China Animal Husbandry and Veterinary Medicine ›› 2023, Vol. 50 ›› Issue (10): 3994-4004.doi: 10.16431/j.cnki.1671-7236.2023.10.013

• Nutrition and Feed • Previous Articles     Next Articles

Safety Evaluation of Recombinant Human Lysozyme on Yellow Feather Broilers

LIU Shuyang1,5, ZHANG Jianling3, WANG Zhilin2, DENG Junjin2, LI Yang2, ZHANG Hua4, HUANG Jinrui4, LIAN Peirong4, CHEN Bixian4, GUO Qiuxia4, HUANG Jiaqi4, ZHANG Haoji1, LI Jiazhou5,6   

  1. 1. Foshan University, Foshan 528000, China;
    2. Agro-Biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China;
    3. Jiangmen Customs Technical Center, Jiangmen 529030, China;
    4. Guangzhou Qilong Biotechnology Co., Ltd., Guangzhou 510663, China;
    5. Institute of Animal Sciences, Guangdong Academy of Agricultural Sciences, Guangzhou 510630, China;
    6. Guangdong Laboratory for Lingnan Modern Agriculture Heyuan Sub-center, Heyuan 517000, China
  • Received:2023-03-07 Online:2023-10-05 Published:2023-09-26

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Abstract: 【Objective】 To study the effects of adding different levels of recombinant human lysozyme to the diet on growth performance,blood physiology,plasma biochemistry,tissue structure changes,and intestinal microbiota structure of Yellow feather broilers,in order to evaluate the biological safety of recombinant human lysozyme application in broilers.【Method】 The experiment was conducted using a single factor completely randomized design,with 192 1-day-old healthy fast Yellow feathered broilers randomly divided into 4 groups,with 48 chickens in each group (male and female in half).The recommended dose group (20 000 U/kg),3 times the recommended dose group (60 000 U/kg),and 5 times the recommended dose group (100 000 U/kg) were set up,and a basic diet group was also set as the control group.The experimental period was 54 days.The fasting weight of Yellow feathered broilers was measured at 21,42,and 54 days,and the feed consumption was counted.The average daily gain (ADG),average daily feed intake (ADFI),and feed to gain ratio (F/G) of the broilers during the experimental period were calculated.At the end of the experiment,8 Yellow feathered broilers were selected from each group to collect blood for testing of routine physiological and plasma biochemical indicators.Collect chicken heart,liver,spleen,lungs,kidneys,jejunum,and ileum tissues for histopathological examination after slaughter.Collect chicken cecal contents and detect the structure of cecal microbiota.【Result】 During the experimental period,all broilers in each dose group displayed normal clinical signs.There was no significant difference in growth performance between the test groups and the control group(P＞0.05).There was also no significant difference in blood physiological parameters(P＞0.05) except than the variation coefficient of red blood cell distribution width,which was considerably greater in 60 000 U/kg group (P＜0.05).The plasma albumin of 60 000 U/kg group was significantly lower than that of the control group (P＜0.05),while other plasma biochemical markers did not significantly differ between the groups (P＞0.05).When broilers fed with various quantities of recombinant human lysozyme were autopsied and histopathologically examined in comparison to the control,no discernible change was discovered.Feeding different levels of recombinant human lysozyme had no significant effect on the diversity and structure of intestinal microflora in broilers (P＞0.05).【Conclusion】 Adding 20 000 U/kg recombinant human lysozyme to the diet of Yellow feather broilers had a safety factor of more than 5 times,indicating that adding less than 100 000 U/kg recombinant human lysozyme to the diet was safe for Yellow feather broilers.

Key words: Yellow feather broiler; recombinant human lysozyme; safety evaluation

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