PSVII-23 Using low-moisture molasses-based blocks to supplement Ca salts of soybean oil to forage-fed beef cows

Abstract

Abstract This experiment compared plasma fatty acid (FA) profile of forage-fed beef cows receiving a molasses-based supplement enriched with Ca salts of soybean oil [(CSSO); 24.7% of dry matter (DM)] via a self-fed low-moisture block (LMB) or hand-fed granular concentrate daily (CONC). Thirty-six cows were allocated to 1 of 9 drylot pens, which were enrolled in a replicated 3 x 2 Latin square design with 2 periods of 42 d. Pens were randomly assigned to receive 1 of the 3 treatments, in a manner that pens did not receive the same treatment in both periods. Cows received hay for ad libitum consumption during the study. Hay intake was recorded daily from d 0 to 42, and LMB intake was recorded from d 14 to 42. The CONC was offered at 0.420 kg/cow daily (DM basis) from d 0 to 13, and then adjusted (d 14 to 42) to match LMB intake. Average LMB intake during the initial 13 d was 0.846 ± 0.107 kg/cow daily (DM basis). Supplement DM intake did not differ (P = 0.39) between LMB and CONC cows from d 14 to 42. No treatments effects were noted (P ≥ 0.40) for hay intake, BCS, and BW. Plasma FA profile did not differ (P ≥ 0.20) between treatments on d 0. From d 14 to 42, plasma concentrations of linoleic acid, ω-6 polyunsaturated FA, and total FA were greater (P < 0.01) in CONC and LMB vs. NOSUPP cows. Plasma concentrations of these FA were also greater (P ≤ 0.03) in LMB vs. CONC cows on d 14, but did not differ (P ≥ 0.35) on d 28 and 42. Inclusion of CSSO into LMB resulted in similar incorporation of ω-6 polyunsaturated and total FA in the circulation compared with CONC offered at the same daily rate.