The effect of milking frequency on the concentration of immunoglobulin G and somatic cell count in colostrum and milk during the first 10 days postpartum
Year: 2025
Type: article
Abstract: The calving period is one of the busiest times of the year in block-calving pasture-based dairy farm systems, and practices such as milking once a day (OAD) or 3 times every 2 d (3-in-2) are attractive options to reduce labor requirements during this period. In early lactation, the composition of milk can impair processability, so in many jurisdictions, there are legislative requirements to withhold colostrum from the milk supply. The objective of this study was to determine the effect of milking frequency on the efficiency of colostrum removal from the udder after calving. Three experimental groups were established, and cows were milked either twice a day (TAD; n=25 cows), 3-in-2 (n = 25 cows), or OAD (n = 28 cows) for their first 10 d after calving. Milk samples were collected at each milking during this period and analyzed for IgG 1 (IgG) and SCC. Using nonlinear regression, IgG concentration reached a constant value after approximately 80 kg of cumulative milk yield, irrespective of milking frequency. Due to differences in the rate of milk accumulation between milking frequencies, the milking number when this point was reached varied. Milking number or day remains a valuable practical measure for farmers to know when milk is suitable for collection. Considering IgG and SCC, the shortest risk period for inclusion of milk into the bulk tank occurred at milking 8 (d 4) for cows milked TAD, milking 7 (d 5) for cows milked 3-in-2 and milking 6 (d 6) for cows milked OAD. Furthermore, the decline in IgG concentration ceased at a higher IgG value for cows milked OAD relative to 3-in-2 and TAD. Consequently, legislative requirements should account for milking frequency if using milking number as a measurement basis. Adjustment of postcalving withholding periods to account for milking frequency, or using accumulated milk volume, would allow farmers to operate smaller groups of animals withheld from the bulk tank than solely using number of milkings, thereby reducing loss of saleable milk, management complexity and increasing accessibility of alternate milking frequencies for reducing pressure on labor resources.
Source: Journal of Dairy Science
Authors: H.R. Williamson, S.J. Lacy-Hulbert, G. Scott, B. Kuhn-Sherlock, J.P. Edwards
Institutions: Lincoln University, DairyNZ, Fonterra (New Zealand)
Language: English
Topic: Animal health and immunology
Subfield: Animal Science and Zoology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $3,500
Awards: G5988835912, G8840701792
OpenAlex ID: W4415716656