Exploring factors associated with bulk tank milk urea nitrogen in Central Thailand

Vet World Vol.11 May-2018 Article-11

Research Article

Veterinary World, 11(5): 642-648

https://doi.org/10.14202/vetworld.2018.642-648

Suppada Kananub¹, Wassana Jawjaroensri², John VanLeeuwen³, Henrik Stryhn³, and Pipat Arunvipas¹

1. Department of Large Animals and Wildlife Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand.
2. Laboratory Unit, Kasetsart University Veterinary Teaching Hospital, Nong Pho, Ratchaburi Province, Thailand.
3. Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Canada.

Background and Aim: The study was to determine seasonal fluctuations and non-nutritional factors associated with bulk tank milk urea nitrogen (BTMUN).

Materials and Methods: A total of 58,364 BTM testing records were collected from 2364 farms in Central Thailand during September 2014-August 2015. Using square root BTMUN as the outcome, other milk components, farm effect, and sampling time were analyzed by univariable repeated measures linear regression, and significant variables were included in multivariable repeated measures linear regression.

Results: The average BTMUN (standard deviation) was 4.71 (±1.16) mmol/L. In the final model, BTM fat and protein percentages were associated with BTMUN as quadratic and cubic polynomials, respectively. BTM lactose percentage and the natural logarithm of somatic cell counts were negatively linearly associated with BTMUN. At the farm level, the BTM lactose association was negatively linear; herd BTMUN decreased following an increase of herd lactose average, and BTM lactose slopes were quite different among farms as well. Sampling time had the highest potency for the estimation of BTMUN over time, with lows and highs occurring in August and October, respectively. The variation in test level BTMUN was decreased by 18.6% compared to the null model, and 6% of the variance could be explained at the farm level.

Conclusion: The results clarify seasonal variation in BTMUN and the relationships among other BTM constituents and BTMUN, which may be useful for understanding how to manage lactating dairy cattle better to keep BTM constituents within normal ranges. Keywords: bulk tank milk urea nitrogen, farm level, non-nutritional factor, Thailand.

Keywords: bulk tank milk urea nitrogen, farm level, non-nutritional factor, Thailand.

How to cite this article: Kananub S, Jawjaroensri W, VanLeeuwen J, Stryhn H, Arunvipas P (2018) Exploring factors associated with bulk tank milk urea nitrogen in Central Thailand, Veterinary World, 11(5): 642-648.

Received: 16-01-2018 Accepted: 18-04-2018 Published online: 18-05-2018

Corresponding author: Pipat Arunvipas E-mail: fvetpia@ku.ac.th

DOI: 10.14202/vetworld.2018.642-648

Copyright: Kananub, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.