Nutritionally Desirable Fatty Acids Including Cla of Cow’s Milk Fat Explained by Animal and Feed Factors

Abstract

This study evaluated the effects of four factors (breed, parity, month of lactation and feeding ration) on the total explained variation (R2) determining composition of nutritionally important fatty acids. Individual milk samples were collected four times over an entire year (March, June, September, and December, respectively) on a conventional farm from two breeds: Czech Fleckvieh (dual-purpose, local) and Holstein (dairy, worldwide). In total, 145 samples (36; 38; 35 and 36, respectively) were analysed. Within the R2, feeding ration and month of lactation were the main factors affecting milk fatty acids composition, whereas breed and parity showed a low effect. A high percentage of the R2 was observed in rumenic acid (52 %), for example, whereas a low percentage was observed in both palmitic acid (30 %) and oleic acid (30 %). This may be due to intra-breed variability affected by different genetic predisposition of each cows, their performance or individual response to changes in feeding ration.

Keywords

• cows
• milk fatty acid
• rumenic acid
• breed
• lactation
• feeding ration