Effect of broiler breeders fed with corn or sorghum diet and canthaxanthin supplementation on production and reproductive performance.

This study was designed to evaluate the effect of corn or sorghum diet and canthaxanthin (CX) supplementation on performance in broiler breeders. A total of 440 females with similar body weight (BW) (3.71 ± 0.14 kg) and 60 roosters were placed in an open-sided house with 20 pens, randomly distributed in a factorial arrangement (2 × 2). There were 4 diets of 2 ingredients; corn (CO) or sorghum (SO) and 2 levels of CX; 6 mg/kg (CX) and 0 mg/kg (NCX) totaling 5 replicate pens of 22 females and 3 males each, from 42 to 65 wk, divided in 2 periods (from wk 42 to 53 and wk 54 to 65). Birds' BW was measured every 28 d and mortality rate was calculated at the end of trial. Egg production (%), egg specific gravity (g/cm3), egg weight (g), yolk weight (%), albumen weight (%), eggshell weight (%) and yolk colorimetric score were measured weekly. Incubation parameters were recorded in 12 incubations to evaluate hatching eggs, hatching (%), hatchability (%), fertility (%), weight of the chicks born and their quality. The BW, mortality, percentage of yolk and albumen weight, fertility and some incubation parameters were not affected (P > 0.05) by diets used. An increase in the egg production, hatching eggs, chicks born and first quality chick by hen at the second period were observed in CX breeder's diets (P = 0.0066; P = 0.0060; P = 0.0368; P = 0.0326). Egg specific gravity and eggshell weight were improved at the first period by SO+CX diet (P = 0.0138; P = 0.0209) and the same effect to egg weight, but at the second period (P = 0.0251). The CX was well absorbed from the diet and effectively transferred to the egg yolk, thereby increasing egg yolk pigmentation in the both periods (P < 0.0001). The CX supplementation in broiler breeder diets improved the productive and reproductive performance (laying% and hatchable eggs) at the second period, also to the both periods improved the egg yolk pigmentation.

Effect of broiler breeders fed with corn or sorghum and canthaxanthin on lipid peroxidation, fatty acid profile of hatching eggs, and offspring performance.

The aim of study was to evaluate the effect on broiler breeders fed with corn or sorghum diets and canthaxanthin on lipid peroxidation, fatty acid, and offspring's performance. A total of 440 females with similar body weight (BW) (3.77 ± 0.11 kg) and 60 roosters were placed in an open-sided house with 20 pens, randomly distributed in a factorial arrangement (2 × 2). There were 4 diets of 2 ingredients; corn (CO) or sorghum (SO) and 2 levels of canthaxanthin; 6 mg/kg (CX) and 0 mg/kg (NCX) totaling five replicate pens of 22 females and 3 males each, from 45 to 65 wk old. The BW was measured every 28 days, carotenoid concentration, thiobarbituric acid reactive substances (TBARS), fatty acid profile (%) in egg yolks, and the performance from two incubations and their offspring were evaluated. The study had the same statistical design as broiler breeders, making a total of 4 groups with 10 replicate pens of 8 chicks each. The BW and mortality were not affected (P > 0.05) by diets. Egg yolks coming from the CO diet had the highest (P < 0.05) lutein (3.8 vs. 0.49 mg/kg) and zeaxanthin (4.25 vs. 0.22 mg/kg) concentration compared to SO diet. The SO+CX diet had the highest CX concentration (P < 0.0001). The SO+CX diet showed the lowest TBARS (P = 0.0002) in the egg yolk compared to the CO+CX diet. Egg yolks coming from breeders fed with CO showed a higher concentration of saturated fatty acids (23.36 vs. 21.44%) and monounsaturated fatty acids (27.17 vs. 24.96%). Egg yolks arising from broiler breeders fed with SO diets showed a higher concentration of polyunsaturated fatty acids compared (15.29 vs. 12.88%). The CX reduced the offspring CO diets mortality and improved their viability at 64 wk-old for the broiler breeders (P < 0.05). CX was well absorbed from the diet and effectively transferred to the egg yolk, thereby increasing its concentration in the yolk. This conferred resistance to oxidative stress to the yolk and also later to the developing embryo and its ultimate performance.

Efficacy of a Brazilian calcium montmorillonite against toxic effects of dietary aflatoxins on broilers reared to market weight.

1. The protective effect of a natural Brazilian calcium montmorillonite (CaMont) against aflatoxins was studied in broiler chickens. 2. A total of 1056-d-old Cobb male broilers were housed in experimental pens (22 chickens per pen) for 42 d. Three levels of CaMont (0, 2.5 and 5 g/kg) and two levels of aflatoxins (0 and 3 mg/kg) were assayed. Each treatment had 8 replicate pens of 22 broiler chickens each. 3. Of all the chickens tested in the experiment, the ones treated with aflatoxins were the most adversely affected. CaMont treatment at concentrations of 2.5 and 5 g/kg improved body weight of chickens at 42 d of age by 13.3% and 22.7%, increased daily feed intake by 9.7% and 24.7%, and improved the productive efficiency index of chickens by 53% and 66.5%, respectively. 4. Dietary CaMont positively affected parameters such as weight of liver, heart and gizzard; however, serum potassium concentration decreased by 15.3% compared with that of chickens given only the aflatoxin-contaminated diet. 5. CaMont did not cause adverse effects in chickens that did not receive aflatoxins. 6. CaMont at pH 8.5 partially reduced the toxic effects of aflatoxins in broilers when included at levels of 2.5 and 5 g/kg in the diet.

Threonine requirements of different broiler genotypes.

The objectives of this work were to study the responses of one Leghorn and two broiler stocks and sexes to different levels of Thr and to estimate their requirements for this amino acid. All experiments were conducted with birds from 1 to 18 d of age. Body weight gain (BWG) and feed consumption were measured on the eighteenth day, and feed conversion ratio (FCR) was calculated. At Day 18, three birds per replicate were killed, and liver and fat pads were collected and weighed. The data were analyzed by the general linear model and nonlinear model procedures of SAS software, and the broken-line linear model was used to estimate Thr requirements of chicks. Experiment 1 had a 5 x 3 factorial design with five levels of Thr (0.63, 0.70, 0.77, 0.84, and 0.91% of the diet), two broiler genotypes (Arbor Acres Classic and High Yield), and one Leghorn genotype (Hy-line W-36), with three replicate pens of eight male birds each. The basal diet was composed of corn, peanut meal (PNM), poultry by-product meal, poultry fat, DL-Met, L-Lys, and L-Ile (23% CP and 3.2 kcal/g of ME). The Leghorn chicks did not respond to Thr supplementation, indicating their requirement was < or = 0.63%. High Yield birds had better BWG and FCR than Classic. The BWG and FCR were reduced more in Classic than High Yield strains by the lowest Thr level. The percentage of liver was higher in the Classic than High Yield strain broilers with Thr supplementation. The second experiment (2 x 2 x 2 factorial design) was conducted to evaluate the effects of two levels of Thr (0.63 and 0.90%), two levels of Ile (0.72 and 0.90%), and two broiler strains (as Experiment 1). There were no responses to Ile for any parameters measured. Experiment 3 (6 x 2 factorial design, corn, PNM-based basal diet) had six Thr levels (0.63, 0.67, 0.71, 0.75, 0.79, and 0.83%) and two broiler strains (as Experiment 1), with four replicate pens of eight male birds each. The High Yield strain broilers grew significantly better at the lowest Thr level, but performance was similar at the higher Thr levels (significant interaction, P = 0.018). FCR was affected by Thr level but not by strain. The Thr requirement of the Classic strain broilers was 0.69 +/- 0.01% for BWG and 0.68 +/- 0.01% for FCR. The Thr requirement of the High Yield strain broilers was 0.68 +/- 0.01% for BWG and 0.69 +/- 0.01% for FCR. The Thr requirements of male versus female High Yield strain broilers were evaluated in a 6 x 2 factorial design, with six Thr levels (Experiment 4), with four replicate pens of eight birds each. Males and females had the same performance and carcass composition results (P > 0.05), except for percentage abdominal fat pads. The Thr requirement was 0.71 +/- 0.01% for BWG and 0.71 +/- 0.01% for FCR for the males and 0.72 +/- 0.008% for BWG and 0.71 +/- 0.001% for FCR for females. Excellent performance was observed from the corn- and PNM-based diet supplemented to contain 0.72% Thr. The Thr requirements of High Yield and Classic broilers (males and females) were similar and greater than for the Leghorn strain studied.

Tryptophan requirements of different broiler genotypes.

Two experiments were conducted with broiler chicks in battery brooders from 1 to 18 d of age to determine Trp requirements and to evaluate the performance of different genotypes (classic vs. high yield and male vs. female). Experiment 1 was a 6 x 2 factorial experiment, with six levels of Trp (0.09, 0.12, 0.15, 0.18, 0.21, and 0.24% of the diet) and two broiler chicken strains (male Arbor Acres Classic and Arbor Acres High Yield). Experiment 2 was a 6 x 2 factorial design with the same levels of Trp as in Experiment 1 and two sexes (males and females); Ross x Ross 308 birds were used. Both experiments had four replicate pens of eight birds each per treatment. The basal diet was based on corn (70.79%), corn gluten meal (17.44%), and gelatin by-product and poultry fat (23% of CP and 3.34 kcal/g of ME). At 18 d of age, three birds per replicate were killed, and livers and fat pads were removed. The broken-line linear model was used to estimate the chicks Trp requirement. Liver or liver fat and fat pad weights (as a percentage of body weight) were affected by dietary Trp level. In Experiment 1, the Trp requirements differed little; for gain they were 0.18 +/- 0.002% and 0.17 +/- 0.002%, and for feed conversion they were 0.16 +/- 0.004% and 0.16 +/- 0.002%, for the Classic and High Yield broilers, respectively. In Experiment 2, the Trp requirement of males was 0.17 +/- 0.003% for BW and 0.17 +/- 0.003% for feed conversion, and that of females was 0.17 +/- 0.003% for body weight and 0.16 +/- 0.001% for feed conversion. There was no apparent difference in the Trp requirement of young broilers due to genetic stock or gender (P > 0.05).