Winter Grazing Research Articles

Nutritive value of winter-collected annual twigs of main European woody species, mistletoe and ivy and its possible consequences for winter foddering of livestock in prehistory

In Central Europe, forest grazing was probably the main way of providing winter feeding for livestock in prehistory; the main components of this diet most likely included annual twigs of woody species ( Acer platanoides, Betula pendula, Carpinus betulus, Corylus avellana, Fagus sylvatica, Fraxinus excelsior, Picea abies, Pinus sylvestris, Populus tremula, Quercus robur, Salix caprea, Tilia cordata and Ulmus glabra), Hedera helix, Viscum album and senescent grassland biomass; however, their nutritive value has never been compared. Biomass samples were collected in the Czech Republic in February 2013 and analysed for concentration of nitrogen, phosphorus, potassium, calcium, magnesium, fibre and lignin. With the help of a recent analogy from the Altai Mountains (Russia), possible consequences of winter grazing on the development of forest vegetation and cattle breeds in prehistory were assessed. Hedera and Viscum were the best forage available in winter, and their nutritive value, according to the highest N and lowest fibre and lignin concentrations, was higher than the nutritive value of all winter-collected annual twigs of woody species. Nutritive value of annual twigs of all woody species was very low, especially compared with the quality of meadow hay, leaf-fodder or senescent steppe grassland biomass. Therefore, Hedera and Viscum might have been preferentially grazed by livestock and collected by ancient farmers for the supplementary feeding of privileged animals. According to recent analogy, annual twigs of woody species were browsed by livestock. Their insufficient quality could be one of the reasons for the low body size of cattle recorded in prehistory. The most realistic model of livestock breeding in prehistory seems to be year-round grazing, opening forests and causing deforestation in the surroundings of prehistoric settlements.

Integration of measures to mitigate reactive nitrogen losses to the environment from grazed pastoral dairy systems

SUMMARYThe need for nitrogen (N) efficiency measures for dairy systems is as great as ever if we are to meet the challenge of increasing global production of animal-based protein while reducing N losses to the environment. The present paper provides an overview of current N efficiency and mitigation options for pastoral dairy farm systems and assesses the impact of integrating a range of these options on reactive N loss to the environment from dairy farms located in five regions of New Zealand with contrasting soil, climate and farm management attributes. Specific options evaluated were: (i) eliminating winter applications of fertilizer N, (ii) optimal reuse of farm dairy effluent, (iii) improving animal performance through better feeding and using cows with higher genetic merit, (iv) lowering dietary N concentration, (v) applying the nitrification inhibitor dicyandiamide (DCD) and (vi) restricting the duration of pasture grazing during autumn and winter. The Overseer®Nutrient Budgeting model was used to estimate N losses from representative farms that were characterized based on information obtained from detailed farmer surveys conducted in 2001 and 2009. The analysis suggests that (i) milk production increases of 7–30% were associated with increased N leaching and nitrous oxide (N2O) emission losses of 3–30 and 0–25%, respectively; and (ii) integrating a range of strategic and tactical management and mitigation options could offset these increased N losses. The modelling analysis also suggested that the restricted autumn and winter grazing strategy resulted in some degree of pollution swapping, with reductions in N leaching loss being associated with increases in N loss via ammonia volatilization and N2O emissions from effluents captured and stored in the confinement systems. Future research efforts need to include farm systems level experimentation to validate and assess the impacts of region-specific dairy systems redesign on productivity, profit, environmental losses, practical feasibility and un-intended consequences.

Soil physical attributes in integrated bean and sheep system under nitrogen levels

Integrated crop-livestock systems (ICLS) can promote higher grain and meat/milk yield as well as reduce soil degradation risks. Thus, this study aimed to evaluate the influence of grazing sheep with moderate intensity and nitrogen doses on soil physical attributes, and bean crop yield (Phaseolus vulgaris Lam.) under rotation with summer corn crop (Zea mays Lam.) and winter pasture with oats (Avena sativa Lam) and ryegrass (Lolium multiflorum Lam.) The experimental design was completely randomized blocks with split-plot; the plots were nitrogen doses and the split-plots were grazing presence or absence. The treatments were nitrogen doses of 0, 75, 150 and 225 kg ha-1 applied on ryegrass and white oat pasture in winter followed by bean crop. Soil density, macroporosity, microporosity and total porosity and bean grain yield were evaluated. When ICLS are managed under no-tillage with moderate grazing, sheep trampling did not affect negatively soil physical attributes, which did not reach critical levels for subsequent growth and development of the bean crop. The black bean yield in summer was not affected by antecedent presence of sheep grazing in winter.

Yield and composition of lucerne stands in Central Otago after different winter grazing and weed control treatments

Abstract The effect of grazing date and time of spraying with a glyphosate/atrazine herbicide combination on a threeyear- old lucerne stand was studied on-farm in Central Otago. Total annual dry matter (DM) yield was highest in the weedy unsprayed control (14.8 t DM/ha) and lowest in the crop sprayed on 18 September (10.1 t DM/ ha). However, lucerne DM yield was highest from the 3 July and 22 August spray treatments (11.4 ± 0.39 t DM/ ha) and lowest in the unsprayed control at 7.7 t DM/ha. Phytotoxicity symptoms of glyphosate on the lucerne tended to be limited to crops sprayed on 18 September. To maximise yield, a winter clean-up grazing (June) followed by a winter herbicide application (July/August) when lucerne was approximately 3 cm high and with

Estimating lichen volume and reindeer winter pasture quality from Landsat imagery

Reindeer and caribou are keystone species in the circumpolar region, and rely on lichens as their main winter forage to survive in some of the most extreme environments on Earth. Lichen mats, however, can be heavily overgrazed at high deer densities, triggering area abandonment or population declines. Although the species' management and conservation require precise information on the quality of winter grazing areas, no reliable and cost-efficient methods are available to date to measure lichen volume across wide and remote areas. We developed a new Lichen Volume Estimator, LVE, using remote sensing and field measurements. We used a Landsat TM land cover mask to separate lichen heath communities from other vegetation types and, therein, we predicted lichen volume from a two dimensional Gaussian regression model using two indexes: the Normalized Difference Lichen Index, NDLI (Band 5−Band 4/Band 5+Band 4), and the Normalized Difference Moisture Index, NDMI (Band 4−Band 5/Band 4+Band 5). The model was parameterized using 202 ground measurements equally distributed across a gradient ranging from 0 to 80 lichen dm3/m2 (R2=0.74 between predicted and observed ground measurements), and was validated with a ten-fold cross validation procedure (R2=0.67), which also showed a high parameter stability. The LVE can be a valuable tool to predict the quality of winter pastures for reindeer and caribou and, thus, help to improve the species' management and conservation.

The relation of biomass production with leaf traits varied under different land‐use and precipitation conditions in an Inner Mongolia steppe

AbstractThe analyses of plant leaf traits that strongly influence aboveground net primary production (ANPP) are indispensable for understanding the process of plant biomass formation. However, there are few studies that have attempted to relate patterns of ANPP under contrasting management practices to plant leaf‐level traits. To assess how leaf traits affect plant biomass accumulation under different land‐use practices, we examined leaf traits and biomass production in three differently managed sites in the Inner Mongolia steppe: a site fenced since 1979 (UG), a winter grazing site (WG), and a heavily grazed site (HG). Low soil water content, leaf area index, and potential growth ability of species at site HG led to low crop growth rate (CGR), net assimilation rate (NAR), and relative growth rate (RGR); resulting in lower ANPP as compared to sites WG and UG. Irrespective of land‐use management, prolonged drought significantly decreases ANPP even though it systematically increases mean CGR and RGR. However, leaf N content and leaf weight ratio are the crucial components necessary to determine the RGR at site WG. This suggests that low leaf N and availability of soil N due to haymaking may be responsible for neither over‐compensatory nor compensatory growth in this site. The low ANPP in dry years is not due to the low mean CGR and RGR but rather to the short effective growing days (referring to the days the vegetation actually grows), suggesting that production‐adjusted grazing regimes may be the most suitable measures for precision land management and avoiding grassland degradation.

Quantitative assessment of aboveground plant production and its components in steppe pasture

The production of aboveground plant matter was assessed in a deserted-steppe pasture in the northern Caspian Depression. This pasture consists of vegetation consumed by animals, matter damaged by trampling (fall), and standing biomass (living and dead standing plants). The consumed mass was estimated from the amount of feces produced in the time of record and the digestion coefficient of the plant consumed. After 500 ha of the pasture were grazed by 850 sheep (1.7 individuals/ha) in the spring and summer (April through September), 29% of the aboveground plant mass remained standing; the consumed biomass constituted 27%, and the biomass destroyed by trampling was 44%. The total aboveground production was 2070 kg/ha, which was the same as in a reserved site (2060 kg/ha), but less than in a pasture experiencing mild winter grazing (2425 kg/ha).

Community level offset of rain use- and transpiration efficiency for a heavily grazed ecosystem in inner Mongolia grassland.

Water use efficiency (WUE) is a key indicator to assess ecosystem adaptation to water stress. Rain use efficiency (RUE) is usually used as a proxy for WUE due to lack of transpiration data. Furthermore, RUE based on aboveground primary productivity (RUEANPP) is used to evaluate whole plant water use because root production data is often missing as well. However, it is controversial as to whether RUE is a reliable parameter to elucidate transpiration efficiency (TE), and whether RUEANPP is a suitable proxy for RUE of the whole plant basis. The experiment was conducted at three differently managed sites in the Inner Mongolia steppe: a site fenced since 1979 (UG79), a winter grazing site (WG) and a heavily grazed site (HG). Site HG had consistent lowest RUEANPP and RUE based on total net primary productivity (RUENPP). RUEANPP is a relatively good proxy at sites UG79 and WG, but less reliable for site HG. Similarly, RUEANPP is good predictor of transpiration efficiency based on aboveground net primary productivity (TEANPP) at sites UG79 and WG but not for site HG. However, if total net primary productivity is considered, RUENPP is good predictor of transpiration efficiency based on total net primary productivity (TENPP) for all sites. Although our measurements indicate decreased plant transpiration and consequentially decreasing RUE under heavy grazing, productivity was relatively compensated for with a higher TE. This offset between RUE and TE was even enhanced under water limited conditions and more evident when belowground net primary productivity (BNNP) was included. These findings suggest that BNPP should be considered when studies fucus on WUE of more intensively used grasslands. The consideration of the whole plant perspective and “real” WUE would partially revise our picture of system performance and therefore might affect the discussion on the C-sequestration and resilience potential of ecosystems.

Energy and economic values of greenhouse sheds to replace winter grazing in northwestern China

AbstractTo demonstrate that winter grazing in northwestern China is counterproductive to animal production, 40 ewes from two farms were kept throughout a winter inside makeshift greenhouse sheds while another 40 ewes were left grazing in the traditional manner. Results show that the average temperature inside the greenhouse was 10, 14 and 4°C higher than outside at 9 am, 12 noon and 9 pm, respectively (all P < 0.001), and that ewes inside the greenhouse lost 3 kg less bodyweight than those outside (P < 0.001). An analysis using the authors' bioeconomic model suggests that the proposed method can save 2.4 MJ day−1 head−1 of metabolizable energy and, at the gross economic benefit of 1191 yuan or $189 year−1, the initial cost of 3000 yuan or $477 can be paid off within three seasons.

Effect of rate of body weight gain in steers during the stocker phase. I. Growth, partitioning of fat among depots, and carcass characteristics of growing-finishing beef cattle1

Two experiments were conducted to examine the effect of growth rate to similar age or BW on fat deposition in stocker cattle grazing dormant native range (DNR) or winter wheat pasture (WP). In each experiment, fall-weaned Angus steers were randomly allotted to 1 of 4 stocker production programs: 1) control, 1.02 kg/d of a 40% CP cottonseed meal-based supplement during grazing of DNR (CON); 2) corn/soybean meal-based supplement fed at 1% of BW during grazing of DNR (CORN); 3) grazing WP at a high stocking rate to achieve a low rate of BW gain (LGWP); and 4) grazing WP at a low stocking rate to achieve a high rate of BW gain (HGWP). In Exp. 1, a subset of steers (3 steers per treatment) was harvested after winter grazing (138 d) at similar age. The remaining WP steers were transitioned into the finishing phase, whereas DNR steers were allowed to graze the same native range pastures for another 115 d without supplementation before entering the feedyard. In Exp. 2, steers grazed their respective pastures until each treatment reached an estimated HCW of 200 kg (262, 180, 142, and 74 d, respectively, for the CON, CORN, LGWP, and HGWP treatments), at which time a subset of steers (4 steers per treatment) were selected for intermediate harvest before finishing. In both experiments, the remaining steers were fed a finishing diet to a common 12th-rib fat thickness of 1.27 cm. In Exp. 1, winter grazing ADG was 0.19, 0.52, 0.68, and 1.37 ± 0.03 kg/d; and in Exp. 2, winter/summer grazing ADG was 0.46, 0.61, 0.83, and 1.29 ± 0.02 kg/d, respectively for CON, CORN, LGWP, and HGWP treatments. At intermediate harvest in Exp. 1, HGWP steers had greater (P < 0.01) 12th-rib fat thickness and marbling scores, compared with the other treatments. However, in Exp. 2, LGWP steers had greater (P < 0.01) marbling scores compared with HGWP steers, which were greater than DNR steers. At final harvest in Exp. 1, LGWP steers had greater (P < 0.01) 12th-rib fat thickness and smaller LM area, compared with the other treatments; however, there were no differences (P = 0.99) in final marbling scores. In Exp. 2, CON steers had lower (P < 0.05) 12th-rib fat thickness and tended (P = 0.10) to have greater marbling scores, compared with the other treatments. These data suggest that changes in the partitioning of fat among depots during the stocker phase may not be reflected after finishing when steers are fed to a common 12th-rib fat thickness.

Twenty Years After Decollectivization: Mobile Livestock Husbandry and Its Ecological Impact in the Mongolian Forest-Steppe

The socioeconomics and the ecological impact of nomadic pastoralism were analyzed using interviews with 87 herder families and secondary information in the western Khangai, Mongolia. The pastoralists had an income above the national average for rural areas in Mongolia. Most herders continued traditional seasonal migration patterns, which involved ca. 10 moves per year over a total distance of ca. 100 km between summer and winter grazing grounds. As elsewhere in Mongolia, the number of goats owned by herders has greatly increased and cashmere has become the main source of cash income. Total livestock numbers rose considerably after decollectivization of the livestock sector in 1992, but in recent years have periodically been reduced by harsh winters, often combined with drought. Due to the high economic risk of these periodic livestock losses, many herders invest in better education for their children to enable them to migrate to the cities.

Impact of grazing on soil properties and cotton yield in an integrated crop–livestock system

The impact of integrating cattle into a sod-based crop rotation was evaluated to understand the short and long-term effects of winter grazing on soil properties and productivity in terms of cotton yield. The rotation consisted of two years of bahiagrass followed by a year each of peanut and cotton. Cattle grazed on oats/rye during the winter. The influence of grazing and irrigation on soil properties such as soil bulk density, organic matter, nitrate N, extractable P, exchangeable K, microbial biomass C, total organic C, and nutrient cycling enzymes (acid and alkaline phosphatases, arylsulfatase, β-glucosidase, and β-glucosaminidase) was examined. Soil bulk density was not significantly affected by grazing at depths lower than 5cm. The percentage of total organic C that occurred as microbial biomass C at all 3 depth levels (0–5, 5–10, and 10–15cm) was significantly greater in the grazed plots (1.66–2.07%) than non-grazed plots (0.8–0.85%) when not irrigated. Significantly greater levels of extractable P, exchangeable K and acid and alkaline phosphatases were also observed in the grazed as compared to non-grazed plots indicating efficient nutrient cycling and potential for greater nutrient availability for the following cotton crop. Average cotton lint yield over 4 years (2007–2010) from irrigated grazed and non-grazed plots were 1774kgha−1 and 1700kgha−1, respectively while the yield from non-irrigated grazed and non-grazed plots was 1613kgha−1 and 1376kgha−1, respectively. Grazing can have a significant positive impact especially on non-irrigated cotton yield with less fertilizer inputs making a more economical crop while utilizing resources year round.

Effects of starch- vs. fiber-based energy supplements during winter grazing on partitioning of fat among depots and adipose tissue gene expression in growing cattle and final carcass characteristics

Fifty-five normal-weaned Angus steers (268 ± 22 kg; 265 ± 16 d of age) were used to evaluate the effects of starch- vs. fiber-based energy supplements for stocker cattle grazing low-quality dormant native range on growth performance, body composition, and adipose tissue development of different fat depots. Steers were randomly allotted to 4 treatments: 1.02 kg·steer(-1)·d(-1) of a 40% CP cottonseed meal-based supplement (CON), corn/soybean meal-based supplement fed at 1% of BW (CORN), soybean hull/soybean meal-based supplement fed at 1% of BW (SBH), or dried distillers grains with solubles fed at 1% of BW (DDGS). All supplements were individually fed 5 d/wk during the 121-d winter grazing phase. After winter grazing, 3 steers per treatment were harvested to determine body composition and carcass characteristics, and collect subcutaneous (SC) and perirenal (PR) adipose tissue samples. The remaining steers grazed cool-season grass pastures for 74 d without supplementation before finishing. Steers were fed a common finishing diet for 113 d before harvest, at which time carcass characteristics were collected at a commercial abattoir. Energy supplementation increased (P < 0.01) winter grazing ADG compared with CON steers, and CORN steers had greater (P < 0.01) ADG than SBH and DDGS steers. Energy supplementation increased (P < 0.04) mesenteric/omental fat mass but did not influence (P > 0.13) 12th rib fat thickness or marbling score at intermediate harvest compared with CON steers. The mRNA expression of genes involved in lipogenesis and markers of adipogenesis were greater (P < 0.05) in PR adipose tissue of energy-supplemented steers compared with CON steers but not in SC adipose tissue. Fiber-supplemented steers had greater (P < 0.01) mRNA expression of fatty acid synthase and fatty acid binding protein 4 compared with CORN steers in PR adipose tissue but not SC adipose tissue. At final harvest, energy-supplemented steers had greater (P < 0.05) KPH and yield grade than CON steers, but no differences (P = 0.75) in marbling score were observed. Neither energy supplementation nor type of energy supplement influenced intramuscular fat deposition in stocker cattle grazing dormant native range. These data suggest that the total energy intake and stage of animal maturity during grazing supplementation were not great enough to influence marbling deposition.

Effect of rate of body weight gain of steers during the stocker phase. II. Visceral organ mass and body composition of growing-finishing beef cattle

Two experiments were conducted to examine the effect of rate of BW gain during the stocker phase on visceral organ mass and body composition of growing-finishing cattle that had grazed dormant native range (DNR) or winter wheat pasture (WP). In each experiment, fall-weaned steers were allotted randomly to 1 of these stocker production programs: 1) control, 1.02 kg · steer(-1) · d(-1) of a 40% CP cottonseed meal-based supplement during grazing of DNR (CON); 2) corn/soybean meal-based supplement fed at 1% of BW during grazing of DNR (CORN); 3) grazing WP at a high stocking rate to achieve a reduced rate of BW gain (LGWP); and 4) grazing WP at a low stocking rate to achieve an increased rate of BW gain (HGWP). In Exp. 1, 3 steers per treatment were harvested after winter grazing (138 d). The remaining WP steers were transitioned into a finishing phase and DNR steers were allowed to graze the same pastures for another 115 d before entering a feedyard. In Exp. 2, steers grazed respective pastures until each treatment reached an estimated HCW of 200 kg (262, 180, 142, and 74 d, respectively, for CON, CORN, LGWP, and HGWP treatments), at which time 4 steers per treatment were randomly selected for intermediate harvest before finishing. At the end of the finishing period, 4 additional steers from each treatment were randomly selected for final carcass measurements. All steers were fed to a common 12th rib fat thickness of 1.27 cm. After winter grazing in Exp. 1, HGWP steers had the greatest (P < 0.01) mesenteric/omental fat, total viscera, total splanchnic tissue mass, and carcass and empty body fat, compared with the other treatments. In Exp. 2 at intermediate harvest, WP steers had greater (P < 0.03) mesenteric/omental fat, total viscera, and total splanchnic tissue mass, compared with CORN steers, with CON steers being intermediate. Also, the WP steers had greater (P < 0.02) carcass and empty body fat, compared with CORN steers, with CON steers being intermediate. At final harvest in Exp. 2, LGWP steers had the least total viscera and total splanchnic tissue mass, compared with the other treatments. However, there were no differences (P > 0.53) among treatments for carcass or empty body fat. Stocker systems using WP or DNR result in cattle with differences in body fat and visceral organ mass before finishing; this may influence feedlot efficiency, even though there were no differences in body fat and visceral organ mass at the end of the finishing period.

‘Snowstorm’, a New Forage Kochia Cultivar with Improved Stature, Productivity, and Nutritional Content for Enhanced Fall and Winter Grazing

‘Snowstorm’ (Reg. No. CV‐8, PI 666938) forage kochia [Bassia prostrata (L.) A.J. Scott; syn. Kochia prostrata (L.) Schrad.] was released on 22 Mar. 2012 by the USDA‐ARS and the Utah Agricultural Experiment Station. Snowstorm was evaluated as OTVSEL and Otavny‐select and was developed as a synthetic cultivar using two cycles of recurrent selection for stature, forage production, and adaptation to semiarid environments. Snowstorm was compared with the standard forage kochia cultivar, Immigrant, and other ARS experimental forage kochia populations. Research has shown that Immigrant can increase rangeland productivity three‐ to sixfold and provides critical protein (&gt;70 g kg−1) during the fall and winter for livestock and wildlife; however, Immigrant is easily covered by snow because of its short stature. In field comparisons with Immigrant, Snowstorm was similar to Immigrant in establishment and adaptation on semiarid rangelands but was 64% taller (77 versus 47 cm), produced 68% more forage (2526 versus 1504 kg ha−1), and had a 22% higher protein content (79 versus 65 g kg−1) and 4% higher digestibility (674 versus 648 g kg−1) (P ≤ 0.05). Furthermore, DNA fingerprinting showed that Snowstorm, Immigrant, and experimental populations were genetically unique and distinct from each other. Snowstorm is named for its ability to extend the grazing season into the fall and winter and because it provides ranchers and land managers a new, taller, more productive, more nutritious forage kochia cultivar capable of increasing carrying capacity and nutritional content of fall and winter grazinglands, including locations where snow cover had limited forage kochia use in the past.

Influence of Winter Grazing on Water and Heat Flow in Seasonally Frozen Soil of Inner Mongolia

Snowmelt infiltration and soil thawing processes are essential for understanding surface and subsurface hydrology under the cold and arid climatic conditions found in grazed Inner Mongolia grassland soils. Over a 6‐yr period (2004–2009), we evaluated the effects of winter grazing and freezing/thawing cycles on (i) soil hydraulic and thermal properties, (ii) the dynamics of field soil moisture and temperature, and (iii) the contributions of snowmelt and soil thawing to the summer water balance. Two adjacent contrasting sites were selected: a site that has been ungrazed since 1999 (UG99), and a site that has been grazed during the winter (WG). The results showed that the freezing/thawing cycles changed soil hydraulic and thermal properties. Associated with those freezing‐induced changes, winter grazing decreased soil moisture by 5–10% throughout the whole year (October 2005 to September 2006), increased soil temperature by 1 to 3°C in summer, and decreased it by 2 to 5°C in winter. The grazed site with lower vegetation/snow cover and larger thermal conductivity had greater freezing rates and larger soil temperature fluctuations on a daily scale than the ungrazed site. Winter precipitation (snow + rainfall) contributed 15% of the total annual water balance for the UG99 site, but only 11% for WG site. We concluded that a detailed analysis of the spring snowmelt infiltration was critical for calculating seasonal water and energy balances in this region to fully understand the hydrological and ecological processes.

Does forest stand structure impact the dynamics of snow on winter grazing grounds of reindeer (Rangifer t. tarandus)?

The landscape in boreal Sweden is dominated by even-aged, single-layered forest monocultures and clear cuts. Few forest stands with a more complex, multi-layered structure remain as landscape elements. We studied the impact that different forest management regimes have on snow conditions and the metamorphosis of snow, and discuss how these factors may affect suitability for reindeer grazing.Over two winters, we recorded the development of snow depth and hardness in clear cuts and two different forest types, and their changes with weather events. In the forests, the dynamics of snow characteristics were analyzed in relation to stand structure and at the level of individual trees.There were no clear differences in snow characteristics between single-layered and multi-layered stands, although snow hardness was more variable in the latter. In single-layered stands, snow depth and hardness were spatially uniformly distributed in relation to stand characteristics. Contrastingly, the complex structure of multi-layered stands did influence snow depth significantly. However, hardness was highly heterogeneous in these stands. Due to the absence of tree effects, clear cuts had deeper but softer snow than forested stands, although hardness increased towards spring.Weather affected the metamorphosis of the snow blanket. The magnitude of the effects depended on both timing and severity of discrete weather events and forest structure, but generally weather had a greater influence on snow cover characteristics than forest structure per se. In their interaction with weather, different forest structures affect the snow and thus suitability as winter grazing area for reindeer. Reindeer herders, therefore, require diversity in the landscape in order to respond to such weather variations and their impact on grazing conditions.

Use of a multilayer snow model to assess grazing conditions for reindeer

AbstractHigh-density snow layers deteriorate grazing conditions for reindeer during winter. We compare two different methods for identifying past winters with difficult grazing conditions for reindeer in Kautokeino, northern Norway. A long-term climate analysis based on monthly values of precipitation and temperature (1900–2011) demonstrated that the reported winters were difficult to identify systematically. The processes leading to hard layers or ground-ice layers occur on daily, not monthly, timescales, and whether or not specific conditions are problematic depends on the development throughout the winter, not just on single values. To better analyse the weather conditions and development over time that favour the formation of high-density snow layers, we apply the multilayer model SNOWPACK over the period 1956–2010. We simulate the evolution of the snowpack by forcing the model with 6 hour interval meteorological data. The model output was analysed by summing up the vertical extent of the simulated high-density snow layers (&gt;350 kg m–3) for each winter. These results were compared with historical records of difficult winter grazing conditions reported in the period 1956–2010. In particular, the heavy losses of reindeer during the catastrophic 1967/68 winter were caused by the occurrence of ground ice together with long snow-cover duration. This unfavourable coincidence is well reproduced by our model results, together with eight of the ten reported difficult winters.

Daily Gain of Japanese Shorthorn Raising Cattle in a Winter Grazing System Utilizing a Spring-Autumn Meadow in Northern Tohoku, Japan(Activation of Public Pasture)

Daily Gain of Japanese Shorthorn Raising Cattle in a Winter Grazing System Utilizing a Spring-Autumn Meadow in Northern Tohoku, Japan(Activation of Public Pasture)

Influence of early weaning beef cows on the performance of male progeny and the need for winter protein supplementation

One hundred and three Hereford × Angus crossbred, spring-calving cows were used to determine the influence of early weaning performance of their male progeny and the need for cowherd winter supplementation. Treatments were early weaned (EW; 115-d of age) and normal weaned calves (NW; 220-d of age). Both intact and castrated male progeny were randomly allotted to early and normal weaning calf management treatments. Following summer grazing and weaning protocols, cows within each weaning group were randomly assigned to receive winter supplementation treatments of LOW (1.26 kg/hd/d) or HIGH (1.81 kg/hd/d) amounts of a protein supplement containing 450 g/kg CP (DM basis). Cows whose calves were weaned early gained more BW and BCS (P P P P = 0.04) BCS but similar (P = 0.74) BW when compared with cows with normally weaned calves that received 100% of their supplement (NWHIGH). Early weaning has the potential to reduce the amount of supplement required during the winter grazing period.