Plasma lipids and fatty acid composition in parrots in relation to the intake of alpha-linolenic acid from two feed mixtures.

The main objective of this study was to find out whether the content of alpha-linolenic acid (ALA) in plasma cholesteryl-esters (CE) or triglycerides (TG) in parrots might serve as an index of ALA intake. The intake of ALA might be a risk factor for atherosclerosis, but on the basis of the fatty acid composition of seed mixtures the intake is difficult to assess due to selective eating of seeds. Parrots were fed two seed mixtures that differed in ALA content according to a cross over design. The macronutrient composition of the diets supplied differed from that of the diets consumed. The diets consumed had higher levels of dry matter, crude protein, crude fat and energy, and lower levels of crude fibre and crude ash. The ALA content, expressed as g/kg diet, was similar for the diet supplied and that consumed, irrespective of the type of diet. The diets had no systematic effect on plasma lipid concentrations. There were marked differences in plasma cholesterol concentrations between parrot species. When the diet with the low ALA content was fed (0.8% ALA of total fatty acids consumed, 1.1 g ALA/kg of diet consumed), the plasma CE and TG did not contain detectable ALA amounts. When the diet with the high ALA content was fed (4.2% ALA of total fatty acids consumed, 6.1 g ALA/kg of diet consumed), the plasma CE and TG contained about 1% ALA of total fatty acids. It is suggested that the content of ALA in plasma CE and TG might be used as an indicator of ALA intake.

Atherosclerosis in parrots. A review.

Atherosclerosis is a common disease in parrots. The disease is found in all common parrot species, but especially in African Grey parrots and Amazons. It is a disease of older birds that is seen in both males and females. The most common sign is sudden death, but clinical symptoms that can be found include dyspnea, lethargy and nervous signs, such as paresis and collapses. Because the clinical signs are seldomly seen, it is difficult to diagnose atherosclerosis and therefore it is mostly an unexpected finding at necropsy. Age and species are determinants of atherosclerosis in parrots. Suggested risk factors include an elevated plasma cholesterol level, diet composition, social stress and inactivity, but research is needed to confirm this.

[Assessment of commercial feeds for parrots]. / Beoordeling van commerciële papegaaienvoeders.

Twenty-five commercial parrot feeds were analyzed and compared with a guideline as to the nutrient requirements of parrots. There was a large variation in the composition of the different feeds. The protein content differed from 10.4 to 20.6%. A total of 18 feeds had a low protein content and thus is only suitable for adult animals during maintenance. The calcium content varied from 0.08 to 2.21 g/100 g. Seven out of the 13 seed mixtures had a calcium content lower than the requirement. Calcium deficiency can lead to rachitis, osteomalacia, secondary nutritional hyperparathyroidism and hypocalcaemia syndrome in African Grey parrots. With the help of the analyzed composition, the different feeds were judged on their quality. Apart from macronutrients, minerals and trace elements, the fatty acid composition of the feeds was also determined. Atherosclerosis is a common disease in parrots, and an important risk factor is elevated plasma cholesterol. Plasma cholesterol is strongly influenced by fat content and fatty acid composition of the diet. Based on the fatty acid composition, the effect of a diet on plasma cholesterol can be predicted. All feeds had a similar, small effect on plasma cholesterol. However, the feeds differed strongly in their alpha-linolenic acid content (0.03-0.65 g/MJ). According to literature data alpha-linolenic acid could have an anti-atherosclerotic effects.

Severity of atherosclerosis in parrots in relation to the intake of alpha-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.

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.