Dietary omega-3 fatty acids (fish oils) have limited effects on boar semen stored at 17 °C or cryopreserved.
To evaluate the influence of dietary supplementation of omega-3 polyunsaturated fatty acids (n-3 PUFA) on storage of boar semen, three experiments were conducted: two involved long-term, fresh semen storage (Exp. 1 and Exp. 2), whereas the other involved cryopreservation (Exp. 3). Boars were allocated randomly to three dietary treatments (for 6-7 mo). In addition to a daily allowance of 2.5 kg of a basal diet, they received: 1) 62 g of hydrogenated animal fat (AF); 2) 60 g of menhaden oil (MO), containing 18% docosahexanoic acid (DHA) and 15% eicosapentanoic acid (EPA); or 3) 60 g of tuna oil (TO), containing 33% DHA and 6.5% EPA. In Experiment 1 (n = 26) and Experiment 2 (n = 18), semen was cooled and stored in vitro for several days at 17 °C before assessment, whereas in Experiment 3 (n = 18), viability, motility, acrosomal integrity, susceptibility to peroxidation (LPO), and DNA fragmentation were determined in fresh and frozen-thawed sperm. In Experiment 1, sperm from boars fed TO had better resistance to fresh storage; even after 7 or 9 d of storage at 17 °C, there were more (P = 0.03) motile sperm in boars fed TO (>60%) than in those fed AF or MO. In Experiment 2, fish oil supplementation did not influence any aspect of sperm quality during semen storage (P > 0.10). In Experiment 3, cryopreservation decreased the proportion of motile and viable frozen-thawed sperm as well as acrosomal integrity and increased DNA fragmentation and LPO (P < 0.01) relative to fresh semen, although sperm quality was unaffected by treatments (P > 0.09). In conclusion, although adding fish oil to the diet failed to significantly improve the quality of cryopreserved boar sperm, inconsistent responses of long-term storage of cooled sperm to dietary n-3 PUFA supplementation warrant further investigation.
Castellano
C-A
CA
Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, Lennoxville STN, Sherbrooke, QC, Canada.
Audet
I
I
Bailey
J L
JL
Laforest
J-P
JP
Matte
J J
JJ
D000818:Animals; D015925:Cryopreservation / Q000662:veterinary*; D019587:Dietary Supplements; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology*; D008297:Male; D012662:Semen Preservation / Q000662:veterinary*; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology; D013552:Swine
D015525:Fatty Acids, Omega-3