| With the extensive application of boar artificial insemination, the preservation of semenhas been taken into account these days. As the normal temperature is more suitable for thesurvival of sperm and its simple operation, the normal temperature storage is moreappropriate for production in the farms. Therefore the normal temperature storage of semen isusually used in the artificial insemination. Part of the extender(powder) used in China at thisstage is prepared by the farms on their own, most of which has the defects of a short timestorage and poor insemination effect and causes much inconvenience to the production andprimary breed improvement station.To investigate the effect of different semen storage liquid at normal temperature andensure the reasonable and efficient use of breeding boar semen, we chose three kinds ofcommon used boar semen storage extender at normal temperature and analyze the spermmotility, the effective survival time, the survival index, pH, total anti-oxidative capacity(T-AOC), the malondialdehyde (MDA) and etc. We obtained the effects of different roomtemperature storage extender on the sperm motility, survival index, and total anti-oxidativecapacity (T-AOC) of boar semen as follows:1. During the preservation of the Large White semen, the No.3extender was the bestamong the extenders tested. Its sperm motility maintained at0.54after5days storage. Theeffective storage time and the survival index were5.5and2.83, respectively, which were bothhigher than those of No.1and No.2.While the No.2extender was better for the storage ofLandrace semen and its sperm motility was significantly higher than that of the No.3extenderafter stored for3d,4d and5d (P <0.05). None of the three extenders had remarkable influenceon the preservation of Duroc semen (P>0.05). It can be inferred that the preservation ofsemen related to not only the formulation of the extender, but also the characteristics of thesemen itself. But the concrete influential factors needed to be further studied.2. The suitable pH could provide a good living environment for sperm during the storageof semen. The following results showed that the pH changes of semen were affected by thepH of extender. The pH value of No.3extender was significantly higher than that of No.2on the4thday (P<0.05) but of no significance than that of No.1(P>0.05). And it was remarkablyhigher than the other two extenders on the5thday (P<0.05) during the preservation of theYorkshire boar semen. And the pH value of No.2extender was dramatically higher than thoseof No.1and No.3extenders on the4thand5thday during the preservation of Landrace boarsemen (P<0.05). At the same time, the pH value of No.2extender was of significance thanthat of No.1on the5thday of the preservation of Duroc boar semen (P>0.05). So the pHvalue changes of the No.3extender was greater than No.1and2with the extension of timeduring the preservation of the Large White semen as well as the No.2extender during thepreservation of the Landrace semen and the Duroc boar semen. Original semen, extender andthe diluting semen are all weakly-alkaline and the pH of extender first decreased, thenincreased with the time change, but finally stabilized. It indicated that weakly-alkalineextenders were more in line with the sperm living conditions. The pH value of semen could bestabilized by the extenders which were added with proper buffer.3. ROS production of semen dilution preservation process can destroy the structure andfunction of sperm, affecting semen preservation. The CAT and T-AOC of sperm decreasedwith the extension of time, but the MDA increased. It implied that the antioxidant capacity ofsperm was strong and the level of oxidative damage was low in the initial storage. And thenthe sperm redox system balance was broken which resulted in the destruction of the structureof sperm, decrease or loss of activity of antioxidant enzymes, intension of oxidation anddestroy of sperm. Beacause of which the content of CAT and T-AOC gradually reduced andthe content of MDA rose on the contrary. |
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