Early posthatch feeding influences small intestine development in broiler chickens

The height of the intestinal villi and the consequent small intestinal surface area are factors that limit broiler growth rate after hatching. Previous studies indicated that in poultry, the greatest increase in relative small intestinal weights and villous heights occurs during the first week after hatching, with villous height continuing to increase in the following weeks of life. This study aimed to evaluate the impact of providing access to feed and water during the hatching window on small intestine development, structure, and morphometry. The experiment was conducted using 100,000 Ross 308 broiler eggs incubated under typical commercial hatchery conditions. Eggs in the experimental group were hatched in HatchCare hatchers (HC) with immediate access to feed and water, while those in the control group were hatched under standard conditions (ST). Samples of the duodenum, jejunum, and ileum were evaluated from each group on days 1, 7, 21, and 35 after hatching. Villous height, width, and surface area (VSA), as well as crypt depth, villus-to-crypt ratio (VCR), and goblet cell number, were morphometrically assessed. Early access to feed increased significantly the VSA in the duodenum and ileum of the HC group on day 7. It also initially increased crypt depth in the jejunum and ileum during the first week of age, followed by a decrease in the jejunum on days 21 and 35. Early feeding had no influence on VCR from day 7 onward in all intestinal segments. The number of goblet cells did not differ in the duodenum and jejunum, but in the ileum, the HC group had fewer goblet cells than the ST group on days 21 and 35. It can be concluded that early feeding has the most beneficial effects on small intestine development during the first week after hatching. However, these effects did not persist until the end of broiler life cycle.