ABSTRACT This study aimed to examine the impact of levels of dietary supplementation with fat-soluble vitamins on the production performance and egg quality of laying hens. Three hundred Hy-Line White W-36 laying hens were evaluated from 28 to 44 weeks of age. The birds were allotted to one of six treatments in a randomized block design with 10 replicates with five birds each. Performance and egg quality parameters were evaluated in four 28-day periods. A corn and soybean meal-based basal diet was formulated so as to meet the nutritional requirements of the animals, with the exception of fat-soluble vitamins. The treatments consisted of dietary supplementation with 0%, 33.3%, 66.7%, 100.0%, 133.3% or 166.7% of fat-soluble vitamins (100% supplementation consisted of 7500 IU, 2000 IU, 10 IU and 1.8 mg of vitamins A, D3, E and K per kilogram of diet, respectively). Eggshell weight, shell thickness, shell strength, feed intake, egg weight, feed conversion per egg mass and feed conversion per dozen eggs showed a quadratic response (p≤0.05) to the treatments, whereas egg mass responded linearly. Optimal results were obtained at an average fat-soluble vitamin supplementation level of 109%, which corresponds to 8175 IU of vitamin A, 2180 IU of vitamin D3, 10.9 IU of vitamin E and 1.96 mg of vitamin K per kilogram of diet.

ABSTRACT This study aimed at evaluating four dietary L-Glutamine (L-Gln) or L-Gln plus L-Glutamate (L-Glu) supplementation programs on the performance, breast yield, and uniformity of broilers. A total of 2,112 one-d-old male Cobb 500(r) broilers were distributed according to a randomized block design in a 2 × 4 factorial arrangement (L-Gln or L-Gln plus L-Glu × 4 supplementation programs), totaling eight treatments with 12 replicates of 22 broilers each. The supplementation programs consisted of the dietary inclusion or not of 0.4% of L-Gln or L-Gln plus L-Glu for four different periods: 0 days (negative control), 9d, 21d, and 42d. Feed intake (FI, g), body weight gain (BWG, g), feed conversion ratio (FCR, kg/kg), coefficient of variation of body weight (CV, %), body weight uniformity (UNIF, %), breast weight (BW, g), breast yield (BY, %), coefficient of variation of breast weight (CVB), breast uniformity (UNIFB), coefficient of variation of breast yield (CVBY), and breast yield uniformity (UNIFBY) were evaluated. Birds fed the diets treatments supplemented with L-Gln or L-Gln plus L-Glu for 9d presented 3% higher BWG (p<0.05) compared with the controls. The L-Gln or L-Gln plus L-Glu supplementation until broilers were 21 days old resulted in 14, 10, 16, and 12% improvements (p<0.05) in CV, UNIF, CVBY, UNIFBY, respectively. The supplementation of 0.4% L-Gln (L-Gln 99%) or L-Gln plus L-Glu (minimum 95%) to pre-starter and starter broiler diets is recommended to improve body weight gain and uniformity.

The objective of this study was to evaluate the performance of male broilers between 21 and 42 days of age fed diets supplemented with an enzyme blend (EB) and containing graded levels of sunflower meal (SFM). In total, 1920 male Cobb broilers were distributed according to a randomized block experimental design in a 4 x 3 factorial arrangement (four SFM dietary levels vs. three feed formulations) with eight replicates of 20 birds each. Dietary SFM inclusion levels were 0, 8, 16, and 24%. Feed formulation included one negative control diet (NC) formulated to supply broiler nutritional requirements, considering EB nutritional matrix values; a diet formulated as the first one, but with the addition of 0.5% EB (NC+EB); and the third diet (positive control - PC) was calculated to supply broiler requirements. Feed intake, weight gain, feed conversion ratio, and carcass parameters were evaluated. There was no effect of EB dietary supplementation on the evaluated performance or carcass parameters (p > 0.05). Increasing dietary addition of SFM reduced weight gain and worsened feed conversion ratio (p > 0.05). The best EEI was obtained with the NC+EB diet containing 8.0% SFM.