Dietary crude protein levels during growth phase affects reproductive characteristics but not reproductive efficiency of adult male Japanese quails

Abstract

Objective The objective was to evaluate the influence of different dietary crude protein (CP) levels during the growth phase on reproductive characteristics and reproductive efficiency as well as the body development of adult male Japanese quail. Methods Three hundred one-day-old male quails were distributed into five treatments with diets containing different CP levels (18%, 20%, 22%, 24%, and 26%) in a completely randomized design, with six replicates of ten birds each. The CP diets were applied only during the growth phase (1 to 35 days). At 36 days of age, the birds were transferred to 30 laying cages with three males and nine females each, and all birds received the same diet formulated to meet production-phase requirements until 96 days of age. Results The growth rate of the birds increased linearly (p0.05). At 35 days of age, higher weight gain was obtained (p0.05) nitrogen retention. Testis size, seminiferous tubular area, number of spermatogonia, and germinal epithelial height at 35 days of age increased linearly (p<0.05) with dietary CP, while the number of Leydig cells decreased (p<0.01). The Sertoli cell number at 60 days of age increased linearly (p<0.01) with dietary CP. Dietary CP levels did not affect cloacal gland size, foam weight, foam protein concentration, semen volume, or flock fertility at 90 days of age. Conclusion Dietary CP concentration affected body and testicular development in male Japanese quails but did not affect reproductive efficiency.

Keywords

• fertility
• growth curve
• quail breeding
• semen quality
• testicular development