Abstract #W259

# W259
The effect of prepartum diets supplemented with oilseeds on maternal and newborn calf plasma fatty acid profile.
R. Salehi*1, M. G. Colazo2, M. Oba1, D. J. Ambrose1,2, 1University of Alberta, Edmonton, Alberta, Canada, 2Alberta Agriculture and Rural Development, Edmonton, Alberta, Canada.

Long-chain polyunsaturated fatty acids (PUFA) have important roles during pregnancy, both in the dam and the fetus. However, limited information is available regarding the transfer of specific PUFA from dam to fetus in cattle. Our objective was to examine the effects of oilseed (oilseed vs. no oilseed) and type of oilseed (canola vs. sunflower) supplementation during late gestation on the fatty acid (FA) profile of maternal and newborn calf plasma. Pregnant Holsteins were assigned to 1 of 3 diets containing 8% rolled sunflower (SUN, high in linoleic acid; 8 cows) or canola seed (CAN, high in oleic acid; 7 cows) on dry matter (DM) basis, or no oilseed (CON; 7 cows), for the last 35 ± 2 d of gestation. Blood samples were collected within 3 h after calving from dam and newborn calf to determine FA profile. Data were analyzed using the Mixed procedure of SAS. The proportion of total saturated FA (TSFA) was higher in CON (46.8 ± 3.7) fed cows than in those fed oilseeds (37.5 ± 2.7). Feeding SUN increased the proportion of total PUFA and linoleic acid (47.8 ± 2.5 and 45.5 ± 2.9) relative to those fed CAN (39.5 ± 2.7 and 36.0 ± 2.9, respectively). Moreover, SUN fed cows had higher TPUFA:TSFA ratio (1.29 ± 0.06) than those fed CAN (0.99 ± 0.06) or CON (0.88 ± 0.06). However, oilseed or type of oilseed supplementation during prepartum period did not affect FA profile of calves. Correlation analysis in CON treatment indicated that calf and dam TSFA were positively associated (R = 0.79, P = 0.03). Total monounsaturated FA (TMUFA, R = −0.66, P = 0.10) and oleic acid (OLA, R = −0.68, P = 0.08) in calf were negatively correlated with dam TSFA in CON treatment. Calf OLA (R = 0.68, P = 0.05) and TMUFA (R = 0.67, P = 0.06) in SUN treatment had positive association with dam total n-6. There was no relationship between dam and calf FA profile in CAN treatment. In summary, oilseed and type of oilseed supplemented during late gestation affected maternal FA profile but not that of newborn calf. Moreover, oilseed supplementation and the type of oilseed supplemented during prepartum period affected the association between maternal and newborn calf FA.

Key Words: sunflower seed, canola seed, fatty acid profile