Lecture 14 Equine infertility
- 1. EQUINE INFERTILITY Prof G.N.Purohit Head Department of Veterinary Gynaecology and Obstetrics College of Veterinary and Animal science Bikaner Rajasthan
- 2. Equids belong to order Perissodactyla which includes family Rhinoceridae Tapiridae and Equidae • Equids Domestic Equus caballus Feral E.Prezwalski Extinct Asiatic wild ass African wild ass Zebra Plains, Mountain, Grevys
- 3. NORMAL EQUINE REPRODUCTION • Breeding season Mares in North Hemisph 15 Feb to 1st Week of July Mares in South Hemisph August to December African wild ass All year (Sp Apr and May) Grevys mountain zebra April to September Burchells zebra April - May
- 4. Estrous cycle Mare Av. 21 days cycle length 5-7 days Donkey mares cycle length 5 to 7 days
- 5. Physiological Breeding Season • 21 day inter-ovulatory interval (estrous cycle) – Estrus (heat): 5 – 7 days • Ovulation: 24 to 48 hours prior to end of heat – Diestrus: 14 – 16 days
- 6. Mating Behavior (Estrus signs) • The mare will allow the stallion to smell and bite. • She will – extend her hind legs, – lift her tail to the side and – lower her rump. – The erect clitoris will be exposed frequently by contractions (winking) of the labia. – The vulva will be elongated and swollen, with the labia partly everted. • The mare should be teased by a stallion for accurate detection. – Attempts to fight the stallion indicate she is not in estrus even though some other signs of estrus are apparent.
- 7. • Some peculiarities of reproduction • Seasonality Uterus Cervix Fallopian tubes Embryonic signals and mobility Ovulation & CL Teasing program
- 8. Sperm survival and capacitation 48 h max 6 days • Gestational length Range from 320 to 360 (mean - 340) days eCG from endometrial cups 35-90 days forming accessory CL P4 from CL low from 120-300 days of gestation Placental progesterone 90 day onwards
- 9. Gestational hormones Mammary secretion electrolytes near foaling
- 10. Foaling Night hours Voluntary postponement of labor • First stage 10 min-5 hr (Av 1hr) rupture of corioallantois • Second stage 15-20 minutes birth of fetus. Not beyond 60-70 min. Third stage Falling of placenta(within 3 hrs) Uterine involution
- 11. Normal Equine serum hormone levels HORMONE Normal value Reprod condition Progesterone > 4 ng/mL Pregnancy 7.2 + 1.8 ng/mL Day 9 post ovulation <1 ng/mL Estrus Testosterone 20-30 pg/mL Normal mare > 70 pg/mL Granulosa cell T Estradiol 2.2 + 1.0 pg/mL Day 5 pre estrus 7.1 + 1.6 pg/mL Estrus onset 6.8 + 1.7 pg/mL Ovulation 4.3 + 0.7 pg/mL Mid estrus Estradiol 17-Beta 5 pg/mL Ovulation 25 pg/mL Day 17 post ovulation
- 12. INFERTILITY TEMPORARY LOSS OF FERTILITY REPRODUCTIVE FAILURES I. Shortness of the breeding season ----Long day breeders ----Jan 1 Birth date ----During early season cycles irregular ----Ovulation failures II. Genital infections and abnormalities Genital Infections Infectious Contagious equine metritis CEM Coital vesicular exanthema (Gen.Pox) Trypanosoma Equiperdum (Dourine)
- 13. • Non infectious Endometritis Pnuemovagina Defects of Perineum Vaginitis, Cervicitis etc.. Genital abnormalities Tumors of the genital tract Congenital abnormalities Cysts Chromosomal abnormalities
- 14. Age • Reported to have the most significant bearing on reproductive performance • Decrease in fertility may be in part due to – An increase in transit time for sperm to reach the oviduct • Anovulatory estrus is greater in mares over 20 yrs • Placental development and blood supply are also adversely effected
- 15. III. Irregularities of the estrous cycle • Long periods of estrum • Long diestrus periods • Irregular periods of estrum • Anestrum • Delayed Ovulation • Nymphomania
- 16. Hypothalamic – pituitary – ovarian homeostasis Majority of hormonal deficiencies are associated with: Pituitary abnormalities Can cause: Prolonged estrus Prolonged di-estrus Silent ovulations Can eventually lead to reproductive failure Synthetic Progesterone has proven successful in treatment
- 17. CEM • First reported in England • Caused by Tayllorella equigenitalis a gram negative coccobacillus. • Venereal and other transmission • Infection and discharge from uterus • Infection localisation on clitoris
- 18. Genital POX • Venereal Transmission • Equine Herpes virus which do not cause abortion • Papules on vulva in female and on Glans and prepuce in male • Spontaneous recovery in 10-14 days.
- 19. DOURINE • Trypanosoma equiperdum • Venereal Transmission • Dollar plaques on skin post recovery • Trypanosomes in genital discharges
- 20. ENDOMETRITIS • Mostly arise due to poor vulvar conformation • Poor labial muscle tone • Abnormalities of perineum • Pathological parturition • Unhygeinic breeding • PMIE • Diagnosis: Physical exam- Rectal & Vaginal Uterine Cytology Uterine biopsy Treatment Antibiotics after sensitivity tests Episioplasty & Perineoplasty in anatomical defects VAGINITIS/ CERVICITIS less common, fibrosis of cervix uncommon Cervical Incompetence Cervix fails to seal Donkey mares
- 21. Mating Induced Endometritis • Streptococcus zooepidemicus – Implicated in 75% of acute endometritis – Cause destruction of RBC – Major role in initiating infection of cervix and uterus – May promote proliferation of other bacteria • Hemolytic Escherichia coli – Second most common cause of uterine infection – Can cause acute endometritis but also severe systemic infection
- 22. Genital abnormalities • Granulosa tumor of ovary common in mares and donkey mares • Endometrial cysts in older mares diagnosed by ultrasonography • Ovarian cysts uncommon Ovariectomy recommended • Mucometra seen in older mares occassionally.
- 23. Granulosa (theca) cell Tumors • Most common tumor within the equine ovary • Important cause of anestrous • Normally effect mares between the ages of 5 and 7 – Usually associated with one ovary – Ovaries are usually polycystic or large solid structures – May weigh up to 18 pounds • Symptoms may cause – Prolonged Estrus – Testosterone producing cysts may cause: • Stallion Like Behavior • Muscular development • Removal of ovary may lead to normal reproduction
- 24. Irregularities of estrus cycle • Long periods of estrous cycle 75% of the irregularities specially in thin maideen mares during early season. Cycle length 10-20 days. • Long disetrus periods Infrequent estrus with prolonged periods of diestrum or anestrum. Mares may accept one stallion but refuse another • Irregular periods of estrun Psychological estrum with no ovulation • Silent estrum Common in fatty or lactating mares. Heavy drought mares exhibit silent estrus more commonly.
- 25. ANESTRUM • Physiologic during winter • Pathological Emaciated mares • Gestattional • Psychological • Lactational DELAYED OVULATION Common in shy breeding mares Nymphomania Severe and Mild type
- 26. Management factors affecting equine fertility • Teasing Program Should be done twice daily Lactating mares should be teased separately Begun 30 days prio to season Foaling mares from 3rd day of foaling Rectal palpation Ultrasonography
- 27. Breeding at the optimum time • Breeding at physiologic season • Manipulation Artificial Lighting • Feeding for weight gain during season • Breeding on the basis of rectal palpation/USG • Careful breeding of foaling mares BREEDING PREPARATION Evaluation prior to season Washing genitals prior to service & careful treatment.
- 28. • The above lectures are also explained in video lectures at my YouTube Channel Govind Narayan Purohit • Kindly share the videos and subscribe to my channel if you like them • Thanks