Effect of dietary glutamine supplementation associated with threonine levels in the intestinal mucosa of broilers challenged with Eimeria sp. from 22 to 42 days of age

The aim of this study was to evaluate the effects of glutamine and threonine supplementation on the ileal mucosa of broilers aged 21-42 days. Six-hundred and forty-one-day old chicks of the Cobb Slow lineage were utilized in this study. From 1 to 21 days of age, the chicks received a commercial diet; and after 22 days, the broilers were distributed in a completely randomized design in a 2 ? 4 factorial scheme (challenge and diet), with 4 replications and 20 chicks per experimental unit. At 22 days of age, the challenged broilers received a commercial vaccine against coccidiosis. A commercial diet was utilized as control and three other diets were formulated with reduced crude protein (-3%), and were corrected with the addition of glutamine (Gln) and glutamic acid (Glu) as non-specific nitrogen sources, and finally supplemented with L-Threonine (Thr) at 0.70, 0.80, and 0.85% digestible threonine, respectively. At 28 days of age, diets with Gln/Glu + Thr resulted in greater ileal villi lengths. Challenge with Eimeria sp. reduced the number of goblet cells and increased the duodenal and jejunal crypt depths. At 42 days of age, an interaction was observed between diet and challenge in relation to ileal villi length; better results were observed in the challenged broilers that received 0.85% Gln/Glu + Thr. The mucosal morphology in the ileal villi extremities was preserved in the challenged broilers that received higher Thr levels in their diets. The results suggested that the inclusion of glutamine and threonine affected the morphometry and mucosa of the ileum, thereby improving the mucosal quality

Use of Vitamin D and Its Metabolites in Broiler Chicken Feed on Performance, Bone Parameters and Meat Quality

The objective of this experiment was to assess the use of different vitamin D metabolites in the feed of broiler chickens and the effects of the metabolites on performance, bone parameters and meat quality. A total of 952 one-day-old male broiler chicks were distributed in a completely randomised design, with four treatments, seven replicates and 34 birds per experimental unit. The treatments consisted of four different sources of vitamin D included in the diet, D3, 25(OH)D3, 1,25(OH)2D3, and 1α(OH)D3, providing 2000 and 1600 IU of vitamin D in the starter (1 to 21 d) and growth phases (22 to 42 d), respectively. Mean weight, feed:gain and weight gain throughout the rearing period were less in animals fed 1α(OH)D3 when compared with the other treatments (p0.05) for various bone parameters. Meat colour differed among the treatments (p>0.05). All of the metabolites used in the diets, with the exception of 1α(OH)D3, can be used for broiler chickens without problems for performance and bone quality, however, some aspects of meat quality were affected