This study aimed to evaluate the influence of age and cyclical heat stress for 1 hour per day on the levels of serum proteins, metabolites, and enzymes in broiler chickens of 21-42 days of age. We used 420 male broiler chickens, Cobb Avian48TM breed, in a completely randomized experimental design, composed of two treatments and six replicates. The treatments consisted of two thermal environments: one in which broiler chickens were raised under natural conditions of temperature and humidity for the first 42 days of age (control) and another in which chickens were subjected to heat stress at 36°C, from days 16 to 42, for 1 hour per day (1200-1300 hours). At 21, 28, 35, and 42 days of age, approximately 5 mL of blood was collected by cardiac puncture in two birds per replicate. In each serum sample, levels of total protein, albumin, globulin, albumin:globulin ratio, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT) activity and uric acid, creatinine, total cholesterol, triglycerides, high-density lipoproteins (HDL), very low density lipoproteins (VLDL), low-density lipoproteins (LDL), and glucose levels were determined. Concerning the environment and the age, no significant differences in the levels of glucose, uric acid, ALT, triglycerides, and very low density lipoproteins were observed. There was a significant interaction between the environment and the age for cholesterol and LDL values. At 21 days of age, cholesterol and LDL-cholesterol (LDL-C) were higher in birds under stress than in the control treatment birds, which did not occur in other age groups. Aspartate aminotransferase activity was higher in chickens under cyclical heat stress than in chickens subjected to control treatment and displayed a cubic response regarding the environment. The age of the birds influenced the values of total protein, albumin, globulin, albumin:globulin (A:G) ratio, creatinine, GGT, and HDL. In conclusion, cyclical heat stress, at 36ºC, for one hour, from days 16 to 42 of age increases serum AST, whereas cholesterol and LDL-C levels increase only at day 21, indicating that birds may have adapted to heat stress. Age influenced the activity of AST and GGT and levels of creatinine, total protein, albumin, globulin, A:G ratio, cholesterol, HDL-C, and LDL-C. Key words: Poultry. Cholesterol. Liver enzymes. Glucose. ResumoObjetivou-se avaliar a influência da idade e do estresse cíclico por calor durante uma hora por dia, nas concentrações das proteínas, metabólitos e enzimas séricas em frangos de corte de 21 a 42 dias de idade. Foram utilizados 420 pintos de corte machos, da linhagem Cobb Avian48 TM , em um delineamento inteiramente casualizado, composto de dois tratamentos e seis repetições. Os tratamentos foram constituídos de dois ambientes térmicos: um para frangos de corte criados em condições naturais de temperatura e umidade do primeiro ao 42° dia de idade (controle); e outro para estressados por calor à 36 °C do 16° ao 42° dia, durante uma hora do dia (12h00m às 13...

This work aimed to investigate the antioxidant capacity of the guava agroindustrial waste as a functional additive in broiler feed to improve the performance and meat quality of boilers. The experiment was conducted in a completely randomized design, consisting of four treatments and six replicates with 12 birds. Treatments included different levels of guava byproduct in the feed: 0, 0.5, 1.0, and 1.5%. We evaluated the performance of broilers at 7 and 21 days old. At 21 days old, two birds from each experimental unit were euthanized for intestine histologic evaluation (duodenum, jejunum, and ileum) and breast and deboned thigh samples were collected for analyzes of pH, colorimetry (L*, a*, and b*), and thiobarbituric reactive substances (TBARS). The use of guava byproduct in the diet at 7 days old did not affect feed intake and feed conversion of the birds. However, the body weight and weight gain increased linearly with the inclusion of the byproduct. At 21 days old, the guava byproduct did not depress the performance of birds. There was no effect of treatments on villus height, crypt depth, and villus:crypt ratio of the duodenum and jejunum of the birds. The inclusion of guava byproduct resulted in lower crypt depth and linear increase in villus:crypt ratio of the ileum. There was no significant difference in pH and colorimetry of the breast and thigh. With increasing inclusion of byproduct, TBARS value was reduced to 0.72%, indicating greater lipid stability in thigh meat in this inclusion amount. Guava byproduct can be used as an alternative antioxidant additive in broiler feed because it does not depress the productive performance and improves thigh meat quality of boilers.

Observou-se que o peso médio das aves, e a conversão alimentar não foram influenciados pela linhagem (P>0,05). Já quando comparado o peso médio e a conversão alimentar entre machos, fêmeas e lotes mistos, observou-se diferenças significativas (P<0,05). Houve diferença significativa (P<0,05) para

Performance and meat chemical composition of quails fed with different sorghum levels instead of corn.Ciência Rural, v.46, n.5, mai, 2016.

Non-ruminants Full-length research article Performance, nutrient digestibility, and intestinal histomorphometry of broilers fed diet supplemented with chondroitin and glucosamine sulfates ABSTRACT-We aimed to evaluate the performance, nutrient digestibility, and intestinal histomorphometry of broilers fed diet supplemented with chondroitin sulfate and glucosamine sulfate. The experiment was carried out with 320 male broiler chicks distributed in a completely randomized design in a 2×2 factorial scheme (0 and 0.1% chondroitin sulfate and 0 and 0.3% glucosamine sulfate), with eight replications of 10 birds. Performance was evaluated at 7 and 21 days of age, nutrient digestibility of the diet was performed from 18 to 21 days of age, and small intestine histomorphometry was evaluated at 21 days of age. Broilers fed diet supplemented with 0.3% glucosamine sulfate showed high final weight and weight gain. A significant interaction was observed between sulfates for digestibility coefficients of nitrogen, mineral matter, and calcium. The use of 0.1% chondroitin sulfate without glucosamine sulfate resulted in a reduced digestibility of nitrogen but increased digestibility of total minerals and calcium. Diets without chondroitin sulfate with 0.3% glucosamine sulfate increased the digestibility coefficients of mineral matter and calcium. A significant interaction was found for jejunum villus height, which was higher in broilers fed diet supplemented with 0.3% glucosamine sulfate, regardless of the inclusion of chondroitin sulfate. Thus, supplementation with glucosamine sulfate in broiler diets contributes to high weight gain and villus height. Sulfates used in isolation promote high digestibility of minerals.