Relationship between the Composition of Lipids in Forages and the Concentration of Conjugated Linoleic Acid in Cow’s Milk: A Review

Abstract

Conjugated linoleic acid (CLA), has been shown to have protective effects against various diseases, such as obesity, arteriosclerosis, diabetes, chronic inflammatory diseases, and cancer. This fatty acid in ruminants results from two processes, biohydrogenation, which takes place in the rumen, and de novo synthesis, carried out in the mammary gland, and it has linoleic and α-linolenic acids as its precursors. The amounts of precursors in the diets of animals are related to the amounts of CLA in milk. In the literature review, it was found that the milk of cows fed fresh forage has a higher amount of CLA because they have a higher amount of linoleic acid and α-linolenic acid compared to other foods used in the diets of cows. The amount of CLA precursors in pastures can be increased through agronomic practices, such as nitrogen fertilization, and regrowth age. It is also a technique used to increase the amount of CLA in milk to obtain a greater benefit regarding its nutritional value.

Lambs supplemented with Amazonian oilseed co-products: Meat quality and fatty acid profile

“…Edible fats from ruminants are the main dietary source of CLA for humans. Some CLA isomers, such as rumenic acid (18:2c9,t11), have health-promoting actions, notably anticancer [ 54 ]. Thus, enrichment of ruminant meat with CLA is often a goal in experiments with growing ruminants [ 27 , 55 ].…”

A meta-analysis to determine the optimal values of precursors in the diet of dairy cows that increase the concentration of conjugated linoleic acid (CLA) in milk

“…In contrast, Kliem and Shingfield (2016) have argued that the highest production of CLA occurs in the first third of the lactation period. However, Mojica-Rodríguez et al (2019) have reported that CLA production in milk is not influenced by the lactation status, contradicting the findings of Acosta-Balcazar et al (2022).…”

“…The CLA content in milk is influenced by intrinsic factors related to the animal, such as breed, number of lactations and lactation period (Flores et al, 2011;Roca-Fernández et al, 2014;Acosta-Balcazar ABSTRACT. The concentration of conjugated linoleic acid (CLA) in dairy products derived from ruminants, such as cow's milk, is mainly influenced by the dietary lipid profile.…”

“…Similarly, the consumption of fresh forage can increase CLA levels in milk, because it provides a higher quantity of linoleic and α-linolenic acid to the cows' diet (Walker et al, 2004;Aguilar et al, 2009;Ortega-Pérez et al, 2013). In fact, these fatty acids make up approximately 95% of the lipid fraction found in pasture forage (Acosta-Balcazar et al, 2022). The content of these precursors is affected by various factors, such as plant species and variety, climate, light intensity, precipitation, fertilisation or growth stage (Kalač and Samková, 2010).…”

Characteristics of mountain vs. lowland dairy products

“…The production of vaccenic acid led to the quantity of linoleic acid + α‐linolenic acid consumed and it was the highest in milk from animals fed with a diet containing low polyphenolic content (Ineichen et al ., 2019). The polyphenols from fed are responsible for ruminal linoleic acid and α‐linolenic acid biohydrogenation inhibition, leading to higher amounts of these compounds in mountain milk, the structure of the polyphenol being also relevant (Acosta Balcazar et al ., 2022).…”