Lecture 10: Sire Fertility Flashcards
Sir Attributes
required for high fertility
- physical soundness
- quality semen
- serving capacity
- P= G+E + GE
Breeding Soundness Exam
assess sire’s ability to fertilize
- history: general supporting information
- general exam: overall physical soundness
- Repro exam: physical examination of repro
- semen exam: production of viable sperm
- mating eval. libido, mating ability
want progressive motility of about 70%
want morphological normal sperm about 80%
Body Composition Score
consider - bone visibility - body outline - ideally 2.5-3.5 BCS will decline over breeding season
Seasonal Influence
trends: season influences sperm quality, BSE - temp, sensitive season influence is delayed - impacts sperm development
Age influence
trend - appears somewhat consistent over time Effects in BSE and Semen Trends: - increase after sexual maturation - decrease with advantage age
Scrotum size influence
quality increases with scrotum size
- not just quantity
- testosterone increases with scrotum size
BSE conclusions
multiple factors influence fertility limitations - fertility is non-binary - cant identify sublte issues - innate variability
benefits
- identify subfertile sires
- improve reproductive efficiency
Artificial Insemination
distribute semen from high-quality sires the dose must be: - properly handled and transported - high quality, fertile semen - form high genetic value sire
Semen Storage
to protect and transport
standards vary with species
- freezing is most common
- boar doesn’t freeze well
extenders
- cryoprotectant
- provide nutrients
Genetic Value
varies by location factors; - aesthetic preference - cultural norms - industrial standards
Fertility Measurements
non return rate (NRR): from breedings without subsequent doses, easy to collect, skewed by external factors
Sire conception rate: from breedings with vet confirmed conception, harder to collect, normalized for external factors
Fertility Factors
several traits influence sperm fertility
- morphology
- motility
- concentration
- chromatin integrity
- plasma membrane integrity
- acrosome integrity
- mitochondrial potential
Sperm Assessment
visual metrics
makler sperm chamber
- manual , time intensive
- cost-efficient
CASA
- automated, efficient
- expensive software
Fixing Fertility
high concentration linked to high fertility
compensable triats; increase concentration improve fertility
incompressible traits: increase concentration has no effect on fertility
Sperm Quality
effect on embryo development
average sperm- more high quality embryos
below average sperm- fewer high quality embryos
