Abstract
Weaning weight and gain in three successive 56-day periods were combined in indexes predicting the genic effects for 368-day weight and for 168-day feed lot gain. Feed consumption in the three 56-day periods was used to predict the genic effects for 168-day post-weaning consumption. The indexes predicting the genic effects for 168-day gain and feed consumption computed from the Lincoln data indicated that accuracy would be increased for both traits by including information from the entire 168-day test. Results of the Fort Robinson analysis also indicate that the additional information about the genic values for final weight and feed lot gain which resulted from adding subsequent 56-day periods to the index was sufficient to justify feeding at least 168-days. In the analyses of feed consumption in three 56-day periods at Fort Robinson, the first period was 90% as accurate in predicting the genic effects for feed consumption as was an index combining all three periods in the most efficient way. Copyright © . .