Estimation of genetic parameters for farrowing traits in purebred Landrace and Large White pigs

Abstract

Genetic parameters were estimated for six reproductive traits related to farrowing events in Landrace and Large White pigs; total number born (TNB), number born alive (NBA), number stillborn (NSB), total litter weight at birth (LWB), mean litter weight at birth (MWB), and gestation length (GL). We analyzed 62,534 farrowing records for 10,637 Landrace dams and 49,817 farrowing records for 8,649 Large White dams. Estimated heritabilities of TNB, NBA, NSB, LWB, MWB, and GL by single‐trait repeatability model analyses were 0.12, 0.12, 0.08, 0.18, 0.19, and 0.29, respectively, in Landrace, and 0.12, 0.10, 0.08, 0.18, 0.16, and 0.34, respectively, in Large White. Genetic correlation between NBA and NSB was unfavorable: 0.20 in Landrace and 0.33 in Large White. Genetic correlations of GL with the other five traits were weak: from −0.18 with NSB to −0.03 with NBA in Landrace, and from −0.22 with NSB to −0.07 with NBA in Large White. LWB had a highly favorable genetic correlation with NBA (0.74 in both breeds), indicating the possibility of using LWB for the genetic improvement of NBA.

Genetic relationship of litter traits between farrowing and weaning in Landrace and Large White pigs

“…We analyzed different datasets for the litter traits at farrowing and weaning. The whole dataset for the litter trait at farrowing was slightly larger than our previous dataset (Ogawa et al, ), but the results were very similar (Table ). In this study, information about the treatment of cross‐fostering was recorded only on the two GGP farms.…”

“…Oh, Lee, and See () also estimated the heritability of LWW to be higher than that of LSW. Similarly, previous studies estimated the heritabilities of LWB and MWB to be higher than that of NBA (Damgaard et al, ; Hermesch, Luxford, & Graser, ; Ogawa et al, ).…”

“…Estimated additive genetic correlations in both breeds between litter traits at farrowing and those at weaning are shown in Table . In all cases, the estimated genetic correlation of LSW was higher with NBA than that with TNB, meaning that NBA is a more useful indicator trait than TNB (Ogawa et al, ; Satoh, ). Estimated values differed slightly between datasets.…”

Genetic parameter estimation for number born alive at different parities in Landrace and Large White pigs

“…68,702 records of NBA for 12,857 Landrace dams and 55,755 records for 10,615 Large White dams born during 1999 to 2016 were provided by Cimco Corporation (Tokyo, Japan), operating two great grandparent (GGP) and grandparent (GP) farms by Specific Pathogen Free system located from northern to southern parts of Japan. Details about defining NBA were in Ogawa et al (). Pedigree data included 79,224 Landrace and 68,615 Large White animals.…”

“…Fitting a single‐trait repeatability model to records at different parities assumes that these are repeated measurements of the same trait. But the response to selection using this model was low in some cases, because not only is the heritability of NBA low (e.g., Damgaard, Rydhmer, Løvendahl, & Grandinson, ; Lopez, Kim, Makumbe, Song, & Seo, ; Ogawa et al, ), but possibly also the records at different parities were not considered as those for genetically different traits (e.g., Baselga, Gomez, Cifre, & Camacho, ; Irgang, Fávero, & Kennedy, ). Several authors hypothesized that partly different genes control reproductive traits in successive parities (Hermesch, Luxford, & Graser, ; Noguera, Varona, Babot, & Estany, ; Roehe & Kennedy, ).…”