Animal Science I

1. Animal Science I Livestock Reproduction

2. Reproductive Terms • Parturition • The process of giving birth • Gestation • The time an animal is pregnant • Estrus • The time a female animal is receptive to breeding • Castration • The process of removing a male animal’s testicles

3. Parturition • The signs of approaching parturition can be observed. • Females begin to exhibit nesting behavior • They becomes restless and attempt to separate from the herd or flock.

4. 1st stage • Dilation of cervix and entry of fetus into the cervix • 2nd stage • Completes the birth of an animal through strong uterine contractions • 3rd stage • Expulsion of afterbirth (placenta) from the uterus. • If the placenta is retained in can interfere with future reproduction.

5. Gestation • Length varies from 174 days for a sow to 337 days for a mare • The new animal is known as an embryo while the organs are forming. • After differentiation and until birth the young animal is a fetus.

6. Estrus • Period of heat or estrus are triggered by the hormone estrogen. • Ovulation takes place during estrus for ewe, sow, mare and some companion animals. • The cat only ovulates after mating. • The number of eggs ovulated varies. • Cows and mares typically ovulates one egg. • Dogs, horses, and cats may ovulates several eggs (15 or more)

7. Castration • Makes the male animals easier to handle • Methods: • Elastrator • Stretches a specially made rubber band over the scrotum which will cut off circulation. • Knife or scalpel • With this method bleeding must be stopped and flies controlled • Budizzo clamps • No Bleeding • Clamp crushes and severs the cords and blood vessels going to the testicles.

9. Reproductive System of a Cow

10. Parts of the Female Reproductive System • Ovaries • Two organs located near the end of the reproductive tract inside the body cavity • Produce ova called eggs

11. Oviducts • Two tubes that carry the eggs from the ovaries to the uterus and are also called the fallopian tubes • Carries eggs from ovaries to uterus

12. Oviduct of a Hen • Infundidbulum • Magnum • Isthmus • Uterus • Vagina with egg inside

13. Infundibulum • Funnel shaped end of each oviduct near the ovary • Picks up eggs at ovulation and directs eggs into oviduct

14. Uterus • Also called the womb • Place where the fetus grows

16. Cervix • Neck of uterus • Separates the uterus from the vagina • Serves as a passageway from sperm to travel from the vagina to the uterus and also seals the uterus during pregnancy

17. Vagina • Connects the vulva to the cervix • Receives the male penis and sperm at breeding • Serves as a passageway fro urine to be expelled

18. Vulva • External opening to female reproductive and urinary systems

20. Livestock and Poultry Male Reproductive Parts

21. Scrotum • Saclike part outside livestock • Holds and protects the testicles • Sheath • Protects the penis from injury

22. Testes or testicles • Two oval structures inside the scrotum in livestock and inside the body cavity of poultry on each side of the backbone • Produce sperm and male sex hormones

24. Epididymis • Long coiled tube connected to each testicle • Stores sperm while they mature

25. Vas deferens • Tube that connect the epididymis to urethra • Seminal vesicles • Open to urethra • Prostrate gland • Near the urethra and bladder • Cowper’s gland • Near urethra

26. Penis • Covered by the sheath • Part that penetrates the female at breeding • Deposits semen in female livestock • Papilla serve this function in poultry

27. Accessory male reproductive glands • Produce fluids to protect and carry the sperm • Cowper’s gland • Prostrate gland • Seminal vesicles

29. Testicles are removed by castration to keep males from breeding

31. Papilla is the organ in male poultry’s cloaca wall that puts the sperm in the hen’s reproductive tract.

32. Poultry Reproductive System • The major difference between livestock and poultry reproductive systems is that the embryo of livestock develops inside the female’s body and the poultry embryo develops outside the body.

35. Chickens (domestic birds) have only the left ovary and oviduct functional at maturity. • This is what produces the eggs • The right ovary and oviduct do not function

36. The ovary produces the ova (eggs) and hormones

37. In poultry eggs the yolk is the ovum.

38. The poultry oviduct has five parts • Vagina • Uterus • Isthmus • Magnum • Infundidbulum

40. The vent is the outside opening to the poultry reproductive tract.

41. The uterus and vagina are part of the egg production and egg laying process.

44. Functions of Poultry Reproductive System • Ovary • Produces ova or yolks and hormones • Infundidbulum • The place where fertilization takes place • Magnum • Secretes the thick egg white or albumen • Isthmus • Adds the two shell membrane

45. Uterus • Secretes the thin white, the shell, and the shell pigment • Vagina • Holds the egg until it is laid • Oviduct • Serves several functions because it is made up of several parts • Infundidbulum • Magnum • Isthmus • Uterus • Vagina

46. Cloaca • Egg passes through • Semen is deposited here during breeding • Vent • Place where eggs pass out of the hen’s body • The outside opening • Egg • Function is reproduction but is eaten as food by humans and wild animals • Incubation time for chickens is 21 days • Incubation time for ducks and turkeys is 28 days

47. Types of Breeding Systems • Purebred Breeding • Mating a registered purebred male and female of the same breed • Angus X Angus

49. Crossbreeding • Mating a male and female of different breeds • Angus X Hereford= Crossbred Calf • Crossbred X Purebred= Crossbred • Crossbred X Crossbred= Crossbred