Relationship between Daily Feed Consumption and Feed Efficiency

Abstract

On the basis of the positive correlations of daily gain with daily feed consumption and daily gain with “desirable feed efficiency” it has been assumed that daily feed consumption and “desirable feed efficiency” would be positively correlated. However, in individually fed swine at the Michigan Agricultural Experiment Station the pigs which ate the most tended to be the least efficient. In 80 boars raised in six groups the relationship between daily feed consumption and “desirable feed efficiency” was negative in all groups and was highly significant (−.37) on a within-group basis. In 18 market hogs handled as two groups, the within-group correlation between daily feed consumption and “desirable feed efficiency” was −.28. In order for pigs which consume more to be more efficient the regression of daily gain on daily feed efficiency must exceed the ratio, gain/feed, for the average of the pigs in the lower end of the feed-consumed scale. This was not the case in any of the boar groups. This comparison was not made in the market hogs because of the limited numbers in this group. The within-lot correlations of “desirable feed efficiency” with feed consumed did not differ significantly between the groups of boars or between market hogs and boars. The relationship between daily gain and daily feed consumed appeared to be linear. These data indicate that breeders can not increase the “desirable feed efficiency” of their swine by selecting those which have large appetites. However, it does not indicate that a breeder can not increase “desirable feed efficiency” by selecting for daily gain. Copyright © . .