TITLE:
Udder Health Status of First Parity Dairy Cows in Early-Lactation Based on Somatic Cell Count Categories
AUTHORS:
Găvan Constantin, Riza Mihaela
KEYWORDS:
Intramammary Infection, Somatic Cell Count, Composite Somatic Cell Count, Milk Urea Content
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.13 No.3,
July
31,
2023
ABSTRACT: The main aim of this study was to investigate the
prevalence of intramammary infection (IMI) in early-lactation of primiparous
cows using milk recording cow composite somatic cell count (CSCC) categories
(combining the first 2 milk recording results after calving). Another aim was
to evaluate the milk urea (MU) content as a
potential supplementary indicator to SCC or CSCC for the identification of IMI in primiparous cows after
calving. This retrospective observational study was conducted on records
of test-day of primiparous cows over a period of 6 years (January 2016 to December 2021. The SCC
data for 158 Holstein Friesian primiparous cows, with their first milk recording 5 to 35 days after
calving and their second milk recording 28 to 56 days in milk (DIM), were
identified. Each primiparous cow was assigned a CSCC category (low-low, low-high,
high-low or high-high) based on the CSCC at the first 2 milking recordings
using the following cut-offs: ≤150,000 cells/ml (low), >150,000 cells/ml (high). The association between CSCC
categories and MV content was analyzed using correlation models. At the first milk recording, a proportion of 63.29% was in the low SCC category, and the rest (36.71%) was in the high SCC
category. At the second milk recording, a proportion of primiparous cows in CSCC categories was 59.49%, 3.80%, 27.85% and
8.86% in low-low, low-high, high-low and high-high, respectively. At the second milk recording, a proportion of 12.66% of primiparous cows was in the high CSCC category and a proportion of 87.34% of primiparous
cows was in the low CSCC category, indicating a poor and a
good udder health, respectively. The association of SCC with MU content in low and in high SCC categories at the first milk recording was
positive and moderate (+0.49) and negative and strong (-0.97), respectively. The association of CSCC
categories with MU contents at the second milk recording was inconclusive. We
concluded that CSCC categories may be a useful tool for identifying
success and problems regarding the udder health of primiparous cows in early lactation.