THE GENETIC FOUNDATION OF FITNESS AND REPRODUCTION TRAITS IN AUSTRALIAN PIG-POPULATIONS .2. RELATIONSHIPS BETWEEN WEANING TO CONCEPTION INTERVAL, FARROWING INTERVAL, STAYABILITY, AND OTHER COMMON REPRODUCTION AND PRODUCTION TRAITS
E. Tholen et al., THE GENETIC FOUNDATION OF FITNESS AND REPRODUCTION TRAITS IN AUSTRALIAN PIG-POPULATIONS .2. RELATIONSHIPS BETWEEN WEANING TO CONCEPTION INTERVAL, FARROWING INTERVAL, STAYABILITY, AND OTHER COMMON REPRODUCTION AND PRODUCTION TRAITS, Australian Journal of Agricultural Research, 47(8), 1996, pp. 1275-1290
Data sets from 2 large Australian piggeries were used to estimate gene
tic parameters for the traits weaning to conception interval (WCIi-1,i
) and farrowing interval (FIi-1,i), number born alive (NBA(i)), averag
e piglet birthweight (BWi), 21-day litter weight (W21(i)), and sow sta
yability (STAY(1i)) recorded for each ith parity, as well as sow avera
ge daily gain (ADG) and backfat (BF) recorded at the end of performanc
e test. Over parities and herds, heritabilities for each trait were in
the ranges: WCI/FI, 0.0-0.10; NBA, 0.09-0.16; BW, 0.11-0.35; W21, 0.1
2-0.23; STAY(1i), 0.02-0.09; ADG, 0.35-0.37; BF, 0.36-0.45. Genetic co
rrelations between NBA(1) and NEA from later parities were significant
ly different from 1. In addition, in 1 herd negative genetic correlati
ons (r(g) = -0.04 to -0.25) were found between sow stayability traits
and NBA(1), but not NEA recorded in later parities. Stayability was un
favourably correlated with ADG and BF, and favourably correlated with
WCI12 However, WCI12 was unfavourably correlated genetically with BF (
r(g) = -0.24) but uncorrelated with ADG. Antagonistic relationships al
so existed between NEA and BW, NEA and W21, and BW and STAY. In additi
on to the traditional traits currently included in pig-breeding progra
ms (e.g. ADG, BF, and NEA), traits such as WCI, BW, and STAY should al
so be considered as selection criteria to minimise the detrimental eff
ects of antagonistic genetic relationships between traits.