54 Trainee Award: Gilt uterine gland density is affected pre- and post-puberty by maternal immune stimulation in late gestation

Abstract Uterine glands provide critical nutrients during pregnancy, but uterine gland number is fixed shortly after birth. Thus, we sought to determine if maternal immune stimulation decreases uterine gland density in offspring. Pregnant sows were treated on day 77 of gestation with lipopolysaccharide (LPS), vaccine (VAC), or saline (CON). Postnatal gilts were sampled from each group. Reproductive tracts were collected from gilts pre-puberty (LPS, n = 4; VAC, n = 6; CON, n = 6) and post-puberty (LPS, n = 3; VAC, n = 5; CON, n = 7). Uteri were weighed. Cross sections were collected from four non-sequential mid-horn segments, fixed, embedded, and sectioned. Sections were stained using hematoxylin and eosin, imaged, and assessed for the number of deep and superficial uterine glands per area (density). Data were analyzed by ANOVA for the fixed effect of treatment. Statistical significance was considered at P ≤ 0.05. In the pre-pubertal phase, there were no differences in deep or superficial uterine gland density among treatment groups. However, uterine weight tended to be reduced in gilts from the VAC group compared with the CON and LPS groups. In the post-pubertal phase, there were no differences in deep or superficial uterine gland density among treatment groups. However, uterine weight was increased in the VAC and LPS groups compared with the CON group. Gestational immune stimulation does not affect uterine gland density in offspring; however, it does alter uterine weight, and thus affects the total number of uterine glands, and perhaps secretory capacity.