PROCESSING ANIMAL FEED 239 



fairly large volumes on their own ranch. Storage temperatures of 0°F 

 or lower are preferable. 



Special Handling. Mink are very delicate animals and are particular 

 about their diet. Mink ranchers insist on having a very high quality feed. 

 This means a feed must be fresh as w^ell as nutritious. It has been found 

 that mink must have a diet that is not excessively high in oil content 

 or the mink may develop what is known as ''yellow fat disease." An oil 

 content of approximately five to eight per cent is preferred. 



Certain feeds cause ''cotton-fur" which is undesirable as it produces a 

 low quality pelt. Feeds prepared entirely from certain species of fish pro- 

 duce Chastek paralysis (caused by thiamine destruction from the presence 

 of the enzyme thiaminase in the fish) so thiamine must be added if these 

 species are fed in high quantity. 



Bacterial spoilage must be avoided in any mink feed. Mink ranchers 

 are particularly cognizant of botulism as severe losses of mink have re- 

 sulted from using contaminated feeds. 



Frozen Whale Meat. A considerable quantity of whale meat is frozen 

 for use as mink feed. Approximately 150 whales are taken each year off 

 the Pacific Coast. These whales are processed in two plants located in 

 California. 



The whale is towed to the processing plant where it is cut up to re- 

 move the various sections. Meat from the loins, shoulders, ribs, and 

 vertebrae are combined to produce a ground mink feed. The meat is 

 cooled, ground, and bagged. It is then frozen in a conventional manner. 



Frozen Zoo Animal Feed. Most zoos feed fish to certain species of ani- 

 mals and birds. Usually, because of the expense, the species of fish avail- 

 able at the lowest price is fed. Thus in many areas herring forms a major 

 fish portion of the zoo diet. The normal processing method for preparing 

 fish for use by zoo animals is freezing in small blocks. 



Frozen Fish Scrap for Fish Hatchery Feed. The practice of using certain 

 portions of fish waste to process hatchery fish food has not become as 

 important as it might have had not the pellets of dry hatchery feeds 

 been developed. However, there is some use of fish waste, especially 

 salmon cannery offal, in preparing frozen hatchery diets. The material 

 utilized is viscera and eggs. The scrap from the iron chink is conveyed in 

 water to a draining table where excess water is allowed to drain away. 

 The viscera is then bagged and moved to the cold storage for freezing. 



LITERATURE CITED 



1. Anon., Current Fishery Statistics, Nos. 2495 and 2541, Washington U.S. Bureau of 



Commerical Fisheries (1960). 



2. Jones, Walter, ''Fishery Resources for Animal Foods," Fishery Leaflet No. 501, 



Washington, U.S. Fish and Wildlife Service (1960). 



