Fatty acid profiles of ram's sperm after removing some fatty acid sources from the diets and persistency of fatty acids in sperm

Background: Mammalian spermatozoa are characterized by a high proportion of polyunsaturated fatty acids [PUFAs], but reliable data concerning dietary effects on fatty acid [FA] profile in ram's sperm and the persistency of FA in the ration to the FA in sperm has not been reported. Therefore, the aim of this study was to determine the stability of saturated and unsaturated FAs in ram's sperm despite removing FA sources from their diet

Materials and Methods: Nine Kalkoohi rams were used in a completely randomized design and they were assigned to 3 groups. The treatments were diet supplemented [35 g/d/ram] by C16:0 [RP-10[registered]], C18: 2 [Sunflower oil; SO] and n-3 [Fish oil; FO] with Vitamin E. Fifteen weeks after the start of the supplemented diet, rams were offered a basal diet without any supplementary FA source for 35 days when the sperm's FA ratio was determined. The data were analyzed by ANOVA [Analysis of variance] using the General Linear Model [GLM] procedure of SAS Institute

Results: Thirty five days after removing the fat supplement from the diet, major FA in sperm consisted of: C14:0, C16:0, C18:0, C18:1 cis, C18:2 cis and C22:6 n-3 docosahexaenoic acid [DHA]. The percentage of C14:0 [p=0.8] and C18:1 cis [P=0.4] were similar among all the treatments. Interestingly, 35 days after the removal of fatty acid source, the percentage of C22:6 was highest in the FO treated group

Conclusion: The different sperm FA profile among various groups suggests that dietary FA had significant direct or indirect impacts on sperm FA profile after 35 days which might lead to physical and chemical changes in sperm characteristics

Improvement of semen quality in holstein bulls during heat stress by dietary supplementation of omega-3 fatty acids

Long-chain polyunsaturated fatty acids [PUFAs] of the omega-3 family are important for sperm membrane integrity, sperm motility and viability. There are evidences to suggest that dietary supplementation with omega-3 fatty acids affects reproduction in men and males of different animal species. Therefore, the aim of current study was to investigate changes in the quality parameters of Holstein bull semen during heat stress and the effect of feeding a source of omega-3 fatty acids during this period. Samples were obtained from 19 Holstein bulls during the expected time of heat stress in Iran [June to September 2009]. Control group [n=10] were fed a standard concentrate feed while the treatment group [n=9] had this feed top dressed with 100 g of an omega-3 enriched nutriceutical. Semen volume, sperm concentration and total sperm production were evaluated on ejaculates collected after 1, 5, 9 and 12 weeks of supplementation. Moreover, computer-assisted assessment of sperm motility, viability [eosin-nigrosin] and hypo-osmotic swelling test [HOST] were conducted. Heat stress affected sperm quality parameters by weeks five and nine of the study [p<0.05]. Supplementation significantly increased total motility, progressive motility, HOST-positive spermatozoa and average path velocity in the fresh semen of bulls [p<0.05]. Dietary omega-3 supplementation improved in vitro quality and motility parameters of fresh semen in Holstein bulls. However, this effect was not evident in frozen-thawed semen