Comparative Growth Performance and Intestinal Morphological Development Between Liangshan Yanying Chicken and Arbor Acres Chicken During the Brooding Stage

The differences in growth performance and intestinal morphology between Liangshan Yanying Chicken (YYJ) and Arbor Acres (AA) broilers during the brooding stage, and to explore the effect of early intestinal development on growth. A total of 120 one-day-old male chicks of each breed were selected and randomly divided into three groups, reared under the same conditions for 28 days to measure body weight, feed intake, and intestinal morphological indices. The results showed that the body weight of AA broilers at 28 days of age was 3.24 times that of YYJ; the average daily gain and average daily feed intake from 1 to 28 days of age were 3.11 and 2.36 times those of YYJ, respectively, while the feed conversion ratio decreased by 24.10% (<i>p</i> < 0.01). Regarding intestinal morphology, the density of each intestinal segment in AA broilers remained significantly higher than that in YYJ. At 1 day of age, the villus height of the duodenum and ileum was 14.44% and 39.20% higher, respectively (<i>p</i> < 0.05 or <i>p</i> < 0.01), and the villus-to-crypt ratio in most intestinal segments at various ages was 78.27% to 91.05% higher (<i>p</i> < 0.01). Correlation analysis indicated that body weight at 14 and 28 days of age was significantly positively correlated with the average daily gain of each stage (<i>p</i> < 0.01), and significantly negatively correlated with the feed conversion ratio (<i>p</i> < 0.01). These findings indicate that the difference in early intestinal morphological development may constitute a key factor contributing to the growth limitation of local chicken breeds. This study provides a theoretical basis for the genetic improvement and nutritional regulation of YYJ.