China Animal Husbandry and Veterinary Medicine ›› 2022, Vol. 49 ›› Issue (5): 1727-1737.doi: 10.16431/j.cnki.1671-7236.2022.05.014

• Nutrition and Feed • Previous Articles     Next Articles

Study on Dietary Crude Protein Requirement of Silky Fowl During 26 to 45 Days of Age

FAN Qiuli1, RUAN Dong1, JIANG Shouqun1, CHENG Zhonggang1, WANG Hanhua2   

  1. 1. Guangdong Key Laboratory of Animal Breeding and Nutrition, Key Laboratory of Animal Nutrition and Feed Science in South China, Ministry of Agriculture and Rural Affairs, State Key Laboratory of Livestock and Poultry Breeding, Institute of Animal Science, Guangdong Academy of Agricultural Science, Guangzhou 510640, China;
    2. Guangdong Wens Foodstuff Group Co., Ltd., Yunfu 527400, China
  • Received:2021-10-19 Online:2022-05-05 Published:2022-04-29

Abstract: 【Objective】 The experiment was conducted to investigate the effects of dietary crude protein level on growth performance,carcass traits and serum biochemical indices of male Silky fowl during 26 to 45 days of age,to investigate the crude protein requirment of Silky fowl at this stage.【Method】 1 625 26-day-old male Silky fowl were assigned to 5 groups with 5 replicates per group and 65 chickens per replicate,dietary crude protein levels were 18.5%,19.5%,20.5%,21.5% and 22.5%,respectively.The experiment lasted for 20 days.Two chickens with close to the average body weight were selected from each replicate for slaughter on the day of the end of this experiment,serum and carcasses were collected for determining carcass traits and serum biochemical parameters.【Result】 ①Dietary crude protein level extremely significantly affected final body,average daily gain and F/G (P<0.01),and with crude protein level increasing,final body weight and average daily gain were increased linearly and quadratically (P<0.01),F/G was decreased linearly and quadratically (P<0.01).Dietary crude protein level had no significant effect on average daily feed intake and survival rate (P>0.05).②Dietary crude protein level significantly or extremely significantly affected carcass weight (P<0.01),half-eviscerated weight (P<0.01) and eviscerated weight (P<0.05),but had no significant effect on breast muscle rate,leg muscle rate and abdominal fat rate (P>0.05).With dietary crude protein level increasing,carcass weight and half-eviscerated weight were decreased linearly and quadratically (P<0.01 or P<0.05).③Dietary crude protein level extremely significantly affected the serum contents of IGF-1 and TC (P<0.01),and with dietary crude protein level increasing,the TC content was decreased linearly (P<0.05).Dietary crude protein level had no significant effects on contents of BUN and TG (P>0.05).【Conclusion】 Dietary 21.5% crude protein level could improve growth performance,19.5% to 20.5% crude protein level could improve carcass traits and 18.5%crude protein level could regulate lipid metabolism.According to the estimation of quadratic curve model,it was suggested that dietary 21.41% to 21.83% crude protein could achieve the best growth performance at this stage.

Key words: crude protein level; Silky fowl; growth performance; carcass traits; serum biochemical indices

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