Damiran, D.Biligetu, B.Pearce, L.Larson, K.Lardner, B.H.A.2023-04-212023-04-212021-03-16https://hdl.handle.net/10388/14612A small-plot study was conducted at Lanigan (lat 51°51´N, long 105°02´W) SK, in the Black soil zone, to compare low-lignin Hi-Gest®360 alfalfa (Medicago sativa L.) to a conventional alfalfa (AC Grazeland, check cultivar). Each cultivar was seeded in August 2017 as both a monoculture and binary mixture (binary) with AC Success hybrid bromegrass (HB). Plants were sampled in 2019 at 3 different maturity stages of alfalfa (1 = 10% bloom; 2 = 40% bloom or commercial harvest stage; and 3 = 100% bloom). Forage was harvested 27 June, and 8 and 29 July, 2019 for stage 1, stage 2 (11 d after stage 1), and stage 3 (21 d after stage 2), respectively. Treatments were replicated 4 times, a total of 48 plots with plot size of 6.2 — 1.2 m. Forage — maturity stage interaction was not observed (P > 0.05) for all measured parameters. AC Grazeland and Hi-Gest exhibited similar (P > 0.05) DMY (2978 ± 405 kg/ha). Likewise, AC Grazeland+HB and Hi-Gest+HB did not vary (P = 0.62; 9120 ± 647 kg /ha) in DMY. There was little difference between Hi-Gest and AC Grazeland (P > 0.05) in nutrient profile. As alfalfa maturity advanced, DMY increased (P < 0.05; 1940, 2970, 4023 kg/ha for stages 1, 2, and 3, respectively). Hi-Gest at stage 3 tended to be greater (P = 0.09; by 35.4%) in DMY than AC Grazeland at stage 2 (4235 kg/ha vs. 3127 kg/ha). In binary system, forages at stage 1 had lower (P < 0.05) DMY (6575 kg/ha) than those at stage 2 (9858 kg/ha) and stage 3 (10650 kg/ha), whereas, forages in stage 2 and stage 3 did not differ (P = 0.12) in DMY. However, in monoculture, forages at maturity stage 3 had lower crude protein (CP; 20.0 vs. 23.1%) and total digestible nutrients (TDN; 60.8 vs. 65.5%), but greater acid detergent fiber (ADF; 36.1 vs. 30.0%) than those at maturity stage 1. The acid detergent lignin (ADL) concentrations of Hi-Gest were 98.8%, 86.7%, and 99.2% (avg. 94.9%) of AC Grazeland alfalfa, for stage 1, stage 2, and stage 3, respectively. No differences (P > 0.05) were observed between AC Grazeland+HB and Hi-Gest+HB for nutrient profiles. The ADL concentration of Hi-Gest + HB was 106.3%, 93.7%, and 90.9% of (avg. 96.7%) AC Grazeland+HB, for the stage 1, stage 2, and stage 3, respectively. Hi-Gest alfalfa had greater (P < 0.05) effective degradable dry matter (EDDM; 7.2% more; 520 vs. 485 g/kg DM), effective degradable CP (EDCP; 14.3% more; 630 vs. 551 g/kg CP), and effective degradable neutral detergent fiber (EDNDF; 6.2% more; 265 vs. 249 g/kg NDF) relative to AC Grazeland alfalfa. In binary system, Hi-Gest+HB had numerically (P > 0.05) greater EDCP (8.2% more; 370 vs. 342 g/kg CP), but had similar EDDM (388.4 g/kg DM) and EDNDF (250 g/ kg NDF) relative to AC Grazeland+HB. In both mono- and binary systems, as the maturity advanced, EDDM, EDCP, and EDNDF declined (P < 0.05). The study further revealed that each percentage unit increase in ADL concentration, the main factor hindering cell wall digestion, decreased EDNDF by 2.1 percentage units (EDNDF, g/kg NDF = 252.54 “ 20.792 — ADL, % DM, r2 = 0.41, n = 48, P < 0.01). The stand establishment costs varied by treatment and were $458.70/ha ($185.60/ac), $233.44/ha ($94.47/ac), $351.50/ha ($142.25/ac), and $464.20/ha ($198.10/ac) for Hi-Gest, Grazeland, Grazeland+HB, and Hi-Gest+HB, respectively. The market value ranked from highest to lowest was AC Grazeland+HB > Hi-Gest+HB > Hi-Gest > AC Grazeland. Compared to conventional alfalfa (AC Grazeland) that was harvested at the commercial harvest stage (stage 2; 40% bloom), Hi-Gest alfalfa harvested at stage 3 (100% bloom) had $169.23/ha and $143.57/ha greater market value in mono- and binary system, respectively. Preliminary results suggest that Hi-Gest alfalfa (in both monoculture and binary systems) did not differ in DMY and nutrient profiles, but was greater in rumen degradation potential relative to AC Grazeland, suggesting Hi-Gest 360 alfalfa is a viable alternative legume in both monoculture and binary systems for the Black soil zone of Saskatchewan.enAttribution-NonCommercial-NoDerivs 2.5 CanadaAlfalfa, High-Lignin, Low-LigninPoster Presentation