Main Article Content
cow, fatty acids, milk fat globules, milk quality
The aim of the study was to verify whether changes in the percentage of fat in highly selected cows produce variations in the physical structure of the fat and changes in milk composition. Individual milk was sampled from 50 cows. Fat was evaluated in each individual in order to create two groups of animals with lower and higher percentage. The group with higher fat content showed a significantly larger diameter of the fat globules, less C14:0 and more C16:1. In conclusion the diameter variations observed result in few changes in milk fatty acid composition, thus maintaining a consistent nutritional quality.
Banks J.M. and Tamime A.Y. 1987. Seasonal trends in the efficiency of recovery of milk fat and casein in cheese manufacture. Int. J. Dairy Technol. 40: 64.
Cebo C., Lopez C., Henry C., Beauvallet C., Ménard O., Bevilacqua C., Bouvier F., Caillat H. and Martin P. 2012. Goat ?s1-casein genotype affects milk fat globule physicochemical properties and the composition of the milk fat globule membrane. J. Dairy Sci. 95: 6215.
Christie W.W. 1982. A simple procedure for rapid transmethylation of glycerolipids and cholesteryl esters. J. Lipid Res. 23: 1072.
Heid H.W. and Keenan T.W. 2005. Intracellular origin and secretion of milk fat globules. Eur. J. Cell Biol. 84: 245.
JMP. 2002. User’s guide, version 5.0. SAS. Inst. Inc., Cary, NC, USA.
Kelsey J.A., Corl B.A., Collier R.J. and Bauman D.E. 2003. The Effect of Breed, Parity, and Stage of Lactation on Conjugated Linoleic Acid (CLA) in Milk Fat from Dairy Cows. J. Dairy Sci. 86: 2588.
Logan A., Auldist M., Greenwood J. and Day L. 2014. Natural variation of bovine milk fat globule size within a herd. J. Dairy Sci. 97: 4072.
Martini M., Salari F. and Altomonte I. 2013a. The macrostructure of milk lipids: the fat globules. Crit. Rev. Food Sci. Nutr. DOI:10.1080/10408398.2012.758626
Martini M., Altomonte I. and Salari F. 2013b. Evaluation of the fatty acid profile from the core and membrane of fat globules in ewe's milk during lactation. Lebensm. Wiss Technol. 50: 253.
Martini M., Altomonte I. and Salari F. 2012. Relationship between the nutritional value of fatty acid profile and the morphometric characteristics of milk fat globules in ewe's milk. Small Rumin. Res. 105: 33.
Michalski M.C., Camier B., Briard V., Leconte N., Gassi J.Y., Goudédranche H., Michel F. and Fauquant J. 2004. The size of native milk fat globules affects physico-chemical and functional properties of Emmental cheese. Lait. 84: 343.
NRC 2001. “Subcommittee on Dairy Cattle Nutrition, Committee on Animal Nutrition, Board on Agriculture and Natural Resources”. 7th Revised Edition. National Research Council, National Academy Press, Washington, D.C.
Olofsson S.O., Boström P., Andersson L., Rutberg M., Perman J. and Borén J. 2009. Lipid droplets as dynamic organelles connecting storage and efflux of lipids. Biochim. Biophys. Acta. 1791: 448.
Wiking L., Stagsted J., Björck L. and Nielsen J.H. 2004. Milk fat globule size is affected by fat production in dairy cows. Int. Dairy J. 14: 909.