A simple speedy method to estimate sperm counts for semen dilution under field conditions in chicken (Gallus domesticus) Zelleke Getnet, Moudgal R.P.*, Asefaasmare Department of Animal Sciences, Alemaya University, Ethiopia * Corresponding author: P.O. Box 246, Alemaya University; Ethiopia
Abstract The pooled semen from Rhode Island Red (RIR) cocks were used to estimate the sperm counts quickly under field conditions for diluting the semen before artificial insemination or storage. This method was developed by increasing or decreasing the concentration of spermatozoa with the removal or addition of seminal plasma from the neat semen in graded manner and observing the time taken in releasing fixed volume through a narrow pipette. Similarly, the time taken by seminal plasma was also recorded. The position of the pipette was perpendicular and the temperature ranged 20–22°C (room temperature) throughout the experiment. The concentrations of spermatozoa using standard hemocytometer counts method were estimated in all these groups. Semen flow index (SFI) was determined as per following formula.
Time taken by semen The regression equation was developed using the standard curve: y = 27.05–9.66x; Where y is SFI, 27.05 is a constant (concentration), when the value of concentration is zero, SFI crosses at, and -9.66 is a slope at which SFI and semen concentration meet (change in SFI for each unit change in sperm concentration) and x is semen concentration to be estimated. Further, the relationship between actual numbers of spermatozoa (hemocytometer), estimated by using the equation, time taken in releasing 0.15 ml semen through 0.2 ml pipette and semen flow index was also determined. Besides, this parameter did not differ significantly (P>0.05) when estimated at 20, 30 or 40°C but the values were more at 10°C. A positive and significant (P<0.01) correlation (r= 0.957) between time taken and spermatozoa concentration was detected. The higher the spermatozoa concentration, the more was the time taken by semen to flow. Time taken and SFI were found significant (P<0.01) and negatively correlated (r = -0.956). A negative and significant (P<0.01) correlation between spermatozoa concentration and SFI (r = -0.950) was also observed. The very close association between the spermatozoa estimated through the present method and standard hemocytometer counts procedure provides another alternative to estimate the sperm count at farm level quickly with minimum inputs. Top Key words Sperm count, method, chicken, semen diluter. Top |