ABSTRACT
Post-hatch delayed placement damages the physical and physiological development of broiler chicks. This study was designed to find adequate levels of betaine inclusion in pre-hatching and pre-starter feed, in order to minimize the negative effects of post-hatch delayed placement on broiler chicks. Newly-hatched chicks were allotted in a completely randomized design, with five treatments, five replicates of ten birds each. Five dietetic levels of betaine (control, 0.070, 0.130, 0.200 and 0.260%) were used in the pre-starter ration, offered to the chicks in the transporting box and during the pre-starter phase. Performance, yolk sac retraction, plasma glucose concentration, weight and histomorphometry of the small intestine were evaluated, after 24 hours of feed access and at 7 days of age. A metabolic trial was performed from seven to ten days of age. Betaine supplementation linearly influenced the chick’s ileum crypt depth after 24 hours in the transportation box. There was a quadratic effect, with an increase in feed intake up to 0.152% betaine supplementation. There was an improvement in the quality of the jejunum with betaine supplementation above 0.1%. The metabolizable coefficient of the ether extract was improved until reaching 0.163% of betaine supplementation. Betaine supplementation around 0.150% increases feed intake, the use of ether extract and interferes with the intestinal villi of chicks at seven days of age.
Keywords:
Delayed placement; glucose; histomorphometry; poultry