<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>The main goal of this study was to determine the effects of body weight traits during the rearing period on subsequent milk production of primiparous dairy cows using Principal Component Analysis. Data on lactation performance records of 109 Red Steppe dairy cow progeny of six bulls maintained at the State Enterprise “Pedigree Reproducers” Stepove”” (Mykolayiv region, Ukraine), during 2001–2014, were utilised for the present study. Heifer body weight at birth, 3, 6, 9, 12, 15, and 18 months of age was measured. Records of 305-day milk yield (kg), milk fat percentage (%), milk fat yield (kg), monthly milk yield (kg) and milk fat percentage (%) in the 1<sup>st</sup>-lactation dairy cows were also available. Principal Components Analysis (PCA) was conducted on the live weights for each heifer between birth and 18 months of age. The first three principal components (PC1-PC3) explained 79.7% of the total variance. Principal component 1 (PC1) showed significant relationship to body weight of heifers at 9, 12, and 15 months of age (post-pubertal period). Body weight at 3 and 6 months of age (pre-pubertal period) had higher scores on the second principal component (PC2). Principal component 3 (PC3) showed significant relationship to body weight of calves at birth. Only groups of heifers with high scores on PC1 and PC2 had significant effect on subsequent milk performance (with the exception of milk fat percentage). Thus, the use of a multivariate technique (Principal Component Analysis) allowed to determine two age intervals of heifers during the rearing period (pre- and postpubertal periods), which were significantly related to subsequent milk production.</p>
</abstract>

The main goal of this study was to determine the effects of body weight traits during the rearing period on subsequent milk production of primiparous dairy cows using Principal Component Analysis. Data on lactation performance records of 109 Red Steppe dairy cow progeny of six bulls maintained at the State Enterprise “Pedigree Reproducers” Stepove”” (Mykolayiv region, Ukraine), during 2001–2014, were utilised for the present study. Heifer body weight at birth, 3, 6, 9, 12, 15, and 18 months of age was measured. Records of 305-day milk yield (kg), milk fat percentage (%), milk fat yield (kg), monthly milk yield (kg) and milk fat percentage (%) in the 1st-lactation dairy cows were also available. Principal Components Analysis (PCA) was conducted on the live weights for each heifer between birth and 18 months of age. The first three principal components (PC1-PC3) explained 79.7% of the total variance. Principal component 1 (PC1) showed significant relationship to body weight of heifers at 9, 12, and 15 months of age (post-pubertal period). Body weight at 3 and 6 months of age (pre-pubertal period) had higher scores on the second principal component (PC2). Principal component 3 (PC3) showed significant relationship to body weight of calves at birth. Only groups of heifers with high scores on PC1 and PC2 had significant effect on subsequent milk performance (with the exception of milk fat percentage). Thus, the use of a multivariate technique (Principal Component Analysis) allowed to determine two age intervals of heifers during the rearing period (pre- and postpubertal periods), which were significantly related to subsequent milk production.

Principal Component Analysis of Body Weight Traits and Subsequent Milk Production in Red Steppe Breed Heifers

Kherson State Agrarian and Economic University

Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.

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

The main goal of this study was to determine the effects of body weight traits during the rearing period on subsequent milk production of primiparous dairy...

Principal Component Analysis of Body Weight Traits and Subsequent Milk Production in Red Steppe Breed Heifers

Published Online: Jun 02, 2022

Page range: 307 - 313

Received: Aug 17, 2021

Accepted: Mar 08, 2022

DOI: https://doi.org/10.2478/prolas-2022-0044

Keywords
body weight, Principal Component Analysis, pre- and post-pubertal periods, milk production, heifers, Red Steppe cattle breed

© 2022 Alexander S. Kramarenko et al., published by Sciendo

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

Principal Component Analysis of Body Weight Traits and Subsequent Milk Production in Red Steppe Breed Heifers

Published Online: Jun 02, 2022

Page range: 307 - 313

Received: Aug 17, 2021

Accepted: Mar 08, 2022

DOI: https://doi.org/10.2478/prolas-2022-0044

Keywordsbody weight, Principal Component Analysis, pre- and post-pubertal periods, milk production, heifers, Red Steppe cattle breed

© 2022 Alexander S. Kramarenko et al., published by Sciendo

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

Keywords
body weight, Principal Component Analysis, pre- and post-pubertal periods, milk production, heifers, Red Steppe cattle breed