Acta Veterinaria et Zootechnica Sinica ›› 2021, Vol. 52 ›› Issue (2): 352-363.doi: 10.11843/j.issn.0366-6964.2021.02.008

• ANIMAL GENETICS AND BREEDING • Previous Articles     Next Articles

Effects of the Number of Subclinical Mastitis Infection during First 60 Days after Calving on SCS of Lactation Months of Holstein Cows

LIANG Yan1,2, WANG Haiyang1, GUO Mengling1, ZHANG Qiang1, GAO Qisong1, LI Mingxun1,2, ZHANG Huimin1,2, YANG Zhangping1,2, MAO Yongjiang1,2*   

  1. 1. College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China;
    2. Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education, Yangzhou 225009, China
  • Received:2020-06-15 Online:2021-02-23 Published:2021-02-24

Abstract: The number of subclinical mastitis (SCM) infection during first 60 days after calving reflects the physiological health of the mammary gland of Holstein cows. This study aimed to explore the effects of the number of SCM infection during first 60 days after calving on somatic cell score (SCS) of lactation months in Holstein cows, and provide scientific reference for farm management for prevention, control and treatment of SCM. A total of 365 105 DHI records of Holstein cows were collected from 12 dairy farms in Jiangsu province from 2017 to 2019, and the impacts of the number of SCM infection during first 60 days after calving on SCS of lactation months of cows with different parities, farm size, tested seasons and calving seasons were analyzed using general linear model (GLM). The results showed that the number of SCM infection in first 60 days after calving had extremely significant effects on milk SCS of lactation months of Holstein cows with different parities, farm size, tested seasons and calving seasons (P<0.01). Holstein cows with 5th and above parity or calved in summer had higher SCM incidence during first 60 days after calving. The SCS of lactation months of cows showed extremely significant increase along with the increasing number of SCM infection in first 60 days after calving in small- and medium-size farms and cows that calved in summer and autumn (P<0.01). The correlation coefficient between SCS in first 60 days after calving and SCS in each lactation month decreased gradually with the increase of lactation months. The lowest correlation coefficients between SCS in first 60 days after calving and SCS from 3rd to 7th lactation month were observed in cows of 1st parity, but higher in cows of 4th parity. Cows calved in autumn showed greater than 0.43 of correlation coefficients between SCS in first 60 days after calving and SCS from 3rd to 5th lactation month, which was higher than other seasons. The results are helpful for dairy farms to predict SCS in mid-late lactation according to the number of SCM infection during first 60 days after calving, so as to guide dairy farms to take relevant measures in time to prevent and control SCM.

Key words: subclinical mastitis (SCM), somatic cell score (SCS), Holstein cows

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