Standard Operating Procedures for Bull Management (1088.47 KB)

Control plates
Inoculate and incubate two control plates in parallel with the operations by using 0.5 ml of
diluents.
e. Interpretation of results
1. Examination of Control plates
In all cases, carryout an initial examination of the control plates to determine whether
colonies are present within the medium. If colonies are present, discard plates and the plates
containing the test sample and recommence the procedure.
If colonies are not present proceed to an examination of the plates containing the test sample.
2. Counting
After 72 hours of incubation at 37°c the colonies are counted by means of the colony
counting equipment or using the naked eye.
Count only well distinguishable colonies, which have grown within the medium and on the
surface of the medium. Reject any plate in which more than half of the surface is overgrown.
Select for the purpose of counting the dilution, which contains between 30 and 300 colonyforming
units (CFU) per dish.
f. Expression of the results
Record the number of CFU counted. Multiply by the dilution factor. Express the results as
the number of microorganism or CFU per sample or per ml of semen.
g. Method of calculation
N = C X D
Where,
N = Number of Colony forming Unit per ml or per straw
C = Number of Colony Counted
D = Dilution factor
If the Colony Forming Unit has to be expressed per straw we have to divide by 2
If the Colony Forming Unit has to be expressed per ml we have to multiple by 2.
Media
Plate count Agar ( Himedia Lab Cat.No.M091)
Casein Enzymatic Hydrolyzed 5.00 gms/litre
Yeast Extract 2.50
Dextrose 1.00
Agar 15.00
Material Required
1. Hot air oven, Autoclave, Pressure cooker (10ltrs), Incubator up to 70° C.