Impact of yam bean pulp on growth performance, gut morphology, digestive development, and digestibility in broilers raised in hot environments.

Abstract

Objective: Rearing broilers in high-temperature environments can impair growth performance, affecting the economic efficiency of broiler production. Dietary fiber sources like yam bean pulp (YBP) may mitigate these effects by promoting digestive organ development and gut integrity, enhancing nutrient absorption and growth. This study aimed to evaluate the impact of YBP inclusion on digestive development, gut morphology, nutrient digestibility, serum lipid profiles, and growth performance in broilers raised under high environmental temperatures.

Methods: Since YBP has not previously been used in poultry diets, its optimal inclusion level was determined using in vitro digestibility measurements, which identified 4% YBP as the optimal initial inclusion level for further in vivo study. Subsequently, the in vivo study was conducted with 200 one-day-old ROSS broiler chicks, randomly assigned to four dietary treatments (0%, 4%, 8%, and 12% YBP; 5 replicates of 10 birds each), and housed in an open system at an average temperature of 32.1±3.7°C. Digestive traits, nutrient digestibility, serum lipid profiles, and growth performance were assessed over 21 days.

Results: Results showed that YBP inclusion (up to 12%) improved gut morphology by increasing villi height and the villi height-to-crypt depth ratio in the duodenum and ileum, alongside dose-dependent improvements in dry matter digestibility. However, crude protein digestibility declined when YBP levels exceeded 8%. Despite these benefits, YBP inclusion did not alleviate heat stress effects on growth performance, digestive organ development, or serum lipid profiles, even at the highest inclusion level.

Conclusion: Dietary YBP can enhance gut morphology and nutrient digestibility in broilers from day 1 to 21, with optimal inclusion levels not exceeding 8%. However, its use does not mitigate the negative effects of heat stress on broiler growth in high-temperature environments.