• Association of food quality and locations by cattle

      Bailey, D. W.; Sims, P. L. (Society for Range Management, 1998-01-01)
      Twelve yearling steers were observed in an 8-arm radial maze to determine the strength of the association between food quality and spatial locations following a 0- or 30-day delay. The study was conducted using 3 qualities of feed, low (straw), medium (alfalfa pellets), and high (grain). During phase 1, all 8 arms contained dehydrated alfalfa pellets. In phase 2, steers were fed either grain or wheat straw, in 2 arms (key arms). The remaining 6 arms contained alfalfa pellets. Six steers received straw in key arms, and 6 received grain. Key arms varied among steers and were selected so a change in arm selection patterns between phases would clearly be associated with corresponding changes in food quality. Straw was placed in arms that steers selected first during phase 1, and grain was placed in arms that were selected last in phase 1. Phase 3 began after a 0- or 30-day delay following phase 2. In this phase, all arms contained alfalfa. Steers rarely reentered a previously entered arm indicating an accurate spatial memory for food location. The sequence of arm selections in phase 2 changed (P < 0.05) from the pattern established in phase 1, which demonstrated that cattle can associate food quality with spatial locations. The delay between phase 2 and 3 did not affect (P > 0.05) the selection patterns of steers that had grain in key arms, but did appear to affect the number and sequence of arm entries for steers receiving low quality food in key arms during phase 2. With no delay, steers that received straw in phase 2 did not enter key arms on the first day of phase 3, but after 30 days animals entered and consumed food in key arms. Steers with no delay entered key arms fewer (P = 0.03) times during phase 3 than steers that began 30 days later. This suggests that strength of the association between food quality and spatial locations can decline over time.
    • Association of relative food availabilities and locations by cattle

      Bailey, D. W.; Rittenhouse, L. R.; Hart, R. H.; Swift, D. M.; Richards, R. W. (Society for Range Management, 1989-11-01)
      Four yearling steers were trained and observed in a parallel-arm maze. The purpose was to determine if cattle had the ability to associate locations with relative food availabilities. The study consisted of 3 phases. In phase 1, all 5 arms contained 0.4 kg of grain. In phase 2, the amount of grain in each arm was systematically varied from 0.1 to 0.8 kg. In phase 3, placement of grain was reversed. Steers performed efficiently in all 3 phases of the study. The overall-mean number of correct choices in the first 5 entrances was 4.69 as compared to 3.73 by chance. Arms selected for choices 2, 3, and 4 during the last 5 trials of phase 2 were different (P<0.05) from those selected during the last 5 trials of phase 3. For the last 5 trials of phases of 2 and 3, arms selected in choices 1, 2, and 3 contained 0.4, 0.6 and 0.8 kg of grain on 85% of the trials. Steers appeared to order their choices from larger to smaller rewards. Steers apparently can remember not only where they have foraged, but also the amount of food found there.
    • Cattle use of foothills rangeland near dehydrated molasses supplement

      Bailey, D. W.; Welling, G. R.; Miller, E. T. (Society for Range Management, 2001-07-01)
      Strategic supplement placement has been shown to be an effective tool to lure cattle to underutilized rangeland. The goal of this study was to determine where cattle grazed when supplement was placed in foothills rangeland. The study was conducted in 4 pastures in northern Montana that were dominated by cool-season grasses. For 2-week periods beginning in October 1998 and ending in January 1999, dehydrated molasses blocks (30% CP) were placed in locations within 3 pastures that were steeper and further from water. Forage utilization was measured at the time of supplement placement and again at removal. Increases in forage utilization during each period (14%) were similar (P > 0.1) at distances of 30 to 600 m from supplement, and increases were additive across periods. Forage utilization was evaluated in a fourth pasture during August and September 1999 at distances of 50 to 3,000 m from the supplement. Forage use declined (P < 0.01) at further distances from supplement, and forage use at distances less than 600 to 800 m from supplement was greater than the average of all measurements collected throughout the pasture. During the autumn and early winter at the 2 pastures located near Havre, Mont., 53% of the cows were observed within 600 m of supplement and 47% were observed at greater distances from supplement. Eighty-one of the 159 cows grazing the 2 pastures near Havre (245 and 330 ha) were fitted with Global Positioning System (GPS) tracking collars. The collared cows spent 37% of their time within 600 m of supplement. Uniformity of cattle grazing can be enhanced by the placement of dehydrated molasses supplement in rugged topography, and the area influenced can include distances up to 600 m from supplement.
    • Genetic influences on cattle grazing distribution: Association of genetic markers with terrain use in cattle

      Bailey, D. W.; Lunt, S.; Lipka, A.; Thomas, M. G.; Medrano, J. F.; Cánovas, A.; Rincon, G.; Stephenson, M. B.; Jensen, D. (Society for Range Management, 2015-03)
      Eighty-seven cows were GPS (Global Positioning System) tracked for 1 to 3 months in mountainous and/or extensive pastures at five ranches located in New Mexico, Arizona, and Montana. The Illumina Bovine HD SNP array, which evaluates approximately 770,000 genetic markers (i.e., single nucleotide polymorphisms; SNPs) across the 30 bovine chromosomes, was used to genotype DNA from these cows and to examine genetic associations with grazing distribution. Terrain use indexes were calculated from tracking data based on normalized averages of slope use, elevation use, and distance travelled from water. Genetic analyses identified a chromosomal region, known as a quantitative trait locus (QTL), associated with these traits. One genetic marker on chromosome 29 identified a gene that has been reported to be involved in locomotion, motivation, and spatial memory. This locus accounted for 24% of the phenotypic variation in use of steep slopes and high elevations, while another QTL on chromosome 17 accounted for 23% of the phenotypic variation. Three other QTLs accounted for 10% to 20% of the variation in terrain use indexes. Using results from the initial high-density genetic marker analyses, a smaller 50-SNP panel was developed targeting previously identified QTL regions and was used to evaluate the 85 cows tracked previously with an additional 73 cows from four ranches. With the 50-SNP panel analyses, multiple genetic markers near or within the gene identified on chromosome 29 confirmed the association with indexes of terrain use. In addition, genetic markers on chromosomes 4, 8, 12, and 17 accounted for a significant portion of the phenotypic variation in terrain use indexes. The associations between terrain use indexes and genetic markers near candidate genes demonstrate that grazing distribution can be inherited and provide a new approach to associate genetic variation with cattle grazing behavior of range beef cattle. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Long-term forage and cow-calf performance and economic considerations of two stocking levels on chihuahuan desert rangeland

      Thomas, M. G.; Mohamed, A. H.; Sawalhah, M. N.; Holechek, J. L.; Bailey, D. W.; Hawkes, J. M.; Luna-Nevarez, P.; Molinar, F.; Khumalo, G. (Society for Range Management, 2015-03)
      Forage and cow-calf productivity on two lightly and two conservatively grazed pastures were evaluated over a 15-year period (1997-2011) in the Chihuahuan Desert of south-central New Mexico. Spring-calving Brangus cows were randomly assigned to pastures in January of each year. Pastures were similar in area (1 098 ± 69 ha, mean ± SE) with similar terrain and distance to water. Utilization of primary forage species averaged 27.1 ± 3.0% in lightly stocked pastures and 39.4 ± 4.0% on conservatively stocked pastures. No differences in perennial grass standing crop (163.5 ± 52.2 kg·ha-1) and calf weaning weights (286.1 ± 2.6 kg) were detected (P &gt; 0.10) between light and conservative treatments. Lightly grazed pastures yielded greater (P &lt; 0.05) kg of calf weaned·ha-1 and calf crop percent than conservatively grazed pastures in 1998 due to complete destocking of conservatively grazed pastures during that slight drought (i.e., rainfall was 75% of normal in 1998). After the initial 5 years of study (1997-2001), all pastures were destocked for 4 years (2002-2005) due to drought as rainfall was only 50% or less of normal. Pastures were then restocked for another 6 years (2006-2011). Postdrought, the percentage change in perennial grass standing forage crop (kg·ha-1) was -4.0 and -14.4 ± 2.5 % (P &lt; 0.09) in the light and conservative grazed pastures across the 6 years, respectively. While conservative stocking rates may provide higher net financial returns than light stocking rates during nondrought years as there were more AU per pasture, potential losses from cattle liquidation during short-term (i.e., 1-year) droughts could nullify this advantage. Results suggest that light grazing use of forage is a practical approach for Chihuahuan Desert cow-calf operations to minimize risk of herd liquidation during short-term drought. © 2015 Society for Range Management. Published by Elsevier Inc. All rights reserved.
    • Mechanisms that result in large herbivore grazing distribution patterns

      Bailey, D. W.; Gross, J. E.; Laca, E. A.; Rittenhouse, L. R.; Coughenour, M. B.; Swift, D. M.; Sims, P. L. (Society for Range Management, 1996-09-01)
      Grazing distribution patterns of large herbivores are affected by abiotic factors such as slope and distance to water and by biotic factors such as forage quantity and quality. Abiotic factors are the primary determinants of large-scale distribution patterns and act as constraints within which mechanisms involving biotic factors operate. Usually there is a proportional relationship between the time large herbivores spend in a plant community and the available quantity and quality of forage. This grazing pattern may result from decisions made by animals at different spatial and temporal scales. Foraging velocity decreases and intake rate increases in areas of abundant palatable forage. These non-cognitive mechanisms that occur at smaller spatial scales (bites, feeding stations, small patches) could result in observed grazing patterns. However, large herbivores also appear to select areas (patches and feeding sites) to graze. Optimal foraging models and other models assume animals use "rules of thumb" to decide where to forage. A cognitive mechanism assumes animals use spatial memory in their foraging decisions. With such abilities, large herbivores could return to nutrient-rich sites more frequently than to nutrient-poor sites. Empirical studies indicate that large herbivores have accurate spatial memories and have the ability to use spatial memory to improve foraging efficiency. Body size and perceptual abilities can constrain the choices animals can make during foraging. A conceptual model was developed to demonstrate how cognitive foraging mechanisms could work within constraints imposed by abiotic factors. Preliminary predictions of the model correspond to observed grazing patterns. Recognizing that large herbivores may use previous experiences to decide where to forage may be useful in developing new techniques to modify grazing patterns. Grazing distribution patterns appear to result from decisions and processes made at a variety of spatial and temporal scales.
    • Modification of cattle grazing distribution with dehydrated molasses supplement

      Bailey, D. W.; Welling, G. R. (Society for Range Management, 1999-11-01)
      A study was conducted in foothill rangelands during the fall to determine if livestock grazing distribution could be improved by strategic placement of dehydrated molasses supplement blocks (30% crude protein). Three pastures were categorized into inaccessible, easy, moderate, and difficult terrain. Moderate and difficult terrain was further divided into 27 to 55 ha subunits (n=32) and randomly assigned to control or supplement treatments. Every 7 to 10 days supplement and salt were moved; then the new supplement and control subunits were evaluated. Cattle use of the control and supplement subunits was compared by measuring forage utilization and fecal pat abundance both before supplement and salt placement and after removal. Measurements were collected near randomly selected sites within both control and supplement subunits. Salt was placed at half of the sites in both subunits while dehydrated molasses blocks were placed at sites only in the supplement subunit. Average daily supplement intake was lower (p<0.05) in the difficult terrain of 1 pasture (190 g) but ranged from 286 to 386 g in the other areas. Cattle consumed more (P<0.001) salt near supplement than in control areas. More (P<0.01) cattle were observed in areas with supplement (32 +/- 8%) than in control areas (3 +/- 2%). Increase in fecal pats was greater (P=0.01) in areas with supplement (3.3 +/- 07 pats/100 m2) than control areas (0.5 +/- 0.5 pats/100 m2) indicating greater use by cattle. Change in forage utilization was also greater (P>0.001) in areas with supplement (17 +/- 2%) than in control areas (-1 +/- 1%). For supllement areas, the incrase in forage utilization was greater (P < 0.05) in moderate terrain than in difficult terrain. Results from this study suggest that cattle can be lured to underutilizated rangeland by the strategic placement of dehydrated molasses supplement blocks.
    • Short-term monitoring of rangeland forage conditions with AVHRR imagery

      Thoma, D. P.; Bailey, D. W.; Long, D. S.; Nielsen, G. A.; Henry, M. P.; Breneman, M. C.; Montagne, C. (Society for Range Management, 2002-07-01)
      A study was conducted to determine the potential of using Advanced Very High Resolution Radiometer (AVHRR) imagery to monitor short-term changes in rangeland forage conditions on a regional scale. Forage biomass and nitrogen concentration were estimated at 6 study sites throughout a typical grazing season (April to October). Study sites were located in northern and southern Montana in areas classified as foothills grassland and shortgrass prairie. Normalized Difference Vegetation Index (NDVI) values from AVHRR imagery (1 km pixels) were used to predict live biomass, dead standing biomass, total biomass, nitrogen (N) concentration and standing N. Values of the NDVI were correlated (r < 0.4, P < 0.01) to live, dead, and total biomass estimates and standing N, but were not correlated to N concentration (r = 0.04, P = 0.8). Relationships between NDVI and vegetative attributes were similar (P > 0.05) for all 6 study sites, which indicates that NDVI could be used to predict forage abundance at multiple locations and at variable dates. Using simple linear regression, NDVI accounted for 63% of the variation in live and total biomass, 18% of the variation in dead biomass, 66% of the variation in standing N, but < 1% of the variation in N concentration. The NDVI obtained from AVHRR imagery was a good predictor of forage abundance as measured by live, dead and total biomass as well as standing N, but it was not related to forage quality as measured by N or crude protein concentration. On a regional basis, land managers could use AVHRR-NDVI values to identify areas with high or low levels of forage abundance that may result from factors such as drought, variable precipitation patterns, or uneven grazing.