Intraday and interday variations of milk fatty acids in dairy cows in early and late lactation

This study aimed to determine an appropriate sampling method for milk FA in a practical farm condition based on intraday and interday variations in milk FA composition during early and late lactation stages. Milk samples were collected in the morning (07:00 –08:00 h) and afternoon (16:30–17:30 h) for five consecutive days during early and late lactation. Within the day, de novo FA as the total FA basis was higher in the morning than in the afternoon, whereas preformed FA as the total FA basis was lower in the morning than in the afternoon. The weighted averages of milk FA composition according to milk yield collected in the morning and afternoon were significantly different between cows in early and late lactation; however, these were not significantly different among the consecutive five sampling days in each period. It was concluded tha t milk samples collected in the morning and afternoon for 1 day are suitable for milk FA determination. These results provide basic data for determining precise sampling methods for practical farms.

Source: Animal Science Journal - April 4, 2024 Category: Zoology Authors: Noriaki Nagahaka, Eisuke Abe, Hiroshi Hiraoka, Makoto Kondo Tags: SHORT COMMUNICATION Source Type: research