Dairy Breeds
- Ayrshire
- Brown Swiss
- Busa
- Canadienne
- Dairy Shorthorn
- Dutch Belted
- Estonian Red
- Fleckvieh
- Friesian
- Girolando
For more breeds go to http://www.thedairysite.com/breeds/dairy/
Reproductive Systems
This will be all about the reproductive system of cattle. You will learn about the male and female reproductive systems along with gestation, estrus, parturiton and hormones involved with the reproductive systems.
Female Reproductive System
Ovaries
-Primary Follicle
- Secondary Follicle
- Tertiary Follicle
- Dominant Follicle
Infundibulum
Fallopian Tube
Uterus
Cervix
- Fertilization
- Gestation
- Parturition
Vagina
- Female organ of copulation at mating.
- Birth canal during parturition
- Serves as an exit passage for urine
- There are 2 ovaries that produce ova (eggs) and the female sex hormones estrogen and progesterone.
- Ovaries are held in place by ligaments.
- Follicles (precursors) to ova develop in the ovary in "waves".
-Primary Follicle
- Secondary Follicle
- Tertiary Follicle
- Dominant Follicle
- The dominant follicle than matures into a Graffian follicle.
- The Graffian follicle then ruptures to release the ova
- the area whee the rupture occurred leaves a "scar".
- This "scar" is called the Corpus Luteum.
Infundibulum
- This plays the role of a big catchers mit. This organ "directs" the ova into the oviduct.
- An ova is about 1/200 inch in diameter. The infundibulum sends the ova into the oviduct or Fallopian tube.
- this is the site of fertilization.
Fallopian Tube
- Is lined with cilia and also involuntary smooth muscle in the "wall" of the tubule.
- The purpose of these muscles and cilia is to propel the egg toward the urteus.
- After leaving the oviduct the egg travels into the uterus.
Uterus
- The uterus is a single body with multiple functions, the most important being the site of implantation and development of the embryo.
- Pregnancies typically develop in one of the uterine horns.
- Attachment between fetus and uterus is made at the level of the caruncle (maternal/uterus) and the cotyldon (fetus/placenta).
- At the posterior end of the uterus is the cervix.
Cervix
- The cervix is a "gate keeper" for the uterus.
- It has functions in:
- Fertilization
- Gestation
- Parturition
- During gestation mucous hardens and forms basically a non-penetrable seal between the uterus and vagina
Vagina
- Has 3 functions:
- Female organ of copulation at mating.
- Birth canal during parturition
- Serves as an exit passage for urine
- The vagina is lined with mucosal cells. under the influence of different hormones these cells change the atmosphere of the vagina according to time of estrous cycle.
- During the rest of the cycle the vagina tends to be sticky or dry.
Male Reproductive system
Testicles
- Sperm cells
- Hormone Testosterone
Epididymis
- Responsible for production of:
- Sperm cells
- Hormone Testosterone
- A sperm cell unites with thee ovum to make the fertilized embryo.
- The hormone testosterone is responsible for the secondary sex characteristics of the male.
- Sperm cells are produced in the seminiferous tubules in the testicles
- Testosterone is produced by leydig (AKA: Interstitial cells).
Epididymis
- Sperm cells "mature" in the epididymis
- Think of the epididymis as a long storage tube for sperm.
- sperm taken directly from the seminiferous tubules does not have the ability to fertilize an ovum.
- However, sperm taken from the epididymis is capable of fertilization.
Scrotum
Vas Deferense
Ampulla
Sperm = Sperm cells
Semen = Sperm cells plus "other fluids"
"other fluids add additional volume and provides nutrition for the sperm
- A two lobed sack that contains the testicles.
- Primary function is controlling the temperature of the testicles.
- for spermatogenesis to be effective and optimal the testicles need to be at a slightly lower temp. than the testicles.
- One muscle associated with the scrotum is called the tunica dartose, which assists with temperature regulation.
Vas Deferense
- Responsible for delivering sperm from the epididymis to the urethra.
- Very near the junction of the urethra and the bladder, each vas deferens joins the urethra.
- The urethra is responsible for final delivery of the sperm.
Ampulla
- Bulls, Stallions, and Rams have an enlargement in the vas deferens called the ampulla.
- the ampulla is a "holding area" for sperm cells that are ready to ejaculate.
- Boars don't have ampulla's.
Sperm = Sperm cells
Semen = Sperm cells plus "other fluids"
"other fluids add additional volume and provides nutrition for the sperm
More Reproduction System Information
Estrus/Estrous
Estrus = "Heat"
Estrous = "Cycle"
Estrous = "Cycle"
Gestation- Period from fertilization until the time of birth.
Parturition
3 Phases
Dystocia
Embryo Transfer
Reproductive Hormones
For more information about theses hormones and more go to https://en.wikivet.net/Reproductive_Hormones_Overview_-_Anatomy_&_Physiology
- Starts with the softening and dilation of the cervix and the start of uterine contractions. This stage lasts from about 2 to 6 hrs in cattle.
- Ends with the expulsion of the fetus. In all farm species this stage takes less time than stage 1. Cows typically spend 2 hours in stage 2.
- Expulsion of the placenta. In cattle it can require as little as 30 minutes but typically requires 3 to 5 hours.
Dystocia
- Prolonged or difficult birth. In farm animals experiencing dystocia, human assistance is often required to prevent loss of pregnancy or loss of dam.
- Common occurance in cattle twins.
- Major source of calf death.
- Causes retained placenta.
- Most common in cattle at the age of 2 yrs and more often if the heifers were bred at a very light weight.
Embryo Transfer
- Removal of an embryo from the mother and placing the embryo into a recipient female.
- The single variable that makes embryo transfer a viable management tool is superovulation.
- In cattle, the average response in 5-12 transferable embryos per superovulation treatment.
- Early embryo transfer was done surgically, now an instrument called the Foley Catheter has made embryo transfer non-invasive and a very efficient procedure.
Reproductive Hormones
- GnRH- Gonadotropin Releasing Hormone
- LH- Luteinizing Hormone
- FH- Follicle Stimulating Hormone
- Prolactin
- Oxytocin
- Estrogen
- Progesterone Random Fun Facts
- Testosterone -Approximately 5% of cattle births have some type of abnormal presentation
- Prostaglandin F2 alpha - At first the fetus is in an abnormal position but turns its self around for a normal exit.
- Pacental Lactogen
- Relaxin
- Cortisol
- Melatonin
For more information about theses hormones and more go to https://en.wikivet.net/Reproductive_Hormones_Overview_-_Anatomy_&_Physiology
Copyright 2015 Animal Management. Last updated July 31, 2015