Investigation into the Use of Local Semen Extenders for Artificial Insemination in Large White Pigs in Nigeria
Abstract
This study presents the results of investigations on the effects of storage and the use of local semen extenders for artificial insemination in Large White pigs in South-Eastern Nigeria. The experiment was conducted with twenty-five adult healthy Large White pigs consisting of five boars and twenty dry sows, their ages ranging from 2-2.5 years. The sows were artificially inseminated with either extended semen (A) serving as control, or semen extended in egg yolk (B), coconut water (C) or fresh raphia palm wine (D) and stored at refrigeration temperature (4-50C) for several days (D0, D1, D2 and D3). One gestation period of 4 months was allowed for each experimental sow. The experiment lasted for 15 months involving 62 inseminations with a total of 54 piglets farrowed.
The study investigated the effects which A, B, C, or D and D0, D1, D2 or D3 have on: (1) Semen quality (sperm motility, percentage live spermatozoa, sperm concentration per ml. percentage abnormal sperm and semen pH and (ii) fertility results (nonreturn rate, farrowing rate and litter size).
In general, the local extenders produced significant effects in semen characteristics. Semen extended in coconut water had the highest values in sperm motility (64.5%) than semen samples with egg yolk (63.70%), fresh raphia palmwine (60.30%) and unextended control semen (45.50%). Egg yolk extended semen ranked second in importance in maintaining optimum sperm motility. Highly significant differences (P<0.01) existed between the length of storage in sperm motility sperm motility of Day 0 (D0) semen samples was often superior to those at other (D1, D2, and D3) storage intervals. Percentage live spermatozoa was significantly (P<0.0) influenced by the type of local extenders used. Semen extended in coconut water gave the highest (P.0.05) live sperm cells. Significant differences (P<0.05) were observed between the local semen extenders in sperm concentration, with semen sample B producing the highest values (277..30 x 106). The duration of storage significantly (P<0.05) affected the sperm concentration per ml. the highest values were recorded at D0, with D3 constantly yielding the lowest concentration of sperm. No significant differences (P.0.05) existed between local extenders in abnormal sperm cells.
However, the duration of storage significantly (P < 0.01) affected the percentage abnormal spermatozoa. Local semen extenders significantly (P<0.01) elevated the semen pH, with the egg yolk extended semen producing the highest pH (7.9) No significant differences were found between length of storage in pH of semen.
The use of local extenders significantly (P<0.05) influenced the nonreturn rate. Semen extended in egg yolk (B) gave the lowest non return with the highest number of sows pregnant. Length of semen storage produced significant (P.0.05) effects on the nonreturn rate of sows. Semen storage up to Day 3 (D3) gave the highest nonreturn rate with the lowest number of sows conceiving. Farrowing rate was significantly (P<0.05) affected by the type of local extenders used. Sows inseminated with semen extended in egg yolk had the highest farrowing rate. Coconut water ranked second in farrowing rate. Duration of storage did not affect the farrowing rate. Litter size was significantly (P<0.05) affected by the local extenders. Sows inseminated with semen storage produced significant differences (P<0.05) in litter size. The first day of semen storage (D0) gave the highest number of piglets farrowed per litter.
This study recommends that coconut water appear to be most suitable for use in extending boar semen. Egg yolk came a very close second. In order to achieve optimum fertility, the extended semen should be used on the first day of collection; and at best should not be stored for more than two days.