Stillbirth rates and their association with swine leucocyte antigen class II haplotypes in Microminipigs

Noriaki Imaeda,Shingo Suzuki,Shino Ohshima,Tatsuya Matsubara,Hitoshi Kitagawa,Asako Ando,Yoshie Kametani,Masaki Takasu,Tetsushi Ono,Takashi Shiina,Naohito Nishii,Asuka Miyamoto,Jerzy K Kulski

doi:10.5713/ab.20.0763

Abstract

ObjectiveMicrominipig (MMP) is a miniature pig with an extra small body size for experimental use. In the present study, the occurrence of stillbirths and their genetic association with swine leukocyte antigen (SLA) class II haplotypes were evaluated in a population of MMPs.MethodsThe occurrences of stillbirth and genetic association with SLA class II haplotypes using 483 stillborn and 2,246 live piglets, and their parents were compared among the three groups of newborn piglet litters; an all stillborn (AS) group consisting of only stillborn piglet litters, a partial stillborn (PS) group consisting of stillborn and live piglet litters, and an all alive (AA) group consisting of only live piglet litters.ResultsThe incidence of stillborn piglets was 483/2,729 (17.7%). Distributions of litter sizes, numbers of stillborn piglets in a litter, parities, and gestation periods were distinct among the three groups. The frequencies of low resolution haplotype (Lr)-0.7 or Lr-0.23 were higher in the AS group than in the PS or AA groups. In sires, the frequency of Lr-0.7 associated with the AS group was significantly higher in the AS group than with the AA group. In dams, the frequency of Lr-0.23 was significantly higher in the AS group than in the PS or AA groups, whereas the frequency of Lr-0.7 was not significantly different.ConclusionThe incidence of stillborn piglets in MMPs appears to be higher than those in other pig breeds. Several traits related with stillbirths such as the number of stillborn piglets and parities of the AS group were different from those of the PS and AA groups. Specific SLA class II haplotypes were associated significantly with a high incidence of stillbirths and could be used as genetic markers to adopt breeding strategies to lower the rate of stillbirth in MMPs.

Highlights

Stillbirth is defined as the birth of a dead fetus
The population of MMPs are distinguished by eight different kinds of swine leukocyte antigen (SLA) class II haplotypes [14] that could be used as genetic markers for analyses of associations with specific phenotypes for various productive or reproductive traits and outcomes
We previously reported associations of the SLA haplotypes with body weights [15] and some reproduc tive traits, such as gestation periods, fertility indices, litter sizes, and numbers of abnormal newborn piglets in MMPs [16]

Summary

Objective

Microminipig (MMP) is a miniature pig with an extra small body size for experi mental use. Distributions of litter sizes, numbers of stillborn piglets in a litter, parities, and gestation periods were distinct among the three groups. The frequencies of low resolution haplotype (Lr)-0.7 or Lr-0.23 were higher in the AS group than in the PS or AA groups. Conclusion: The incidence of stillborn piglets in MMPs appears to be higher than those in other pig breeds. Several traits related with stillbirths such as the number of stillborn piglets and parities of the AS group were different from those of the PS and AA groups.

INTRODUCTION

MATERIALS AND METHODS

RESULTS