Animal and vegetable fats in milk replacers for veal calves. 5. Fatty acid patterns in various adipose tissues

Relationships between dietary fatty acid composition and either melting point or fatty acid profile of adipose tissue in broilers

Data on the fatty acid composition of the diet and that of the adipose tissue in broilers were collected from the literature. The linear regression between the dietary and the adipose tissue unsaturated to saturated fatty acids ratio (U/S ratio) was calculated because the U/S ratio of adipose tissue fat determines its melting point, which is an indicator of the consistency of poultry fat. For 54 data points from three different experiments, the linear correlation coefficient of the relationship between dietary and adipose tissue U/S ratio was 0.77. The regression equation for linoleic acid in adipose tissue as a function of dietary linoleic acid was calculated. The linoleic acid content of adipose tissue was expressed as weight percentage of total fatty acids. Intake was expressed as either weight percentage of total fatty acids or as energy percentage of total dietary metabolizable energy. The linear correlation coefficients were 0.68 and 0.78 as based on 116 or 91 data points from 15 or 12 different experiments. Significant correlations were also found for α-linolenic acid. The linoleic acid content of adipose tissue was found to be correlated (r=0.87) for 25 data points with that in consumable broiler meat, which may affect serum cholesterol concentrations in humans. With the help of the regression formulas presented it may be possible to formulate broiler diets in relation to consumer health and product quality.

Severity of Atherosclerosis in Parrots in Relation to the Intake of α-Linolenic Acid

Atherosclerosis is a common disease among parrots, but little is known about possible risk factors. Important risk factors in humans are an elevated plasma cholesterol concentration and increased platelet aggregation; high intakes of polyunsaturated fatty acids have beneficial effects. In this study, we tried to establish a relationship, if any, between dietary fatty acids and the severity of atherosclerosis in parrots. We collected dead parrots and scored the degree of atherosclerosis in the beginning of the aorta and the brachiocephalic arteries. It was not possible to assess the intake of fatty acids with food questionnaires so fatty acid composition of adipose tissue and breast muscle had to be used as an index of the dietary fatty acid composition. In all, 202 birds were collected. Gender was not related with atherosclerosis, but the degree of atherosclerosis increased with age and among the various species; African grey parrots appeared to be the most susceptible. The contents of linoleic acid in breast muscle or adipose tissue were not associated with the severity of atherosclerosis. For the relative percentage of alpha-linolenic acid in either breast muscle (P = 0.09; n = 175) or adipose tissue (P = 0.056; n = 21), a borderline significant relation with the degree of atherosclerosis was found. Parrots without atherosclerosis had significantly higher levels of alpha-linolenic acid than did the other animals. On the basis of these data, we suggest tentatively that a high dietary intake of alpha-linolenic acid protects against the development of atherosclerosis in parrots.

The intake of polyunsaturated fatty acids by cats is reflected in their adipose tissue

To find out whether the composition of the subcutaneous adipose tissue of cats reflects the intake of polyunsaturated fatty acids, we performed a feeding trial. Six groups of kittens were fed on diets with variable combinations of corn, linseed, and fish oil. After 5 months, biopsies of subcutaneous adipose tissue were analysed for their contents of linoleic, alpha-linolenic, eicosapentaenoic, and docosahexaenoic acid. The observed strong correlations between dietary and fat tissue polyunsaturated fatty acids indicate that the fatty acid composition of adipose tissue may be used as an index of the fatty acid composition of the diet. Thus, in epidemiological studies on the possible relationship between dietary fat type and feline disease the fatty acid composition of adipose tissue might be a useful measure.