ANSC 1401 TTU Final, Animal Science 1401 Final Exam Diagram | Quizlet

Reproductive Efficiency

The number of live offspring born in a given period

5 factors influencing reproductive efficiency

Physiology of animal

Genetic Potential

Nutrition

Season of year

Other environment factors

How does reproductive efficiency affect maintenance?

more offspring means less cost/unit

How does reproductive efficiency affect selection?

more offspring means more genetic improvement

Species differences

management, environment, and goals vary by species

Primary sex organ of the male

Testis

Within the testicle, sperm are produced by the seminiferous tubules

Gamete (sperm) function

Within the testicle, testosterone is produced by the interstitial cells

Endocrine function

Long tube attached to the side of the testicle that functions as an area for sperm maturation and storage

Epididymis

A tube that transports sperm from the epididymis to the urethra.

vas deferens

Reservoir where the vas deferens joins the urethra in animals that ejaculate rapidly. Temporary storage for sperm.

ampulla

Do boars and dogs have ampulla?

No

Rapid ejaculators

Bull, stallion, ram, buck

Its secretions nourish and stimulate activity of sperm. Opens into urethra close to opening of bladder

Prostate gland

Neutralize urine residues and stimulate activity of sperm. Opens into urethra

Vesicular glands (seminal vesicles)

Neutralize urine residues, add volume to ejaculate, and opens into urethra

Bulbourethral glands (cowpers glands)

What do the cowper glands do in boar semen?

Form gel that plugs sow cervix

Are seminal vesicles large in boars?

Yes

Large muscular canal from bladder through penis. Passageway for sperm and urine

Urethra

Organ of copulation and passageway for urine/semen

Penis

Free end of the penis

Glans penis

Spongy tissue that fills with blood making penis erect

Cavernosum tissue

Two types of cavernosum tissue

Fibroelastic, vascular

Cavernosum tissue with sigmoid flexure

fibroelastic

Cavernosum tissue without sigmoid flexure

vascular

Species with fibroelastic cavernosum tissue

bull, boar, ram

Species with vascular cavernosum tissue

stallion, dog

Contains and protects testicles

Scrotum

Regulates temperature of testicles

Cremaster muscle

How many degrees cooler is the testicular temp. from the rest of the body?

4-5*F

"Hidden" testicle in body cavity

Cryptorchid, monorchid

Castrated horse

Gelding

Castrated chicken

Capon

Methods of castration

knife, burdizzo, emasculator, elastrator

Effects of castration

no secondary sex characteristics, slower growth, fatten more quickly, higher meat quality, exhibit fewer behavior problems

secondary sex characteristics in males

physical features, relation to hormone production

Chemical messengers within body that regulate body functions

Hormones

Produced in the hypothalamus of the brain. Stimulates LH and FSH release

Gonadotropin releasing hormone (GnRH)

Produced by the anterior pituitary gland

Gonadotropic

Stimulates development of sperm in the seminiferous tubules

Follicle stimulating hormone FSH

Stimulates secretion of testosterone by Leydig cells of testes

Luteinizing hormone FH

Gonadal. Produced by interstitial cells of testicles. Stimulate growth of reproductive tract, sperm, masculine voice, crest, thick horns, whiskers, libido, social dominance

Testosterone

Primary female sex organ, produces ova and hormones, estrogen and progesterone

Ovary

Mature follicle

Graafian follicle

Follicle ruptures and releases egg

Ovulation

Site formerly occupied by ovum is filled with blood

Corpus hemorrhagicum

If pregnant, corpus hemorrhagicum filled with cells, produces this to secrete progesterone

Corpus luteum (yellow body)

If pregnancy does not occur, regresses to form this

Corpus albicans (white body)

Site of fertilization

Oviducts/fallopian tube

Funnel to pick up ovulated egg

Infundibulum

Site of placental, embryonic, and fetal development. Produces hormone prostaglandin-F2-a

Uterus

Cartilaginous organ that connects uterus to vagina

Cervix

During estrus, the cervix is

moist and open

During pregnancy, the cervix is

sealed

Copulatory organ of female, bladder opening, and birth canal

Vagina

Highly sensitive organ at lower tip of vagina

Clitoris

What does stimulation of the clitoris after AI cause

increased conception rates

External female genitalia

Vulva

Produced in the hypothalamus. Stimulates LH and FSH release

Gonadotropin releasing hormone GnRH

Female pituitary hormones

FSH, LH, prolactin, oxytocin

Produced by anterior pituitary gland. Stimulates growth of follicles on ovary

Follicle stimulating hormone FSH

Produced by anterior pituitary gland. Causes Graffian follicle to rupture and form corpus luteum

Luteinizing hormone LH

Produced by anterior pituitary. Stimulates uterine contractions and milk letdown in mammals

Oxytocin

Gonadal female hormones

estrogen, progesterone, relaxin

Produced from follicle on ovary. Responsible for development of secondary sex characteristics, duct growth in mammary glands, estrus, prepping the uterus for pregnancy, and motility of uterus during estrus

estrogen

Produced by corpus luteum. Prevents ovulation and maintains pregnancy. Completes uterine growth. Increases development of milk production tissues in udder

Progesterone

Produced by ovaries or placenta. Causes relaxation of cartilage and ligaments in pelvis to assist parturition

Relaxin

Animals with diffuse placenta

mare and sow

Animals with cotyledonary placenta

cow and ewe

Transmits nutrients from mother to young, wastes from young to mother, protects from shock, prevents transmission of bacteria and secretion of hormones

placenta

6 advantages in reproduction

AI

superovulation

embryo transfer

estrous synchronization

in vitro fertilization

freezing embryos

Age at puberty (mo.)- Mare

15-24

Age at puberty (mo.)- Cow

10-18

Age at puberty (mo.)- Sow

7-10

Age at puberty (mo.)- Ewe

7-10

Estrous cycle length (mare, cow, sow)

19-21 days

Estrous cycle length (ewe)

15-17 days

Estrus (heat)- mare

96-216 hours

Estrus (heat)- cow

12-24 hours

Estrus (heat)- sow

24-72 hours

Estrus (heat)- ewe

24-36 hours

Gestation- Mare

340 days

Gestation- Cow

283 days

Gestation- Sow

114 days

Gestation- Ewe

148 days

Offspring in sow

8-12

Ovulation time vs. estrus- Mare

24-48 hours end

Ovulation time vs. estrus- Cow

before 12-24 hours end

Ovulation time vs. estrus- Sow

after 35-45 hours beginning

Ovulation time vs. estrus- Ewe

from 24-36 hours from beginning

Advantages of AI

Widespread use of good sires

Greater availability of sires

Overcome incompatibilities

Less danger of males

Reduce reproductive disease

Rapid proof of sire

More uniform crop

Disadvantages of AI

Widespread use of poor sires

Inbreeding

Need trained personnel

Spread of genetic defects

More checking/confinement

Too much use show winner

Potential genetic defects using AI

BLAD, Curly Calf

Semen collection techniques

artificial vagina

mechanical manipulation

electrical stimulation

Microscopic evaluation of semen

Concentration of sperm, motility, and morphology

Extension and freezing of semen benefits

nutrients, buffer, antibacterial agents, glycerol

Sperm diluents

egg yolk (citrate), milk, fruit and vegetable juices, glycerol, antibiotics

Ejaculates from cattle

300-400

Ejaculates from sheep/goats

20-30

Ejaculates from hogs

10-20