Free Access
Reprod. Nutr. Dev.
Volume 45, Number 6, November-December 2005
Page(s) 721 - 727
Reprod. Nutr. Dev. 45 (2005) 721-727
DOI: 10.1051/rnd:2005056

Dietary supplementation with safflower seeds differing in fatty acid composition differentially influences serum concentrations of prostaglandin F metabolite in postpartum beef cows

Mark H.J. Granta, Brenda M. Alexandera, Bret W. Hessa, Jeff D. Bottgera, Doug L. Hixona, Edward A. Van Kirka, Terry M. Nettb and Gary E. Mossa

a  University of Wyoming Department of Animal Science, Laramie 82071, USA
b  Colorado State University, Fort Collins 80523, USA

(Received 14 January 2005; accepted 26 May 2005)

Abstract - Synthesis and secretion of prostaglandin F2$\alpha$ (PGF2$\alpha$) is elevated following parturition and exerts divergent effects on the re-establishment of fertile estrous cycles in cows. The objective of these experiments was to determine if oil seed supplements differing in fatty acid composition differentially influence serum concentrations of the specific PGF2$\alpha$ metabolite, PGFM. Safflower seed supplements were formulated to provide 5% of dry-matter intake as fat. In Trial 1, 24 multiparous beef cows were individually fed control (beet pulp-soybean meal) or cracked high-linoleate safflower seed (78% 18:2n-6) supplements for 80 d postpartum. Linoleate supplemented cows had greater (P < 0.001) serum concentrations of PGFM than control cows. In Trial 2, primiparous beef cows (n = 36) were individually fed control (cracked corn-soybean meal), cracked high-linoleate (76% 18:2n-6) or -oleate (72% 18:1n-9) safflower seed supplements for 92 d postpartum. As in Trial 1, serum concentrations of PGFM were greater (P $\leq$ 0.04) in linoleate than control or oleate supplemented cows. Serum concentrations of PGFM, however, did not differ (P = 0.40) among oleate and control supplemented cows. Although potential impacts on reproductive performance remain to be proven, dietary oil supplements high in linoleate, but not oleate, increased serum concentrations of PGFM compared to control supplements.

Key words: beef cows / lipid supplementation / prostaglandin

Corresponding author: Mark H.J. Grant

© INRA, EDP Sciences 2005