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 (R 2 ) 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 R 2 , 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 R 2 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.

Role of Fatty Acids in Milk Fat and the Influence of Selected Factors on Their Variability—A Review

“…Three FAs that are referred to as HFA [ 114 ] are lowest at the start of lactation but increase as lactation progresses. By contrast, the proportions of C18:1 c 9 and LA, which are considered to have cardioprotective effects, are present in higher amounts early in lactation [ 16 , 81 ]. RA is another FA with health benefits [ 115 ].…”

“…Some factors affecting the FA profile of milk (such as altitude, breed, lactation order (parity), lactation stage (days in milk), and diet) have been described previously [ 8 , 9 , 10 , 11 , 12 , 13 ]; nevertheless, these factors continue to be studied because of their wide-range of variation and their large number of possible mutually combined effects. In some studies using multifactorial datasets, the main factors affecting milk FA composition were feeding ration, herd, cow´s individuality, and lactation stage; whereas, breed and parity showed only small effects [ 10 , 14 , 15 , 16 , 17 ]. Although animal factors evidently affect the FA profile of milk fat [ 18 ], the main factors are related to dairy cow nutrition [ 19 ].…”

The antioxidant components of milk and their role in processing, ripening, and storage: Functional food

“…Transfer efficiency is the term used to refer to the amount of fatty acids that can be transferred from dietary fat. Many studies illustrated that the transfer efficiency ranges from 2% to 4% for eicosapentaenoic acid (EPA) which is lower than docosapentaenoic acid (DHA) [ 32 ]. It was found that feeding fish oil in a rumen-protected manner increases transfer efficiency.…”

“…Fish oil at recommended level in dairy diet seems to increase milk LA compared to vegetable oils. Combination of both fish and vegetable oils enrich with LA has the potential effect to increase milk LA level like soybean and sunflower [ 32 , 38 ]. Yu and Hu [ 39 ] found that, when cereals were substituted with lupin seeds, there was an improvement in milk production and higher concentration of milk protein and fat.…”