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This study aimed to evaluate the effects of okara inclusion in diet for growing broilers on performance, carcass yield, blood and bone variables, quality and lipid oxidation of meat, and economic viability. For that, 575 Cobb 21-d-old male broilers were distributed in a completely randomized design with four levels of okara inclusion (25, 50, 75, and 100 g of okara kg−1diet) and a control group with five replicates and 23 birds each. There was no significant difference (P > 0.05) of okara levels on the performance variables, carcass yield, bone variables, and serum triglycerides, calcium and phosphorus at 42-d-old. Serum cholesterol levels showed a quadratic response (P −1of diet. Okara can be included in diets for broilers up to the level of 100 g kg−1without affecting the performance, carcass yield, bone variables, and lipid oxidation of meat. However, the best economic results were observed up to 50 g of okara kg−1of diet.

Three experiments were carried out to evaluate the levels of digestible valine in diets with reduced crude protein on the performance, carcass yield and muscle fiber diameter of male broilers during the pre-starter (1 to 8 d of age), starter (9 to 21 d of age) and grower phases (21 to 42 d of age). A total of 1,080 chickens in the pre-starter phase, 900 in the starter phase and 864 in the grower phase were distributed in a completely randomized design with six treatments, consisting of a control positive diet (C+) and diets with 2 percentage points (p.p.) reduction of crude protein level and five graded levels of digestible valine (Val), with six replicates of 30, 25 and 24 birds per experimental unit, respectively. The recommended level of TID Val in the low-protein diets for broilers in the pre-starter, starter and grower stages were 1.028; 0.905 and 0.789%, respectively. The reduction of 2 percentage points of the crude protein level in diets based on corn and soybean meal impaired (p ≤0.05) the feed conversion ratio in the starter and grower stages. Likewise, the reduced-protein diets decreased (p ≤0.05) muscle fiber diameter, but did not affect (p> 0.05) carcass and parts yields, or abdominal fat percentage at 42 days.

1. The objective of this study was to determine the optimum glycine+serine (Gly+Ser) concentration in low-crude protein (CP) diets that have adequate or high concentrations of dietary threonine (Thr) for broiler chickens in the initial growth phase. 2. Treatments consisted of four concentrations of dietary Gly+Ser (18.4; 19.8; 21.2 and 22.6 g/kg) and two concentrations of dietary Thr (9.3 and 10.7 g/kg, corresponding to 100 and 115% of the required Thr, respectively). 3. At 21d, interactions were observed between dietary Gly+Ser and Thr concentrations for the feed conversion ratio, creatine content in the pectoral muscles and serum concentrations of uric acid. There was a quadratic effect of the concentrations of Gly+Ser in the diets with 9.3 g Thr/kg on the feed conversion ratio and creatine content in the pectoral muscles, with an optimisation concentration of 20.8 and 21.1 g Gly+Ser/kg, respectively. 4. Diets containing 10.7 g Thr/kg negatively affected the feed conversion ratio, relative breast weight, creatine content in the pectoral muscles, serum concentrations of uric acid and ammonia in poultry compared to diets containing 9.3 g Thr/kg. 5. The need for Gly+Ser in diets with low-protein concentration (190 g CP/kg) and adequate concentration of Thr (9.3 g/kg) is 20.8 g/kg for broilers in the 1- to 21-d phase.

The objective of this experiment was to assess the use of different vitamin D metabolites in the feed of broiler chickens and the effects of the metabolites on performance, bone parameters and meat quality. A total of 952 one-day-old male broiler chicks were distributed in a completely randomised design, with four treatments, seven replicates and 34 birds per experimental unit. The treatments consisted of four different sources of vitamin D included in the diet, D3, 25(OH)D3, 1,25(OH)2D3, and 1(OH)D3, providing 2000 and 1600 IU of vitamin D in the starter (1 to 21 d) and growth phases (22 to 42 d), respectively. Mean weight, feed:gain and weight gain throughout the rearing period were less in animals fed 1(OH)D3 when compared with the other treatments (p 0.05) for various bone parameters. Meat colour differed among the treatments (p>0.05). All of the metabolites used in the diets, with the exception of 1(OH)D3, can be used for broiler chickens without

The objective of this study was to evaluate the effect of inclusion of dehydrated cassava starch residue (DCSR) on the performance, gastrointestinal tract characteristics and carcass traits of ISA Label JA57 slow-growing broilers. A total of 510 broilers at 21 were distributed in a randomized experimental design with 5 treatments (2, 4, 6, 8, and 10 % DCSR inclusion) and a control group, 5 replicates, and 17 birds per experimental unit. The DCSR inclusion from 21 to 49 days of age negatively influenced (P 0.05) weight gain and feed intake and did not affect (P 0.05) feed conversion in the broilers with increasing of DCSR inclusion. From 21 to 79 days, DCSR inclusion impaired (P 0.05) weight gain, feed conversion, and poultry litter quality with increasing of DCSR inclusion. The level of blood triglycerides showed a quadratic response (P 0.05) at 79 days of age with the highest value predicted to occur at 5.45 % of DCSR inclusion. DCSR levels affected (P 0.05) the gastrointestinal organ characteristics, cecal content pH, and pigmentation of the shank, breast, and thigh meat of the birds but did not alter (P 0.05) the other parameters of carcass quality and yield, cuts, and percentage of abdominal fat. In conclusion, DCSR inclusion levels above 2 % compromised broiler performance.

The objective of this study was to evaluate the effect of dietary restriction and inclusion of alfalfa (Medicago sativa L.) and Bermudagrass (Cynodon dactylon cv Coastal) hays in the diets of ISA Label JA57 slow-growing male broilers on performance, gastrointestinal tract characteristics, and economic viability. A total of 272 broilers at 21 days old were distributed in a randomized experimental design with four treatments, four replicates, and 17 birds per experimental unit. The treatments consisted of ad libitum concentrated feed (control intake), feed restriction (80% of the control intake), and feed restrictions with supplementation of alfalfa hay (80% of the control intake+20% alfalfa) or Bermudagrass hay (80% control intake+20% Bermuda). Dietary restriction, with and without hay inclusion, negatively affected (P