ANSC 1401 - TTU (Reproduction)

Reproductive Efficiency

number of live offspring born in a given period

Factors Influencing Reproductive Efficiency

1) physiology of the animal

2) genetic potential

3) nutrition

4) season of the year

5) other environmental factors

Testis

primary sex organ of the male

Gamete (Sperm) Function

within the testicle, sperm are produced by the seminiferous tubules

Endocrine Function

within the testicle testosterone is produced by the interstitial cells

Epididymis

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

Vas Deferens

a tube that transports sperm from the epididymis to the urethra. A portion is removed during a vasectomy

Prostate Gland

its secretions nourish and stimulate activity of sperm. opens into the urethra close to the opening of the bladder

Vesicular Glands

a pair of glands in the male reproductive system that secrete a thick fluid that nourishes sperm and contributes to semen.

Bulbourethral Glands

neutralize urine residues, add volume to the ejaculate, form gel in boar semen that plugs cervix in sow, opens into the urethra

Urethra

large muscular canal extending from the bladder through the full length of the penis serving as a passageway from sperm and urine

Penis

organ of copulation in the male and passageway for urine and semen, the free end of the penis is called the glans penis

Cavernosum Tissues

spongy tissue that fills with blood making he penis ridged and erect in preparation for mating

Types of Penis

1) Fibroblastic - sigmoid flexure - bull, boar, ram

2) Vascular - no sigmoid flexure - stallion dog

Scrotum

contains and protect testicles as well as regulates temperate, testicular temperature is 4-5 degrees F cooler than body temperature

Cryptorchid

"hidden" testicle in body cavity (both, one)

Castration

produces a steer, barrow, wether, gelding, stag or capon

Methods of Castration

knife, burdizzo, emasculator, elastrator

Effects of Castration

no secondary sex characteristics, grow more slowly, fatten more quickly, have higher meat quality, exhibit few behaviors problems, etc.

Hormones

chemical messengers within the body that regulate body functions

Gonadotropin Releasing Hormone (GnRH)

produced in the hypothalamus of the brain, stimulates LH and FSH release

Gonadotropin

produced by the anterior pituitary gland

Follicle Stimulating Hormone (FSH) - Male

stimulates development of sperm in the seminiferous tubules

Luteinizing Hormone (LH) - Male

stimulates secretion of testosterone by Leydig cells of testes

Gonadal - Male

testosterone, produced by the interstitial cells of the testicles, stimulates growth of reproductive tract, perm, masculine voice, crest, thick horns, whiskers, libido, social dominance

Ovary

primary sex organ that produces ova (eggs) and the hormones, estrogen, and progesterone

Follicle

mature follicle is called a Graafian follicle, limit on how many babies a female can have

Ovulation

follicle ruptures and releases eggs

Corpus Hemorrhagicum

site formerly occupied by the ovum is filled with blood

Corpus Luteum

if pregnant, the corpus hemorrhagicum is filled with cells and produces ———— to secrete progestoreon to maintain pregnancy

Corpus Albicans

if pregnancy does not occur, the coupus leteum regresses to form

Oviducts

fallopian tubes, site of fertilization, infundibulum - funnel to pick up ovulated egg, ampulla, isthmus

Uterus

site of placental, embryonic and fetal development, produces the hormone prostaglandin

Cervix

cartilaginous organ that connects uterus to vagina, during estrus the ——- is moist and open, during pregnancy, the ——- is sealed

Vagina

copulatory organ of the female, birth canal, bladder also opens into the vagina

Clitoris

highly sensitive organ at the lower tip of the vagina, homologous to the penis in the male, stimulation of the clitoris after AI may increase conception rate

Vulva

external genitalia, homologous to scrotum of the male

Follicle Stimulating Hormone (FSH) - Female

produced by the anterior pituitary gland, stimulates growth of follicles on ovary

Luteinizing Hormone (LH) - Female

produced by the anterior pituitary gland, causes Graffian follicle to rupture (ovulation) and corpus luteum to form

Prolactin

produced by anterior pituitary, initiates and maintains lactation (milk production)

Oxytocin

produced by the posterior pituitary, stimulates uterine contractions and milk letdown in mammals

Estrogen

produced from follicle on ovary, responsible for development of secondary sex characteristics and general appearance such as finer hair, feminine voices, manners and body contours different from males, duct growth in mammary glands, estrus or heat period when female is receptive to mating, prepares uterus for pregnancy, increases motility of uterus and oviducts during estrus

Progesterone

produced by the corpus leteum, prevents ovulation and maintains pregnancy, completes uterine growth initiated by estrogen and prepares uterus for pregnancy, functions to increase development of milk producing issues in udder

Relaxin

produced by ovaries or placenta, causes relaxation of cartilage and ligaments in pelvis to assist parturition

Fertilization

1) insemination

2) ovulation

3) site

4) transport of gametes

5) effect on reproductive efficiency

Placenta

transmission of nutrients from mother to young, transmission of wants from young to mother, protection from shock, prevention of transmission of bacteria and secretion of hormones

Advances in Reproduction

1) artificial insemination

2) superovulation

3) embryo transfer

4) estrous synchronization

5) in vitro fertilization (test tube babies)

6) freezing embryos