Productivity in a Crossbred Herd of Swine

Records available for the rotation breed cross herd at the North Central Substation, Eureka, provide a look at what happens to herd performance, over time, in a herd in which an attempt is made to apply information learned from research about breeding for performance. This herd is maintained under conditions and management similar to many commercial swine operations. Herd management was described in some detail in A.S. Series 65-26 (S.D.S.U. Swine Day, 1965). The breeding program is a systematic rotation breed cross, with a new generation each year. Replacement gilts are selected from each pig crop with emphasis on litter performance, growth rate, and minimum backfat. Herd boar replacements represent the Hampshire, Duroc and Yorkshire breeds and are used in that order so that a cycle of use is completed every three years. Boars are chosen principally for growthiness and meatiness from purebred herds doing some testing including carcass evaluation