Relation between Weight at Birth and 21, 56, and 154 Days of Age In Pigs

Abstract

The correlation coefficients between the various successive weight periods were obtained from data on the 3/4 Duroc x 1/4 English Large Black Landrace line of pigs of the University of Puerto Rico's Agricultural Experiment Station, Mayagüez Campus. These periods were at birth, at 21 days, at weaning time, and at 154 days of age. The data of 41 boars, 86 barrows, and 138 gilts covering the period from the fall of 1961 to the fall of 1965 were included. All the correlation coefficients found were positive and significant, with the exception of birth to weaning, and to 154 days, and 21 days to 154 days of age in the boars. Those between the weaning weight and at 154 days of age were on the order of over +0.60 for all sexes. This fact was further confirmed by the logistic equation used with the same data and included here. Even though the boars were heavier than the barrows in all the weight periods, and these, in order, to the gilts, only at birth and at 154 days of age, there was a significant difference in favor of boars and barrows as compared with gilts.