Effect of dietary linoleic acid, vitamin E and ethoxyguin on fertility of male chickens

Adult male chickens were fed diets low in linoleic acid, vitamin E and ethoxyquin or high in linoleic acid with or without added vitamin E or ethoxyquin for 25 weeks. Fertilizing capacity and sperm concentration of semen were adversely affected with males fed the high linoleic acid diet without vitamin E or ethoxyquin. The addition of vitamin E or ethoxyquin to the high linoleic acid diet overcame these adverse effects. The low linoleic acid diet without vitamin E and ethoxyquin had no adverse effect on fertilizing capacity and concentration of semen. No differences were evident for males fed any of the diets as far as semen volume, hatchability of fertile eggs, body or testes weights or feed consumption were concerned. During the 26th and 27th weeks increasing the number of sperm inseminated failed to improve fertility of the males fed the diet high in linoleic acid without vitamin E. The results indicate that diets high in linoleic acid but without vitamin E affect fertilizing capac ity as well as the number of sperm produced. Adamstone and Card ( 1) reported testicular degeneration resulting after a vita min E-deficient diet was fed to Rhode Island Red males for a 2-year period. Al though no differences were observed at one year, an adverse effect on fertilizing capacity was noted with a limited number of males after 2 years. More recently Machlin et al. (2) reported adverse effects on fertility as well as egg production of White Leghorn layers fed diets low in vitamin E but containing a high level of linoleic acid. They showed that lowered fertility and egg production were overcome by addition of vitamin E or ethoxyquin to the diet. In the absence of the high level of linoleic acid as well as vitamin E and ethoxyquin no adverse effects on fertility or egg production could be observed during the 6 weeks of their experiment. The relationship of vitamin E to linoleic acid metabolism has been reviewed by Scott (3). Evidence is cited indicating that vitamin E functions as a biological antioxidant that protects against encephalomalacia in chicks by preventing the breakdown of linoleic acid to 12-oxo-cis-9-octadecenoic (keto) acid. Whether or not the same relationship exists with adult poultry has not been established, but the data re ported with layers (2) suggest such a pos sibility. In view of a previous interest in the area of nutrition as related to male fertility (4), the present experiment was undertaken to determine whether linoleic acid would ex ert a detrimental effect on fertilizing ca pacity of adult male chickens fed diets with or without vitamin E or ethoxyquin.