Responses of broilers challenged by Eimeria maxima fed with different levels of dietary balanced protein.

This study aimed to evaluate the effects of different dietary balanced protein (BP) levels on the gut health, amino acid apparent ileal digestibility (AID), footpad dermatitis lesions, and litter quality in broiler chicks infected with Eimeria maxima. A total of 2400 male 14-day-old Cobb500 broilers were randomly allotted into 10 treatments with six replications containing 40 birds each in a factorial design of 5 × 2. The treatments consisted of five levels of BP (6.66%, 13.32%, 19.98%, 26.64%, and 33.3%), and broilers unchallenged (NCH) or challenged (CH). Broilers in the CH group received 1 mL of Eimeria maxima inoculum (7 × 103 sporulated oocysts/mL). Oocyst count in excreta, visual intestinal modifications score, morphology, and morphometrics of the ileum were used to determine gut health status. Additionally, amino acids and CP AID, litter quality, and footpad dermatitis were evaluated. An ANOVA and Kruskal-Wallis tests followed by post-hoc tests were performed. The oocyst count in the CH group increased with an increase in dieatary BP (P = 0.08). The incidence of intestinal modifications was higher in the CH group (P < 0.05) and increased with increasing dietary BP (P < 0.05). Morphometrics were impaired by the challenge (P < 0.05), and by the two highest BP levels (P < 0.05). Amino acids AID (methionine, methionine + cystine, arginine, and serine) were reduced by E. maxima challenge. An increase in dietary BP resulted in poor litter quality and high prevalence of of footpad dermatitis (P < 0.05). The E. maxima challenge and increased BP decreased gut health, litter quality, and cause a high incidence of footpad dermatitis.

Modelling Broiler Requirements for Lysine and Arginine.

Six assays were conducted to investigate male and female broiler responses to standardized ileal digestible (SID) lysine (Lys) and arginine (Arg). Response data were modeled to estimate the efficiency of utilization (k) of both amino acids and adjust factorial models to predict bird intake for SID Lys and SID Arg. In each assay, 1280 Cobb 500® broilers (640 male and 640 female) were randomly assigned to one of sixteen dietary treatments with four replicates of 20 birds. Dietary treatments consisted of crescent levels of SID Lys or SID Arg based on the dilution technique. The values of k determined for each phase (1- to 14-, 15- to 28-, and 29- to 42-d-old) and sex were contrasted using linear regression with groups (sex and phase). The estimated efficiencies were 0.79 for Lys and 0.62 for Arg, which were unaffected by phase or sex. Factorial models based on body weight and weight gain (M1) and on body and feather protein weight and deposition (M2) were applied to estimate the SID Lys and Arg intake for growth. The amino acid intake based on M2 had a lower error of prediction. Broiler chickens require 94.9 and 92.9 mg/d of SID Lys and SID Arg to deposit 1 g of body protein.

Different levels of selenomethionine on the meat quality and selenium deposition in tissue of finishing pigs.

The aim of the study was to verify the influence of selenomethionine (SM) supplementation on performance, carcass yield, characteristics of meat quality and Se tissue deposition of finishing pigs. A total of 128 hybrid pigs with an average weight of 76 kg were distributed in randomized blocks according to body weight in eight treatments and eight replicates. The experimental treatments were two Se levels from sodium selenite-SS (0.3 and 0.6 ppm), four Se levels from SM (0.3, 0.4, 0.5 and 0.6 ppm) and two combinations of SS with SM (SS 0.15 + SM 0.15 ppm and SS 0.3 + SM 0.3 ppm) providing 0.3 and 0.6 ppm Se in the diet respectively. The feeds were based on corn and soya bean meal. After 30 days on test, were analysed the performance indices and the pigs were slaughtered at commercial slaughterhouse. The cold carcass yield, the physicochemical characteristics of the loin meat and the Se content in muscle and liver were evaluated. There was no significant difference in performance indices (p > .05); however, there was a linear effect on the increase in pig carcass yield by increasing SM (p < .05). The use of SM solely or combined with SS provided higher Se deposition in muscle compared to SS (p < .05). The highest Se deposition in muscle occurred for SM at 0.4 ppm (p < .05). The SS provided higher Se deposition in liver (p < .05). The SM presented best results for meat quality compared to other sources (p < .05). The level of 0.4 ppm Se promoted the best results for the indices of yellow, luminosity, cooking loss and pH (p < .05). The use of SM at any level promotes higher oxidation stability of pig meat (p < .05). The supplementation of SM at a level of 0.4 ppm promotes better physicochemical characteristics and higher Se deposition on swine meat.

Supplementation of selenomethionine at different ages and levels on meat quality, tissue deposition, and selenium retention in broiler chickens.

The aim of the present study was to verify the effect of selenomethionine (SM) supplementation in the diet of chickens on performance, carcass yield, apparent retention, meat quality, and selenium (Se) deposition in tissues. In the first experiment, 2,100 day-old male chicks from the Hubbard Flex strain were randomly distributed in 84 plots with 12 treatments and 7 replicates. The treatments consisted of SM (1,600 ppm) supplementation at levels of 0.3 and 0.5 ppm in substitution of sodium selenite (45.7%) in different preslaughter phases. In the second experiment, 224 day-old male chicks from Hubbard Flex strain were randomly distributed in 28 metabolic cages. Poultry were distributed in 4 treatments with 7 replicates (8 poultry) in the experimental period from 1 to 21 D and experimental plot with 4 poultry aged from 22 to 42 D. Treatments consisted of 4 SM addition levels (0.3, 0.4, 0.5, and 0.6 ppm). In both experiments, the performance (1 to 21 and 1 to 42 D), carcass yield and cuts, apparent retention of Se (33 to 35 D), physical and chemical characteristics of the breast meat were evaluated: objective color, drip loss (DL), cooking loss (CL), pH, peroxide value, and Se deposition in tissues. In experiment I, it was found that SM at 0.3 ppm improved the weight gain and feed conversion of 1 to 42 D. The use of SM at 0.5 ppm resulted in lower DL and CL. The highest Se deposition in muscles was obtained using the SM at 0.5 ppm of 1 to 42 D. Using the SM at 0.5 ppm, only in the last week there was a deposition similar to the use of SM at 0.3 ppm of 1 to 42 D. In experiment II, it can be observed that increased SM levels provided lower DL and lower pH values. Se deposition in tissues of broiler chickens increased linearly at the SM level from 0.3 to 0.6 ppm.