AndrologyAndrology ofof thethe BullBull

Spermatogenesis/Spermatogenesis/ Hormones/Hormones/ BreedingBreeding SoundnessSoundness Spermatogenesis:Spermatogenesis:

TheThe processprocess byby whichwhich stemstem cellscells developdevelop intointo maturemature spermatozoa.spermatozoa. ThereThere areare threethree phases:phases: (1)(1) SpermatocytogenesisSpermatocytogenesis (Mitosis)(Mitosis) (2)(2) MeiosisMeiosis (3)(3) SpermiogenesisSpermiogenesis Spermatogonium

1/ SPERMATOCYTOGENESIS

2/ MEIOSIS

Spermatids

3/ SPERMIOGENESIS

Spermatozoa

Epididymal Maturation

Spermatogonium

Mitosis

Primary Spermatocyte

1st Meiosis

Secondary Spermatocyte

2nd Meiosis

Spermatids

Spermatozoa

Epididymal Maturation Spermatogonium

15 Days

Primary Spermatocyte 15 days

Secondary Spermatocyte

1 - 2 Days

Spermatids

15 days

Spermatozoa 21 days

Epididymal Maturation Spermatogonium 4 15 Days

Primary Spermatocyte 15 days 1 Secondary Spermatocyte

1 - 2 Days

Spermatids 2 15 days

Spermatozoa 3 21 days

Epididymal Maturation Sensitivity to Disruption- 1: Most sensitive/ 4: Least sensitive BloodBlood--TestesTestes BarrierBarrier

„ Tight junction between adjacent Sertoli cells. „ Large molecules cannot pass from the blood into the lumen of a seminiferous tubule „ The spermatogonia are in the basal compartment (deep to the level of the tight junctions) „ More mature forms are in the adluminal compartment. „ The function of the blood- testis barrier may be to prevent an auto-immune reaction. LeydigLeydig CellsCells Æ Stimulated by LH ÆÆ SecreteSecrete TESTOSTERONE Æ FSH increases number of LH receptors SertoliSertoli CellsCells Æ Stimulated by FSH Æ “Nurse” cells of the testes ÆÆ SecreteSecrete ESTRADIOL andand INHIBIN Æ -ve Feedback Æ Supports Spermatogenesis ÆForms Blood- Testes Barrier Æ Requires FSH and testosterone Æ Produces Androgen-binding protein (ABP) TestosteroneTestosterone

„ TargetTarget CellsCells Æ Cells of Spermatogenesis Æ Accessory Sex Glands Æ Genitalia Æ Anabolic effect (muscles) „ MaintainMaintain TargetTarget ConcentrationsConcentrations Æ -ve Feedback: Estradiol & inhibin Æ Autoregulation Æ -ve feedback Maintained in Testes: Æ ABP binding testosterone Æ Pampiniform Plexus A- Testicle B- Epididymis (head) C- Epididymis (body) D- Epididymis (tail) E- Ductus deferens F- Mesorchium G- Ampulla H- Vesicular Gland I- Prostate K- Urethra L- Bulbourethral gll M- Bulbospongiosus N- Crus penis O- Ischiocavenosus P- Penis R- Glans Penis S- Retractor penis T- Urinary bladder U- Pelvic symphysis V- Rectum AA-- HeadHead ofof EpididymisEpididymis BB-- BodyBody ofof EpididymisEpididymis CC-- TailTail ofof EpididymisEpididymis DD-- DuctusDuctus DeferensDeferens EE-- EpididymalEpididymal LigamentLigament FF-- MesorchiumMesorchium GG-- TesticularTesticular bursabursa FunctionFunction ofof thethe EpididymisEpididymis

1/1/ ConcentrationConcentration ofof SpermSperm (head(head andand body)body)-- ÆÆ AbsorptionAbsorption ofof excessexcess fluidfluid ÆÆ IncreaseIncrease storagestorage capacitycapacity 2/2/ MaturationMaturation ofof SpermatozoaSpermatozoa ÆÆ ChemicalChemical changeschanges withinwithin spermsperm 3/3/ StorageStorage ofof SpermSperm (tail)(tail) ÆÆ SpermSperm cancan ageage inin epidydimisepidydimis BreedingBreeding SoundnessSoundness ExaminationExamination

1/1/ HistoryHistory

2/2/ PhysicalPhysical examinationexamination ÆÆ GeneralGeneral ExaminationExamination ÆÆ GenitalGenital ExaminationExamination ÆÆ ExternalExternal GenitaliaGenitalia ÆÆ InternalInternal GenitaliaGenitalia 3/3/ SemenSemen EvaluationEvaluation HistoryHistory

„„ AgeAge ofof firstfirst serviceservice „„ DateDate ofof lastlast serviceservice „„ PreviousPrevious ExaminationsExaminations „„ DiseaseDisease && VaccinationVaccination HistoryHistory „„ TransportTransport „„ BreedingBreeding systemsystem-- RatioRatio ofof bullsbulls toto cowscows „„ HerdHerd healthhealth history/history/ ConceptionConception ratesrates GeneralGeneral PhysicalPhysical ExaminationExamination

„ GeneralGeneral ConformationConformation DefectsDefects „ EyesightEyesight „ MasticationMastication problemsproblems „ LocomotoryLocomotory problemsproblems „ HereditaryHereditary DefectsDefects „ BodyBody ConditionCondition ExternalExternal GenitaliaGenitalia „ ScrotumScrotum „ TesticlesTesticles „ SpermaticSpermatic cordcord „ EpididymidesEpididymides „ SheathSheath „ PenisPenis „ ScrotalScrotal CircumferenceCircumference

ScrotalScrotal CircumferenceCircumference InternalInternal genitaliagenitalia

Rectal Examination: „ Prostate Gland (8) „ Seminal vesicles (7) „ Cowper’s Gland (10) „ Ampulla (6) Æ Size Æ Symmetry Æ Width Æ Consistency Æ Pain on palpation „ Inguinal Rings SemenSemen CollectionCollection SemenSemen EvaluationEvaluation

„ EvaluateEvaluate semensemen qualityquality ÆÆ volume,volume, ÆÆ color,color, ÆÆ consistency,consistency, ÆÆ massmass motilitymotility (overall(overall movementmovement observedobserved inin thethe microscopy,microscopy, "waves"),"waves"), ÆÆ individualindividual motilitymotility ofof spermsperm cellscells ÆÆ semensemen morphologymorphology (that(that is:is: normal/abnormalnormal/abnormal lookinglooking cells)cells) NormalNormal ParametersParameters

ParameterParameter NormalNormal ValuesValues „ Ejaculate volume 5 ml (range 1-15 ml) „ Sperm concentration 1200 million/ml (300-2500 million/ml) „ Total sperm per ejaculate Typically 4-5 billion „ Progressive motility Greater than 30% „ Morphology Greater than 70% normal

http://www.vivo.colostate.edu/hbooks/pathphys/reprod/semeneval/bull.html

ColorColor

„ Opacity:- Indication of concentration „ Color--acceptable color ranges from milky to creamy „ (Note: This indicates sperm per cubic millimeter of 500,000 or above. „ Other colors indicating less than 500,000 sperm/cu mm would be opalescent (cloudy) to watery.) Mass/Mass/ IndividualIndividual MotilityMotility

„ Bulls: > 30% progressively motile sperm „ Adversely affected by; Æ heat Æ cold Æ residue on collection equipment Æ wrong pH or osmolality Æ Sexual inactivity Live/Live/ DeadDead StainingStaining Live/Live/ DeadDead StainingStaining MajorMajor defectsdefects

AA--ProximalProximal CytoplasmicCytoplasmic DropletDroplet BB-- PyriformPyriform headsheads CC-- Folded/Folded/ CoiledCoiled TailsTails DD-- MiddleMiddle piecepiece DefectsDefects EE-- MaldevelopedMaldeveloped FF-- CratersCraters

MinorMinor defectsdefects

AA-- DistalDistal cytoplasmiccytoplasmic dropletsdroplets BB-- TaillessTailless normalnormal headsheads CC-- SimpleSimple bend,bend, terminallyterminally coiledcoiled tailtail DD-- narrow,narrow, smallsmall oror giantgiant headsheads EE-- AbaxialAbaxial implantationimplantation FF-- AbnormalAbnormal AcrosomesAcrosomes