Supplemental polyethylene glycol affects intake of and preference for sericea lespedeza by cattle12

Abstract

We tested the hypothesis that supplemental polyethylene glycol (PEG), a polymer that neutralizes the effects of tannins, would increase intake and preference of cattle for fresh-cut sericea lespedeza (SL; Lespedeza cuneata), a legume with high concentrations of condensed tannins. Sixteen crossbred steers (initial BW of 249 +/- 6.6 kg) were randomly assigned to 2 treatments: 1) grain supplement with PEG (PEG-S) and 2) grain supplement without PEG (control). To assess intake, we conducted a trial with 6 sample periods, each 6 d in duration, with steers fed SL and prairie hay (PH) in separate meals. Steers were fasted overnight and fed their respective supplements (with and without PEG) at 0800 h. Animals were then offered fresh-cut SL from 1050 to 1550 h, PH was fed from 1600 to 2000 h, and they were without food from 2000 to 0800 h the next day. To assess preference, we conducted 1-d tests in which steers had simultaneous access to SL and PH on the day following periods 2 to 6. As with the intake experiment, steers were fasted overnight and fed their respective supplements at 0800 h, but from 1050 to 1250 h all steers had access to SL and PH simultaneously. We weighed steers before and at the completion of the study and calculated ADG. Steers treated with PEG consumed more SL per unit of BW than control steers in periods 2 to 6 (period x treatment interaction, P < 0.001). In contrast, controls consumed more PH than steers given PEG (period x treatment x day interaction, P = 0.009). The PEG-S steers consumed more total DM (SL + PH) than controls in periods 3, 5, and 6 but not in periods 1, 2, and 4 (period x treatment interaction, P = 0.004). Sericea lespedeza intake as a percentage of total DMI was greater for the PEG-S steers every day except d 1 and 2 of period 1 (period x treatment x day interaction, P = 0.03). Averaged across the 5 preference tests, PEG-S steers selected a greater proportion of SL than did control steers (39 vs. 9%), and the magnitude of the difference was greater in the later tests (test x treatment interaction, P = 0.004). The PEG-S steers had greater ADG than controls (0.44 vs. 0.24 kg/d; P = 0.005). Our results indicate PEG increases intake of and preference for SL and suggest that PEG supplementation of cattle may increase intake of SL and improve ADG in pastures that contain SL.

Season Progression, Ontogenesis, and Environment Affect Lespedeza cuneata Herbage Condensed Tannin, Fiber, and Crude Protein Concentrations

“…The wide TCT range, from 133.5 g kg −1 in Texas on date 3 to 46.1 g kg −1 in Louisiana on date 1, a 190% difference, reflected those that appeared in other fractions, especially ECT. Total CT concentrations were similar to what others have reported for SL in general (121–142 g kg −1 ; Terrill et al, 1990; Mantz et al, 2009) and AU Grazer, specifically (125 g kg −1 ; Mechineni et al, 2014).…”

How planting configuration influences plant secondary metabolites and total N in tall fescue (Festuca arundinacea Schreb.), alfalfa (Medicago sativa L.) and birdsfoot trefoil (Lotus corniculatus L.): Implications for grazing management

“…Condensed tannins were isolated and purified from BFT as described by Mantz et al. () using the methods developed by Terrill et al. () and Reed ().…”

“…Two subsamples were taken from each composite plant sample for independent analysis for total N using a Leco FP-528 nitrogen/ protein determinator (St. Joseph, MI), and a mean value was computed over the two subsamples. Birdsfoot trefoil samples were analysed for CT as described by Mantz, Villalba, and Provenza (2008) using the methods developed by Terrill, Rowan, Douglas, and Barry (1992) and Reed (1986). Tall fescue samples were analysed for EV using the HPLC methods developed by Rottinghaus, Garner, Cornell, and Ellis (1991) and Hill, Rottinghaus, Agee, and Schultz (1993).…”

“…Condensed tannins were isolated and purified from BFT as described by Mantz et al (2008) using the methods developed by Terrill et al (1992) and Reed (1986). Saponins were isolated and purified from Alf using a modification (A.K.…”

Plant Secondary Metabolites in Alfalfa, Birdsfoot Trefoil, Reed Canarygrass, and Tall Fescue Unaffected by Two Different Nitrogen Sources

“…Birdsfoot trefoil samples were analyzed for CT as described by Mantz et al (2008) using methods developed by Terrill et al (1992) and Reed (1986). Each ground BFT sample was weighed (500 mg) in triplicates in 50‐mL centrifuge tubes.…”