馬的繁殖障礙
DESCRIPTION
馬的繁殖障礙. 母馬季節發情的調控機制. Photoreceptors in the eyes. increasing day light. decreasing day light. neurotransmission. Pineal. Melatonin. Melatonin. Hypothalamus. portal system. GnRH. GnRH. Anterior pituitary. blood circulation. Gonadotropine. Gonadotropine. Ovaries. - PowerPoint PPT PresentationTRANSCRIPT
母馬季節發情的調控機制
Photoreceptors in the eyes
Pineal
Hypothalamus
Anterior pituitary
Ovaries
increasing increasing day lightday light
decreasing decreasing day lightday light
neurotransmissionneurotransmission
portal systemportal system
blood circulationblood circulation
MelatoninMelatoninMelatoninMelatonin
GnRHGnRHGnRHGnRH
GonadotropineGonadotropineGonadotropineGonadotropine
• 將出生的小馬皆以該年將出生的小馬皆以該年 11 月月 11 日為其通用日為其通用出生日(出生日( universal birthdayuniversal birthday ),因此馬主),因此馬主希望在早春天或冬天時配種,使母馬能在希望在早春天或冬天時配種,使母馬能在春天產下小馬。 春天產下小馬。
• 19701970 年英國統計該年全國馬的懷孕率只有年英國統計該年全國馬的懷孕率只有61.2%61.2% ,到了,到了 19891989 增加到增加到 72.4%72.4% 。可見獸。可見獸醫對馬的繁殖之貢獻。 醫對馬的繁殖之貢獻。
馬繁殖的評估方法馬繁殖的評估方法 • breeding historybreeding history• general health and general health and perineal conformation• bacterial culture swab samples, smear• examination of reproductive tract• endometrial biopsy• ultrasonic or endoscopic examination• hormone analysis• chromosome analysis
Pre-breeding reproductive exam
Objective: evaluate the potential for a mare to become pregnant and carry a foal to term
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X400, 1-2 mild, 3-5 moderate, > 5 severe
X100, > 18 severe endometritis
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Seasonal endometrial atrophySeasonal endometrial atrophy
Normal, active endometriumNormal, active endometrium
Chronic endometritisChronic endometritis
Periglandular fibrosis
endometritisendometritis
Northern semi-sphereNorthern semi-sphere
Subtropical TaiwanSubtropical Taiwan
These mares are not only possible defined seasonal breeders, but
also year-round breeders that could be bred throughout the year in
Taiwan.
Most eukaryotic cells contain two full sets of chromosomes. Characteristic Most eukaryotic cells contain two full sets of chromosomes. Characteristic chromosome number in some common species of organisms are as follows:chromosome number in some common species of organisms are as follows:
As shown above, the diploid chromosome numbers of horse and donkey are 64 As shown above, the diploid chromosome numbers of horse and donkey are 64 and 62, respectively. A mule is the offspring of a mare (female horse) and a and 62, respectively. A mule is the offspring of a mare (female horse) and a jackass (male donkey). The offspring of a male horse (stallion) and a female ass jackass (male donkey). The offspring of a male horse (stallion) and a female ass (jenny donkey) is called a hinny. The chromosome number of a mule is 63.(jenny donkey) is called a hinny. The chromosome number of a mule is 63.
SpeciesSpecies Diploid Chromosome NumberDiploid Chromosome Number
CarpCarp 104104
DogDog 7878
HorseHorse 6464
DonkeyDonkey 6262
CowCow 6060
HumanHuman 4646
MonkeyMonkey 4242
House mouseHouse mouse 4040
AlligatorAlligator 3232
FrogFrog 2626
母馬繁殖障礙之原因母馬繁殖障礙之原因• Non-infectiousNon-infectious
– Structural Structural
Defective vulva
Defective vestibulovaginal constriction
Persistent hymen
Uterine abnormality
Ovarian abnormality
Developmental abnormality
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PneumovaginaPneumovagina
氣膣:陰道黏膜蒼白, Vulva 傾斜 80
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UrovaginaUrovaginaBack
Persistent hymen, failure of the Persistent hymen, failure of the mmüllerian duct to fuse with the üllerian duct to fuse with the urogenital sinus.urogenital sinus.
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hydrosalpinxhydrosalpinx
leiomyosarcomaleiomyosarcoma
endometritisendometritis
子宮頸粘連子宮頸粘連
CerivitisCerivitis To
其他子宮的疾病其他子宮的疾病• 子宮囊腫 • 子宮萎縮或擴張子宮萎縮或擴張
– 子宮黏膜的萎縮或是子宮肌肉收縮無力而使子子宮黏膜的萎縮或是子宮肌肉收縮無力而使子宮蓄積的液體無法排出而引起慢性子宮內膜炎。宮蓄積的液體無法排出而引起慢性子宮內膜炎。
• 子宮黏連子宮黏連
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子宮囊腫子宮囊腫母馬最常見的子宮異常,會影響馬的懷孕。 母馬最常見的子宮異常,會影響馬的懷孕。 • endometrial cystsendometrial cysts
• lymphatic cysts lymphatic cysts – endometrial cystsendometrial cysts 可能會影響授精後的胎囊早可能會影響授精後的胎囊早
期的著床,而較大的期的著床,而較大的 lymphatic cystslymphatic cysts 除了妨礙除了妨礙胚胎早期著床外,對後期胎兒營養的吸收也有胚胎早期著床外,對後期胎兒營養的吸收也有極大的妨礙。極大的妨礙。
endometrial cystsendometrial cysts
endometrial cystsendometrial cysts Back
卵巢的疾病卵巢的疾病• 卵巢腫瘤 • 卵巢血腫• 性腺先天發育不良
卵巢腫瘤卵巢腫瘤• 不常發生,但主要以不常發生,但主要以
granulosa theca cell granulosa theca cell tumortumor (( GTCTGTCT )為)為主,常具有分泌主,常具有分泌hormonehormone 的功能而造的功能而造成行為的改變 。成行為的改變 。
卵巢腫瘤卵巢腫瘤• 有雙側性,也有時單側,有雙側性,也有時單側,
單側時>單側時> 10cm 10cm ,且另,且另一邊縮小而無功能。一邊縮小而無功能。
卵巢腫瘤卵巢腫瘤• 單側腫瘤割除後仍可再繁殖,而大部分單側腫瘤割除後仍可再繁殖,而大部分 GTCTGTCT
為良性且單側性發生。為良性且單側性發生。
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卵巢血腫卵巢血腫• 濾泡不排卵而一直長濾泡不排卵而一直長
大就有可能會充血再大就有可能會充血再慢慢退化 ,甚至到下慢慢退化 ,甚至到下次排卵及黃體形成時次排卵及黃體形成時都還未退化。 都還未退化。
• 臨床症狀正常,週期臨床症狀正常,週期正常,對側卵巢消長正常,對側卵巢消長正常。正常。
• 須與卵巢腫瘤及不排須與卵巢腫瘤及不排卵的大濾泡作區別診卵的大濾泡作區別診斷。 斷。
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卵巢腫瘤卵巢腫瘤
卵巢血腫卵巢血腫
Normal ovaryNormal ovary
性腺先天發育不良性腺先天發育不良an open cervix of a mare with gonadal dysgenesis (63,X)
Chromosomal abnormality (63,X) genital tract
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母馬繁殖障礙之原因母馬繁殖障礙之原因• Non-infectiousNon-infectious
– Functional abnomalitiesFunctional abnomalities
No estrus behaviorNo estrus behavior-Anestrus due to ovarian acyclicity
-Anestrus caused by a prolonged luteal phase
--Behavioral anestrus (silent estrus)
Shorten luteal phase
Irregular or prolonged estrus
Ovulatory dysfunction
Multiple ovulationMultiple ovulation
Gestational failureGestational failure
Anestrus due to ovarian acyclicityAnestrus due to ovarian acyclicity
• Winter anestrus Winter anestrus – 在冬天因短日照而呈發情休止在冬天因短日照而呈發情休止
• Lactation-related anestrusLactation-related anestrus– 分娩後看不見母馬的發情 ,有可能是分娩後看不見母馬的發情 ,有可能是 prolactinprolactin
的抑制腦下垂體分泌的抑制腦下垂體分泌 gonadotrophingonadotrophin 。。• Anestrus Anestrus
– 以以 PRIDPRID 治療 治療
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Anestrus caused by a prolonged luteal Anestrus caused by a prolonged luteal phasephase
• Persistence of luteal activity Persistence of luteal activity – 黃體的滯留黃體的滯留 (( 超過超過 15-1615-16 天天 )) 在馬常發生。而 在馬常發生。而
diestrus ovulationdiestrus ovulation 也會造成黃體期的延長。也會造成黃體期的延長。
new CL mature CLmature CL
• PyometraPyometra– 因子宮黏膜腺體萎縮, 因子宮黏膜腺體萎縮, PGFPGF2α2α 無法製造釋出而無法製造釋出而
造成黃體期的延長。造成黃體期的延長。
• Pseudopregnancy Pseudopregnancy – 胚胎早期死亡。胚胎早期死亡。– 胚胎已死亡,若子宮內膜杯已形成,母馬可能胚胎已死亡,若子宮內膜杯已形成,母馬可能
不發情 。 不發情 。
Anestrus caused by a prolonged luteal Anestrus caused by a prolonged luteal phasephase
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Behavioral anestrus(silent estrus)Behavioral anestrus(silent estrus)
• 6%6% 母馬出現發情症狀相當不明顯 ,有濾母馬出現發情症狀相當不明顯 ,有濾泡發育且有排卵 。常出現於繁殖季節早期泡發育且有排卵 。常出現於繁殖季節早期的女馬或是帶著小馬的母馬。 的女馬或是帶著小馬的母馬。
• 在受訓練的小女馬給予非同化性類固醇也在受訓練的小女馬給予非同化性類固醇也會有些雄性化 。會有些雄性化 。
• 一大群母馬在一起而沒有公馬在附近時 。一大群母馬在一起而沒有公馬在附近時 。• 應增加發情的觀察,或定期以超音波監控應增加發情的觀察,或定期以超音波監控
卵巢週期,以減少人為的疏忽,因為這些卵巢週期,以減少人為的疏忽,因為這些馬的發情期比較短。 馬的發情期比較短。 BackBack
Shorten luteal phaseShorten luteal phase
• 馬在交配時子宮常受到汙染而有短暫的子馬在交配時子宮常受到汙染而有短暫的子宮內膜炎,約宮內膜炎,約 72~9672~96 小時後自癒。但如果小時後自癒。但如果子宮內膜炎延續到第子宮內膜炎延續到第 55 、、 66 天時便會促使天時便會促使子宮提早分泌子宮提早分泌 PGFPGF2α2α 而溶解黃體,使得整而溶解黃體,使得整個週期變短。 個週期變短。
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Irregular or prolonged estrusIrregular or prolonged estrus
• 發情期延長在馬少見,多發生在春天開始發情期延長在馬少見,多發生在春天開始或冬天結束的過渡時期或是卵巢腫瘤。或冬天結束的過渡時期或是卵巢腫瘤。
• 有些是發情行為怪異而被誤判為發情期過有些是發情行為怪異而被誤判為發情期過長。 長。
Irregular or prolonged estrusIrregular or prolonged estrus
• 在季節過渡時期母馬對公馬的反應不一。在季節過渡時期母馬對公馬的反應不一。• 有的濾泡太小而不排卵且退化,有的濾泡存在時間有的濾泡太小而不排卵且退化,有的濾泡存在時間
較長,但其結構仍屬正常。較長,但其結構仍屬正常。Autumn anovulatory follicle
• 診斷:直腸檢查或超音診斷:直腸檢查或超音波檢查可發現>波檢查可發現> 30mm30mm的的 folliclefollicle 。若已有黃。若已有黃體出現,便表示已經開體出現,便表示已經開始有排卵的週期。 始有排卵的週期。
• 治療:因不易配種懷孕,治療:因不易配種懷孕,故以故以 hCGhCG 或者是或者是GnRHGnRH誘導排卵,此誘導排卵,此外配合外配合 1616 小時的光照小時的光照效果較佳。效果較佳。
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Ovulatory dysfunctionOvulatory dysfunction
• Anovulatory haemorrhagic folliclesAnovulatory haemorrhagic follicles– 有時成熟濾泡不排卵而只有形成血體,這種血有時成熟濾泡不排卵而只有形成血體,這種血
體會長期存在而慢慢退化。體會長期存在而慢慢退化。
• Anovulatory follicles in aged maresAnovulatory follicles in aged mares– 通常超過通常超過 2020 歲的老母馬,雖有發情但不排卵。 歲的老母馬,雖有發情但不排卵。
Ovulatory dysfunctionOvulatory dysfunction
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Multiple ovulationMultiple ovulation
• 雙排卵發生機率約雙排卵發生機率約 8~25%8~25% ,且排卵間隔,且排卵間隔可能達可能達 24-7224-72 小時之久。小時之久。
• 容易造成雙胞胎懷孕,容易造成雙胞胎懷孕,流產率高。若未流產流產率高。若未流產則胎兒也容易因發育則胎兒也容易因發育不成熟而死亡。 不成熟而死亡。
• 胚胎死亡則要等子宮胚胎死亡則要等子宮內膜杯退化內膜杯退化 (( 約約 90-90-150150 天天 )) ,母馬假懷孕,母馬假懷孕結束後才又回到動情結束後才又回到動情週期。 週期。
Multiple ovulationMultiple ovulation
• 在配種後在配種後 14~1614~16 天天之間,因胎囊尚在之間,因胎囊尚在游離狀態,可用超游離狀態,可用超音波監控,將較小音波監控,將較小的胎囊擠碎。的胎囊擠碎。
• 配種後配種後 16~3016~30 之間,若兩胎囊在同一子宮角之間,若兩胎囊在同一子宮角不易擠碎,則須考慮注射不易擠碎,則須考慮注射 PGFPGF2α2α中止懷孕。中止懷孕。
• 若超過若超過 37~3837~38 天以上,注射天以上,注射 PGFPGF2α2α 作人工流產。作人工流產。
• 上述方法若無效,則須藉助外科手術或以超上述方法若無效,則須藉助外科手術或以超音波由陰道進行尿囊穿刺術進行人工流產音波由陰道進行尿囊穿刺術進行人工流產。 。
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母馬繁殖障礙之原因 母馬繁殖障礙之原因 • InfectiousInfectious
– Endometritis: bacterial/fungalEndometritis: bacterial/fungal– MetritisMetritis– PyometraPyometra
子宮內膜炎子宮內膜炎• 母馬的子宮內膜炎多是細菌等微生物的感母馬的子宮內膜炎多是細菌等微生物的感染所造成,少數為非感染病原所引起。染所造成,少數為非感染病原所引起。
• 在正常母馬交配完在正常母馬交配完 24~7224~72 小時內所發生的小時內所發生的endometritisendometritis 可自然痊癒,待囊胚在可自然痊癒,待囊胚在 55 天後天後下降至子宮時便不影響囊胚的正常發育。下降至子宮時便不影響囊胚的正常發育。
• 若若 endometritisendometritis 若一直持續到第若一直持續到第 44 天,子宮天,子宮內膜炎就可能分泌內膜炎就可能分泌 PGFPGF2α2α 而溶解黃體,囊而溶解黃體,囊胚自然無法繼續發育下去。 胚自然無法繼續發育下去。
引起引起 endometritisendometritis 的細菌 的細菌 • Contaminants: α-hemolytic Contaminants: α-hemolytic StreptococciStreptococci, ,
Staphylococcus Staphylococcus spp.spp.
• Opportunist: Opportunist: Streptococcus zooepidemicusStreptococcus zooepidemicus (acute endometritis) and (acute endometritis) and E. coliE. coli
• Venereally transmitted: Venereally transmitted: Taylorella Taylorella equigenitalisequigenitalis, , Klebsiella pneumoniaeKlebsiella pneumoniae, , Pseudomonas aeruginosaPseudomonas aeruginosa
子宮內膜炎子宮內膜炎• 子宮防禦機制不佳或是一般老馬和經產馬子宮防禦機制不佳或是一般老馬和經產馬
較容易感染子宮內膜炎。較容易感染子宮內膜炎。• 這些母馬子宮內常會蓄積液體,有可能是這些母馬子宮內常會蓄積液體,有可能是
胚胎的死亡或是黃體期縮短有關,而這些胚胎的死亡或是黃體期縮短有關,而這些蓄積的液體正是細菌滋長的溫床。蓄積的液體正是細菌滋長的溫床。
(polymorphonuclear neutrophils)
子宮內膜炎子宮內膜炎• 病馬無感染症狀而最後成為病馬無感染症狀而最後成為 carriercarrier ,而,而
在交配時會互相傳染,種公再交配時再在交配時會互相傳染,種公再交配時再傳染給其他母馬。傳染給其他母馬。
Sorry! I’m a carrier!
子宮內膜炎的診斷 子宮內膜炎的診斷 • 在在 proestrusproestrus 時先作子宮內釣菌培養及時先作子宮內釣菌培養及
smearsmear 作作 cytologycytology 。 。 neutrophilneutrophil 的存在是的存在是判定子宮內膜炎的依據 。判定子宮內膜炎的依據 。
an acute endometritis associated with Streptococcus infection.
•A positive culture with a negative cytology A positive culture with a negative cytology should be disregarded as a contaminant. should be disregarded as a contaminant.
•A positive culture with a positive cytology A positive culture with a positive cytology should be interpreted as isolation of a should be interpreted as isolation of a pathogen and sensitivity performed. pathogen and sensitivity performed.
•A negative culture and positive cytology A negative culture and positive cytology may indicate noninfectious inflammation or may indicate noninfectious inflammation or a problem with sample handling. a problem with sample handling.
子宮內膜炎的診斷 子宮內膜炎的診斷
子宮內膜炎的診斷 子宮內膜炎的診斷 • The value of uterine cytology is usually The value of uterine cytology is usually
limited to documentation of an active limited to documentation of an active inflammatory response.inflammatory response.
• When a mare presented for examination When a mare presented for examination early during estrus, she can be bred during early during estrus, she can be bred during the same estrus if the uterine cytology the same estrus if the uterine cytology suggests inflammation is not a problem.suggests inflammation is not a problem.
子宮內膜炎的診斷 子宮內膜炎的診斷 • biopsybiopsy 可辨別急性可辨別急性
或慢性的子宮內膜或慢性的子宮內膜炎。炎。
Chronic endometritis with lymphocyte infiltration into lamina propria. This type of inflammation may not be detected with uterine cytology.
Normal, active endometriumNormal, active endometrium
子宮內膜炎的診斷 子宮內膜炎的診斷 • 超音波檢查子宮內液體的蓄積很方便且又超音波檢查子宮內液體的蓄積很方便且又準確。 準確。
其他其他• 黴菌造成的子宮感染黴菌造成的子宮感染
不常見,但以感染不常見,但以感染Candida Candida albicans albicans ,, Aspergillus Aspergillus spp.spp. 為主。為主。
• 除除 EHV-1EHV-1 ,, EHV-4EHV-4及及 EVAEVA 引起母馬的流引起母馬的流產外,產外, EHV-3EHV-3 會經交會經交配或生殖道檢查傳染,配或生殖道檢查傳染,公母馬皆易感染。公母馬皆易感染。
馬媾疫馬媾疫 (dourine)(dourine)
• 馬媾疫由馬錐蟲馬媾疫由馬錐蟲 Trypanosoma equiperdumTrypanosoma equiperdum引起,藉由交配而傳染。 引起,藉由交配而傳染。
• 馬的馬的 CEMCEM 為一高度傳染性為一高度傳染性的性病,只有馬類是自然宿的性病,只有馬類是自然宿主。主。
• 病原病原 Taylorella equigenitalisTaylorella equigenitalis為為 G”G” -”球桿菌。-”球桿菌。
• 在母馬與感染公馬交配後在母馬與感染公馬交配後10-1410-14 天產生急性化膿性子天產生急性化膿性子宮炎,陰道並排出大量的膿宮炎,陰道並排出大量的膿樣黏液。 樣黏液。
Contagious Equine MetritisContagious Equine Metritis
• 母馬第一次感染母馬第一次感染 CEMCEM 後造成暫時性不孕,後造成暫時性不孕,公馬則成為公馬則成為 carriercarrier 。自然感染由交配而傳。自然感染由交配而傳播,或間接由污染的器械而傳染,故播,或間接由污染的器械而傳染,故carriercarrier 往往是急性爆發的來源。往往是急性爆發的來源。
• 由子宮、陰蒂溝(由子宮、陰蒂溝( clitoral fossaclitoral fossa )及陰蒂)及陰蒂竇隙(竇隙( clitoral sinusesclitoral sinuses )釣菌作細菌分離)釣菌作細菌分離培養。培養。
• 本病由本病由 carriercarrier 傳染,因此臨床上以確診帶傳染,因此臨床上以確診帶原者較重要。 原者較重要。
子宮內膜炎的預防子宮內膜炎的預防• 注意配種時的清潔工作。注意配種時的清潔工作。• 減少配種次數。減少配種次數。• 分娩前後的衛生。分娩前後的衛生。• 在配種前可先作外陰部的釣菌培養。懷疑在配種前可先作外陰部的釣菌培養。懷疑
有感染的母馬禁止自然交配,應至少有感染的母馬禁止自然交配,應至少 33 次次(( 每週一次每週一次 )) 的陰蒂及子宮內膜的釣菌培養的陰蒂及子宮內膜的釣菌培養為陰性才可再配種。 為陰性才可再配種。
子宮內膜炎的治療子宮內膜炎的治療• Antibiotic therapy Antibiotic therapy
• Plasma (tropin effects, phagocytosis-Plasma (tropin effects, phagocytosis-promoting action)promoting action)
• Hormone therapyHormone therapy
• Uterine infusion, uterine lavageUterine infusion, uterine lavage
• OxytocinOxytocin
• Opsonins:Opsonins:
– Opsonins are substances that enhance Opsonins are substances that enhance neutrophil phagocytosisneutrophil phagocytosis by reacting with by reacting with invading organisms in a manner to render them invading organisms in a manner to render them more susceptible to engulfment.more susceptible to engulfment.
– Complement and IgGComplement and IgG are considered to be are considered to be more important of presently known opsonins.more important of presently known opsonins.
– Intrauterine plasma infusion (Intrauterine plasma infusion (autologousautologous plasmaplasma 100ml) combined with uterine lavage 100ml) combined with uterine lavage has a good approach to treatment of chronic has a good approach to treatment of chronic infectious endometritisinfectious endometritis
子宮蓄膿子宮蓄膿• 子宮受到細菌或黴菌感染,使子宮內蓄積子宮受到細菌或黴菌感染,使子宮內蓄積
大量炎症滲出液,最常分離到的細菌為大量炎症滲出液,最常分離到的細菌為Streptococcus zooepidemicusStreptococcus zooepidemicus 。。
子宮蓄膿子宮蓄膿
• 出現出現 pyometrapyometra 的母的母馬很少出現明顯的馬很少出現明顯的全身性症狀。全身性症狀。
子宮蓄膿子宮蓄膿• 診斷:根據直腸檢診斷:根據直腸檢查,超音波檢查及查,超音波檢查及子宮分泌物等來作子宮分泌物等來作診斷 。診斷 。
子宮蓄膿的治療子宮蓄膿的治療• 以大量生理鹽水行子宮灌洗。以大量生理鹽水行子宮灌洗。• 若有黃體則先注射若有黃體則先注射 PGFPGF2α2α溶解黃體,並讓溶解黃體,並讓
子宮頸鬆弛。子宮頸鬆弛。• 注射注射 oxytocinoxytocin 。。• 子宮局部治療需給廣效性抗生素。子宮局部治療需給廣效性抗生素。• 配種前必須再檢查子宮內是否有細菌。 配種前必須再檢查子宮內是否有細菌。
Uterine lavageUterine lavage
End
Days of the Estrous Cycle in Mares
• 母馬動情週期約母馬動情週期約 20~2320~23 天,通常發情持續天,通常發情持續 66天,而天,而 diestrusdiestrus 約約 1515 天。排卵通常在發情天。排卵通常在發情的最後的最後 1~21~2 天。天。
The most effective method to induce estrous cycles in The most effective method to induce estrous cycles in anestrous mares is by:anestrous mares is by:
1.1. administering hCG intramuscularly onceadministering hCG intramuscularly once
2.2. administering GnRH intramuscularly onceadministering GnRH intramuscularly once
3.3. administering prostaglandin Fadministering prostaglandin F22αα intramuscularly intramuscularly
onceonce
4.4. exposing the mares to 16 hours of light and 8 exposing the mares to 16 hours of light and 8 hours of darkness about 2 months before the hours of darkness about 2 months before the estrous cycles are scheduled to commenceestrous cycles are scheduled to commence
Which of the following is Which of the following is leastleast likely to affect likely to affect reproductive cyclicity after a mare has entered the reproductive cyclicity after a mare has entered the physiological breeding season?physiological breeding season?
1.1. an artificial lighting programan artificial lighting program
2.2. intravenous injection of hCG on the second or intravenous injection of hCG on the second or third day of estrusthird day of estrus
3.3. intramuscular injection of prostaglandin Fintramuscular injection of prostaglandin F22αα
every 9-11 daysevery 9-11 days
4.4. oral administration of progesterone for 14 -21 oral administration of progesterone for 14 -21 days days
Pseudopregnancy in mares:Pseudopregnancy in mares:
1.1. occurs when the mare retains the CL because of occurs when the mare retains the CL because of early embryonic death. early embryonic death.
2.2. occurs when the CL persists for about the occurs when the CL persists for about the duration of gestation because the mare is not duration of gestation because the mare is not pregnancy.pregnancy.
3.3. occurs when the endometrial cups produce eCG.occurs when the endometrial cups produce eCG.
4.4. does not occur in mares because of the normal does not occur in mares because of the normal luteolytic process in non-pregnant mares. luteolytic process in non-pregnant mares.
Multiple ovulations in mares:Multiple ovulations in mares:
1.1. are extremely rare. are extremely rare.
2.2. occur in about 75% of all mares and are occur in about 75% of all mares and are generally dual ovulations.generally dual ovulations.
3.3. are generally triple ovulations occurring 1 day are generally triple ovulations occurring 1 day apart.apart.
4.4. occur in about 20% of mares and are generally occur in about 20% of mares and are generally dual ovulations. dual ovulations.
Thank you for your attentions!