The study analyzed the impacts of two probiotics (Ecobiol® and GutCare®) on growth performance, carcass and cut yields, intestinal morphometry and lesion score, biochemical parameters, and short-chain fatty acid concentration in chickens using a challenge model combining coccidiosis vaccine and Clostridium perfringens. A total of 880 one-day-old male broilers (Cobb 500) were randomly assigned to four treatments with 10 replicates and 22 birds per experimental unit (EU). The treatments consisted of: PC: positive control with the inclusion of 80 g ton-1 of Enramax® (8% enramycin) until 35 d of age; NC: negative control without the inclusion of growth-promoting probiotic; BA: NC with the inclusion of 1000 g ton-1 of Ecobiol® (Bacillus amyloliquefaciens - CECT 5940); BS: NC with the inclusion of 500 g ton-1 of GutCare® (Bacillus subtilis - DSM 32315). Diets used maize–soybean meal in a threephase plan. Broiler chickens on the BA and BS diets had higher feed consumption, body weight gain, and improved feed conversion efficiency at 28 and 42 d when compared to the birds in the negative control. Broiler chickens fed PC, BA, and BS diets had a higher villus height and absorption area in the jejunum at 28 d, compared to the birds in the negative control. There was more butyric acid production by the intestinal microbiota at 28 d of age in broilers on the BA diet. Supplementing with 1000 g/ton of BA and 500 g/ton of BS effectively substituted the 8% enramycin antibiotic, enhancing broiler growth during an induced intestinal challenge.

Here we tested how feeding with exogenous enzymes affects the performance, carcass yield, and ileal digestibility in broilers from 21- to 42-days-old. The study included 1008 male broilers randomly distributed into six diets: positive control (PC), corn and soybean meal containing all the nutritional requirements; negative control (NC), with a 120 kcal.kg-1 reduction in metabolizable energy relative to the PC; enzyme complex one (NC + 100 ppm of endo-1,4-beta-xylanase); enzyme complex two (NC + 200 ppm of xylanase, amylase and protease); enzyme blend one (NC + 100 FXU kg-1 of xylanase and 200 FXU kg-1 of amylase); and enzyme blend two (NC + 100 FXU kg-1 of xylanase and 300 FXU kg-1 of amylase). The enzyme complex two (CN + 100 FXU.kg de xilanase e 300 FXU.kg de amilase) and enzyme blend two (NC + 100 FXU kg-1 of xylanase and 300 FXU kg-1 of amylase) had greater weight gain, feed conversion, carcass yield, and digestibility of nutrients than the NC (P < 0,05). We found that enzyme complex two and enzyme blend two valued their nutritional matrix promoting better performance and digestibility of broilers.

Alpha-amylase improves carbohydrate digestion, increasing the available energy to maximize the performance of broiler chickens. This study evaluated the inclusion of alpha-amylase in diets with metabolizable energy (ME) valorization on growth performance, carcass yield, and intestinal health of broiler chickens. A total of 640 male broiler chickens (Cobb 500) were distributed in a completely randomized design with four treatments and eight repetitions of 20 birds each. The treatments were: PC (positive control), NC (negative control with a reduction of 100 kcal ME per kg diet), 100g-AA (NC + 100 g alpha-amylase per kg of diet), and 200g-AA (NC + 200 g alpha-amylase per kg diet). At 42 days, broiler chickens in the PC and supplemented groups (100g-AA and 200g-AA) showed better ME utilization, and at 21 and 42 days, greater weight gain (P<0.05). Broiler chickens supplemented with 100g-AA and 200g-AA had better digestibility of dry matter, ash, and gross energy (P<0.05) at 42 days. The ileal digestibility of starch was higher in the 100g-AA and 200g-AA groups compared to the PC group (P<0.10) at 42 days. The concentration of butyric acid in the cecal content was higher in the 200g-AA group compared to the PC group (P<0.05) at 35 days. Supplementation of alpha-amylase in diets with reduced ME is a viable strategy to optimize the performance of broiler chickens.

Chromium-methionine (CrMet) provides essential nutrients and bioactive compounds that may enhance meat quality and reduce stress-related issues in broiler chicken. This study aimed to evaluate the effects of chromium-methionine on carcass yield, relative weights of the liver and fat pad, incidence and severity of myopathies, muscle color quantification, water-holding capacity, cooking loss, shear force, lipid peroxidation in breast muscle, and composition of breast meat in broiler chickens subjected to cyclic heat stress. A total of 1,000 one-day-old male Cobb 500 broiler chickens were divided into 10 replicate pens with 20 birds each, following a completely randomized design with five doses of dietary treatments (0; 0.25; 0.50; 1.0; and 2.0 mg CrMet kg-1 diet). Experimental broiler chickens were kept in thermoneutral conditions for 21 days, then subjected to cyclic heat stress (31.1 °C and 60.2% humidity) from 09:00 am to 03:00 pm until 42 days of age. Statistical analysis included Tukey’s test and regression analysis. Myopathy scores were assessed using the Kruskal-Wallis test and Dunn’s test, all at a significant level of 5%. Inclusion of 0.50 and 1.0 mg CrMet reduced woody breast severity scores. At 15 minutes postmortem, birds fed 0.50 mg CrMet had less redness (a*) than controls and birds fed 2.0 mg CrMet; birds fed 2.0 mg CrMet had lower lightness (L*) than those fed 0.25 and 1.0 mg CrMet. Lipid peroxidation was lower in birds fed 0.50 mg CrMet at 60 days compared to control. Crude fat was lower in birds fed 1.0 mg CrMet. Chromium-methionine supplementation at 0.50 and 1.0 mg/kg diet improved meat quality and reduced woody breast in broiler chickens.

The effects of enzyme supplementation on the performance, yield, and blood profile of broilers fed corn and soybean diets from 1 to 42 days of age were evaluated. A total of 960 male broilers were used, distributed in a completely randomized design, with six treatments and eight replications. Two diets were used: a positive control formulated to meet the birds’ nutritional requirements (Diet 1) and a negative control diet with reduction of 150 kcal.kg-1 of metabolizable energy (Diet 2) and 12% amino acid in the initial phase and 18% during the growing and finishing phases. Further diets were based on the negative control with enzymes: enzyme complex 1, composed of 125 g ton-1 protease; enzyme complex 2, composed of 100 g ton-1 amylase, protease, and xylanase; enzyme complex 3, composed of 500 g ton-1 amylase, protease, and xylanase; and enzyme complex 4, composed of 125 g ton-1 protease and 500 g ton-1 beta-mannanase. Enzymatic supplementation did not improve performance during the initial and growing phases due to nutritional imbalance, resulting in the worst weight gain and feed conversion during the finishing phase. Carcass yield, leg yield, abdominal fat, and pancreas were altered by enzymatic supplementation. Triglyceride levels influenced abdominal fat deposition, and the serum levels of albumin and alanine aminotransferase were altered by enzymatic supplementation. Enzymatic supplementation was not effective in restoring broiler performance, carcass yield, and cuts, with changes in the serum biochemical profile of the broiler chickens.