238 FISHERY INDUSTRIAL PRODUCTS 



Jones- stated that the largest potential source as raw material for feed- 

 ing the nation's 25,000,000 dogs and 29,000,000 cats is undoubtedly fish. 

 As this utilization of fish increases, no doubt improved processing methods 

 and more diversified pet food products will be needed. 



Handling Methods for Preparing Frozen Mink Feed. The most im- 

 portant frozen fish utilization in animal feeding is in the mink-raising 

 industry. In recent years considerable expansion of fur farming in areas 

 adjacent to fishing ports has taken place. ]\Iany of the mink ranchers 

 have formed cooperatives for the special purpose of obtaining and proc- 

 essing feeds. Fish is their main source of material. Alink feed includes 

 whole fish, fillet waste, cannery offal, and whale meat. 



Raw Material. In most instances, the fish material utilized as mink feed 

 is obtained from fish processing plants. The buyer usually hauls bulk 

 loads by truck to his processing plant or ranch. In some areas, especially 

 in the Great Lakes region, whole fish such as sheepshead are purposely 

 taken for use as mink feed. On the Pacific Coast whole sole and turbot 

 are utilized in preparing mink feed. In some cases mink ranchers even 

 own and operate fishing vessels. 



Grinding. The first step in processing the fish into mink feed is grind- 

 ing, which is usually accomplished by using a medium size (10 to 25 hp) 

 grinder of the plate and screw type. Grinding plates of approximately 

 % inch openings are preferred. 



Packaging. The next step after grinding may be either freezing or 

 packaging, depending upon the particular plant procedure. If the ma- 

 terial is packaged prior to freezing, one of two types of package are 

 commonly used. A multi-wall paper bag is most popular. The bags may 

 be filled from an automatic hopper and stitched by machine. An alter- 

 nate package is the fiber carton which is sometimes lined with waxed 

 paper. The multi-wall bags are usually filled to 50 pounds net contents 

 while the cartons may contain lesser amounts. 



Freezing. If the ground product is frozen prior to packaging it is usu- 

 ally placed in metal trays. In any case, the bags, cartons, or trays of 

 material to be frozen are placed in a freezer at temperatures between 

 — 40 and 0°F. The colder temperature is preferred. Blast, plate, or coil 

 freezers are commonly used. After the freezing cycle is completed the 

 bags are moved directly to a cold storage warehouse. The boxed material 

 is often ice glazed on the top surface to prevent dehydration. The feed 

 frozen in trays is removed from the trays and ice glazed. These frozen 

 blocks are then packaged in cartons and are placed directly in the cold 

 storage warehouse. 



Storage. Frozen mink feed may be stored in any of several warehouses. 

 The cooperative may have its own cold storage or it may rent space. 

 Some individual farmers have cold storage facilities to accommodate 



