ABSTRACTPendulous crop is a physiological disorder, which etiology is still unknown and it is characterized by abnormal dilation of the crop of poultry. This article aims at reporting a case of high incidence of pendulous crop in male and female broilers Cobb 500, as well as to discuss its possible causes and consequences. In an experiment with broilers performed at the experimental facilities of Laboratório de Ensino Zootécnico of UFRGS, a high incidence (9.5%) of pendulous crop was observed. Genetic predisposition is the most frequently documented and accepted cause of that condition. Despite presenting the same live weight as normal broilers, birds with pendulous crop had lower carcass weight due to dehydration and malnourishment, and should be culled after diagnosis. Therefore, further studies on the origin and control of this physiological disorder are warranted.

Four Nutritional Programs (NP) used in the Brazilian poultry industry were tested in two broiler strains (Cobb 500 and Ross 308). NP varied in the concentrations of their main essential amino acids (AA) and were classified as Low, Regular, High and Mixed (high AA concentrations up to 21 days and regular concentrations after that). Minimum digestible Met+Cys/Lys, Thr/Lys, Arg/Lys, Ile/Lys, and Val/Lys ratios were 0.74, 0.64, 1.05, 0.65 and 0.75, respectively, in all NP, and no minimum amount of CP was fixed. There were no interactions between strain and NP for any of the evaluated responses. From 1 to 47 days of age, birds fed the Low NP presented lower average body weight and body weight gain (BWG). The high NP allowed for better feed conversion ratio (FCR), followed by the Regular and the Mixed NP. Ross 308 broilers were heavier, presenting worse FCR due to higher FI. Birds fed the High NP had lower carcass yield than those fed the Low NP. The Low and Regular NP had lower costs per WG when compared with the High NP. Low and Regular NP presented higher gross margin returns compared with the High NP. The Regular and Mixed NP are the most recommended, presenting intermediate performance and higher economic returns.