**3. Conclusion**

the bioavailability of CLA is measured either the total contents of CLA in blood circulation after ingestion or the total contents of CLA disposition in the liver, mammary fat, peritoneal fat and plasma. The composition of CLA isomers mixture can also influence the incorporation and bioavailability of CLA to tissue and organs. To date, most of the human studies evaluated by only blood measurements, which are different from animal models regarding the bioavailability and distribution modes of CLA according organs, model of dietary supplementation

**Food Product Fat (g)/serving CLA(mg)/g fat CLA (mg)/serving**

 mL of milk (2% fat) 5.1 4.1 20.9 mL of condensed milk 14.1 7.0 98.7 mL of fermented buttermilk (2%) 5.2 5.4 28.1 g of plain yogurt (2–4% fat) 4.9 4.8 23.5 g of yogurt (1–2% fat) 2.7 4.4 11.9 g of processed cheese 12.3 5.0 61.5 g of cheddar cheese 16.6 4.1 68.1 mL of butter 11.7 4.7 55.0 mL cream 17.1 4.6 78.7 mL ice cream 11.8 3.6 42.5

 g of lamb meat 12.7 5.8 73.7 g of ground beef 12.3 4.3 52.9 g of veal 6.1 2.7 16.5 g of fresh ground turkey 6.5 2.6 16.9 g of chicken 12.1 0.9 10.9 g of pork 13.8 0.6 8.3 Large egg yolk 5.3 0.6 3.2 g of salmon 5.7 0.3 1.7

15 mL of safflower oil 13.8 0.7 9.7 15 mL of sunflower oil 13.8 0.4 5.5

A very recent study by Rodriguez-Alcala et al. (2015) was conducted on oral absorption and disposition of CLA isomers from naturally enriched goat milk cheese conducted to evaluate the bioavailability of CLA. The oral doses of 153 mg vaccenic acid, 46 mg rumenic acid were fed to rats on kilogram body weight basis. The maximum concentration value of vaccenic acid and rumenic

or enrichment [97, 99].

**Table 4.** Availability of CLA content from food products.

*Milk and milk products*

34 Bovine Science - A Key to Sustainable Development

*Meat and meat products*

*Vegetable oils*

Enhanced or enriched dairy fats produced by dietary manipulation are considered wellabsorbed and bioactive source of essential fatty acids with beneficial health effects in humans. However, most of the studies related to effect of CLA on human health were conducted on commercial CLA that was differentially available and dispersed in body organs and tissues and hence have different health effects. Further, there are not conclusive studies on the moderation of CLA and its dietary source on average human intake. The extrapolation from rat animal models to human intake must be taken with cautions due to difference in dietary requirements. To meet recommended intake of CLA, several efforts have been made to enhance the level of CLA naturally and natural enhanced CLA in dairy food is more health effective. The manipulation of dairy ration type and composition seems to be one of the most suitable strategies for enhancement of CLA in enriched dairy products. Manipulation of the animal's diet can result in up to 8- to 10-fold increase in the concentration of CLA in milk. As consumers become more conscious of the link between diet and health, milk designed to have enhanced levels of CLA may provide new market opportunities for milk and milk products such as butter and cheese.
