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Kommisrud E, Paulenz H, Sehested E, Grevle IS: Influence of boar and semen parameters on motility and acrosome integrity in liquid boar semen stored for five days. Acta vet. scand. 2002, 43, 49-55. -Ninety ejaculates from a total of 76 AI boars were extended in Beltsville Thawing Solution (BTS). Boar identity, breed, weight of the ejaculate and sperm concentration were registered. Motility and acrosome integrity were assessed after storage at 16-18°C for 6, 30, 54, 78, and 102 h. Storage time had a significant influence on both motility (p<0.01) and acrosome integrity (p<0.001). The Least Square Means for percentage of motility showed a small decline from 79.8% after 6 h of storage to 78.4% at 102 h. Motility at 78 and 102 h was significantly different from motility at 6 h (p<0.05). The percentage of sperm cells with normal acrosomes declined throughout the experiment. The Least Square Means for 6, 30, 54, 78, and 102 h of storage were 93.9%, 90.6%, 88.0%, 84.8%, and 78.2%, respectively. The decrease in acrosome integrity from one storage time to the next was highly significant throughout the trial (p<0.001). There was a significant influence of boar (p<0.001) and sperm concentration (p<0.01) on motility, while acrosome integrity was affected only by boar (p<0.001). Breed of the boars and weight of the ejaculate did not influence the dependent variables. longtime storage; sperm concentration.

Summary Pooled ejaculates from six fertile boars were frozen under controlled conditions in Teflon® FEP‐film plastic bags (5 ml) and maxi‐straws (2.5 ml) using 3 % glycerol as cryoprotectant. The percentages of both post‐thaw motility and normal apical ridges were significantly higher (P< 0.001) for the bags (54.5 and 75 %) than for the maxi‐straws (40.1 and 59.4 %) respectively. For evaluation of the in vivo fertilizing capacity of the frozen‐thawed spermatozoa, 26 gilts were inseminated once 24 h after the first observation of standing reflex in their second oestrus, with 5 ml of semen (containing 5 billion spermatozoa) reconstituted in 80 ml of BTS from either bags or maxi‐straws. Ova were recovered from the oviducts/uteri 2–4 days following insemination and examined for cleavage and sperm binding to the zona pellucida (ZP). Significantly higher rates (P < 0.02) of fertilized ova were found in the bag‐inseminated (75%) than in maxi‐straw inseminated gilts (63%); and similarly their ova had significantly more spermatozoa in the ZP, irrespective of whether they were fertilized or non‐fertilized. This study confirmed that the plastic bags are suitable and may be used for packaging single insemination doses of deep frozen boar semen for routine A. I. work.

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Contents The effect of dietary supplementation with cod liver oil (CLO), which is rich in n‐3 polyunsaturated fatty acids (PUFAs), on resistance to cold shock and on freezability of boar semen was investigated. Ejaculates from 29 fertile Norwegian Landrace boars, randomly divided into control (n = 15) and CLO‐group (n = 14), were frozen before and after a 12 week period of daily oil supplementation. Before each freezing, semen samples were taken to determine the fatty acid composition of the spermatozoa. Docosahexaenoic acid (22 : 6n‐3; DHA) was the major fatty acid in total lipids. The n‐3 fatty acid DHA increased in the CLO‐group from 25.5 to 32.1% at the expense of the n‐6 docosapentaenoic acid (22 : 5n‐6), which decreased from 11.3 to 4.2% (p < 0.0001). The concentration of these fatty acids were unchanged in the control group. There was also a significant decrease of other PUFAs in the CLO‐group (p < 0.05). Eicosapentaenoic acid (20 : 5n‐3) was not found in any sample. At four different steps of the preservation process (30, 15, 5°C and after freezing/thawing) both motility and acrosome integrity were assessed. No significant differences were found either within or between the groups at any of the steps. In conclusion, CLO‐supplementation alters the lipid composition of the membranes of boar spermatozoa, however, this does not seem to have any beneficial effect on cold shock and freezability of boar semen.