Acta Veterinaria et Zootechnica Sinica ›› 2023, Vol. 54 ›› Issue (2): 642-655.doi: 10.11843/j.issn.0366-6964.2023.02.021

• ANIMAL NUTRITION AND FEEDS • Previous Articles     Next Articles

The Effect of Tail Docking on Growth Performance, Fat Deposition Distribution and Slaughter Performance in Lanzhou Fat-tailed Sheep

SONG Shuzhen1*, LIU Junbin2, ZHU Caiye2, XU Hongwei3, LIU Lishan1, KONG Yanlong4   

  1. 1. Institute of Animal & Pasture Science and Green Agriculture, Gansu Academy of Agricultural Sciences, Lanzhou 730070, China;
    2. College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China;
    3. Life Science and Engineering College, Northwest Minzu University, Lanzhou 730030, China;
    4. Yongjing Ruilin Technology and Science Co. Ltd., Yongjing 731603, China
  • Received:2022-04-28 Online:2023-02-23 Published:2023-02-21

Abstract: The objective of this study was to observe the effects of tail docking on the growth performance, slaughter performance, fat deposition distribution and serum adipokines in Lanzhou fat-tailed sheep. The results were expected to provide reference for improving the production of fat-tailed sheep by fat deposition intervention. Eighteen 5 days old healthy Lanzhou fat-tailed lambs with clear genealogy and uniform weight were randomly divided into control group(C group) and test group(T group), 9 lambs each group,the tail from T group lambs were ligated with rubber band. The two groups were fed with the same diet in the trial period, with the feed concentrate-roughage ratio of 70:30, and the animals had free access to the water. The trial lasted for 240 days. The results were showed as follows:1) Average daily gain of tail docking sheep was significantly lower than that in C group (P<0.05) in the first 30 days. There was no significant difference in average daily gain between the two groups during 31~240 d (P>0.05). 2) The body weight of tail docking sheep was significantly lower than that in C group in the first three stages (0~90 d)(P<0.05), but there was no significant difference between the two groups in other stages (P>0.05). The feed to gain ratio in tail docking group was significantly lower than that in C group (P<0.05) during 61~90 d, and there was no significant difference between the other stages (P>0.05). 3) Serum TNF-α in the tail docking group was significantly higher than that of the control group (P<0.05) during 0~60 d, and was numerically higher during 61~240 d (P>0.05). Serum GLU, LEP, RETN and ADPN in the tail-docking group were higher, and the difference between two group increased with the extension of test period, but the difference was not significant (P>0.05). Serum TG, IL-6 and NEFA were not significantly different in the trial period (P>0.05). 4) The tail fat and total fat index in tail docking group were significantly lower (P<0.05). The subcutaneous fat, kidney fat, abdominal fat and visceral fat index in tail docking group were significantly higher (P<0.05). There was no significant difference in heart fat, omentum fat and mesenteric fat index (P>0.05), but tail length, tail middle width, tail circumference and tail weight index decreased significantly (P< 0.05) in tail docking group compared with the control growp. 5) The slaughter rate of sheep in the tail docking group significantly increased compared with the control group (P<0.05), while backfat thickness, GR value and eye muscle area were numerically higher compared to the control group with no significant difference (P>0.05). The meat color (brightness, redness, yellowness) and pH of the Longissimus dorsi muscle had no significant difference between two groups (P>0.05). The shear force was significantly lower in tail-docking group (P<0.05). Water loss and cooking loss had no significant difference between the two groups (P>0.05). The results showed that tail docking at the early age of Lanzhou fat-tailed sheep could decrease the tail size, weight and fat weight proportion, change the distribution of fat deposition, and make more fat deposits in muscle and other parts of the body, thus improve the slaughter rate and improve the quality of meat.

Key words: tail docking, serum adipokines, fat deposition, slaughter performance, meat quality

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