HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Foote, W. C. Articles by Casida, L. E. Search for Related Content PubMed Articles by Foote, W. C. Articles by Casida, L. E.

Age at Puberty of Gilts Produced by Different Systems of Mating¹

University of Wisconsin, Madison

Abstract

Observations were made during four years on the age at puberty in gilts in the swine breeding experimental herd maintained by the Wisconsin Agricultural Experiment Station in cooperation with the Regional Swine Breeding Laboratory. The numbers of gilts used were, in 1950, 150; 1951, 106; 1952, 95; 1954, 162. The mean age at puberty of the inbred gilts in 1950 was 227.7 days. They were significantly older at puberty than the line-cross gilts (193.5 days).

The mean ages at puberty for the gilts representing the four systems of mating in 1951 (inbred, 244.0; two-line cross, 214.5; three-line cross, 198.4; four-line cross, 208.2) differed only in respect to inbreeding and line crossing, with no significant difference between the different line crosses.

Inbreeding of a gilt was shown to have a significant effect on the age at which she reached puberty. The effect of inbreeding of the dam was not shown to have a significant effect on the age at puberty of her off-spring.

Significant differences were found between the inbred and line-cross gilts when classified into 154-day-weight classes to remove much of the effect of differences in growth rate.

The 1952 studies indicated a significant difference between purebreds and crossbreds. Differences between different line crosses were non-significant, as they were in 1951.

Differences in age at puberty in 1954 were found between mating types within the purebred and crossbred systems of mating as well as between the two systems.

Differences shown between the average age at puberty of the reciprocal crosses between two breeds and the average age at puberty of their purebred parents suggest non-additive inheritance.

¹ Paper from the Department of Genetics No. 611 and the Department of Animal Husbandry, published with the approval of the Director of the Agricultural Experiment Station, supported in part by the Research Committee of the Graduate School from funds supplied by the Wisconsin Alumni Research Foundation.

² Ralston-Purina Fellow.

³ Aid was given in collection of some of the data in this study by C. C. O'Mary, A. A. Gerbitz, J. A. Will, G. E. Bradford, F. W. Wolfe, Jr., C. S. Chung, L. A. Whitehair, and M. M. Lehr.