Researches On Low Temperature (4℃) Preservation Of Boar Semen

Boar spermatozoon, whose structure is very sensitive to temperature change, is more suitable to being stored in liquid status rather than in frozen status. The4℃preservation, as a low temperature storage, which temperature falls in between room temperature and cryopreservation, is not only more convenient and economical than cryopreservation, but also more durable than the room temperature preservation. The objective of this study was to perform a further systematic study and provide the technological support for the porcine artificial insemination.This study involved two parts as followed:1) optimization and screening of the basic semen diluent and pretreatment method of low-temperature preserved semen. Semen samples were collected from healthy adult boars by groved-hand technique and then diluted in six kinds of different diluents before storage under4℃to search for the optimal formula of the basic diluent and the effects of different pretreatments on low temperature preservation under4℃of boar semen with spermatozoa survival effective time, spermatozoa survival overall time and spermatozoa survival index being measured. To evaluate the reproductive performance of the optimal diluent and pretreatment, the conventional artificial inseminations were experimentally performed on sows with low dose of spermatozoa stored under4℃for2-3days. The results showed that a) the diluent6, containing glucose, sucrose, egg yolk, penicillin and gentamycin, demonstrated significantly higher spermatozoa survival effective time (129.60h), spermatozoa survival overall time (235.20h) and spermatozoa survival index (92.57h) than the other five diluents (P<0.05) b) the effect of directly diluting semen with seminal plasma was superior to that of centrifugalizing semen before dilution (P<0.05) c) A1:2or1:3proportion of dilution was significantly more conducive to low temperature preservation (P<0.05)4)83.33%Conventional artificial insemination of pigs sows inseminated with low dosage of low-temperature prerservered semen became pregnant. And all impregnated sows gave birth to piglets (the average litter size10.9, the average number of live born piglets per litter9.9).