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วารสารเทคโนโลยีชีวภาพการผลิตปศุสัตว์

Relationship between Milk Composition and Reproductive Traits of Holstein Crossbred Dairy Cows in
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Central Part of Thailand

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Wiroch Sampanporn Somsak Prempree
2

Abstract
The data of first service conception rate (FSC), number of service per conception (NSPC), days from
calving to first service (DTFS), and day open (DO) were collected from 2,988 Holstein crossbred cows that calved

and milked from 1997 to 2017. All cows were in 464 farms located in the central part of Thailand. Effects of
environmental factors, farm management and milk composition from calving to 120 postpartum on reproductive
traits were studied. The statistical model in this study were used an interaction effect between herd, year and
season of insemination, genetic group, heterosis, lactation number, age at calving, fat percentage (PFAT), protein
percentage (PPRO), fat-protein ratio (FP Ratio), and the variation of inseminated cows. The parameters in the

statistical model were test at the level of significant of α = 0.05 and compared the least square means of the
studied factors by t-test. The results showed that FSC was 0.37  0.42 %, NSPC was 2.53  1.93 times,

DTFS was 97.08  36.94 days, and DO was 172.09  87.50 days. The interaction effect between herd, year and
season of insemination had an effect on the variation of all traits in this study. However, genetic group, lactation
number, and age at calving affected only the variation of DTFS and DO. In addition, the increasing of DTFS and
DO was observed in high fraction of Holstein breed and age at calving. On other hand, decreasing of DTFS and
DO was determined in cows with high lactation number. Additionally, the milk composition, it did not have any

effect on all traits in this study. This indicated that the application of milk composition as an indicator was not
suitable for evaluating reproductive performance of Holstein crossbred dairy cows.

Key words: Dairy Crossbred, Milk Composition, Reproductive Traits

1 Registered No. : 61(2)-0208-033
2 Bureau of Biotechnology in Livestock Production, Department of Livestock Development, Patumthani, 12000
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