Dietary crude protein levels affect structural bone quality, estradiol concentration and laying performance of pearl gray guinea fowl (Numida meleagris)

• The dietary crude protein level at 19% during rearing (12-26 weeks) improve the laying performance in guinea fowl; • The dietary crude protein level at 19% during rearing (12-26 weeks) improve the structural bone quality; • The dietary crude protein level at 19% during rearing (12-26 weeks) increase the estradiol concentration at 26 weeks of age. Guinea fowl ( Numida meleagris ) breeding is not practised enough because of several problems including the lack of information relating to environmental factors for better optimization performance of the species. The present study evaluated the effect of dietary crude protein levels between the 12th and 26th week of age on growth and egg-laying performance, bone and egg quality, serum calcium, phosphorus, and estradiol levels of local female Pearl Gray guinea fowl. A total of 384 Pearl Gray guinea fowl were randomly separated into 3 treatments of 8 replicates each with 16 birds per pen. Low level ( LL ), normal level ( NL ), and high level ( HL ) were the 3 experimental treatments and were respectively fed with diets containing 15%, 17%, and 19% crude protein ( CP ) between the 12th and 26th week of age. The results showed that the HL group had significantly lower feed intake ( FI ) (P < 0.05) than those of the other groups. In addition, the guinea fowls fed with 19% crude protein had a significantly higher (P < 0.05) concentration of oestrogen in plasma than that of the LL group. An increase in crude protein levels in the diet, significantly (P < 0.05) reduced the robusticity index and increased the Seedor index in the femur and tibia, respectively. In conclusion, a high level of dietary crude protein for female guinea fowl between the 12th and 26th week of age improves the quality of structural bones at the start of lay. The level of crude protein required before laying is 19%.