Effect of supplementing the diet of male chickens with oils rich in n-6 polyunsaturated fatty acids on the fatty acid profiles of the testis and liver

Since the n-6 polyunsaturated fatty acid, docosatetraenoic acid (22:4n-6), is a major functional constituent of avian spermatozoa, the effects of two dietary oils rich in fatty acids which are metabolic precursors of 22:4n-6 on the fatty acid profiles of testicular lipids were investigated during a 39 week period of supplementation from 21 to 60 weeks of age. The effects on liver lipids were determined for comparison. Dietary supplementation of male chickens with Arasco Oil, which provides a large amount of arachidonic acid (20:4n-6), increased the proportion of 20:4n-6 in liver phospholipid by almost 2.5-fold. Although liver phospholipid normally contains very little 22:4n-6, this proportion was significantly increased as a result of Arasco feeding, indicating that the conversion of 20:4n-6 to 22:4n-6 was occurring. The phospholipid of the testis contains much higher proportions of 20:4n-6 and particularly of 22:4n-6 than the liver; supplementation with Arasco Oil significantly increased the proportions of both these polyunsaturates in testis phospholipid but the magnitude of this effect was much lower than that which occurred in the liver. Dietary supplementation with Evening Primrose Oil which contains \u3b3 -linolenic acid (18:3n-6) resulted in significant increases in the proportions of 20:4n-6 and 22:4n-6 in liver phospholipid, although the extent of this increase was less than that produced by the Arasco Oil. By contrast, the feeding of Evening Primrose Oil did not alter the fatty acid composition of phospholipid in the testis. The findings raise the possibility that dietary supplementation with Arasco Oil may modulate the fatty acid profile of avian spermatozoa in a way which could potentially be beneficial for fertility. Moreover, the weights of the testes were almost doubled as a result of supplementation with Arasco Oil or Evening Primrose Oil

The preferential mobilisation of C20 and C22 polyunsaturated fatty acids from the adipose tissue of the chick embryo : potential implications regarding the provision of essential fatty acids for neural development

The aim of this study was to determine the relative mobilisation of the different fatty acyl components of the triacylglycerol (TAG) of the chick embryo's adipose tissue in the light of the specific requirements of the developing neural tissues of the embryo for C20-22 polyunsaturated fatty acids. Pieces of adipose tissue, obtained from embryos at various developmental stages, were incubated in vitro in Dulbecco's Medium containing serum albumen. The fatty acid compositions of the initial tissue TAG and of the free fatty acid (FFA) mobilised from the tissue during 1 h of incubation were determined and compared. The composition of the FFA released into the medium under conditions of basal (i.e., unstimulated) lipolysis was markedly different in several respects from that of the TAG from which it originated. The polyunsaturated fatty acids, 20:4n-6, 20:5n-3, 22:5n-3 and 22:6n-3, were consistently found to be preferentially released into the medium, whereas the major fatty acyl constituents of the tissue, 16:0 and 18:1n-9, were selectively retained in the TAG. For example, at day 18 of development, the proportions (% w/w of fatty acids) of 20:5n-3 and 22:6n-3 released into the incubation medium were respectively 6.5 and 7.5 times higher than in the original tissue TAG. Glucagon stimulated the overall rate of mobilisation by approx. 2-fold and also partially suppressed the preferential mobilisation of C20-22 polyunsaturates. These results may be relevant to the elucidation of the means by which essential polyunsaturates are delivered from the yolk to the neural tissues of the embryo, with the implication of a mediatory role for the embryonic adipose tissue in this transfer

Dietary fish and evening primrose oil with vitamin E effects on semen variables in cockerels

1. Our aim was to determine the effect of n-3 (2%, wt/wt, fish oil rich diet) and n-6 (2%, wt/wt, evening primrose oil rich diet) fatty acid dietary supplementation and their combination with two concentrations of vitamin E (40 vs 200 mg/kg) on semen variables and on fatty acid and vitamin E profiles of spermatozoa in broiler breeders at 32, 42 and 52 weeks of age. 2. The inclusion of fish oil in the cockerel diets increased the docosahexaenoic acid proportion in the sperm phospholipid fraction, which was almost threefold higher compared to the other two groups irrespective of vitamin E supplementation. 3. In contrast, an increase in the proportion of total n-6 polyunsaturates, mainly 22:4n-6, was observed in the evening primrose oil group compared to the control only when the dietary content of vitamin E was increased to 200 mg/kg. 4. Sperm concentration was decreased in the fish and evening primrose oil groups if vitamin E was 40 mg/kg, but such an effect was prevented in the fish, not the evening primrose oil group, by increasing the vitamin E to 200 mg. 5. The proportion of motile spermatozoa was improved by the increased supplementation of vitamin E in all oil treatments

The effect of vitamin E, green tea extracts and catechin on the in vitro storage of turkey spermatozoa at room temperature

Turkey semen has to be stored under aerobic conditions. The spermatozoan phospholipid content of avian and mammalian species are characterised by high levels of long-chain polyunsaturated fatty acids. It has been reported that peroxidation of the polyunsaturated lipids in spermatozoa results in loss of motility and membrane integrity and therefore lower fertilising capacity. The effects of lipid- (vitamin E) and water- soluble antioxidants (green tea extracts and catechin) added to a standard diluent were assessed during in vitro storage of turkey spermatozoa at room temperature. Semen was collected from 15 male turkey breeders and pooled. The sperm quality parameters measured were the motility index and the proportion of damaged spermatozoa during in vitro incubation for up to 48 hours. Vitamin E (1000 ppm) significantly lowered the proportion of damaged spermatozoa after 6, 24 and 48 hours of storage at room temperature. The motility index was significantly higher in the vitamin E treatment after 6 hours of storage. Catechin and green tea extracts (100 ppm) significantly increased the proportion of intact spermatozoa after 48 hours of incubation but had no effect on the motility index. The vitamin E treatment resulted in a significantly lower proportion of damaged spermatozoa compared to that of catechin and green tea extract treatments after 48 hours of incubation. Furthermore the fatty acid and phospholipid class profiles of turkey spermatozoa, before and after induced peroxidation, were determined in control and vitamin E supplemented diluents. The proportions of n-6 long chain polyunsaturated fatty acids (PUFA, mainly 20:4 and 22:4), phosphatidyl ethanolamine (PE) and phosphatidyl serine (PS) decreased after 1 hour of incubation in the presence of Fe2+ at 37\ub0C. Vitamin E (200 ppm) prevented the loss of PUFA, PE and PS during induced peroxidation. We suggest that the inclusion of vitamin E into the diluent protects the integrity of spermatozoan membrane lipids during in vitro storage

The effect of dietary supplementation with docosahexaenoic acid on the phospholipid fatty acid composition of avian spermatozoa

This study represents an attempt at the dietary manipulation of the fatty acid composition of chicken spermatozoa in order to enhance the levels of n-3 polyunsaturates at the expense of the n-6 fatty acids, which normally predominate in the lipids of avian semen. Male chickens were provided with either a control diet supplemented with maize oil or the test diet supplemented with fish oil (Tuna Orbital Oil) from 10 weeks of age. Semen samples were collected from the birds after 30 and 48 weeks of supplementation. The fish oil diet induced a significant but limited increase in the proportion of 22:6n-3 in the spermatozoan phospholipid in parallel with an equivalent decrease in the proportions of 20:4n-6 and 22:4n-6. However, since the maximal level of 22:6n-3 in the phospholipid that was achieved by fish oil feeding was less than 10% (wt/wt of fatty acids), these changes fell far short of representing a switch from the typical avian pattern to that more characteristic of the n-3 enriched mammalian semen. Analysis of the fatty acid compositions of the constituent classes of phospholipid in the spermatozoa indicated that, in both dietary states, the phosphatidylethanolamine fraction contained much greater proportions of n-6 and n-3 C20-22 polyunsaturates than the phosphatidylcholine fraction. The results indicate that the typical fatty acid profile of the spermatozoa of domesticated poultry, characterised by the predominance of C20-22 n-6 polyunsaturates, displays a considerable degree of resistance to manipulation by dietary means and does not adopt the 'mammalian' type of profile following supplementation with n-3 fatty acids

The lipid and antioxidant changes in semen of the broiler fowl from 25 to 60 weeks of age

Spermatozoa and seminal plasma from cockerels at the beginning and end of their reproductive periods were examined for their lipid composition and associated antioxidant capacities. The significant reduction in concentration of spermatozoa with age was associated with a large increase in lipid concentrations in spermatozoa and in seminal plasma. This change in lipid concentration was accompanied by increases in the proportions of phospholipid and free cholesterol; in constrast, the proportions of these lipid moieties in seminal plasma were reduced. The major phospholipid fractions in the spermatozoa and seminal plasma were phosphatidyl choline and phosphatidyl ethanolamine. There was a large decrease with age in the proportion of phosphatidyl ethanolamine and a commensurate increase in that of phosphatidyl choline in the spermatozoa and seminal plasma. These major changes in phospholipid content were accompanied by a decrease in the amount of phosphatidyl serine in the spermatozoa and increases in phosphatidyl inositol and cardiolipin in both spermatozoa and seminal plasma. The reductions in the proportions of phosphatidyl ethanolamine were accompanied by considerable reductions in the content of the major polyunsaturated fatty acids 20:4 (n - 6) and 22:4 (n - 6). The changes in lipid composition owing to ageing were associated with a marked reduction within the spermatozoa of the major antioxidant enzyme glutathione peroxidase. The role of these changes in the specific combinations of polyunsaturated lipids and in antioxidant capacity in the reduction in fertility with age are discussed

Effects of dietary supplementation with alpha-linolenic acid on the phospholipid fatty acid composition and quality of spermatozoa in cockerel from 24 to 72 weeks of age

The aim of this study was to investigate the effects of supplementing the diet of the male chicken with \u3b1-linolenic acid (18:3n-3) on the phospholipid fatty acid composition, motility and fertilizing ability of chicken spermatozoa. The birds in the control group received a diet supplemented with soybean oil rich in linoleic acid (18:2n-6) whereas those in the test group were supplemented with linseed oil rich in \u3b1-linolenic acid. A number of age-related changes in the lipid parameters of the spermatozoa were observed in control birds. Between 24 and 72 weeks of age the amount of total lipid in the spermatozoa of control birds increased by approximately 2.4 times and the proportions of cholesterol and free fatty acid also increased significantly, whereas the proportions of phospholipid and triacylglycerol decreased. In addition, the proportion of phosphatidylcholine in the total phospholipid increased, whereas the proportion of phosphatidylserine decreased during the same period. The proportion of docosatetraenoic acid (22:4n-6) in the phospholipid decreased significantly between 24 and 72 weeks of age. The concentration of spermatozoa in the semen of control birds increased to a maximum at week 39 and had decreased significantly by week 72. Supplementation with \u3b1-linolenic acid had little or no effect on the proportion of docosahexaenoic acid (22:6n-3) in the phospholipid profile of the spermatozoa. However, supplementation with \u3b1-linolenic acid did produce a significant but small increase in the proportion of docosapentaenoic acid (22:5n-3) recorded at 39 and 54 weeks. Thus, this study shows that the fatty acid composition of the sperm phospholipid demonstrates a marked resistance to dietary manipulation. Supplementation with \u3b1-linolenic acid significantly enhanced semen fertility at week 39. The results suggest that the small increase in the proportion of n-3 fatty acids in the sperm phospholipids induced by enriching the diet with \u3b1-linolenic acid is associated with a significant improvement in semen quality at 39 weeks of age

Lipid and antioxidant composition of chicken semen and its susceptibility to peroxidation

The antioxidant composition of the chicken seminal plasma and spermatozoa and the effect of sperm storage on fatty acid composition of the phospholipid fraction were investigated. Chicken semen displayed ' range of antioxidants including vitamin E, ascorbic acid, glutathione , superoxide dismutase and glutathione peroxidase. Ascorbic acid was almost equally distributed between seminal plasma and spermatozoa. In contrast, reduced glutathione and vitamin E were located mainly in the spermatozoa. The main form of glutathione peroxidase (GSH-Px) was Se-dependent GSH-Px, which was found in both the seminal plasma and the spermatozoa. On the other hand, superoxide dismutase (SOD) was mainly located (67%) in the spermatozoa. Cu,Zn-SOD was found only in seminal plasma but both forms of the enzyme (Cu,Zn-SOD and Mn-SOD) were found in spermatozoa. The toxic effect of H 2O 2 and cumene hydroperoxide on sperm motility was determined. Sperm incubation for 12 hours at 20\ub0C was associated with a significant decrease in the proportion of 22:4n-6 in the phospholipid fraction. The inclusion of Fe 2+ in the incubation medium at 37\ub0C further increased the rate of lipid peroxidation as indicated by the significant decrease in the proportion of 20:4n-6, 22:4n-6, 22:5n-3 and 22:6n-3 in the phospholipid. Free radical-trapping activity of seminal plasma was measured. Possible mechanisms involved in sperm antioxidant protection are discussed