<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The effect of first lactation yield and herd production level on longevity was studied using data from the SYMLEK database on 12045 Polish Holstein-Friesian cows in 1371 farms from the active population in Pomerania and Kujawy. The cows first calved in 2008 and were used or disposed from the herds by the end of 2015. FREQ, GLM and CORR procedures from the SAS package were used in the statistical calculations. The optimum level of first lactation milk from the viewpoint of longevity varies according to herd production level, which serves as a measure of the quality of rearing conditions. If the living conditions are not adapted to the high milk production of first calvers, there is a possibility that their productive life will be shortened and number of calvings decreased. The percentage of voluntary culling decisions by the breeder, which included the sale for further breeding, low milk yield and old age, averaged 9% and decreased with increasing herd production level from 16% to around 6%. The main reason for culling was infertility (around 40% on average). Culling due to infertility was particularly common among the cows which produced more than 11000 kg milk as first calvers.</p></abstract>

The effect of first lactation yield and herd production level on longevity was studied using data from the SYMLEK database on 12045 Polish Holstein-Friesian cows in 1371 farms from the active population in Pomerania and Kujawy. The cows first calved in 2008 and were used or disposed from the herds by the end of 2015. FREQ, GLM and CORR procedures from the SAS package were used in the statistical calculations. The optimum level of first lactation milk from the viewpoint of longevity varies according to herd production level, which serves as a measure of the quality of rearing conditions. If the living conditions are not adapted to the high milk production of first calvers, there is a possibility that their productive life will be shortened and number of calvings decreased. The percentage of voluntary culling decisions by the breeder, which included the sale for further breeding, low milk yield and old age, averaged 9% and decreased with increasing herd production level from 16% to around 6%. The main reason for culling was infertility (around 40% on average). Culling due to infertility was particularly common among the cows which produced more than 11000 kg milk as first calvers.

Longevity of Cows Depending on their First Lactation Yield and Herd Production Level

Annals of Animal Science

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The effect of first lactation yield and herd production level on longevity was studied using data from the SYMLEK database on 12045 Polish Holstein-Friesian...

Longevity of Cows Depending on their First Lactation Yield and Herd Production Level

Published Online: Oct 27, 2017

Page range: 1171 - 1183

Received: Jul 06, 2016

Accepted: Feb 21, 2017

DOI: https://doi.org/10.1515/aoas-2016-0096

Keywords
cow, longevity, first lactation, production level

© 2017 Anna Sawa et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Longevity of Cows Depending on their First Lactation Yield and Herd Production Level

Published Online: Oct 27, 2017

Page range: 1171 - 1183

Received: Jul 06, 2016

Accepted: Feb 21, 2017

DOI: https://doi.org/10.1515/aoas-2016-0096

Keywordscow, longevity, first lactation, production level

© 2017 Anna Sawa et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
cow, longevity, first lactation, production level