Artificial Insemination, Estrus Sychronization, and Embryo Transfer

A.I.

I. General

	1. History
		A. Early Arabs stole semen from Arabian Stallions
		B. 1780--Spallanzani
			a. Successful AI of Dogs
		C. 1900s--Livestock
		D. Became popular in cattle 60s & 70s
		E. Successful in Cattle, Sheep, Goats, Swine, Horses, 
		   Dogs, Cats, Poultry, Lab Animals, Humans, and Insects.
	2. Advantages
		A. Genetic Improvement
		B. Control of Venereal Diseases
		D. Accurate Breeding Records
		E. Economic
		F. Safety
	3. Disadvantages
		A. Need trained technician
		B. Need to corral and restrain females

II. Semen Collection

	1. Mounting Dummies and Teaser Animals
		A. Swine are easiest to train to mount dummies
		B. Good footing needed
		C. Teasing before mounting increases success
	2. Frequency of Semen collection
		A. Bulls
			a. Twice Daily 2 days/week--Frozen Semen
			b. 3 times a week otherwise
		B. Sheep
			a. Many times a day for several weeks
		C. Boars and Stallions
			a. Every other day
			b. If everyday is required for short period, 
 			   let rest for 2-3 days between intensive 
			   collection
	3. Artificial Vaginas
		A. Bulls, Stallions, & Sheep (sometimes Swine)
		B. Simulates Natural Copulation
			a. Temperature--45 C
			b. Pressure
			c. Lubrication
		C. Timing and Angle are very important
		D. Collector must think safety	
	4. Electroejaculation
		A. Rectal Probe
		B. Increase Voltage in Pulses (1-10 V)
			a. Low Voltage--Accessory Gland Secrestion
			b. Higher Voltage--Ejaculation
		C. Semen Volume Higher
		D. Sperm Concentration Lowere
		E. Doesn't work well in Boars
	5. Massage method
		A. Rectal Massage of vescicular glands and ampullae
		B. Massage of Sigmoid Flexure

III. Insemination

	1. Estrus Detection
		A. Very important
	2. Timing
		A. Sperm need to be in oviduct at ovulation 
		B. Cows--12 hours after first seen in heat
			Ewe--Last half of estrus if Single, or Double AI
			Sows--Late first day or early second day of heat
			Mare--Every second day during estrus
	3. Procedure
		A. Cattle
			a. Rectovaginal technique
			b. Straw inseminating gun or pipet
		B. Sheep
			a. Speculum
			b. Straw inseminating gun or pipet
		C. Swine
			a. Cork screw pipet or "golden pig"
			b. Pipet hooked to bottle
		D. Horse
			a. Vaginal method
			b. Straw inseminating gun or pipet
	4.	Record Keeping
		A. Also very important

Estrus Sychronization

I. Why?

	1. Management tool
		A. Control when animals come into heat, are bred, and 	
		   undergo parturition
			a. Have beef cows calve early in season
			b. Have sows farrow so the pigs reach market weight 
			   at optimal times
			c. Can have dairy cows at end of lactation or 
			   dry during hot summer months
		B. Labor considerations
			a. Intense at known times
			b. Less Heat Detection
		C. Decrease Parturition Interval if combined with Culling
	2. Methods
		A. Cattle
			a. Prostaglandin (Lutylase, Estrumate)
				--one injection
				--two injection
			b. Progesterone/Estrogen (Sychromate B)
				--Implant of Norgestomet 
				  (synthetic progesterone)
				--I.M. injection of Norgestomet/Estradiol 
					Valerate
				--Not FDA approved for Dairy Cattle
			c. Other combination sex steroid/prostaglandins 
				also used
		B. Sheep
			a. Progesterone/PMSG
			b. Prostaglandin
		C. Swine
			a. Progesterone
		D. Horse
			a. Progesterone
			b. Prostaglandin
			c. Prostaglandin/hCG

Embryo Transfer (ET)

I.	General Information

	1.	An embryo in early development (morula/early blastocyst) 
		is transferred from a donor animal to a recipient animal

	2.	First accomplished in 1890

	3.	Successful in sheep, goats, swine, cattle, 
		and horses

	Advantages

		a.	Can increase offspring from genetically 
			superior females
		b.	Obtain offspring from animals that can't carry 
			pregnancies to term

	Disadvantages

		a.	Costly
		b.	Need Trained Technician
		c.	Need to corral and restrain females



II.	Steps involved in E.T.

	1.	Estrus Synchronization of Donor 
		and Recipients

	2.	Superovulation of Donor
		A.	PMSG
		B.	Not possible in horses

	3.	Artificial Insemination of Donor

	4.	Embryo Collection of Donor
		A.	Usually non-surgical

	5.	Microscopic Examination of Embryos
		A.	Select healthy embryos
		B.	Extra Embryos can be frozen

	6.	Transfer of Embryo to Recipient
		A.	Surgical
		B.	Non-surgical