Abstract: 【Objective】 The aim of this study was to explore the requirements for metabolizable energy (ME) and crude protein (CP) of Qingyuan partridge chickens from 1 to 30 days. 【Method】 A total of 2 160 healthy 1-day-old female Qingyuan partridge chickens with similar body weights were randomly assigned to 9 groups,with 6 replicates per group and 40 birds per replicate.A two-factor design with;
3. levels of ME and 3 levels of CP was employed.The ME levels were set at 12.77,12.35,and 11.93 MJ/kg,while the CP levels were set at 21.5%,20.5%,and 19.5%.The experimental period lasted for 30 days.The average daily weight gain (ADG),average daily feed intake (ADFI),and feed-to-weight ratio (F/G) of the chickens from 1 to 30 days of age were calculated.At the end of the experiment,five birds were randomly selected from each replicate.Two of these birds were used for blood sampling and breast muscle collection to determine serum biochemical indicators,as well as the CP and crude fat content in the breast muscle.The remaining three birds were used to measure body composition and the deposition rates of energy and CP. 【Result】 ①As the dietary ME level decreased from 12.77 MJ/kg to 11.93 MJ/kg,the ADG of Qingyuan partridge chickens was significantly decreased (P＜0.05),while the F/G was decreased with increasing ME levels (P＜0.05).Chickens in the high ME group had significantly lower ADFI (P＜0.05),whereas those in the low ME group had significantly lower final body weight (P＜0.05).② Serum analysis revealed that chickens in the high ME group had significantly higher total cholesterol levels than those in the low ME group (P＜0.05).When the ME level was reduced to 11.93 MJ/kg,serum uric acid content was significantly decreased (P＜0.05).Additionally,when the dietary CP level was reduced to 19.5%,serum uric acid content was also significantly decreased (P＜0.05).An interaction between ME and CP levels was observed for serum total cholesterol and uric acid content in Qingyuan partridge chickens (P＜0.05).③ Moreover,when the ME level decreased from 12.77 MJ/kg to 11.93 MJ/kg,the crude fat content in the breast muscle of Qingyuan partridge chickens was significantly decreased (P＜0.05),whereas the CP content in the breast muscle was significantly increased (P＜0.05).④ In terms of body composition,when the ME level was reduced from 12.77 MJ/kg to 11.93 MJ/kg,the energy and crude fat content in the body of Qingyuan partridge chickens were significantly decreased (P＜0.05).The body crude fat content was also significantly decreased when the CP level was at its lowest (P＜0.05).⑤The deposition rates of energy and CP in Qingyuan partridge chickens were significantly decreased with decreasing ME levels (P＜0.05).Chickens in the high and intermediate CP groups showed significantly higher energy and CP deposition rates than low CP group (P＜0.05).An interaction between ME and CP levels was observed for energy and CP deposition rates in Qingyuan partridge chickens (P＜0.05), with higher CP deposition rates when ME levels was highest and CP levels were lower.⑥ Using BW^0.75/ADG as the independent variable to establish the metabolic energy and crude protein requirement models for Qingyuan partridge chickens. Based on the models, the recommended ME and CP requirements for 1-30-day-old Qingyuan partridge chickens were 12.28 MJ/kg and 20.07%, respectively. 【Conclusion】 In summary, the growth performance of 1-30-day-old Qingyuan partridge chickens was predominantly influenced by dietary ME levels, while serum biochemical indicators and body composition were jointly regulated by the interactive effects of dietary ME and CP levels.By establishing requirement models, the ME and CP needs for this stage were determined as 12.28 MJ/kg and 20.07%, respectively.

Key words: Qingyuan partridge chickens; crude protein requirement; metabolizable energy requirement