Animal Science 434TerminologyTerminology (cont.)Types of CyclicitySlide 5Type of CyclicityPowerPoint PresentationSlide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Causes of AnestrusSlide 16Gestational AnestrusSlide 18Slide 19Slide 20Slide 21Slide 22Seasonal AnestrusSlide 24Silent OvulationLactational AnestrusSuckling Effect on LHSlide 28Slide 29Nutritional AnestrusMenstrual CycleSlide 32Slide 33Variation in Menstrual Cycle LengthMenstural Cycle LengthAnimal Science 434Reproductive Cyclicity in the FemaleTerminology•Estrus is a noun.–The cow is displaying estrus.•Estrous is an adjective.–The length of the estrous cycle is 21 days. •Oestrus and Oestrous–British and European spellings•Estrus and Heat are synonymousTerminology (cont.)•Anestrus –When the female is not having repeated estrous cycles.Types of CyclicityPolyestrusPolyestrusTypes of CyclicitySeasonally PolyestrusSeasonally PolyestrusShort day breeders(Fall)Long day breeders(Spring)Type of CyclicityMonoestrusMonoestrusDog Wolf BearAverage Reproductive CyclesSpecies Length of Length of Ovulation Length ofEstrous Cycle Estrus Pregnancycow 21 days 18 hr 11 hr after 282 days polyestrus end estrusewe 17 days 29 hr near end 148 daysseasonal (fall) estrussow 21 days 48-72 hr 35-45 hr 115 days polyestrus after startestrusmare 21 days 4-8 days 3-6 day of 335 daysseasonal (spring) estrus polyestrus (1-2 days before end ofestrus)Variation in Cycle TypesExample Type of Follicular Ovulation & CL Cycle Development CL Formation FunctionCow, ewe, Long Spontaneous Spontaneous Spontaneoussow, marerats, mice, Short Spontaneous Spontaneous Inducedhamsters (4 days) (prolactin)rabbit, cat, Induced Spontaneous Induced Inducedmink, ferret, (LH surge)otter, alpacaAtresiaCLCAOvulationCLDays Relative to the Gonadotropin Surge012345678-1- 2- 3- 4- 5- 6-7LHFSHPGF2αEstradiolProgesteroneMetestrusDiestrusProestrusDiestrusEstrusAtresiaCLCAOvulationCLDays Relative to the Gonadotropin Surge012345678-1- 2- 3- 4- 5- 6-7LHFSHPGF2αEstradiolProgesteroneMetestrusDiestrusProestrusDiestrusEstrusFollicular PhaseProestrus•follicle enlarges•estrogen increases•vascularity of the female reproductive tract increases•endometrial glands begin to grow•estrogen levels peakEstrus•allows male to mount•estrogen decreases•LH surge occurs •ovulation 24-48 hr after surge of LH•uterine motility high with contractions moving toward oviduct•sperm transport is optimal•cervical mucus volume increasesAtresiaCLCAOvulationCLDays Relative to the Gonadotropin Surge012345678-1- 2- 3- 4- 5- 6-7LHFSHPGF2αEstradiolProgesteroneMetestrusDiestrusProestrusDiestrusEstrusFollicular PhaseAtresiaCLCAOvulationCLDays Relative to the Gonadotropin Surge012345678-1- 2- 3- 4- 5- 6-7LHFSHPGF2αEstradiolProgesteroneMetestrusDiestrusProestrusDiestrusEstrusLuteal PhaseLuteal PhaseMetestrus•estrogen low•ovulation in cow•corpus hemorrhagicum present•uteruscontractions subsideendometrial glands continue to grow and become coiledin cattle bleeding occurs•FSH increasestriggering growth of folliclesAtresiaCLCAOvulationCLDays Relative to the Gonadotropin Surge012345678-1- 2- 3- 4- 5- 6-7LHFSHPGF2αEstradiolProgesteroneMetestrusDiestrusProestrusDiestrusEstrusLuteal PhaseLuteal PhaseDiestrus•progesterone high•FSHIncreases at some point to cause growth of ovulatory follicle•Uterussecrets fluid but volume gradually decreasescontraction stopCL regresses at the end of this period if female is not pregnant due to PGF releaseCharacteristics of Estrous CyclesCharacteristics of Estrous CyclesCow Ewe Sow MareEstrous cycle (days) 21 17 21 21Proestrus (days) 3-4 2-3 3-4 2-3Estrus 12-18 hr 24-36 hr 48-72 hr 4-8 daysMetestrus (days) 3-4 2-3 2-3 2-3Diestrus (days) 10-14 10-12 11-13 10-12Causes of AnestrusPregnancyPresence of OffspringSeasonStressPathologyNutritionGestational AnestrusGestational AnestrusGestational Anestrus•Progesterone during pregnancy–negative feedback•After parturition anestrus continues–progesterone exposure during pregnancy–hypothalamus •Lacks estradiol positive feedback•allows time for uterine involutionSeasonal AnestrusSeasonal AnestrusHorses are long day breeders!Horses are long day breeders!Sheep are short day breeders!EstradiolEstradiolNegativeFeedbackPositiveFeedbackEstradiolEstradiolSeasonal Anestrus•just like entering puberty•silent ovulation++Silent OvulationAnestrusEstrusLactational AnestrusLactational AnestrusSuckling Effect on LHLactational Anestrus•Suckling•Other offspring factors–visual encounter–olfactory encounter–auditory encounter•Prolactin–inhibits GnRH release–major infertility problem in women who are not lactatingNutritional AnestrusMenstrual CycleMenstrual CycleFSHLHLHEstradiolEstradiolProgesteroneProgesteroneFollicleOvulationCorpus LuteumCorpusAlbicans2 4 6 8 10 14 16 18 20 22 24 26 28 212Anterior Pituitary HormonesOvarian HormonesOvaryUterineEndo-metriumRecruitmentSelectionDominanceRecruitmentFSHLHLHEstradiolEstradiolProgesteroneProgesteroneFollicleOvulationCorpus Luteum2 4 6 8 10 14 16 18 20 22 24 26 28 212Anterior Pituitary HormonesOvarian HormonesOvaryUterineEndo-metriumMensesMensesMensesMenses5days5days5 days5 daysFollicular PhaseFollicular Phase9 days9 daysLuteal PhaseLuteal Phase14 days14 daysVariation in Menstrual Cycle Length35-daycycleOvulation14 days14 daysMensesFoll. Phase Luteal PhaseMenses28-daycycleMensesLuteal PhaseMensesFoll. Phase25-daycycleMensesFoll. PhaseMensesLuteal Phase14 days14 days5 days5 days5 days5 days5 days5 days6 days6 days9 days9 days16 days16 days14 days14 daysBreastTendernessBreastTendernessMenstural Cycle Length•AGELength15 - 19 year olds 35 days30 year olds 30 days35 year olds 28 daysVariationMore in teenagersLess in women in peak reproductive
View Full Document
Unlocking...