• Estimation of fecal output with an intra-ruminal continuous release marker device

      Adams, D. C.; Short, R. E.; Borman, M. M.; MacNeil, M. D. (Society for Range Management, 1991-05-01)
      Efficacy of a continuous release marker device (CRD) containing chromium oxide to estimate fecal output was evaluated in two 12-day grazing trials with beef steers (n = 10, trial 1; n = 7, trial 2). Trial 1 was conducted on mature green irrigated tall wheatgrass (Elytrigia pontica [Podp.] Holub) pasture during September. Trial 2 was conducted on dormant native range during December. Fecal output was determined by total fecal collection (TFC) and the CRD for each steer. Fecal output estimates from the CRD were based on a chromium release rate (980 mg/day) provided by the manufacturer. Estimates of daily fecal dry matter output (kg) in trial 1 were 2.70 and 2.69, and in trial 2 were 3.19 and 2.89 from the TFC and CRD, respectively. Differences between TFC and CRD were not significant in trial 1 (P = 0.59) but were significant in trial 2 (P < 0.01). When averaged over days and animals, estimates of daily fecal dry matter from CRD were within 1% of TFC in trial 1 and 10% of TFC in trial 2. Estimates of daily fecal dry matter from CRD were influenced by sampling day and steer (P < 0.01); however, there was no consistent pattern to day or animal variation. Multiple days and animals are required for both TFC and CRD. We conclude that CRD provides an acceptable estimate of daily fecal output. However, to improve accuracy, TFC can be used on a subsample of animals as a double sampling technique to adjust estimates derived from CRD.
    • Heifer Production on Rangeland and Seeded Forages in the Northern Great Plains

      Haferkamp, M. R.; MacNeil, M. D.; Grings, E. E.; Klement, K. D. (Society for Range Management, 2005-09-01)
      Integrating use of seeded perennial cool-season grass pastures with native rangeland can increase available forage and provide a high plane of nutrition for grazing livestock. Our objective was to compare performance of yearling beef heifers grazing native rangeland with those grazing an integrated system that included seeded forages. Twice-replicated, 3-ha pastures seeded to either ‘Rosana’ western wheatgrass (Pascopyron smithii [Rydb.] A. Love), ‘Luna’ pubescent wheatgrass (Elytrigia intermedia [Host] Nevski), or ‘Hycrest’ crested wheatgrass (Agropyron cristatum [L.] Gaertn. ssp. desertorum [Fisch. ex Link] A. Love) were grazed in spring, whereas twice-replicated, 3.24-ha pastures seeded to either ‘Alkar’ tall wheatgrass (Thinopyrum ponticum [Podp.] ZW Liu RC Wang), ‘NewHy’ hybrid wheatgrass (Elymus hoffmannii KB Jensen KH Asay), ‘Bozoisky’ Russian wildrye (Psathyrostachys juncea [Fisch.] Nevski.), or ‘Prairieland’ Altai wildrye (Leymus angustus [Trin.] Pilger) were grazed in autumn. Native rangeland was grazed during summer in the integrated system and spring, summer, and autumn in the rangeland treatment. Heifers exhibited greater weight gains on seeded pastures than on native rangeland in spring and autumn of most years. In 2 out of 3 years, heifers that grazed native rangeland during spring gained more (P = 0.012 for gain head-1 and P = 0.021 for gain head-1 day-1) while grazing native rangeland during summer than heifers that grazed seeded pastures in spring. Spring + summer gains averaged (mean +/- SE) 0.56 +/- 0.01 kg head-1 d-1 and 73.1 +/- 1.6 kg head-1. Livestock managers need to consider their livestock marketing and management strategies when using seeded pastures for seasonal grazing.  
    • Influence of storage, temperature, and light on germination of Japanese brome seed

      Haferkamp, M. R.; Karl, M. G.; MacNeil, M. D. (Society for Range Management, 1994-03-01)
      Japanese brome (Bromus japonicus Thunb.), an alien annual grass, is an important component of some northern mixed-prairie communities. Understanding the relationship between environment and population dynamics for this species is critical for efficient management of infested ranges. Our objective was to determine the germination pattern of seed harvested in the Great Plains with varying collection dates, storage conditions, incubation temperatures, and light regimes. Seeds were collected from inflorescences (nondisseminated seed) during July in Oklahoma a Montana and during November and December in Montana. July collections were stored in paper sacks in a laboratory, and November and December collections were divided into thirds and stored in an unheated warehouse, oven-dried at 46 degrees C, or frozen at -18 degrees C. Seeds were germinated in 2 regimes, where temperatures alternated every 12 hours and light was provided during the hours of high temperature. One regime provided 10 days of prechilling (0 and 10 degrees C) followed by 18 days of a warm temperature (8 and 23 degrees C) (chilling). Another regime consisted of 28 days of the warm temperature (warm). Samples of seeds were also imbibed in the warm regime with 12-hour or intermittent periods of light. July collections germinated rapidly to > 90% regardless of temperature. November and December collections stored in the warehouse germinated > 70% in the warm regime, but germination was reduced to < 20% with chilling, suggesting secondary dormancy was induced by imbibition at 0 degrees C. Oven drying was the only treatment that consistently reduced maximum germination. Darkness enhanced 7-day germination, but light improved 28-day germination, and more recently collected seeds were more sensitive to light than older ones. These and earlier findings from Kentucky suggest Japanese brome seeds grown in different locations respond similarly to changing environmental conditions.
    • Influence of temperature on germination of Japanese brome seed

      Haferkamp, M. R.; Palmquist, D.; Young, J. A.; MacNeil, M. D. (Society for Range Management, 1995-05-01)
      Japanese brome (Bromus japonicus Thunb.), an introduced annual grass, is now common in some northern mixed-prairie communities. This species has the potential to alter both the seasonality of standing crop and forage quality. We sought to gain a greater understanding of Japanese brome seed germination by subjecting seed to a series of 55 constant or alternating temperature regimes following 3 to 9 months of dry laboratory storage. Cold and moderate temperature regimes provided optimum germination conditions (defined as not lower than the maximum observed minus one-half its confidence interval at the 0.05 level of probability). Extremely cold or warm temperatures suppressed germination. Germination of afterripened seed over a wide range of temperature combinations, many of which occur during fall in the Northern Great Plains, should enhance establishment and perpetuation of Japanese brome on rangelands.
    • Predicting Nitrogen Content in the Northern Mixed-Grass Prairie

      Haferkamp, M. R.; MacNeil, M. D.; Grings, E. E. (Society for Range Management, 2005-03-01)
      Forage quality and quantity are important factors affecting livestock production from grazing lands. ‘‘Greenness’’ has been proposed as an indicator of herbage quality in semiarid environments, particularly nitrogen (N) content. The objective of this study was to assess the potential of estimating N content of forage using dead:green ratios and accumulated growing-degree- days (AGDD). Standing crop samples were collected April through October over 3 years from each of 3 replicated grazing regimes on a silty range site in eastern Montana. Samples were sorted into live, current dead, and old dead components, then dried, ground, and analyzed for N content. The AGDD for base temperature 45 degreesF (7.2 degreesC) was calculated from National Oceanic and Atmospheric Administration (NOAA) reported monthly average temperatures for Miles City. An equation to predict percent N in the total standing crop from percent dead forage and AGDD was developed using multiple linear regression. This equation accounted for 75.9% of variation in percent N, and prediction error variance was 0.026. To validate this equation, data were obtained from samples collected from April through September in an independent study of 8 areas on silty and clay- pan range sites grazed during autumn and winter. Samples from these sites were treated and analyzed in the same manner as those used to develop the equation. The developed equation was used to predict percent N for the validation data. The resulting correlation between predicted and actual values was 0.79. The regression coefficient for actual values on predicted values was 0.995 +/- 0.125. The intercept did not differ from 0.0 (P = 0.22), and prediction error variance was 0.042. This equation has utility for predicting N level of forage from Northern Great Plains rangelands.  
    • Quality and persistence of forages in the Northern Great Plains

      Haferkamp, M. R.; Grings, E. E.; Heitschmidt, R. K.; MacNeil, M. D. (Society for Range Management, 2002-09-01)
      Integrating use of seedings of perennial cool-season grasses with native range is used to increase available forage and for maintaining a high plane of nutrition for grazing livestock. Our goal was to evaluate performance of yearling cattle and stand persistence of 3 released wheatgrass cultivars. Twice replicated 3-ha pastures were seeded to 'Rosana' western wheatgrass [Pascopyron smithii (Rydb.) A. Love], 'Luna' pubescent wheat-grass [Elytrigia intermedia (Host) Nevski], and 'Hycrest' crested wheatgrass ([Agropyron cristatum (L.) Gaertn.] ssp. desertorum (Fisch. ex Link) A. Love) in autumn 1994. Yearling steers (n = 8) grazed from 9 May to 12 June 1997 and 24 April to 15 June 1998. Yearling heifers grazed from 27 April to 18 June 1999. Hycrest produced the largest herbage standing crop in spring 1997 (912 kg ha(-1)) and 1998 (1,223 kg ha(-1)) (P < 0.05), but by spring 1999 standing crops averaged 656 kg ha(-1), and cultivars were not significantly different. Digestible organic matter standing crop did not differ among pastures of seeded species, but declined (P < 0.05) from May to June each year. Crude protein standing crop varied among cultivars (P < 0.05) in April and May 1998 and May 1999; however, no clear trends emerged. Crude protein standing crops consistently declined from April-May to June. Average daily gains were similar among cultivars in 1997, but greater (P < 0.05) on Hycrest (1.28 kg day(-1)) than Rosana (1.03 kg day(-1)) in 1998. Gains on Hycrest (0.74 kg day(-1)) and Rosana (0.78 kg day(-1)) were greater (P < 0.05) than on Luna (0.52 kg day(-1)) in 1999. These findings show in some years, Hycrest provided more forage in spring than Rosana, and will allow an increase in livestock numbers. Based on the encroachment of invading species, persistence of Luna is marginal of the 335-mm precipitation zone in the Northern Great Plains.
    • Suppression of annual bromes impacts rangeland: Animal responses

      Haferkamp, M. R.; Grings, E. E.; Heitschmidt, R. K.; MacNeil, M. D.; Karl, M. G. (Society for Range Management, 2001-11-01)
      Presence of annual bromes (Bromus spp.), introduced annual weedy grasses, can alter seasonal patterns of forage production and quality and require management changes for efficient use of infested rangelands. We determined biological impacts of the presence of brome by comparing livestock performance on brome infested rangeland to similar sites on which brome had been suppressed by autumn application of atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)- 1,3,5-triazine-2,4-diamine] at 0.56 kg ha(-1) in 1992 and 1993. Each treatment was randomly assigned to three, 12-ha pastures. Vegetation was measured for 5 months (May to September) each year from 1993 to 1995. Each pasture was stocked with 8 crossbred steers of British breed origin (Bos taurus) from mid-May to mid-September 1993 and 1995 and to mid-August 1994. Initial body weights averaged 329 kg SD = 31 in 1993, 273 kg SD = 14 in 1994, and 272 kg SD = 21 in 1995. Brome suppression and environment influenced plant species in diets, diet quality, and livestock performance. Brome suppression reduced percentage of annual grasses in diets from 14% to 10%. Annual grasses were replaced in the diet by a variety of forb and grass species [western wheatgrass [Pascopyrum smithii Rydb. (Love)], and blue grama [Bouteloua gracilis [H.B.K.] Lag. ex Griffiths]], with specific replacement depending on year and month. Steer gains were increased from 0.92 to 1.04 +/- 0.02 kg head(-1) day(-1) (P < 0.02) and from 69 to 81 +/- 2.8 kg ha(-1) (P < 0.05) with brome suppression. This experiment demonstrated that improvement in livestock performance can be expected with the suppression of annual bromes on semiarid rangelands.
    • Suppression of annual bromes impacts rangeland: Vegetation responses

      Haferkamp, M. R.; Heitschmidt, R. K.; Grings, E. E.; MacNeil, M. D.; Karl, M. G. (Society for Range Management, 2001-11-01)
      Presence of invading annual bromes (Bromus spp.) can alter seasonal patterns of forage production and quality and require management changes for efficient use of infested rangelands in the Northern Great Plains. We studied biological impacts of the presence of brome by comparing brome infested rangeland to similar sites in which brome had been suppressed with autumn applications of atrazine [6-chloro-N-ethyl-N'-(1-methylethyl)- 1,3,5-triazine-2,4-diamine] at 0.56 kg ha(-1) in 1992 and 1993. Each treatment was randomly assigned to three, 12-ha pastures. Vegetation was measured for 5 months (May to September) each year from 1993 to 1995. Each pasture was stocked with 8 cross-bred steers (Bos taurus) from mid-May to mid-September 1993 and 1995 and to mid-August 1994. The forage base varied temporally by date and year, but generally was not less than 800 kg ha(-1). Brome suppression increased (P less than or equal to 0.05) crude protein concentration for western wheatgrass (Pascopyrum smithii Rydb. [Love]) in July (7.1 vs. 9.1%) and August (6.0 vs. 7.1%). With the variation in annual brome stands among years, as influenced by growing conditions, this experiment demonstrated that improvement in forage nutritional quality can be expected from suppression of annual bromes on semiarid rangelands.