PMID- 35287733 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20220323 IS - 1674-9782 (Print) IS - 2049-1891 (Electronic) IS - 1674-9782 (Linking) VI - 13 IP - 1 DP - 2022 Mar 15 TI - Associations between testicular development and fetal size in the pig. PG - 24 LID - 10.1186/s40104-022-00678-3 [doi] LID - 24 AB - BACKGROUND: Impaired reproductive performance is the largest contributing factor for the removal of boars from commercial systems. Intrauterine growth restricted piglets represent 25% of the total number of piglets born and have impaired reproductive performance. This study aimed to improve the understanding of temporal changes in testicular gene expression during testes development in fetuses of different size. The lightest and closest to mean litter weight (CTMLW) male Large White x Landrace littermates were collected at gestational days (GD) 45, 60 and 90 (n = 5-6 litters/GD). RESULTS: Testes weight and testes weight as a percentage of fetal weight were not associated with fetal size at GD60 or 90. Fetal plasma testosterone was not associated with fetal size at GD90. There was no association between fetal size and seminiferous tubule area and number, number of germ or Sertoli cells per tubule. The lightest fetuses tended to have wider seminiferous tubules compared to the CTMLW fetuses at GD90 (P = 0.077). The testicular expression of KI67 (P