Progeny Testing of A. I. Boars on the Basis of Their Daughters' Farrowing Results

Abstract

Effect of size of piggery, season and other systematic factors on litter size at birth, proportion of stillborn piglets and nonreturn rate (success of insem.) were studied in four field materials (N: A.I./I=5 150; A.I./II=3733; A.I./III=34093; sow recording= 1470 litters). The following heritability estimates were obtained, 0.16–0.22 (±0.06) for litter size, 0.08 (±0.04) for proportion of stillbirths and 0.00 (±0.03) for nonreturn rate. Effect of three selection models on improvement of litter size were compared: (1) selecting sows on their own records (not utilising information on the sire), (2) selecting sows on an index composed of their own records and the sires' progeny tests, (3) as (2) plus mild selection of boars on the basis of their own progeny test. Making many generalizations, restrictions and approximations in applying the above models the relative breeding efficiency would be as follows: (1) 100; (2) 118; (3) 160, indicating the advantage of utilising the sires' progeny test information.

Key Words:

• A.I. boars
• progeny testing
• daughters' fertility
• breeding program