Generally, the supplier of semen is usually a breeder or A.I. facility. We use an area A.I. facility that will collect, analyze, store our own bulls' semen as well as serve as a "destination" point for other shippers to send us their semen. A portable semen tank is about the size of a 5 to 7 gallon container and is usually shipped UPS. A nominal tank rental charge of about $25 is made by the shipper plus an average of about $65 or so for shipping charges, round trip for the tank. Our A.I. facility charges 5 cents per straw per month to store our semen (our own collected units as well as those we have purchased from outside sources). The tanks are "charged" with liquid nitrogen at the facility. Liquid nitrogen is EXTREMELY cold and if I'm correct the temperature is approximately "absolute zero".