Genetic and sex influences on the histomorphometric characteristics of porcine adrenals under hot humid climatic condition

Histomorphometric measurements of the adrenal glands of three straight-bred and two cross-bred lines of pigs maintained in hot humid climatic conditions showed that adrenal gland function is not affected by sex. Striking breed influences were however observed in the parameters studied. Paired absolute adrenal weight was higher in Large White (LW) pigs than in the others but the relative adrenal weight was similar and higher in LW, Landrace (LD), West African indigenous (WA) and two-way cross (2X) pigs than in three-way cross (3X) pigs. The adrenal cortex thickness was thinnest in WA pigs while the area of the cortical zone and the cortex/medulla ratio were respectively smaller in WA and 3X and WA and 2X pigs than in the others. Relative paired adrenal weight did not change during early pregnancy unlike the thickness and area of the cortex and the cortex/medulla ratio which were highly increased.