• Journal of Dairy Science and Biotechnology
• /
• v.32 no.2
• /
• pp.63-70
• /
• 2014

Automatic milking systems (AMS) have been increasingly introduced to Korean dairy farms. However, in comparison with conventional milking systems (CMS), some negative changes in milk quality are being observed. The use of AMS leads to an increase in milking frequency, which in turn might result in higher physical stress on the milk, possibly causing changes in the milk fat globule (MFG) membrane. Therefore, the purpose of this study was to examine the effect of the different milking systems on the milk quality, with a focus on milk fat properties. At the same time, we studied the effect of feeding the dairy cows with protected fat. Raw milk samples were taken monthly from individual cows as well as from bulk tanks at four AMS and four CMS dairy farms. We measured quality-related parameters such as MFG size distribution, free fatty acid content and composition, and acid values. Although most results showed no significant differences with regard to the milking system, we found a relatively high positive correlation between MFG size and milk fat content. Moreover, larger MFG size was observed in the milk when cows had been fed protected fat. The significantly higher (P< 0.05) free fatty acid content of milk observed under this experimental condition could be attributed to higher milking frequency as a result of using AMS.

• Journal of Dairy Science and Biotechnology
• /
• v.33 no.3
• /
• pp.209-214
• /
• 2015

This study was carried out to investigate the effects of different milking systems (AMS, automatic milking system and CMS, conventional milking system) and of supplemental fat feeding on milk composition and milk fat characteristics. The composition, MFG (milk fat globule) size, fatty acids (FAs), and free fatty acids (FFAs) of the milk from 4 AMS and 4 CMS dairy farms were analyzed on the basis of the milking system and feeding of protected fat. The milking system did not affect milk composition, MFG size, and milk FAs, but FFA content of AMS milk were significantly higher than that of CMS milk. Feeding of protected fat resulted in the production of milk much higher in LCFAs (long chain FAs); however, the milk composition was not affected by fat supplementation. Cows administered protected fat supplements produced milk containing MFGs with a large average diameter.