RESUMO Objetivou-se avaliar o efeito da suplementação de cromo-metionina em dietas para frangos de corte criados em estresse por calor, no período de 22 a 43 dias de idade, nos parâmetros de qualidade da carne. Foram utilizados 336 frangos de corte, machos, da linhagem Cobb 500, com 21 dias de idade, distribuídos em delineamento em blocos inteiramente ao acaso, com quatro blocos (cada câmara climática), seis tratamentos (0; 0,10; 0,20; 0,40; 0,80 e 1,20mgkg-1 de Cr na forma de Cr-metionina), oito repetições e sete aves por unidade experimental. Aos 43 dias de idade, duas aves por unidade experimental foram selecionadas e abatidas para avaliação da qualidade da carne de peito, por meio dos parâmetros de pH15min, pH24h, luminosidade (L*), teor de vermelho (a*), teor de amarelo (b*), croma (C*), ângulo hue (Hº), capacidade de retenção de água, perda de peso por cozimento e força de cisalhamento. Houve efeito quadrático (P=0,0070) na capacidade de retenção de água da carne de peito. A suplementação de CrMet não afetou (P>0,05) os demais parâmetros de qualidade da carne. Assim, recomenda-se a suplementação de 0,59mgkg-1 de CrMet para frangos de corte para melhoria da capacidade de retenção de água do peito.

ABSTRACT The objective of this study was to determine the metabolizable energy, standardized ileal amino acid digestibility (SIAAD) and digestible amino acid values of wheat meal (WM), wheat gluten meal (WGM), meat bone meal (MBM) and poultry-by-product meal (PPM) in diets for broilers. In the first experiment, the total excreta collection method was used, with 180 chicks with 14 days, distributed in a completely randomized design, with 4 feeds + reference diet with 6 replicates and 6 broilers each. In the second experiment, 180 broilers from 24 to 28 days old were used, distributed in a completely randomized design, with 4 feeds + one protein free diet with 6 replicates and 6 broilers each. The AMEn values of WM, WGM, MBM and PPM were 3052, 3174, 1556 and 3200 (kcal/kg), respectively. The average SIAAD of the essential and non-essential amino acids of WM, WGM, MBM and PPM were 74.21, 97.50, 69.28 and 83.08; 76.32, 96.42, 63.93 and 77.66, respectively. The values of the main digestible limiting amino acids were 0.18, 1.42, 0.41 and 0.94 for methionine; 0.20, 1.48, 1.73 and 2.73 for lysine; 0.23, 1.67, 0.72 and 1.89 for threonine; and 0.35, 3.22, 1.38 and 2.47 for valine, respectively for the feedstuffs in study.

Shrimp waste meal (SWM) is a by-product from the processing of shrimp for human consumption. The value of SMW in feeding poultry is not well documented. The objective of this study was to determine the energy value and optimal inclusion level of SWM in the diet of growing chickens. A total of 180 one-day-old broilers were randomly assigned to five treatments with 0, 50, 100, 150 and 200 g/kg of SWM included in their diet. There were six replicates of six birds for each treatment. Dry matter intake (DMI) was not affected by the level of SWM that was fed. Retained dry matter varied from 72.39% in the diet that did not contain SWM to 66.97% in the diet with 200 g/kg of SWM. Nitrogen retention (NR) ranged from 54.70% to 70.10%; N ingested was between 18.71% and 24.03%. Energy intake ranged from 73.57% to 69.33% for the control and the diet with 200 g/kg of SWM, respectively. NR improved with increasing SWM inclusion levels. The apparent metabolizable energy (AME) and corrected apparent energy metabolizable (AMEn) ranged from 2928 to 2527 kcal/kg and 2774 to 2329 kcal/kg, respectively, relative to the control and 200 g/kg SWM diets. The energy consumption, in kcal/kg, of SWM consumed was AME = 2332-6.971 x SWM and AMEn = 21138.128 x SWM. High levels of SWM reduce the dry matter metabolization coefficient and metabolizable energy values in broilers during the growing phase, so it is recommended that up to 100 g/kg should be included, which would provide an AMEn of 1300.2 kcal/kg for free-range chickens in dry matter.