Paul G. Jefferson

Potential utilization of native prairie grasses from western Canada as ethanol feedstock

The utilization of native grass species for potential biomass feedstocks of the emerging ethanol industry requires more information about their cellulose and hemicellulose concentration. Ten native species were grown at seven sites across the prairie region of western Canada for two to four growing seasons. Northern wheatgrass, Elymus lanceolatus, produced high concentrations of cellulose (363 g kg-1) but low concentrations of hemicellulose (266 g kg-1). Green needlegrass, Nasella viridula, produced high concentrations of both constituents (351 and 307 g kg-1). Four warm-season grasses, big bluestem, Andropogon gerardii, little bluestem, Schizachyrium scoparium, prairie sandreed, Calamovilfa longifolia, and switchgrass, Panicum virgatum, had 346, 342, 340 and 338 g kg-1, respectively, concentrations of cellulose and also exhibited a positive response to temperature that resulted in increased hemicellulose concentration. Accumulated thermal time (degree day base 10°C) was correlated to hemicellulose concen...

Forage quality of seeded native grasses in the fall season on the Canadian Prairie Provinces

Jefferson, P. G., McCaughey, W. P., May, K., Woosaree, J. and McFarlane, L. 2004. Forage quality of seeded native grasses in the fall season on the Canadian Prairie Provinces. Can. J. Plant Sci. 84: 503‐509. There is renewed interest in re-seeding native grasses in the prairie region of western Canada but there is limited information on their forage quality for fall grazing. We evaluated forage quality in early fall of nine native and one introduced grass species for 2 to 4 yr at five locations. The neutral detergent fiber (NDF) was high due to the advanced growth stage of the plants but varied among grass species at all sites. Western wheatgrass, Pascopyrum smithii, exhibited the lowest NDF and highest in vitro organic matter digestibility (IVOMD). Northern wheatgrass, Elymus lanceolatus, exhibited the highest crude protein while western wheatgrass ranked second highest for crude protein. Indiangrass, Sorghastrum nutans, exhibited the highest P and Ca concentrations, while green needle grass, Nasella viridula, and mammoth wildrye, Leymus racemosus, exhibited the lowest concentrations. Acid detergent fiber (ADF) was not highly correlated to IVOMD, presumably due to the mature phenological stage at sampling. Western wheatgrass forage was nutritionally adequate to maintain a dry beef cow during the second trimester of pregnancy. Other species did not “cure on the stem” as had been previously reported and would require supplementary energy and protein to be utilized for fall pastures.

Comparative forage yield, water use, and water use efficiency of alfalfa, crested wheatgrass and spring wheat in a semiarid climate in southern Saskatchewan

Crested wheatgrass (Agropyron cristatum L. Gaertn.) and alfalfa (Medicago sativa L.) are introduced forage species used for hay and grazing by cattle across western Canada. These species are well adapted to the semiarid region but their long-term responses to water stress have not been previously compared. Two alfalfa cultivars with contrasting root morphology (tap-rooted vs. creeping-rooted) and two crested wheatgrass (CWG) cultivars with different ploidy level (diploid vs. tetraploid) were compared with continuously cropped spring wheat (Triticum aestivum L.) for 6 yr at a semiarid location in western Canada. Soil water depletion, forage yield, water use efficiency, leaf water potential, osmotic potential and turgor were compared. There were no consistent differences between cultivars within alfalfa or CWG for variables measured. However, these two species exhibit different water stress response strategies. Leaf water potential of CWG was lower during midday stress period than that of alfalfa or wheat. ...

Leaf and stem nutritive value of timothy cultivars of different maturity at an irrigated site in southwestern Saskatchewan

Leaf and stem structural components contribute to variation in nutritive value among timothy (Phleum pratense L.) cultivars. Modelling timothy growth and nutritive value requires a better understanding of this variation. A trial of 11 timothy cultivars was conducted on irrigation at Swift Current, Saskatchewan from 1995 to 1997. Leaf:stem ratio, forage yield, days to maturity, N, P, acid detergent fiber (ADF) and neutral detergent fiber (NDF) concentrations, N/P ratio and P uptake of leaf and stem components were determined for spring growth forage. Two N fertilizer rates (100 and 150 kg N ha-1) did not consistently affect leaf and stem nutritive value. Cultivars differed in maturity, stem P, stem N, stem NDF, leaf NDF and leaf ADF in all 3 yr. Days to maturity was correlated to stem P concentration (r = 0.59, P < 0.05, to 0.77, P < 0.01) and leaf ADF concentration (r = 0.59, P < 0.05, to 0.82, P < 0.01) in all 3 yr but not to stem NDF concentration. Days to maturity was correlated to stem N concentration...

Reevaluation of row spacing/plant density of seeded pasture grasses for the semiarid prairie

Previous research in the semiarid prairie at Swift Current, Saskatchewan, indicated that optimum row spacing for forage production was 60 or 90 cm for crested wheatgrass (Agropyron cristatum [L.] Gaertner) and Russian wild ryegrass (Psathyrostachys juncea [Fisch.] Nevski). However, recent research suggested that harvest method affects forage yield estimates from row spacing experiments. An experiment with three row spacings of mixtures of alfalfa (Medicago sativa L.) with crested wheatgrass and Russian wild ryegrass was harvested mechanically and by hand. Yield differences between methods of harvesting were affected by row spacing; larger differences were observed at 15 cm than at 60 cm spacing, particularly for Russian wild ryegrass. The highest hand-harvested forage yield estimates were observed in the narrowest row spacing. In a second experiment, plant density was evaluated for the same grasses using square grid spacings of 30, 45, 60, 75 and 90 cm. Decreasing plant density was associated with decreas...

Switchgrass (Panicum virgatum L.) Cultivar Adaptation, Biomass Production, and Cellulose Concentration as Affected by Latitude of Origin

Ten cultivars of switchgrass (Panicum virgatum L.) of northern and southern origins that had demonstrated adaptation to North Dakota were evaluated for biomass production, cellulose concentration, and nutritive value in the southern Canadian prairie region: Saskatchewan and Manitoba. In this region, cultivars adapted to northern latitudes present interest for biomass production. Latitude of origin of the cultivars was positively correlated to stand density (, ), biomass production (, ), and cellulose (, ), and negatively correlated with organic matter digestibility (, ) and N (, ). Dacotah and ND 3743, the northern origin cultivars, were more persistent in Brandon, MB (94 to 100% stand density) and exhibited higher cellulose and hemicellulose concentrations than southern cultivars. Southern cultivars produced higher biomass than northern-origin cultivars until they suffered significant stand and biomass decline. Cave-in-Rock, the southern origin cultivar, did not persist in the third year after seeding. However, southern-adapted cultivars exhibited better nutritive value for grazing cattle. We conclude that switchgrass production in the southern Canadian prairie should utilize the USA cultivars from northern latitudes or adapted Canadian cultivars should be developed.

The decline in hay yields : A Saskatchewan perspective

Yield data collected by Statistics Canada show that annual hay yields have been declining in several Canadian provinces including Saskatchewan for the past 31 yr. Data from Saskatchewan provincial statistics on Beef Cow number, Area Harvested for Hay, Value of Land and Buildings, and Fertilizer Price Index were used to examine the relationships between hay yield and these variables. Weather from 16 sites across Saskatchewan’s agricultural region for the April, May, and June (AMJ) period was also examined from 1973 to 2003. Precipitation during AMJ was positively correlated to hay yield, but the difference between maximum and minimum temperatures (Δtemperature) was negatively correlated. Fertilizer Price Index was negatively correlated to hay yield, suggesting that producers are reducing fertilizer input to this crop resulting in lower yields. Step-wise regression analysis suggested that fertilizer cost was the most important variable, which explained 38% of the variation in hay yield. When fertilizer pric...

Effect of rumen degradable energy supplementation on forage utilization and performance of steers grazing stockpiled cool season perennial grass pastures

Añez-Osuna, F., Penner, G. B., Larson, K., Jefferson, P. G., Lardner, H. A. and McKinnon, J. J. 2015. Effect of rumen degradable energy supplementation on forage utilization and performance of steers grazing stockpiled cool season perennial grass pastures. Can. J. Anim. Sci. 95: 255-265. The objective of this study was to evaluate the effects of supplementing rumen degradable energy using blended by-product pellets that differed in starch and degradable fiber content on forage utilization and performance of steers grazing stockpiled cool-season perennial grass (CSPG) pastures. Forty-five yearling crossbred steers (334±23.5 kg) stratified by body weight (BW) were randomly assigned to one of nine pastures (five steers/pasture) of mature cool-season perennial grasses. Each pasture was randomly assigned (n=3) to one of three treatments: no supplement (CON); low-starch/high degradable-fibre (LSHF; 40.3% starch; 29.5% NDF) pellet and high-starch/low-degradable fibre (HSLF; 48.6% starch; 22.8% NDF) pellet, both fed daily at 0.6% of BW (DM basis). The grazing period lasted 70 d (from early-August to mid-October). Over the 70-d study, forage CP decreased from 9.9±0.82 to 6.9±0.59% of DM and digestible energy content decreased from 2.6±0.04 to 2.2±0.04 Mcal kg-1 of DM. Treatment did not affect forage utilization (P=0.50; 73.4±3.15%) or forage DM intake (P=0.90; 9.0±1.54 kg d-1). Final BW and average daily gain (ADG) were not different (P>0.05) between LSHF (435±6.4 kg and 1.4±0.10 kg d-1) and HSLF (439±10.4 kg and 1.5±0.14 kg d-1) treatments. However, supplemented steers had higher (P<0.05) final BW and ADG than the control steers (402±5.6 kg and 1.0±0.09 kg d-1). These results show that unsupplemented beef steers grazing stockpiled CSPG pastures were limited in both energy and protein intake and that supplementation with by-product feed pellets formulated to supply protein and energy either as starch or degradable fibre equally improved animal performance.

Beef cattle grazing behaviour differs among diploid and tetraploid crested wheatgrasses (Agropyron cristatum and A. desertorum)

Iwaasa, A. D., Jefferson, P. G. and Birkedal, E. J. 2014. Beef cattle grazing behaviour differs among diploid and tetraploid crested wheatgrasses (Agropyron cristatum and A. desertorum). Can. J. Plant Sci. 94: 851-855. A study was conducted over 4 yr (1999, 2000, 2002 and 2003) at Swift Current to evaluate the forage preferences of steers grazing five different crested wheatgrass (CWG) cultivars: Kirk (2n=28), Fairway (2n=14) and Parkway (2n=14) [Agropyron cristatum (L.) Gaertn.], Hycrest (2n=28) (A. cristatum×A. desertorum) and Nordan (2n=28) [(A. desertorum (Fisch. Ex Link) Schult.)]. Animal grazing frequencies for each CWG cultivar patch were converted to percentages (Grazing%) for each grazing time period. Grazing% for Kirk and Hycrest CWGs were similar with Nordan having higher (P<0.05) Grazing% compared with the hybrid and diploid CWGs. Contrasts revealed no differences (P=0.48) in Grazing% between diploid versus hybrid cultivars, while higher (P<0.01) Grazing% were observed for tetraploid compared with diploid and hybrid CWG cultivars. For forage nutritive values, significant Cultivar (P<0.01) and Year (P<0.0001) main effects were observed. Overall mean values for percent crude protein (%CP) and percent acid detergent fibre (%ADF) for Nordan, Kirk, Hycrest, Fairway and Parkway were 10.6±0.3 and 29.2±0.4, 11.0±0.3 and 28.7±0.4, 10.4±0.3 and 29.7±0.4, 9.9±0.3 and 28.5±0.4, and 10.0±0.3 and 28.7±0.4, respectively (± SE). Correlation coefficients between Grazing% and all nutritive value constituents were low and not significant. This study observed grazing preference differences among different CWG cultivars that may lead to grazing management strategies to improve pasture utilization potential and animal production.

Early seedling growth and forage production of diploid and tetraploid crested wheatgrass and Russian wildrye cultivars

Cultivars selected for improved seedling vigour may also differ in seedling growth and subsequent forage production. The objective of this project was to compare three cultivars of crested wheatgrass (CWG) and four cultivars of Russian wildrye (RWR) for seedling growth in a greenhouse (GH) trial and two field trials when seeded at 15, 30 and 45 mm depths. Cultivars were Goliath, Kirk and Parkway CWG and SCR39903, Swift, Tetracan, and Tom RWR. Seedling emergence, tiller number, and seedling biomass were determined at 28 d after seeding (DAS) in all three trials. In addition, forage dry matter (DM) yield was determined for 2 yr in the field trials. Small-seeded diploid Parkway crested wheatgrass had reduced emergence at 45 mm seeding depth compared with larger-seeded tetraploid Kirk and Goliath. Goliath had reduced tillering compared with the other two CWG cultivars. The emergence of Tetracan tetraploid RWR was greater at deeper seeding depth than diploid cultivars, SCR39902, Swift and Tom in Field Trial 2,...