Evaluating Semen: Sperm Motility and Morphology Flashcards
Obtaining Semen Sample
Artificial Vagina
Stallion and Trained Bull
Interior compartment is filled with warm water
Provides temperature stimulation and pressure stimulation
Obtaining semen sample
Manual Stimulation
Dog and Boar
Obtaining Semen Sample
Electroejaculation
Bull, Billy / Ram, Wildlife
Semen Motility
Chart
To evaluate semen supplies should be?
All slides, stains, cover slips, and semen should be kept WARM at all times
Sperm Morphology
Sperm Viability
While it is obvious taht a sperm must be viable to fertilize on oocyte, the criteria that define a viable sperm are not clear
Viability stains (eosin or propidium iodine) rely on a permeable plasma membrane to define a non-viable sperm
This measures only a single aspect of viability
Only modest correlations have been reported between this type of a viability measurement and fertility
Abnormal Sperm Morphology
Rather than different insults causing different morphologic abnormalities - it appears that, a number of different insults cause “stress” which result in specific abnormalities to germ cells in specific phases of development/maturation
Inherited Sperm Abnormalities
Knobbed defect
Dag defect
Tail stump defect
Azoospermia / oligospermia
Decapitated defect
Rolled head / nuclear crest / giant head syndrome
Sperm morphology classification systems
Primary abnormalities
believed to arise during spermiogenesis in the seminiferous tubules due to pathological processes in the seminiferous epithelium
Abnormal heads, abnormal midpieces, proximal cytoplasmic droplets
Sperm Morphology Classification Systems
Secondary Abnormalities
Believed to arise after the sperm cells had left the testis such as abnormal epididymal function
Bent tails, coiled tails
Sperm Morphology Classification Systems
Major abnormalities
Those that have been correlated to impaired fertility
Sperm Morphology Classification Systems
Minor Abnormalities
Those that seem to be of minor importance
Sperm Morphology Classification systems
Compensable abnormalities
Those defects taht cause an affected sperm cell to fail to reach and therefore fail to fertilize the ovum - increasing the dose of sperm for A.I. will result in more total normal sperm and improved fertility
Tail problems that preclude forward motility
Sperm Morphology Classification Systems
Uncompensable Abnormalities
These defects taht don’t prevent a sperm cell from reaching and fertilizing the ovum but that prevent noral development of the embryo - increasing the dose of sperm for A.I. will result in the same % of abnormal sperm and hence the same fertility
Fertility Dose-Response Curve
Fertility plateaus at about 5-10 million sperm cells
Bull C has compensable sperm abnormalities
Bull D has non-compensable traits
Distal Midpiece Reflex
Minor - secondary abnormality
Coiled tail
Minor - Secondary abnormality
Detached Head
Minor - Secondary Abnormality
Distal Droplet
Minor - Secondary Abnormalilty
*NOT ABNORMAL
Elongated Head
Major - Primary Abnormalilty
Misshapen head
Major - Primary Abnormality
Proximal Droplet
Major - Primary Abnormality
Pyriform Head and Bent Midpiece
Major - Primary Abnormality
Reversed Tail
Minor - Secondary Abnormality
