Abstract #284

# 284
Including sunflower seed in prepartum diet positively influenced postpartum ovarian function without affecting uterine health.
R. Salehi*1, M. G. Colazo2, U. Basu1, A. Ruiz-Sanchez1, D. J. Ambrose1,2, 1University of Alberta, Edmonton, Alberta, Canada, 2Alberta Agriculture and Rural Development, Edmonton, Alberta, Canada.

We investigated the influence of prepartum dietary oilseed supplementation on postpartum (pp) uterine inflammatory status (UIS) based on polymorphonuclear cells (PMN): normal (≤8% PMN) or subclinical endometritis (SCE; > 8% PMN), and associations among SCE, pro/anti-inflammatory cytokine gene expression and resumption of ovarian cyclicity. We hypothesized that feeding a diet containing sunflower seed (SUN; high linoleic acid) will induce pro-inflammatory effects in the early pp uterus facilitating early resumption of cyclicity. During late gestation (last 5 wk), Holstein cows received 1 of 3 diets supplemented with 8% DM rolled sunflower seed (SUN; n = 10) or canola seed (CAN; high oleic acid; n = 9), or no oilseed (CON; n = 9). Ovaries were scanned 2×/wk until 35 d pp to record first appearance of a 10 (DF) or 16 mm (PreOVF) follicle, and ovulation. Endometrial cell sampling was done 25 ± 1 d pp for cytology and gene expression. Data were analyzed using PROC MIXED, CORR and REG of SAS. Prepartum diets did not influence SCE incidence (SUN: 4/10; CAN: 4/9; CON: 3/9). The mRNA expressions of interleukin (IL)-1β, IL-6, IL-8, IL-10, tumor necrosis factor (TNF)-α and interferon (INF)-γ were not affected (P > 0.05) by either prepartum diet or diet × UIS interaction. Feeding SUN prepartum hastened (P < 0.05) the establishment of PreOVF and increased the proportion of cows ovulating within 35 d pp. Regardless of prepartum diet, cows with SCE had higher (P < 0.05) mRNA expression of IL-1β, IL-8, IL-10 and TNF-α than normal cows. The intervals from calving to DF formation and first ovulation were not affected by UIS; however, PreOVF formed earlier (P < 0.01) in normal (13.2 ± 0.9) than in SCE (18.7 ± 1.4 d) cows. The mRNA expression of IL-1β, IL-8, IL-10 and TNF-α were positively correlated with each other (P < 0.01) and with PMN% (P < 0.07). The interval to PreOVF was determined by IL-1β, IL-8, IL-10, IFN-γ expression, PMN%, and the interval to DF. In summary, feeding SUN prepartum positively influenced pp ovarian function without affecting UIS. Increased endometrial expression of pro-inflammatory cytokines is likely linked to delayed establishment of PreOVF.

Key Words: endometritis, ovarian function, cytokine