1. Dairy Reproduction Basics
DAIRY LEADERS OF TOMORROW
Lesson 2.6: What is the Reproduction Process in Dairy Cattle?
Slide Show courtesy of Jason Gehrke

2. Events of Reproduction
Puberty- Age at which reproductive organs become functional
Female- Reproduction Process
Estrous cycle- Repetitive cycle occurring when female is not pregnant
Estrus- “Heat” or receptivity to mating
Fertilization- Egg & Sperm unite
Only real male contribution is the sperm
Gestation- Length of pregnancy
Parturition- Act of giving birth

3. Age of Puberty Cattle: 6 to 12 Months Sheep: 5 to 7 Months
Swine: 4 to 8 Months
Horses: 12 to 15 Months
Humans: 9 to 16 YEARS

4. Gestation Length Cattle: 285 Days Sheep: 147 Days Swine: 114 Days
Horses: 336 Days

5. Parturition Names in Species
Cattle: Calving
Sheep: Lambing
Swine: Farrowing
Horses: Foaling

6. Signs of Estrus Swollen Vulva Mucus Discharge Restless Behavior
Female Interest to Male

7. Signs of Estrus Cattle: Visually active mounting
Sheep: Few external signs
Swine: Brace with pressure to back, vocal grunting
Horses: Tease with Stallion and will go nose to nose

8. Estrus Cycle Cattle Sheep Swine Horse 6 to 27 Hours 24 to 36 Hours
Duration of Estrus Cycle
Length of Estrus Cycle
Cattle
Sheep
Swine
Horse
6 to 27 Hours
24 to 36 Hours
48 to 72 Hours
3 to 8 Days
19 to 23 Days
14 to 19 Days
10 to 37 Days

9. Male Transfer of Sperm Two Different Ways Natural Insemination
Male seeks out female in estrus
All controlled by male and female interaction
Artificial Insemination (AI)
Human transfers semen past female cervix and into the uterus
Human is in control of male product and female interaction
No contact between male and female

10. Artificial Insemination (AI) Pros
Conception rate is high
Extends use of superior males
One male can fertilize many females
Reduce incidence of reproductive diseases
Individual straw per female limits passing of disease
Improves record keeping and management
Easily know the sire & date of conception
Can accelerate genetic improvements

11. Artificial Insemination (AI) Cons
Need to know Estrus Cycle of animal
Cost intensive
Animal owner is responsible for the cost of the semen, breeding equipment and arming service

12. Reproductive Hormones
Female
Estrogen- critical for follicle development
Progesterone- sustains pregnancy and inhibits new follicle development
Relaxin- causes ligaments around birth canal to relax
Oxytocin- causes milk letdown
Lutenizing Hormone- Induces ovulation of a mature follicle
Follicle Stimulating Hormone- Promotes development of the follicles

13. Basic AI Process Check for Heat Have all necessary tools
Make sure tools are clean
Clean her exterior surface
Go through the AI process for the species being bred
Assessment, record important information (date, time, who to… etc)

14. AI: Use in Farm Animals Dairy Cattle: Most popular breeding method
Beef Cattle: limited use (herds hard to monitor)
Sheep: limited use (need to use microscope)
Swine: intermediate use
Horses: restricted by breed associations

15. Female Reproductive System
Ovaries
Produce egg
Egg contains ½ of genetic makeup
Oviducts
Site of fertilization
Transport embryos to uterus
Uterus
Site of embryonic development during gestation

16. Female Reproductive System
Cervix
Connects uterus and vagina
Serve as barrier during pregnancy
Vagina
Female organ of copulation at mating
Opening of bladder
Vulva
External opening of reproductive system