Effect of different dietary energy/protein ratios on growth performance, reproductive performance of breeding pigeons and slaughter performance, meat quality of squabs in summer

Large-scale pigeon farming in China is gradually increasing. However, studies on the basic nutritional requirements of breeding pigeons during lac-tation, which greatly influence the productivity and eco-nomic benefits of pigeon breeding, remain scanty. The objective of this study was to determine the optimal die-tary energy/protein ratio requirements for lactating pigeons in summer. A total of 576 pairs of Mimas breed-ing pigeons were randomly divided into 12 groups (n = 48 per treatment), and each pair bred 4 squabs. A two-way ANOVA design with different protein levels (15%, 16%, 17%, and 18%) for factor A and different energy levels (12.6 MJ/kg, 12.8 MJ/kg, and 13.0 MJ/ kg) for factor B was used to design 12 groups of experi-mental diets for feeding. The experiment lasted for 28 d. We found that ME level had little effect on breeding pigeons, but the CP level and dietary energy/protein ratio significantly affected the reproductive and growth performance of the pigeons. The lowest total weight loss (P < 0.01), and the highest egg production (P < 0.01)were observed in group 11 (18% CP, 12.8 MJ/kg). It had no effect on egg quality. Both ME and CP levels sig-nificantly affected the growth performance, slaughter performance and meat quality of squabs, and there was a strong interaction between CP and ME. The fastest growth rate (P < 0.01) was observed in group 11 (18% CP, 12.8 MJ/kg). The best CP and ME combination for the eviscerated weight, pectoral muscle weight, organ weight, 45 min meat color (L* , a* , b*), pH, and muscle fiber characteristics were also group 11. Finally, the regression model revealed that the best dietary energy/ protein ratio was 17.92 to 19.02 kcal/g for squabs and 16.72 kcal/g for the breeding pigeons. There was a strong interaction between energy and protein levels in breeding pigeons during the lactation period, and the best production performance was at 18% CP 12.8 MJ/kg. And this is recommended to be applied as the energy/protein ratio dietary requirement for breed-ing pigeons during lactation in the summer "2 + 4" pattern.