Growth performance, jejunum morphology and mucin-2 gene expression of broiler Japanese quails fed low-protein diets supplemented with threonine
Ashkan Emadinia, Majid Toghyani, Amir Davar Foroozandeh, Sayed Ali Tabeidian & Maryam Ostadsharif
Abstract
The present experiment was conducted to examine the effects of threonine supplementation in low-protein diets on growth performance, jejunum morphology, and mucin-2 gene expression in meat-type Japanese quails. A total of 800 broiler quails were assigned to 8 dietary treatments based on a factorial arrangement (2 4) across 1-35-day period. Experimental treatments consisted diets with 180 g/kg (CP180), 200 g/kg (CP200), 220 g/kg (CP220), and 240 g/kg (CP240) crude protein content each supplemented with 100% and 110% threonine requirement of broiler quails. Growth performance of broiler quails was not affected by interaction of dietary protein and threonine contents while daily weight gain was higher in birds received CP240 than those given CP180 and CP200 (p < .05). Carcase yield increased in response to consumption of diets with 200 g/kg protein content and 110% threonine requirement compared to those receiving the other dietary treatments (p < .05) except for birds in CP240 group. Villus height to crypt depth ratio was higher in birds subjected to CP200 and CP240 each supplemen