Cattle which are not reproductively cycling should not be included in an estrus synchronizing program using prostaglandins. The Upjohn Company has developed a prostaglandin product called Lutalyse. Estrumate, marketed by ICI Pharmaceuticals, is a synthetic prostaglandin. There may be other natural and synthetic prostaglandin products coming on the market in the future. Use of a particular prostaglandin product for estrus synchronization will be dependent upon cost and availability.
Prostaglandins regulate the female reproductive cycle by causing luteolysis.
This is a term meaning destruction or forced regression of the luteal tissue or corpus luteum. The corpus luteum is sometimes referred to as the CL, and is commonly known as the yellow body on the ovary. The CL is a group of cells that persist on the ovary around the empty egg sac after an egg is released during ovulation. About five days after ovulation, the CL begins producing appreciable amounts of progesterone. Progesterone is a hormone which prevents the immediate development of another egg on the ovary, and thus prevents the cow from coming into heat.