Fatty acid interrelationships in plasma, liver, muscle and adipose tissues of cattle fed safflower oil protected from ruminal hydrogenation

Abstract

Steers were given diets containing formaldehyde‐treated casein‐safflower oil supplements, in which the constituent 18∶2 was protected from ruminal hydrogenation. A similar group was given unsupplemented diets. The fatty acid compositions of plasma, liver, muscle and adipose tissue lipids were determined in both groups of cattle after 0, 2, 4 and 8 weeks of experimentation. The proportion of 18∶2 in the triglycerides was markedly increased on feeding the supplement and the rate of incorporation into the plasma triglycerides was higher than that in the triglycerides of muscle and adipose tissue. Associated with this increase there were compensatory decreases in the proportions of 16∶0 and 18∶1 but no consistent change in the proportion of 18∶0. The proportion of 18∶2 in the plasma phospholipids and cholesteryl esters was initially much higher than in the triglycerides and this was further increased by feeding the safflower oil supplement. A linear relationship existed between the proportion of 18∶2 in the phospholipids and cholesteryl esters of plasma. The supplement also caused substantial increases in the proportion of 18∶2, both in phospholipids from liver and muscle and in cholesteryl esters from liver, and there were compensatory decreases in the proportions of other unsaturated fatty acids, e.g., 18∶1, 18∶3, 22∶6. These studies demonstrate that when ruminal hydrogenation was circumvented by feeding formaldehyde‐treated casein‐safflower oil particles, the linoleic acid was absorbed and the pattern of incorporation into plasma and tissue lipids was similar to that in nonruminants.

The effect of dietary fats on the plasma lipid composition of sheep

“…In the sheep receiving diet D, the increase in the concentration of PUFA achieved within the plasma was associated with those fractions (the cholesteryl esters and phospholipids) which already carried the major part of the circulatory PUFA. The ability to increase the PUFA content of these fractions even further under these conditions as opposed to the triglyceride fraction where the concentration of PUFA remains relatively low has b~en explained in terms of the transitory nature of the supply of PUFA from the intestine and the differential rates for the turnover and hydrolysis of the various plasma lipid components (31,32). In contrast, by feeding diet B~ these effects were largely overcome and by creating a pattern of lipid metabolism similar to that which would be expected to operate within the nonruminant animal, a permanently high level of 18:2 was achieved within the plasma triglycerides.…”

Protection of fatty acids against ruminal biohydrogenation in cattle

“…Polyunsaturated fatty acid levels in tissues of cattle and sheep were significantly elevated by feeding formaldehyde-treated lipid [29][30][31]. Approximately 18-25% of the linoleic acid consumed in formaldehyde-treated lipid was stored in body tissues of cattle [32], while 50-60% storage was reported for sheep [31,33].…”

Opportunities and Implications of Pasture‐Based Lamb Fattening to Enhance the Long‐Chain Fatty Acid Composition in Meat

“…These methods have been successful to varying degrees and have included reducing the nitrogen content of the diet, reducing feed particle size, feeding with more mature forages, and using calcium salts (Seabrook and others ). However, the most successful method involved encapsulating PUFAs in formaldehyde‐treated protein (Scott and others ; Cook and others ; Dewhurst and others ). Scott and others () discovered a significant increase in PUFAs in adipose, plasma, and milk triglycerides (TAGs), from 2% to 5% to 20% to 30%, when animals were fed megalac.…”