Lecture 14: Sexual Behavior (cont.)B. Applied Reproductive Behavior of theMale: Semen Collection and ProcessingText: Ch. 10 and 11Animal Science 434Age When Semen Can BeCollectedBull 12 monthsBoar 6 - 8 monthsRam 6 - 9 monthsStallion 20 - 24 monthsDog 8 - 12 monthsEffect of Age on Sperm OutputSperm OutputAge in Months10 20 30 40 50 600BullSemen Collection• Sexual arousal» Sight, sound, smell, touch» Best mount - LiveCollection on a Live MountCollection on a Live MountSemen Collection• Sexual arousal» Sight, sound, smell, touch» Best mount - Live» Alternative mount - dummies• Bull• Stallion• Boar• RamCollection of a Bull on aDummyStallion Collection on aPhantomBoar Collection on a DummyRam Collection on a DummySemen Collection (cont.)• Sexual Preparation» False mounts• In bulls can increase sperm collected by 100%» Novelty• Change mounts, location, other males present» Breed and species differences• Beef bulls less libido than dairy bulls• Arab stallions more libido than Quarter horse stallions• Rams less libido than bulls or male goatsSemen Collection (cont.)• Frequency of collection» As increase frequency/wk• decrease sperm/ejaculate• Increase sperm recovered/wkEffect of Collection Frequency on Sperm OutputItem Dairy Beef Sheep Swine Horses# of collections 1-6 1-6 7-25 2-5 2-6Volume (ml) 5-8 3-6 0.8-1.2 150-300 30-100Concentration(million/ml) 1000-2000 800-1500 2000-3000 200-300 200-400Total sperm/ejac.(billion) 7-15 5-10 1.6-3.6 30-60 5-10Total sperm/wk(billion) 15-40 10-30 25-40 100-150 15-30Motile sperm(%) 50-75 40-75 60-80 50-80 40-75Normal sperm(%) 70-95 65-90 80-95 70-90 70-90ArtificialVaginasWaterWaterCollection coneCollection vialInner LinerCharacteristics of AV• Temperature» Bull, stallion, ram - 45°C• Pressure• Friction» Lubrication essentialElectroejaculation• Useful if male won’t or can’t mount» Get urine often» Poorer quality ejac.• Used in rams and beef bullsMassage Method• Stimulate by rectal massage» Seminal vesicles» Vas deferensSemen Evaluation• Appearance (color)» No debris» No puss» No urine• Volume• Motility• Concentration» Hemocytometer, spectrophotometer• MorphologyPreservation of Semen• Extenders (7 components)» Nutrients• Glucose, fructose» Cold shock prevention• Milk, skim-milk, egg yolk» Buffer• Citrate, Tris» Osmotic pressure• The buffer componentPreservation of Semen (cont.)» Inhibit bacterial growth• antibiotics» Increase volume» Cryoprotectant• glycerolPreservation of Semen (cont.)• Liquid Semen» Collect semen» Semen quality exam» Extend 1:3 (semen:extender)• Minimal extension rate» Cool to 5°C over 2 hours• OK for bull, stallion, ram• Boar - cool to 15°CPreservation of Semen (cont.)» Once cooled, extend semen to final amount• Bovine (inseminate 0.5 ml)– 2 to 5 million sperm/ml• Equine (inseminate 1 billion sperm)– 25 to 50 million sperm/ml– If don’t cool then inseminate 500 million motile sperm• Swine (inseminate 1.5 to 6 billion sperm in 50 ml)– 30 to 120 million sperm/mlPreservation of Semen (cont.)• Frozen semen» Follow instruction for collecting and cooling semen» After cooling to 5°C, extend to 2X the finalconcentration desired• If want final concentration to be 40 million/ml then dilute to80 million to ml at this time» Hold semen for 4 to 6 hours at 5°C• Equilibrates semen to the coldPreservation of Semen (cont.)» Add the cryoprotectant• Mix extender with 2X final cryoprotectant amount, 1:1 withextended semen• Do this in small portions to minimize cryoprotectanttoxicity» Package semen• 0.5 ml French straws• Ampules» Freeze semen• Liquid nitrogen vapor– Static– Mechanically controlled• Dry ice depressions for pellet freezingPreservation of Semen (cont.)• Storage» In a liquid nitrogen tankLiquid NitrogenTankTemperature in Neck of StorageTankLiquid Nitrogen -196°CTemperature of Straws If Low LNConclusions on LN Tank• Maintain LN level as high as possible.• Keep extra tank (narrow neck) with onlynitrogen so semen storage tank can be refilledwhen opened.• Enter semen storage tank only when needed• Do not hold canes above neck of LN tankThawing• Use the procedures recommended by thesemen supplier!!!» 35°C water for 30 - 60 seconds» Ice water for 3 minutes» Pocket thaw• Have thawing container near LN tank whenremoving
View Full Document
Unlocking...