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.

Growth curves of broilers fed different nutritional relationships using the Gompertz model

The study aimed to evaluate performance and growth curves of broilers fed different nutritional relations. A total of 1,440 Cobb-500 male day-old chicks were assigned to eight treatments in a 2 x 2 x 2 factorial arrangement with six replicates of 30 birds each. The main factors were nutritional density (control and high), lysine source (HCl and sulfate), and calcium pidolate (presence and absence). Analyses were made for body weight gain (BWG), and feed conversion rate (FCR) at 21, and 42 days of age. The growth curves were adjusted by weighing a bird per plot every three days. Data for BWG were tested by ANOVA to evaluatethe effects of treatments and their interactions at 5% significance, and the Gompertz model was adjusted by NLS. Birds fed a high nutritional density had higher BWG and lower FCR. Calcium pidolate and different sources of lysine did not influence the FCR of broilers, however a triple interaction was evidenced for BWG at 1 to 42 days of age. The day with maximum gain adjusted by Gompertz of all treatments was at the 32ndday of age and the maximum weight (A) was around 5.85 kg.(AU)

Metabolizable energy values of soybean meals and soybean oil for broilers at different ages

One trial with six analyses of different diets at different ages was carried out to determine the values of apparent (AME), corrected (AMEn), true (TME) and true corrected (TMEn) metabolizable energy of SBM and SBO for broiler chickens from 1 to 42 days of age. Three Brazilian SBM samples and one SBO were evaluated by replacing part of the basal diet with the test ingredient (300 g kg-1 for SBM and 100 g kg-1 for SBO). A total of 1.368 one-day-old male Ross 308 birds were assigned into 36 metabolic cages according to weight in a completely randomized experimental design with six replicates for each test ingredient and basal diet. Six more replicates of fasted birds were used for the determination of metabolic energy and N losses at each age. Four days of adaptation followed by three days of excreta collection for energy measurement. The birds were reared until each age, in solid floor pens with a corn/soybean basal diet. The total excreta collection method was used. The AME, AMEn, TME and TMEn of SBM and SBO increased (p < 0.05) until 28 days and after this time no difference (p >0.05) was observed.(AU)

Metabolizable energy values of soybean meals and soybean oil for broilers at different ages

One trial with six analyses of different diets at different ages was carried out to determine the values of apparent (AME), corrected (AMEn), true (TME) and true corrected (TMEn) metabolizable energy of SBM and SBO for broiler chickens from 1 to 42 days of age. Three Brazilian SBM samples and one SBO were evaluated by replacing part of the basal diet with the test ingredient (300 g kg-1 for SBM and 100 g kg-1 for SBO). A total of 1.368 one-day-old male Ross 308 birds were assigned into 36 metabolic cages according to weight in a completely randomized experimental design with six replicates for each test ingredient and basal diet. Six more replicates of fasted birds were used for the determination of metabolic energy and N losses at each age. Four days of adaptation followed by three days of excreta collection for energy measurement. The birds were reared until each age, in solid floor pens with a corn/soybean basal diet. The total excreta collection method was used. The AME, AMEn, TME and TMEn of SBM and SBO increased (p 0.05) was observed.