Acta Veterinaria et Zootechnica Sinica ›› 2020, Vol. 51 ›› Issue (12): 3023-3032.doi: 10.11843/j.issn.0366-6964.2020.12.012

• ANIMAL GENETICS AND BREEDING • Previous Articles     Next Articles

Analysis of Non-genetic Factors Affecting SCC Change Pattern of Holstein Cows in Jiangsu Province

LIANG Yan, ZHANG Qiang, GAO Qisong, WANG Haiyang, GUO Mengling, LI Mingxun, ZHANG Huimin, YANG Zhangping, CHEN Zhi*, MAO Yongjiang*   

  1. College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
  • Received:2020-05-26 Online:2020-12-25 Published:2020-12-23

Abstract: The objective of this study was to explore the influence factors of SCC change pattern of Holstein cows in Jiangsu. Based on the division of 9 SCC change patterns, 253 706 DHI records of Holstein cows from 2017 to 2019 in 12 dairy farms in Jiangsu province were analyzed, and the least squares model was used to explore the influence of different farm size, parities, calving seasons, calving intervals, and 305-days milk production on SCC change pattern. The results showed that the distribution of SCC patterns at different levels of each factor was significantly different (P<0.01). Among them, the percentage of lower to maintain pattern was the highest, and lower to infection pattern was the lowest for cows in farm with more than 5 000 cows. The percentage of infected to maintain pattern was the highest, and lower to maintain pattern was the lowest for cows in farm with less than 1 000 cows. The percentage of lower to maintain pattern was the highest, and infected to healed pattern was the lowest for cows with parity 1. The percentage of lower to infection pattern was the highest, and lower to maintain pattern was the lower for cows with parity 5. The percentage of lower to infection pattern was the highest, and lower to maintain pattern was the lowest for cows calving in spring. The percentage of susceptible to reduce pattern was the highest, lower to infection pattern was the lowest for cows calving in summer. The percentage of lower to infection pattern was the highest for cows with calving interval more than 441 d, and lowest for cows with calving interval with 300-400 d. The percentage of lower to infection pattern was the highest for cows with 305-days milk production of 3 000-5 000 kg. The percentage of lower to maintain pattern was the highest, and infected to healed pattern was the lowest for cows with 305-days milk production was 9 001-11 000 kg. The results indicate that different farm sizes, parities, calving seasons, calving interval, and levels with 305-days milk production have certain influences on the distribution of the SCC change patterns in Holstein cows. The results provide references for the prediction of subclinical mastitis in Holstein cows.

Key words: SCC change pattern, non-genetic factors, Holstein cows

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