors did not observe a difference between the feed conversion in broilers fed a control diet, without protein reduction, in relation to animals fed a diet with protein reduction and supplementation of only the limiting essential amino acids.…”

“…Darsi et al (), Hernandez et al (), Vasconcellos et al () and Vasconcellos et al () did not observe a difference for the variables mentioned above in broilers fed a control diet in relation to a diet with protein reduction and supplemented only with limiting essential amino acids.…”

“…Lowering costs and increasing productive efficiency are key premises considered in the commercial production of broilers, laying hens and quails. In this sense, the reduction of dietary crude protein levels based on the ideal protein concept and the supplementation of limiting amino acids are subject of several research efforts (Gheisari, Asasi, Mostafa, & Mohsenifard, ; Hernandez et al, ; McGill, Kamyab, & Firman, ; Vasconcellos et al, ; Vieira et al, ).…”

“…Several research studies try to elucidate the cause of the impaired performance in broilers fed diets with reduced protein levels. The hypotheses include: decreases in digestible glycine levels (Namroud et al, 2010;Vasconcellos et al, 2015Vasconcellos et al, , 2011Yuan et al, 2012); decreases in digestible lysine levels (Saima, Jabbar, Mehmud, Abbas, & Mahmood, 2010); decreases in digestible glycine/threonine ratio (Waldroup, Jiang, & Fritts, 2005b); changes in electrolyte balance (Han, Suzuki, Parsons, & Baker, 1992;Vieira et al, 2015); decreases in the ratio between essential and non-essential amino acids (Waldroup et al, 2005a); reductions in dietary nitrogen levels (Bregendahl, Sell, & Zimmerman, 2002); reductions in feed intake (Namroud et al, 2010); changes in serum levels of triiodothyronine, thyroxine and ammonia (Carew, Evarts, & Alster, 1998;Namroud et al, 2008Namroud et al, , 2010; changes in the concentration of intestinal transporters, as well as in the absorption efficiency (Corzo, Loar, Kidd, & Burgess, 2011;Nyachoti, Omogbenigun, Rademacher, & Blank, 2006;Tuitoek, Young, de Lange, & Kerr, 1997;Wu et al, 2015) and increases in fat content in the carcass (Yamazaki, Murakami, & Takemasa, 1998), which reduces muscle tissue deposition.…”