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