Dietary strategies to enrich milk with healthy fatty acids – A review

Abstract

Feed is the main factor impacting the composition and quality of milk of dairy animals. Therefore, the present review explores the effects of feed and nutrition on milk fat content and levels of healthy fatty acids (FA) in milk consumed by humans. Milk and dairy products are two main sources of healthy and unhealthy FA in human nutrition. The concentrations of FA in milk depend mainly on diets; therefore, milk FA concentrations and ratios can be greatly altered by some feeding strategies. Dietary supplementation of the diets of dairy livestock with vegetable seeds or oils, microalgae and phytogenic feed additives, and feeding of some grasses can enhance the contents of healthy FA, including n-3 FA, α-linolenic acid, conjugated linoleic acid (CLA) and, generally, unsaturated FA in milk and dairy products. Enrichment of milk with healthy FA may make milk a source of anticarcenogens (CLA and polyphenols) for human health. This review, therefore, focusses on the current research findings on enrichment of milk with healthy FA and summarizes some effective supplementation strategies to alter milk FA profile.

Replacing the Concentrate Feed Mixture with Moringa oleifera Leaves Silage and Chlorella vulgaris Microalgae Mixture in Diets of Damascus Goats: Lactation Performance, Nutrient Utilization, and Ruminal Fermentation

“…It is well documented that milk fatty acids profile is highly sensitive to dietary changes [ 14 , 36 ]. Concentrations of milk fatty acids are greatly influenced by the type of fatty acids consumed by animals.…”

“…C. vulgaris also contains other biological active components such as antioxidants, provitamins, vitamins, pigments, a growth phytonutrient known as the C. vulgaris growth factor (CGF), unsaturated fatty acids (UFA), glycoproteins and carotenoids [ 11 ]. Experiments [ 3 , 13 ] showed that C. vulgaris improved ruminal bacterial growth and altered ruminal biohydrogenation of monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) due to their effects on ruminal microbes, especially those involved in the metabolism and biohydrogenation of fatty acids in the rumen [ 11 , 14 ]. Recently, Kholif et al [ 3 ] observed that the inclusion of C. vulgaris in the diets of lactating Boer goats improved nutrient intake and digestibility, ruminal fermentation, lactational performance and milk nutritive value; however, other researchers [ 15 ] observed weak effects on feed intake, digestibility or daily milk production when feeding C. vulgaris to lactating Finnish Ayrshire cows.…”

Utilization of Waste Date Palm Leaves Biomass Ensiled with Malic or Lactic Acids in Diets of Farafra Ewes under Tropical Conditions

“…The treatments increased the fat contents in milk. Fat concentration in milk is related to diet composition and metabolic processes in the rumen, and this variable is often used as an indicator of rumen health and fiber adequacy in dairy animals [ 46 , 47 ]. The increased milk fat content may be related to increased ruminal acetate concentration, as acetate is the main precursor of fatty acid synthesis in the mammary gland [ 47 ].…”

“…Fat concentration in milk is related to diet composition and metabolic processes in the rumen, and this variable is often used as an indicator of rumen health and fiber adequacy in dairy animals [ 46 , 47 ]. The increased milk fat content may be related to increased ruminal acetate concentration, as acetate is the main precursor of fatty acid synthesis in the mammary gland [ 47 ]. Iqbal et al [ 48 ] observed that feeding lactating cows a diet containing barley grain steeped in lactic acid increased milk fat content without affecting milk production and other variables of milk.…”

“…Around 60% of milk fatty acids come from plasma uptake, whereas the remaining amounts are synthesized in the mammary gland [ 50 ]. The observed alterations in ruminal fermentation and expected changes in the ruminal microbial population and biohydrogenation may be associated with altered milk fatty acid profiles [ 47 ].…”