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

<p>The objective of this study was to assess the effects of parity and of days in milk (DIM) on milk urea (MU) and other milk components in Holstein dairy cows. Milk yield was lower (P &lt; 0.05) in primiparous cows compared with multiparous cows and tended to increase until the third parity and then decrease. The MU concentration was lower (P &lt; 0.05) at the first lactation than at the other lactations. Milk fat and protein contents were higher (P &lt; 0.05) in the primiparous cows than that in multiparous cows and were reduced until the third parity and then increased. Lower (P &lt; 0.05) milk lactose content was found in primiparous cows and tended to increase until the third parity and then decreased. Primiparous cows had lower (P &lt; 0.05) daily protein and fat yields compared with multiparous cows. The lowest value of milk yield was recorded during the first lactation with a peak of lactation between 61—90 DIM and a persistence of lactation of 3 %. The highest milk yield was confirmed at the third and fourth lactations with a peak of lactation between 61—90 DIM and a persistence of lactation of 7 % and 6 %. The effect of DIM on MU confirmed a significant (P &lt; 0.01) positive relationships in primiparous and multiparous cows. The lowest level of MU concentration was found between 0—30 DIM. The content of MU increased and the maximum was achieved between 271—305 DIM. It is suggested that although MU for nutritional management and measures of production or reproduction are used, non-nutritional factors should be considered.</p>
</abstract>

The objective of this study was to assess the effects of parity and of days in milk (DIM) on milk urea (MU) and other milk components in Holstein dairy cows. Milk yield was lower (P < 0.05) in primiparous cows compared with multiparous cows and tended to increase until the third parity and then decrease. The MU concentration was lower (P < 0.05) at the first lactation than at the other lactations. Milk fat and protein contents were higher (P < 0.05) in the primiparous cows than that in multiparous cows and were reduced until the third parity and then increased. Lower (P < 0.05) milk lactose content was found in primiparous cows and tended to increase until the third parity and then decreased. Primiparous cows had lower (P < 0.05) daily protein and fat yields compared with multiparous cows. The lowest value of milk yield was recorded during the first lactation with a peak of lactation between 61—90 DIM and a persistence of lactation of 3 %. The highest milk yield was confirmed at the third and fourth lactations with a peak of lactation between 61—90 DIM and a persistence of lactation of 7 % and 6 %. The effect of DIM on MU confirmed a significant (P < 0.01) positive relationships in primiparous and multiparous cows. The lowest level of MU concentration was found between 0—30 DIM. The content of MU increased and the maximum was achieved between 271—305 DIM. It is suggested that although MU for nutritional management and measures of production or reproduction are used, non-nutritional factors should be considered.

Effect of Parity and Days in Milk on Milk Urea Concentration and Milk Components in Holstein Dairy Cows

Department of Animal Nutrition and Husbandry

University of Veterinary Medicine and Pharmacy in Košice

Folia Veterinaria

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

The objective of this study was to assess the effects of parity and of days in milk (DIM) on milk urea (MU) and other milk components in Holstein dairy cows....

Effect of Parity and Days in Milk on Milk Urea Concentration and Milk Components in Holstein Dairy Cows

Published Online: Jul 04, 2022

Page range: 1 - 8

Received: Mar 04, 2022

Accepted: Apr 08, 2022

DOI: https://doi.org/10.2478/fv-2022-0011

Keywords
milk yield, non-nutritional factors, urea in milk

© 2022 P. Timkovičová Lacková et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Effect of Parity and Days in Milk on Milk Urea Concentration and Milk Components in Holstein Dairy Cows

Published Online: Jul 04, 2022

Page range: 1 - 8

Received: Mar 04, 2022

Accepted: Apr 08, 2022

DOI: https://doi.org/10.2478/fv-2022-0011

Keywordsmilk yield, non-nutritional factors, urea in milk

© 2022 P. Timkovičová Lacková et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
milk yield, non-nutritional factors, urea in milk