Show UL LT t V FA C tl 0 45 WATCH STANDARDS OF COD LIVER OIL po potency tency for rats does not apply to chickens Dart department ment supplied by th the united states ot of agriculture WN U S service e arvice any source of vitamin D that is to be included in mixed feeds intended for poultry should be purchased on the basis of its guaranteed potency for chickens instead of rats the potency of commercial sources of vitamin D is customarily measured by tests made with rats which do not react to the different sources of this vitamin as do chickens the aman may obtain vitamin D from cod liver oil sardine oil 0 other ther fish liver and fish 0 oils lis and irradiated products in the ca case se of cod liver oil new standards have been adopted and if it Is to be sold as such it must now contain at least 85 international vitamin D units and a at t least GOO international vitamin A un units its per 0 grain any cod liver oil that does doe S not meet these requirements quire ments mus must A be labeled cod liver oil not U S P 11 the designation poultry U S P has been used recently but it Is mis misleading leadin g and its use is not official until some satisfactory chicken unit of vitamin D potency has been established cod liver oil may be purchased on oa the basis of the number of international vitamin D units it contains per gram all other sources of vitamin D should be purchased on the basis of the minimum quantity expressed as per cent of the feed required to protect young growing chicks against rickets rackets although the official method of stating vitamin D potency Is to give the number of international units per gram some carriers of cod liver oil are still marked with the number of units per ounce and often the unit meant Is not the international unit the purchaser should remember that all units of vita vitamins vitamin minD JD potency are not equal and that an ounce is more than as times as heavy as a gram |