Acta Veterinaria et Zootechnica Sinica ›› 2022, Vol. 53 ›› Issue (9): 2955-2969.doi: 10.11843/j.issn.0366-6964.2022.09.013

• ANIMAL GENETICS AND BREEDING • Previous Articles     Next Articles

Analysis on the Change of BCS in Early Lactation and Its Effects on Production Performance and Productive Lifespan in Holstein Cows

ZHOU Fuzhen, ZHOU Bu, DAI Xu, WANG Haiyang, GUO Mengling, LIANG Yan, YANG Zhangping, MAO Yongjiang*   

  1. College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, China
  • Received:2022-01-10 Online:2022-09-23 Published:2022-09-23

Abstract: The purpose of this study was to explore the changes of body condition score (BCS) in early lactation and its effects on production performance and productive lifespan of Holstein cows. In this study, the BCS, culling records and dairy herd improvement (DHI) of 7 811 Holstein cows in early lactation from January 2018 to December 2020 were collected from a large farm in Jiangsu province. The effects of days in milk (DIM), parity and calving season on BCS, and the impacts of BCS changes on early lactation performances and productive life span of Holstein cows were analyzed by multivariate analysis of variance. Using Cox regression to draw the survival curve of Holstein cows with different BCS in early lactation, and the culling reasons of dairy cow with different BCS were tested by chi-square test. The results showed that the average BCS of Holstein cows in early lactation was (2.95±0.32). Parity, calving season and DIM had extremely significant effects on BCS in early lactation (P<0.01). The BCS of cow at the first parity and calving in summer was the highest in early lactation. The BCS of cows during 5-30 DIM, 31-60 DIM and 61-100 DIM gradually and significantly decreased. BCS of cows in early lactation had extremely significant effects on milk yield, milk fat percentage, milk protein percentage, somatic cell score(P<0.01). Milk yield and peak milk yield decreased significantly with the increase of BCS (P<0.01). In early lactation, BCS was significantly correlated with milk yield and peak milk yield (with the negative coefficient), and correlated with milk protein percentage (with the positive coefficient) (P<0.01). The changes of BCS in cows during early lactation had significant effects on SCS and peak milk yield (P<0.05). BCS in early lactation had extremely significant effect on culling parity and age (P<0.01). The survival curve showed that the cows with BCS of 2.75 had the highest survival probability. BCS had a highly significant effect on the distribution of cows culling at parity 2 and 4, and calving in winter (P<0.01). The distribution of BCS culling in early lactation of low-yielding culled cows was significantly different (P<0.01). Holstein cows with BCS of 2.75 in early lactation had the better production performance and the lowest culling risk. This study provides a reference for feeding and management of Holstein cows during early lactation of large-scale cattle farms.

Key words: Holstein cows, early lactation, body condition score (BCS), production performances, culling analysis

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