Effects Of Pasture Management Research Articles

Effects of pasture management and supplementation on the productive performance of recently lambed ewes.

The hypothesis was tested that the performance of lactating ewes is affected by the supplementation level and pasture management. Two supplementation levels (0.5 and 1.0% of body weight, BW) and two pasture managements (mowed and non-mowed) were tested. Forty adult ewes (2 years old) with an average weight at lambing of 62.97 ± 7.0kg (day 0) and an average the body condition score of 2.5 points (day 0) were evaluated. Verminosis was monitored with periodic deworming. The number of eggs per gram of feces (EPG) of ewes at lambing was used as a covariate for performance assessments. Ewes lost an average of 7.5kg over the 90 days post-partum (12% BW). The weaning rate was 53%. The body condition of the ewes was influenced by the post-partum period. The ewes mobilized their body reserves in the first 30 days of lactation. Mowing management negatively affected the nutritive value of the forage. Supplementation with 0.5% BW was sufficient for nutritional management post-partum. Pasture management (mowed vs. not mowed) cannot prevent post-partum weight loss. Supplementation levels and pasture management altered the morphological and chemical components of the pasture.

Effect of pasture management on bioactive compounds of Lolium multiflorum and Avena strigosa for dairy cows and its effect on milk quality

ABSTRACT This study aimed to evaluate the effects of pasture management on bioactive compounds and its effects on milk quality. The total phenolic content in Avena strigosa and Lolium multiflorum was greater in the agroecological (AGR) compared to conventional (CON) management, and in the AGR was greater in two fixed cutting intervals. However, for plants collected at variable cutting intervals representing the farmer’s standard practices no differences were found. The milk produced in the CON showed the highest total carotenoids (winter and autumn), zeaxanthin (summer), and vitamin A (autumn) compared to AGR. Thus, pasture-based systems, when well managed, improve milk quality.

Effect of pasture management on enteric methane emissions from goats.

The effect of pasture management on CH4 emissions was investigated from goats in a tropical climate. Two experiments were conducted in a "Tanzania Guinea grass" (Panicum maximum Jacq.) pasture to assess enteric CH4 production in a completely randomized design. Emissions from light, moderate, and heavy grazing intensities were analyzed in the first experiment, and variations between grazing days were explored in the second experiment. Grazing intensity was defined as 2.4, 1.6, and 0.8 post-grazing leaf area index. Pasture management employed intermittent grazing with variable stocking rate using Anglo Nubian female adult goats. SF6 tracer gas technique was used to measure CH4 production. Grazing intensity was not found to affect CH4 emissions per animal, dry matter forage intake (DMI), and gross energy (GE) intake. However, the second experiment showed that CH4 production was influenced by the grazing day. CH4 emissions were 18.1gday-1, and the variables were 0.88gkg-1 of metabolic weight, 17.45gkg-1 of DMI, and 5.5% of GE. CH4 production increased linearly with the grazing day, possibly reflecting a reduction in forage quality. These findings suggest that the day of occupation in intermittent grazing has a greater effect on CH4 emissions than that by grazing intensity and that a single day grazing of Tanzania Guinea grass could mitigate CH4 emissions.

Accelerometer activity tracking in horses and the effect of pasture management on time budget.

Accelerometry is an accepted means of quantifying human physical activity. Quantitative physical activity tracking could be beneficial for studies into equine health and disease prevention, for example in relation to obesity management. Validate accelerometer use in grazing horses, determine between-day repeatability, and assess the effects of pasture size on time budget (i.e. duration in each activity category). Proof of concept. Accelerometers (ActiGraph) were positioned at the poll. Horses underwent 5min of observed activity in three categories: standing, grazing and ambulating. Receiver-operating characteristic curve analysis, used on ten second data epochs, calculated cut points between the activities. A 20-day study was then undertaken on 6 horses at pasture. Time in each category (per day) was deduced; a Mann Whitney U test was performed to compare standard vs. small paddock and day vs. night turn out. Cut-off values with the optimum sensitivity (94.7-97.7%) and specificity (94.7-96.8%) were found to be <127.6 counts for standing, 127.6-702.7 counts for grazing and >702.7 counts for ambulating. Repeatability was analysed descriptively: Median (IQR) of the between-day difference in minutes standing, grazing and ambulating were 46.9 (21.3-87.9), 77.3 (40.2-124.5) and 15.6 (6.8-40.2) respectively. Median times standing and ambulating were significantly different between standard and small paddocks: standing: 8.7 vs. 10.3h (P<0.001); ambulating: 55.7 vs. 39.6min (P=0.002). There was no significant difference in the median time spent grazing. There were significant differences between day and night: standing: 32.95% vs. 50.97% (P=0.001), grazing: 60.81% vs. 46.77% (P<0.001) and ambulating: 4.57% vs. 2.40% (P<0.001). Small sample size and lack of cross-validation of cut-off points on independent, 'unseen' data. Accelerometry can differentiate standing, grazing and ambulating in horses. Our proof-of-concept study demonstrates modifying pasture size influences activity budgets; opening avenues into studying obesity management.

Validity and repeatability of accelerometer activity tracking in horses and the effect of pasture management on time budget

Validity and repeatability of accelerometer activity tracking in horses and the effect of pasture management on time budget

Recent pasture management determines biodiversity and productivity, and past management determines forage quality

ABSTRACTAgro-ecosystem management focuses on developing grassland systems that meet sustainable productivity and biodiversity targets. Pasture management affects productivity and biodiversity, but the effects of previous management impacts are difficult to predict. Our objective was to identify the effects of key management factors and their timing on current biodiversity and productivity in public pastures in northeastern Japan. We surveyed pasture management histories (stocking rate, mowing frequency, fertilizer application and pasture renovation by plowing) from 1991 to 2010. We divided the data into periods and examined productivity, forage quality and biodiversity (plants and burrowing rodents). We included these parameters into generalized linear models, and found that recent fertilization level, mowing frequency and renovation were the most important factors affecting plant species diversity. In contrast, recent and past stocking rates were the dominant factors for productivity and forage quality, respectively. Thus, biodiversity and productivity were affected by different factors, suggesting that pasture management can balance the competing goals of biodiversity conservation and productivity improvement. From the effects of pasture management on biodiversity, forage productivity and quality, avoiding intensive pasture management is a practical application. In addition, a time lag effect of grazing pressure on forage quality should be considered during future pasture management.

Effects of pasture management on soil fertility and microbial communities in the semi-arid grasslands of Inner Mongolia

Purpose Grasslands are an important ecosystem covering about a quarter of the earth’s surface. Different management practices of grassland ecosystems can have a major impact on the sustainability of these ecosystems. The objective of this study was to determine the impact of different pasture management practices on soil properties and microbial communities in the semi-arid grassland ecosystem in Inner Mongolia.

Effects of pasture management on poultry welfare and meat quality in organic poultry production systems

Outdoor access is a defining characteristic of organic poultry that provides poultry with fresh grass, insects and worms that may lead to enhanced product quality. There is evidence that meat from pastured-based poultry may contain some additional nutritional benefits through lower fat content, as well as higher vitamin and mineral contents. At the same time, under good pasture management, bird health and welfare can be achieved. This review gives an overview on the pasture management practices that can be employed to prevent potential risks in organic poultry systems such as uncontrolled weather conditions or mortality due to predators. This paper discusses the various effects of pasture management on (a) poultry health and welfare, including physical comfort, absence of hunger and disease, possibilities to perform motivated behaviours and (b) meat quality, including both consumer and nutritional quality and sensory attributes as related to pasture synthesis and intake.

Subhumid pasture soil microbial communities affected by presence of grazing, but not grazing management

Management-intensive rotational grazing has been shown to stimulate net primary production in subhumid pastures compared to extensive grazing strategies. The degree to which this represents a direct effect on plant developmental stage and community composition, and/or indirect effects of grazing on microbial community structure and nutrient feedback to production is an open question. To better understand whether the effects of pasture management on microbial communities led to indirect nutrient feedbacks, we analyzed microbial lipids and environmental and physical factors of surface soils under four pasture management treatments – management-intensive rotational grazing, continuous grazing, harvesting for hay, and an unmanaged control. Principal component analysis indicated microbial community structure under our two grazed treatments was different than that of ungrazed treatments. While there was no effect of treatments on total microbial biomass, guild comparisons revealed lower fungal-to-bacterial ratios, lower arbuscular mycorrhizal fungi concentrations, and higher actinomycete biomarkers in soils under grazing, irrespective of grazing management treatments. Gram-positive and anaerobic bacteria biomarker abundance was greater in treatments that included grazing and no management when compared to the treatment where biomass was harvested mechanically. There was no evidence of treatment effects on either Gram-negative bacteria or saprotrophic fungi. Regression tree analysis identified litter quality as the main correlate of differences in the microbial community between grazed and ungrazed treatments. Lower root C:N predicted lower F:B and biomarkers of the bacterial guilds Gm+ and actinomycetes, which were dominant in the grazing treatments, while higher root C:N predicted higher F:B and the guild biomarkers of AMF, which dominated in the ungrazed treatments. These results indicate that greater forage production observed in humid and subhumid regions under management-intensive rotational grazing likely stems from the direct effects on plant developmental stage and plant community composition rather than microbial mediated nutrient feedbacks from altered quantity and quality of plant litter. If the potential for a more favorable C balance in subhumid pastures is realized, greater biomass production and therefore greater litter inputs as a result of the direct effects of management-intensive rotational grazing on plant communities is the most likely mechanism.

The status and importance of crude protein and macro minerals in native pastures growing on Vertisols of the central highlands of Ethiopia

The effects of pasture management, season and soil nutrient status on crude protein (CP) and macro mineral concentration of native pasture was studied in the Vertisol areas of the central Ethiopian highland. Soil and herbage samples from 18 continuously grazed (CG) and 12 seasonally grazed (SG) pasture sites were analyzed for N, P, Ca, Mg, K and Na. Soil and dry season CG pasture samples were collected in January and February 2001 (dry season: November-February), while wet season CG and SG pasture samples were collected during September 2001 (wet season: April-October). The Potassium concentration (2.55%) of mixed herbage samples from SG pasture exceeded the K values (1.80%) from CG pasture (P<0.01). Significant (P<0.01) differences of CP and macro minerals concentrations were noted among forage species. The mean CP and K concentrations of herbage from CG pasture were higher (P<0.01) during the wet than during the dry season (5.97 and 1.80% vs. 3.18 and 0.79%), while the opposite was true for Ca (0.49% vs. 0.61%) (P<0.05). Regarding soil macro minerals and the corresponding herbage macro mineral concentrations, significant (P<0.05) but inconsistent correlations were found for Ca, P, Mg and Na. The results suggest that pasture management, season and to some extend soil nutrient status, can affect herbage CP and macro mineral composition. The levels of CP in CG pasture and that of P and Na in both CG and SG pastures may fall below the requirements of grazing livestock. Resting at critical stages of the growth cycle of the forage species encouraged the recovery of desirable species. For this reason resting of pasture can contribute significantly to the quality of the native pastures of the Vertisols of the central Ethiopian highlands and should be encouraged.

Effects of pasture management and off-stream water on temporal/spatial distribution of cattle and stream bank characteristics in cool-season grass pastures123

A 2-yr grazing experiment was conducted to assess the effects of grazing management on cattle distribution and pasture and stream bank characteristics. Six 12.1-ha cool-season grass pastures in central Iowa were allotted to 1 of 3 treatments: continuous stocking with unrestricted stream access (CSU), continuous stocking with stream access restricted to 4.9-m-wide stabilized crossings (CSR), or rotational stocking with stream access restricted to a riparian paddock (RP). Pastures were stocked with 15 fall-calving Angus cows (Bos taurus L.) from mid-May to mid-October for 153 d in 2008 and 2009. A global positioning system (GPS) collar recording cow position every 10 min was placed on at least 1 cow per pasture for 2 wk of each month from May through September. Off-stream water was provided to cattle in CSU and CSR treatments during the second of the 2 wk when GPS collars were on the cattle. A black globe temperature relative humidity index (BGTHI) was measured at 10-min intervals to match the time of the GPS measurements. Each month of the grazing season, forage characteristics (sward height, forage mass, and CP, IVDMD, and P concentrations) and bare and fecal-covered ground were measured. Stream bank erosion susceptibility was visually scored in May, August, and October (pre-, mid-, and post-stocking). Cattle in RP and CSR treatments spent less time (P < 0.10) within the stream zone (0 to 3 m from stream center) in June and August and in the streamside zone (0 to 33 m from stream zone) in May through August and May through September, respectively, than cattle in CSU pastures. However, off-stream water had no effect on cattle distribution. Compared with the CSU treatment, the CSR treatment reduced the probability (P < 0.10) that cattle were within the riparian zone (0 to 36 m from stream center) at BGTHI of 50 to 100. Bare ground was greater (P < 0.10) in pastures with the CSU than CSR and RP treatments in the stream and streamside zones in September and October and in July and September. Streams in pastures with the CSU treatment had less stable banks (P < 0.10) mid- and post-stocking than RP or CSR treatments. Results show that time spent by cattle near pasture streams can be reduced by RP or CSR treatments, thereby decreasing risks of sediment and nutrient loading of pasture streams even during periods of increased BGTHI.

Effects of pasture management and fertilizer regimes on botanical changes in species‐rich mountain calcareous grassland in Central Europe

AbstractA 3‐year experiment was conducted in Central Europe to examine the effects of three managements, viz. continuous cattle grazing from April to September, mowing once in July and abandonment of grazing, and two levels of fertilizer application, no fertilizer and 400 kg ha−1of a NPK fertilizer, on changes in plant species composition and summer biomass of dry matter (DM) in a calcareous mountain grassland containing many plant functional types. Different managements led to changes in species composition due to species‐specific responses. Low creeping and rosette species were associated with grazing, while grasses and tall forbs correlated with mowing and abandonment of grazing, probably because of their ability to outcompete rosette species. There was a negative relationship between the number of species and above‐ground biomass and a positive relationship between number of species and below‐ground biomass, suggesting that these species‐rich communities allocate more to below‐ground organs when not grazed. The application of fertilizer had no effect on species composition but it indirectly increased competitive asymmetry for light and increased the number of plant extinctions. It is concluded that continuation of cattle grazing is an acceptable form of grassland management at the study site and that species and functional group compositions can rapidly change with changing environmental conditions such as abandonment of grazing or application of fertilizer.

Litter Mass, Deposition Rate, and Chemical Composition in Bahiagrass Pastures Managed at Different Intensities

ABSTRACTPlant litter is an important pathway of nutrient return to the soil in grazed swards, but the effects of pasture management on litter mass and composition are not well understood. This research evaluated the effect of management intensity, defined in terms of N fertilization and stocking rate (SR), on litter mass, deposition rate, and chemical composition in continuously stocked ‘Pensacola’ bahiagrass (Paspalum notatum Flügge) pastures growing on Pomona and Smyrna sands. Treatments were three management intensities: Low (40 kg N ha−1 yr−1 and 1.3 animal units [AU, one AU = 500 kg live weight] ha−1 SR), Moderate (120 kg N ha−1 yr−1 and 2.7 AU ha−1 SR), and High (360 kg N ha−1 yr−1 and 4.0 AU ha−1 SR). Greater management intensity resulted in less litter mass on the pasture early in the growing season and more litter mass later in the season. Rate of litter deposition was generally greatest for High and ranged between 23 and 40 kg organic matter (OM) ha−1 d−1 compared with 13 to 30 kg OM ha−1 d−1 for Low and Moderate management intensities. Increasing management intensity from Low to High resulted in greater litter N (14.1 vs. 22.9 g kg−1) and P (0.8 vs. 1.3 g kg−1) concentrations and lesser C:N (∼40 vs. 22), C:P (649 vs. 433), and lignin:N (5.8 vs. 4.4) ratios. More intensive pasture management was associated with greater litter deposition rate and litter quality than less intensive management, suggesting a larger nutrient contribution from litter in intensively managed swards.

Effect of blood metabolites, body condition and pasture management on milk yield and postpartum intervals in dual-purpose cattle farms in the tropics of the State of Veracruz, Mexico

Research was conducted on typical smallholder farms with dual-purpose cattle (DPC) ( Bos indicus× B. taurus) in the coastal north-central area of Veracruz, Mexico. The study was divided into two phases. The aim of the first phase was to investigate the effect of blood metabolites, body condition and pasture management on milk yield and postpartum intervals, in order to investigate if the former are suitable indicators of the reproductive and nutritional status of DPC. One hundred and sixty-five calvings of crossbred cows were recorded from January 1992 to November 1994 on 12 small farms. Milk samples were collected twice a week for progesterone analysis. Blood samples and BCS were taken once a month. However, in Phase II emphasis was placed on the effect of pasture management upon reproductive and productive performance of DPC. Records of four farms were obtained from June 1995 to November 1996. Stocking rates were 0.40, 0.87, 0.35 and 1.5 cows/ha for farms A, B, C and D, respectively. Farms A and C used a slow rotation while B and D used a rapid rotation. In Phase I, the changes in BCS during the last month of pregnancy and first month postpartum did not correlate ( p>0.05) with milk yield or reproductive performance. Blood the metabolite profiles were not consistently related to productive or reproductive variables. The effect of farm and season was significant ( p<0.05) on most of the response variables and low productivity on overstocked farms lead to the conclusion that the low reproductive performance of DPC was linked to poor pasture management. During Phase II, farms A (FA) and D (FD) produce more milk than the others. Days to first service, days open, and calving interval were similar for farms B (FB) and C (FC), highest for Farm A, and lowest for Farm D. The forage availability mean was above the critical range of 6–8 kg of dry matter per 100 kg of liveweight (kg DM/100 kg LW) in all farms (range from 6.1±5.0 to 21.1±11.2 kg DM/100 kg LW). Farm D had the highest stocking rate (1.5 cows/ha), a rapid rotation (10 paddocks), a good forage availability (7.1±3.9 kg DM/100 kg LW) with a good quality for a tropical pasture (11.6±2.4% crude protein), and an economic energy supplementation. These results suggest this type of management could be more widely employed to improve the productivity of DPC on smallholder farms in the Mexican tropics.

Effects of pasture management on N2O and NO emissions from soils in the humid tropics of Costa Rica

Emissions of nitrous oxide (N2O) and nitric oxide (NO) from agricultural soils in the tropics are important in the global budgets of these trace gases. We made monthly measurements of N2O and NO emissions from pastures with three different management systems on volcanic soils in northwestern Costa Rica: traditional (no N input from fertilizer or legumes), pastures with a grass‐legume combination, and pastures fertilized with 300 kg N ha−11 yr−1. Average annual N2O emissions were 2.7 ng N cm−2 h−1 from the traditional pastures, 4.9 ng N cm−2 h−1 from the grass‐legume pastures, and 25.8 ng N cm−2 h−1 from the fertilized pastures. Average annual NO emissions were 0.9, 1.3, and 5.3 ng N cm−2 h−1 from traditional, grass‐legume and fertilized pastures, respectively. In a separate experiment the effects of ammonium, nitrate, and urea‐based fertilizer mixtures on nitrogen oxide fluxes were compared. We measured nitrogen oxide fluxes following four different fertilization events. Nitrogen oxide fluxes were among the highest ever measured. The difference in soil water content between the fertilization events had a far greater effect on N2O and NO emissions than the effect of fertilizer composition. We conclude that the concept of “emission factors” for calculating N2O and NO emissions from different types of N fertilizer is flawed because environmental factors are more important than the type of N fertilizer. To estimate fertilizer‐induced N2O emission in tropical agriculture, stratification according to soil moisture regime is more useful than stratification according to fertilizer composition.

Effect of pasture management on the contributions of fixed N to the N economy of ley-farming systems

The effects of different management regimes on N2 fixation by subterranean clover (Trifolium subterraneum) in annual pastures and lucerne (Medicago sativa) in perennial-based pastures were examined in 5 experiments and 55 commercial paddocks, in which the pastures were grown in phased rotation with crops. The objectives were to quantify the inputs of fixed N2 and to determine ways of increasing nitrogen (N) inputs into ley-farming systems of southern New South Wales and north-eastern Victoria. Estimates of annual amounts of N2 fixed, based on above-ground herbage production in grazed pastures, ranged from 5 to 238 kg N/ha for subterranean clover and from 47 to 167 kg N/ha for lucerne. Legume reliance upon N2 fixation for growth (Pfix) was high (&gt;65%) in most annual and perennial pastures examined. The levels of Pfix were generally unaffected by management treatments. As a consequence the amounts of N2 fixed were predominantly regulated by the legume content and herbage yield of pastures rather than by any marked differences in the ability of the legume to fix N. When all experimental results were combined with on-farm measurements of N2 fixation, the data indicated that lucerne and subterranean clover fixed 22-25 kg N for every tonne of legume dry matter produced. Management inputs to annual pastures which improved the productivity of subterranean clover and the amounts of N2 fixed included applications of superphosphate and the removal of grass species with herbicide, although the response to these treatments was not consistent across all sites in all years. Potential inputs from N2 fixation were high in annual pastures, and improved management during a good clover season enhanced the levels of mineral N detected in the soil profile (0-200 cm) the following autumn by 100-200 kg N/ha. However, year-to-year variability in annual pasture productivity and clover content resulted in large fluctuations in amounts of N2 fixed. Perennial pastures containing lucerne provided consistently greater annual herbage production, had more stable legume contents, and fixed on average 90-150% more N2 than neighbouring subterranean clover-based pastures. Even during the 1994 drought when annual pastures failed, lucerne still managed to fix &gt;70 kg N/ha. It is proposed that lucerne-based pastures could represent a more reliable means of improving soil fertility for subsequent crops than annual pastures.

Population dynamics of Stylosanthes hamata and S. scabra in north-eastern Queensland: effects of superphosphate application, timber treatment, and stocking rate

The effects of pasture management (superphosphate application, timber treatment, stocking rate) on the herbage yields and population dynamics (seed production, seedling numbers, plant longevity) of Stylosanthes hamata cv. Verano and S. scabra cv. Seca grown in grass-legume mixtures were measured from 1982 to 1992 at 2 sites, Hillgrove (extractable phosphorus, 50 mg/kg) and Cardigan (extractable phosphorus, 6 mg/kg), near Charters Towers, north-eastern Queensland. Stylosanthes hamata was higher yielding during the first 3 years at both sites but subsequently S. scabra produced the larger yields. This resulted in S. hamata dominating the legume component in the early years but the proportion of S. hamata then declined, so that by the final year, S. hamata contributed &lt;20% of the legume mixture at both sites. Both seed yields and seedling numbers varied widely between years for both species at both sites. In the early years there were more S. hamata seedlings but in the later years S. scabra had greater seedling numbers. Seed yield and seedling numbers were not significantly affected by superphosphate but both were higher for S. hamata on plots with live trees than on plots with killed trees; numbers of seeds and seedlings of S. scabra were not affected by tree killing. Seed and seedling numbers of both species tended to be greatest at the intermediate stocking rates. Survival of both S. hamata and S. scabra at both sites conformed to Deevey"s Type II curve (i.e. death rate was constant with age). The S. scabra plants lived considerably longer than the S. hamata plants. Pasture treatments had less influence on longevity than on seed production and seedling numbers. Seed production and seedling establishment of both species were marginal for their persistence in the region, and management should aim for seed set and subsequent seedling establishment to occur sufficiently frequently to allow the legumes to persist.

The effects of pasture management on population density and diseases of porina (Lepidoptera: Hepialidae).

Abstract In a field trial carried out at three sites over 2 years at Owaka, South Otago, mob stocking of pasture by sheep in February caused up to 75% mortality of porina (Wiseana spp.) larvae. Mob stocking in March had less effect, suggesting that small larvae, living on or near the soil surface and forming a high proportion of the populations until late February, were most affected. There was no evidence that mob stocking affected the prevalence of virus diseases in porina populations, but microsporidial infections and parasites were higher in mob stocked compared with untreated or haymaking treatments. Haymaking did not effect porina density in the first year; it did, however, effect both porina density in the second year and virus prevalence in each year, the effects varying between sites. The reasons for this were not understood.