Terminology for giving birth – “Parturition”

1. Terminology for giving birth – “Parturition” • Cattle – calve • Sheep – lamb • Swine – farrow • Horses – foal • Dogs – whelp • Cats – queen • Goats – kid

2. Hormones of female reproduction Hormone Source Function estrogen follicle estrus; mating behavior uterine growth, mucus progesterone corpus luteum maintain pregnancy prostaglandin uterus kills corpus luteum FSH pituitary follicle development LH pituitary ovulation formation of CL

3. LH and FSH During the Estrous Cycle LH Progesterone Hormone Concentration FSH 5 10 15 Estrus Estrus Days Relative to Estrus

4. The Estrous Cycle in Cattle LH 2nd 1st Progesterone Wave Wave Hormone Concentration Estradiol FSH 5 10 15 Estrus Estrus Days Relative to Estrus

5. Avian Reproductive Tract See Figure 11-13 Purdue University; Avian Sciences Net

6. Reproduction in Poultry • Female • Right ovary & oviduct fail to develop after hatching • ovulate starting at puberty starting at 20-25 weeks • 24+ hours from one ovulation to next

7. Chicken reproductive tract Oviduct Ovum Ovary (University of Alberta & CBHEMA, 1999)

8. Chicken ovary (University of Alberta & CBHEMA, 1999)

9. Oviduct:infundibulum – 30 min – egg pickup; sperm storage, fertilization magnum - 3 hrs – secretes albumen isthmus – 1.5 hrs – adds shell membranes Uterus – 18-20 hrs – shell formation New yolk is ovulated 30 min after laying egg Purdue University; Avian Sciences Net Fig 11-13 and 11-14 in book

10. Boar reproductive tract

11. Male reproduction • Organs • Gonads – testicles • supported by scrotum (none in poultry) • Temperature regulation in testes • blood vessel system to exchange heat in blood – pampiniform plexus • muscle to raise and lower testes – cremaster muscle • muscles in scrotum contract and expand

12. Ram Reproductive Tract

13. Male reproduction • Organs • Testicles-cont. • Produce gametes; spermatozoa • spermatogenesis – process of production & development of male gametes • occurs in seminiferous tubules • Produce male sex hormones (androgens) • testosterone by interstitial cells

14. Cross – section of testes – Seminiferous Tubules No figure in text

15. Spermatozoa

16. See Fig. 11-6 Bull reproductive tract University of Kentucky; AgriPedia

17. Male reproduction • Organs • Epididymis Concentration, storage, maturation, & transport of spermatozoa • Vas deferens– transport of spermatozoa from epididymis to urethra • Urethra – common excretory duct for urine & semen (not present in birds) • Accessory glands • add fluid volume, nutrients, and buffers to semen • sperm + accessory gland fluid = SEMEN • 3 Accessory glands: 1 prostate gland 2 seminal vesicles 2 bulbourethral (Cowper’s) gland

18. Male reproduction • Organs • Penis– organ of copulation Types include: • fibroelastic – - sigmoid flexure (S-shaped portion) straightens upon erection; allows for extension - bull, ram, boar • vascular – increased blood flow causes engorgement/erection - stallion

19. Bull Reproductive Tract

20. Penis types FIBROELASTIC BULL BOAR RAM STALLION VASCULAR

21. Semen characteristics of male animals

22. Reproductive management tools • Artificial insemination Why is AI used? • maximize genetic improvement • greater access to superior genetics; individual matings • reduce mating costs • control reproductive diseases • use of dead or injured sires • Safety

23. Semen Collection in Males • Electroejaculation • Massage accessory glands • Hand pressure (boars)

24. Reproductive management tools • Artificial insemination Some keys to success are: • detection of estrus • behavioral changes • standing to be mounted; restless • proper timing of insemination • viable sperm available at time of ovulation • breed ~12 hours before ovulation • technician skill • correct placement of semen in reproductive tract • cervix

25. Reproductive management • Artificial insemination Species use of AI Dairy - 70% of all cows Poultry– 95% turkeys; difficult natural mating: chickens use natural mating Swine – >80% Horses– increasing with greater use of extended semen Beef - < 10% of all cows, increasing Sheep – increasing but limited; flocks dispersed

26. AI procedures in females Sheep -surgical or speculum Swine -corkscrew Horses - like cattle See Figure 11-9 in text – much better!

27. Reproductive management • Estrous synchronization – controlling estrous cycle so females express estrus around same time • Reasons to use: 1. with AI - decrease expense of time & labor for detection of estrus 2. for success of embryo transfer • Methods: 1. hormonal – induce ovulation; restart estrous cycle; suppress estrus 2. natural – weaning (sows & beef cattle)

28. Reproductive management • Embryo transfer (ET) – transferring fertilized embryos from one female to another How is ET used? • superovulate and inseminate donor cow • synchronize estrus of recipient females • flush embryos of donor and transfer to recipient or freeze Why is ET used? maximize use of superior genetics (females) - many offspring/female/year

29. Figure 11–7:  Specific cleavage stages at given times after fertilization in the cow (281-day gestation) and the sow (114-day gestation). (Source: Bearden and Fuquay, 1997, p. 91. Used with permission.)

31. Parturition • Initiated by the fetus – stress • Corticosterone from Adrenal • Decreased progesterone • Foals and lambs – like cattle • Piglets – either way • Oxytocin – contractions • Relaxin – birth canal expansion • Estrogen, Prostaglandin

32. Reproductive management • Breeding Soundness Exams • to determine physical ability of an animal to breed • typically males • Evaluates: • Physical attributes • body condition, health, • Reproductive Anatomy • testicle size; organ abnormalities (ie. penis) • Semen Quality • semen color & volume; sperm concentration & abnormalities