Natural variation of bovine milk fat globule size within a herd.
Native milk fat globule (MFG) size, pH, total fat, protein, and lactose composition in milk from individual cows was examined in autumn and spring 2012 and autumn 2013. Mean MFG diameters ranged between 2.5 and 5.7 µm. Some cows were observed to consistently produce small or large MFG throughout the sampling period, though trends were not consistent across all cows. Small-MFG milk contained more total polar lipids; however, the relative proportion of individual polar lipids did not differ with MFG size, with the exception of phosphatidylcholine, which was greater in small-MFG milk. No significant correlation between MFG size and proximate composition, including calculated fat yield or pH, was found. This work revealed a natural cow-to-cow variation in MFG size exists, which could potentially be exploited to improve the functionality of milk for manufacturing and some products.
CSIRO Animal, Food and Health Sciences, Werribee, Victoria, Australia 3030. Electronic address: amy.logan@csiro.au.
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A
Logan
Department of Environment and Primary Industries, Ellinbank Centre, Farming Systems Research Division, Ellinbank, Victoria, Australia 3821.
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M
Auldist
Department of Environment and Primary Industries, Ellinbank Centre, Farming Systems Research Division, Ellinbank, Victoria, Australia 3821.
J
J
Greenwood
CSIRO Animal, Food and Health Sciences, Werribee, Victoria, Australia 3030.
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L
Day
D000818:Animals; D005260:Female; D006017:Glycolipids / Q000032:analysis*; D006023:Glycoproteins / Q000032:analysis*; D066292:Lipid Droplets; D018613:Microscopy, Confocal; D008892:Milk / Q000737:chemistry*
D006017:Glycolipids; D006023:Glycoproteins; C110367:milk fat globule
milk fat globule size; milk functionality; natural cow-to-cow variation