Pasture Botanical Composition Research Articles

A short-term effect of multi-species pastures and the plant’s physiological response on pasture growth

Multi-species pastures that include species with dissimilar physiological responses to water restriction (i.e., dehydration avoidance) and species that have a greater soil water access (i.e., deep-rooted species), can buffer the reduction in summer growth experienced by more shallow-rooted species and can out-yield pastures with less capacity to access soil water. The aim of the present study was to evaluate the performance of multi-species pastures comprising both deep-rooted and shallow-rooted species, under grazing by sheep, in relation to pasture growth, the seasonal changes in pasture botanical composition, and the plants’ physiological responses to field conditions across the year. The evaluated pastures were: Bromus valdivianus (Bv); Lolium perenne + Trifolium repens (Lp); Plantago lanceolata (Pl); B. valdivianus + L. perenne + T. repens (grass mixture pasture, GM); and B. valdivianus + L. perenne + T. repens + P. lanceolata (complex mixture pasture, CM). Herbage mass, net photosynthesis, leaf water relations and soil water content (SWC) at 10, 40 and 70 cm soil depths were evaluated. The SWC fluctuation through the year was related to rainfall within each season, and differences between the treatments were taken as an indirect indicator of soil water access and soil water uptake by the roots. During the soil water restriction period, mixed pastures based on species that differed in their soil water access buffered the reduced growth rate of the sensitive species, due to a decrease in competition for water uptake within the deeper soil layer (CM pasture). A shift of dominance between species, as measured in the CM pasture, buffered the reduction in pasture growth rate seen in the monocultures. The Bv pasture, which is tolerant of water restriction, had a similar annual yield to the multi-species pastures (both GM and CM). The present study highlighted the capacity of the deep-rooted species (B. valdivianus and P. lanceolata) to avoid periods of soil water restriction by extracting water from deeper soil layers.

EFFECT OF MANAGEMENT PRACTICES AND HARVESTING STAGE ON BOTANICAL COMPOSITION, BIOMASS YIELD, AND NUTRITIONAL VALUE OF NATURAL PASTURE UNDER TRADITIONAL LIVESTOCK PRODUCTION SYSTEM IN THE CENTRAL HIGHLANDS OF ETHIOPIA

<p><em><strong>Background: </strong></em>Natural pasture is an essential source of livestock feed worldwide, particularly in Ethiopia. Though pastureland coverage and management practices are changing over time, studies are limited in addressing the status under the dynamics of smallholder management conditions. <em><strong>Objective:</strong> To evaluate natural pasture botanical composition, biomass yield, and nutritional value under different management and stages of harvesting in the central highlands of Ethiopia. <strong>Methodology:</strong> The pasture was harvested at three stages (pre-flowering, mid-flowering, and after full flowering) under different management (extensive, semi-intensive where urea was used as a fertilizer, and seasonal grazing). Quadrats of 0.25 m<sup>2</sup> were used for herbaceous species identification, biomass yield estimation and nutritive value analysis. Chemical composition of the samples were analyzed using Near-Infrared Reflectance Spectroscopy</em>. <strong>Results:</strong> Thirty-one herbaceous species were identified (38.71% grasses, 19.35% legumes, 9.67% sedges, and 32.26% forbs), which belong to 11 families.<em> </em>The total biomass yield under semi-intensive management practice at full maturity stage was greater than seasonally grazed and extensively managed pasture. The species richness, species evenness Shannon-Wiener diversity (H’ max) and maximum possible diversity (H’max) were similar (P>0.05) under all management practices. <em>Natural pasture </em>condition score was fair under seasonal grazing, while the score was excellent under extensive and semi-intensive management. Metabolizable energy (ME), and <em>in vitro</em> organic matter digestibility (IVOMD) were higher (P<0.5) under extensive management compared to the semi-intensive management. The pasture harvested at the pre-flowering stage had higher (P<0.05) CP content, IVOMD, and ME, but low neutral detergent fiber, acid detergent fiber and acid detergent lignin values. <strong>Implications:</strong> The findings provide new insights into improving the biomass yield and quality of the pasture in semi-intensive pastureland management, and harvesting after the full flowering stage. <strong>Conclusion:</strong> <em>This study recommended</em> semi-intensive management and harvesting after the full flowering stage for higher pasture biomass yield, pasture condition, and nutritional value in the highlands of Ethiopia. Further study is required to investigate the combined effects of fertilizer (organic, inorganic) application and other management on biomass yield and quality of natural pasture in similar and other areas in the highlands of Ethiopia. </p><iframe class="ginger-extension-synonympopup" style="left: 134.956px; top: 88.8px; z-index: 56; padding: 0px; visibility: hidden; height: 152px;" src="chrome-extension://kdfieneakcjfaiglcfcgkidlkmlijjnh/ginger-popup/index.html"></iframe>

Dairy Sheep Grazing Management and Pasture Botanical Composition Affect Milk Macro and Micro Components: A Methodological Approach to Assess the Main Managerial Factors at Farm Level.

Simple SummaryStudies on the management factors that affect milk components at the farm level are important for understanding how to transfer the results from experimental study. Plant phenological stages and partially fresh herbage intakes affect the lactose and milk fatty acid profile. The botanical composition of the grassland partially affects the milk’s phenol content. A few small relationships between plant phenols and milk colour could be of interest to explain the changes in milk colour parameters.The fatty acid profile, vitamins A and E, cholesterol, antioxidant power colour and the phenols profile of Sarda sheep milk from 11 commercial sheep flocks managed under permanent grassland were investigated. In each farm, the structural and managerial data and milk samples were collected during four periods (sampling dates, SD): January, March, May, and July. Data from the milk composition (fat, protein, casein, lactose, and somatic cell count), 68 fatty acids, 7 phenols, 1 total gallocatechin equivalent, ferric reducing antioxidant power, vitamins A and E, cholesterol, degree of antioxidant protection, and the colour (b *, a * and L *) were analyzed by multivariate factorial analysis using a principal component analysis approach. A proc mixed model for repeated measurement to point out the studied factors affecting significant macro and micro milk composition was also used. Only the first five components were detailed in this paper, with approximately 70% of the explained variance detected. PC1 presented the highest positive loadings for milk lactose, de novo FA synthesis and the BH intermediate, whereas OBCFA had negative loadings values. The PC2, LCFA, UFA, MUFA, vitamins E, and DAP showed positive loadings values, while SFA had a negative value. The PC3 showed a high positive loading for total phenols and non-flavonoids. PC4 presented a high positive loading for the milk macro-composition and negative values for n-3 FAs. The PC5 is characterized by high positive loadings for the a * and L * colour parameters whereas negative loadings were detected for the milk flavonoids content. These preliminary results could help to establish future threshold values for the biomarkers in milk sourced from grazing dairy sheep in natural, permanent pasture-based diets.

Impact of Shading of a Silvopastoral System on Microclimate and Botanical Composition of Polyphytic Pasture: A Preliminary Study in the Subtropics

Impact of Shading of a Silvopastoral System on Microclimate and Botanical Composition of Polyphytic Pasture: A Preliminary Study in the Subtropics

Could forage peanut in low proportion replace N fertilizer in livestock systems?

Palisadegrass [Urochloa brizantha (Hochst. ex A. Rich.) R. D. Webster cv. Marandu] is widely used in Brazil and is typically managed with little or no N fertilizer, which often leads to pasture decline in the long-term. The current relationship between beef price and fertilizer cost in Brazil does not favor fertilizer use in pastures. Legume inclusion is an alternative to adding fertilizer N, but often legumes do not reach a significant proportion (> 30%) in pasture botanical composition. This study evaluated herbage responses to N inputs and pasture species composition, under intermittent stocking. Treatments included palisadegrass-forage peanut (Arachis pintoi Krapov. & W.C. Greg. cv. Amarillo) mixture (mixed), unfertilized palisadegrass (control), and palisadegrass fertilized with 150 kg N ha-1 yr-1 (fertilized). Treatments were applied over two rainy seasons with five growth cycle (GC) evaluations each season. Response variables included herbage biomass, herbage accumulation, morphological components, total aboveground N of forage peanut (TAGNFP), and contribution of biological N2 fixation (BNF). Herbage biomass was greater for fertilized palisadegrass [5850 kg dry matter (DM) ha-1] than for the palisadegrass-forage peanut mixture (3940 kg DM ha-1), while the unfertilized palisadegrass (4400 kg DM ha-1) did not differ from the mixed pasture. Nitrogen fertilizer increased leaf mass of palisadegrass (2490 kg DM ha-1) compared with the control and mixed treatments (1700 and 1310 kg DM ha-1, respectively). The contribution of BNF to the forage peanut ranged from 79 to 85% and 0.5 to 5.5 kg N ha-1 cycle-1. Overall, benefits from forage peanut were minimal because legume percentage was less than 10%, while N input in the system by N-fertilizer increased palisadegrass herbage biomass.

Seventy years of data from the world\u2019s longest grazed and irrigated pasture trials

Pastures are the most widespread land use, globally. The Winchmore trials were established in 1948–1949 in Canterbury, New Zealand and examined either different rates of phosphorus (P) fertiliser on the same irrigation schedule (Fertiliser trial), or different irrigation scheduling at the same rate of P application (Irrigation trial). About 96,000 records of soil chemistry and physical data and pasture yield and botanical composition are available along with nearly 7000 soil samples. These data have been used in 475 publications that have explored topics as diverse as: improvements in sheep, dairy and deer production; the efficacy and scheduling of irrigation; improvements in pasture and crop production; agronomic and environmental soil and water research; and entomology. In addition to above topics, these data are invaluable for calibrating models to predict long-term issues like the accumulation of soil carbon or contaminants like cadmium and informing policy on climate change and agricultural practices. The data and soil samples are available for use and may yet yield discoveries, unforeseen 70 years ago.

Pasture botanical composition and forage quality at farm scale: A case study

The importance of maintaining mountain pastures in preserving environmental services is widely known. However, in mountainous regions, environmental and vegetation heterogeneity at the farm scale affect farm management. This study was conducted at the summer pasture of Malga Serona (northeastern Italy) to introduce a discussion of appropriate management at the farm scale. Forty botanical surveys were performed, where an herbage sample from a 100×100 cm surface was collected in each survey. The number of species, the average Landolt index, and the pastoral value (PV) were calculated for each survey. For each herbage sample, nutrient content was measured. We observed differences in botanical composition and in forage quality within the study area. We found that the PV varied from 35.6 to 52.2, NDF from 41.0 to 52.0% and crude proteine from 12.3 to 15.8%. Areas with lower PV and lower forage quality were marginal and were found in surveys with high abundance of Sesleria varia (Jacq.) Wettst., or with species usually present in under-grazed pastures. It is necessary to study botanical composition and forage quality of pastures at the farm level, and to utilize the whole grazing surface in order to maintain and restore high-quality forage.

Use of pasture botanical composition data on the accuracy of satellite pasture biomass estimates

Pasture biomass estimates are valuable to farmers, and satellite pasture biomass estimates can potentially provide the required data for less time and labour. However, the accuracy of satellite estimates of pasture biomass can be affected by the botanical composition of the pasture. In this study, botanical composition data were combined in linear regression models and a general additive model with on-farm and satellite pasture biomass estimates to quantify the increase in predictive power from including botanical composition data. The inclusion of botanical composition data improved the accuracy (model R2) of the satellite pasture biomass estimation; the smallest increase was 0.035 (from 0.725 to 0.760) and the largest increase was 0.111 (from 0.599 to 0.710). Improving the accuracy of satellite estimations of pasture biomass will allow farmers to make more timely and accurate grazing management decisions.

Botanical Composition of Yearling-Steer and Mature-Ewe Diets in the Kansas Flint Hills

Awareness of herbivore diet composition is an essential element of rangeland stewardship. Objectives of our experiment were to characterize diet selection by yearling steers and mature ewes grazing native tallgrass prairie, changes in dietary preferences that occurred with advancing season, and overlap in selection patterns between ewes and steers. Eight contiguous native tallgrass pastures (31 ± 3.3 ha) were grazed by yearling beef steers (n = 279 per yr) from 15 April to 15 July for two grazing seasons. Mature ewes (n = 813 per yr) subsequently grazed four of the eight pastures (0.15 ha per ewe) from 1 August to 1 October each year. Beginning 1 May, five fresh fecal pats were collected along four permanent transects per pasture at 2-wk intervals until steers were removed on 15 July. Subsequently, fecal grab samples were collected from 25 designated ewes per pasture on 15 August and 15 September. Microhistological analyses were conducted on fecal samples to estimate dietary botanical composition, using 17 grass, forb, and browse species from the experimental site as reference standards. Botanical composition of pastures was estimated annually in October. Diet selection was evaluated using Kulcyznski’s Similarity Index. The proportions of total graminoids and total forbs in steer diets were not different (P = 0.37) among sampling periods. Steer diets were dominated by graminoids (≥ 88.4% of diets) throughout the experiment. Steers and ewes exhibited strong preference for Bouteloua gracilis, Buchloe dactyloides, Dalea purpurea, and Liatris punctata. Ewes also demonstrated strong preferences for Vernonia baldwinii and Ambrosia artemisiifolia. Steers avoided Lespedeza cuneata and Symphyotrichum ericoides, whereas ewes did not avoid any of the reference standards. Ewes selected approximately equal proportions of graminoids and forbs (58% and 42% of diets, respectively), and proportions did not differ (P = 0.67) between sampling periods. Diet selection by mature ewes and yearling steers overlapped by 65% under the conditions of our experiment.

Resposta de pastagens de Trachypogon plumosus consorciadas com Stylosanthes capitata cv. Lavradeiro a níveis de fósforo e potássio

Was evaluated the effect of phosphate (0, 40, 80 and 120 kg of P2O5 ha-1) and potassic fertilization (0, 40, 80 and 120 kg of K2O ha-1) on the forage yield, chemical composition and macronutrients extraction of native pastures of Trachypogon plumosus intercropping with Stylosanthes capitata cv. Lavradeiro in Roraima´s savannas. The effects of phosphate and potassic fertilization on legume forage yield were positive and linear, while for the grass and sum of components (grass + legume) were quadratic and the maximum yields estimated with the application of 73.8 and 105.1 kg of K2O ha-1 and 84.5 and 108.5 kg of P2O5 ha-1, respectively. Nitrogen, phosphorus, calcium, magnesium and potassium contents and extraction of grass and legume were quadratically affected by phosphate and potassic fertilization. Macronutrient extractions by grass and legume, independently of phosphate and potassic fertilization, were higher for N and K, followed by Ca, Mg and P. Phosphate and potassic fertilization provided grass and legume forage with better quality and lower fiber contents. Considering the overall availability of forage and pasture botanical composition - satisfactory grass/legume relationship - the use of phosphate levels between 80 and 90 kg of P2O5 ha-1 and 60 and 70 kg de K2O ha-1 can allow the establishment and yield stability and persistence of grass-legume mixture.

Rendimiento de forraje, composición química y extracción de macronutrientes de Trachypogon plumosus consorciado con Stylosanthes capitata cv. Lavradeiro bajo niveles de potasio

Was evaluated the effect of potassium fertilization (0, 40, 80 and 120 kg of K2O ha-1) on the forage yield, chemical composition and macronutrients extraction of Trachypogon plumosus native pastures intercropping with Stylosanthes capitata cv. Lavradeiro in Roraima´s savannas. The effects of potassium fertilization on legume forage yield were directly proportional to K levels, while for grass the adjustment was quadratic and the maximum value estimated with the application of 69.9 kg of K2O ha-1. Nitrogen, calcium, magnesium and potassium contents of the grass and legume were quadratically affected by potassium fertilization, while the macronutrient extraction by the grass was quadratic, and linear and positive for forage legume. Macronutrient extractions by grass and legume, independently of potassium fertilization, were higher for N and K, followed by Ca, Mg and P. Potassium fertilization provided grass and legume forage with better quality and lower fiber contents. Considering the overall availability of forage and pasture botanical composition - satisfactory grass/legume relationship - the use of potassium levels between 80 and 100 kg of K2O ha-1 allow the establishment and yield stability and persistence of grass-legume mixture.

Estimation of ergovaline intake of cows from grazed perennial ryegrass containing NEA2 or standard endophyte

Abstract Ergovaline concentration was measured monthly from December 2015 to April 2016 in herbage of perennial ryegrass pastures containing NEA2 or standard endophyte (SE) in the Waikato, Manawatu and Canterbury. Ergovaline concentrations were then combined with estimated pasture intake, pasture botanical composition and cow liveweight data from experimental dairy farm systems in the Waikato and Canterbury to estimate dairy cow ergovaline intake (mg/kg LW0.75/day). For the diploid ryegrass 'Trojan' with NEA2 estimated ergovaline intake ranged from 0.01 to 0.029 mg/kg LW0.75/day, levels at which no significant animal production effects have been reported. Ergovaline intake of tetraploid ryegrass 'Bealey NEA2' was at least an order of magnitude lower than this. For the diploid ryegrass, 'Bronsyn' with SE, ergovaline intake was 0.016 to 0.056 mg/kg LW0.75/day, which at the highest level carried a ~20% risk of causing animal production effects for 15% of the samples. AR1 and AR37 pastures, used as controls, contained nil or trace amounts of ergovaline. Keywords: alkaloid, Epichloë festucae var. lolii, Lolium

The economic value to dairy systems of genetic gains in the nutritive value of perennial ryegrass in grass–clover pastures

Perennial ryegrass (Lolium perenne L.) breeding efforts have focussed on improving pasture nutritive value by altering flowering behaviour and increasing ploidy. However, the gains in farm profitability that this has delivered are not known. The flowering behaviour, botanical composition and nutritive value of pastures based on 24 perennial ryegrass cultivar–endophyte combinations released in New Zealand since 1970 were compared under grazing for 3 years in the Waikato region of New Zealand. Cultivars were grouped into the following three functional groups for data analysis: mid-season-heading diploids, late- and very late-heading diploids, and late- and very late-heading tetraploids. The first of these groups included older, ‘standard’ cultivars, while the latter two groups were dominated by cultivars released since 2002. The appearance of reproductive tillers in grazed pastures was delayed by 4–8 weeks for the late- and very late-heading cultivars, resulting in pastures that maintained a greater proportion of green leaf and had a greater metabolisable energy (ME) concentration during spring. Tetraploid pastures had a greater ME concentration than did diploid pastures, largely due to the greater ME concentration of the perennial ryegrass component of these pastures. The gains in pasture nutritive value achieved by broadening the range of perennial ryegrass functional types have the potential to deliver economic benefits in the range of NZ$54/ha.year (late-heading diploids compared with mid-heading diploids) to NZ$232/ha.year (tetraploids compared with mid-heading diploids) to New Zealand dairy farmers. Potential economic gains can be diminished by changes in pasture botanical composition both over time and between functional groups.

Perennial ryegrass breeding and the scaling issue: a review of system experiments investigating milk production and profit differences among cultivars

Results of studies designed to determine whether or not differences measured among perennial ryegrass cultivars in small-plot studies translate into differences in milk production and profit in dairy whole-system studies were reviewed. Only three experiments were identified that met the criteria for fully self-contained systems repeated over multiple years required to account for annual feed supply–demand balance, its interaction with animal intake and production, and the influence of inter-annual climate variability on these processes. Collectively, these studies provide evidence of improvement in animal production, associated with genetic gains from ryegrass breeding, albeit through shifts in factors such as heading date (as it affects herbage quality and grazing efficiency) and host plant by endophyte interactions, rather than through gains in dry-matter yield. The latter remains unresolved, despite substantial evidence for gains from small-plot trials of dry-matter yield increases in the order of 0.5% per annum. These studies also highlighted the number of factors that have to be taken into account in the design and conduct of such studies, including gaining clarity about the size of the differences that can be expected and ensuring sufficient statistical power. Implementing objective management rules that allow cultivars to express their potential and capture differences through the grazing animal will ensure sufficient measurement intensity to enable differences (if observed) in milk production and profit to be explained. This should guard against confounding factors such as the differential effects of insect pests on plant performance, and consequent changes in pasture botanical composition mediated by ryegrass endophyte strains. Despite these difficulties, more experiments of this type are required to quantify and, ultimately, increase the value being delivered by ryegrass breeding to pasture-based dairy production systems in temperate regions. Therefore, there is a need for whole-system studies to be undertaken to provide valuable new information and give farmers the confidence to invest in the use of new cultivars.

Productive responses of breeding Cashmere goats and their kids to different stocking rates on improved upland pastures.

Although goat meat production could be an option for diversification in improved upland pastures in northern Spain, precise information on the optimal grazing management to enhance goat performance and maximize production per unit land area is lacking. The objective of this study was to compare the effects of 3 stocking rates, high stocking rate (HSR; 20 goats/ha), medium stocking rate (MSR; 15 goats/ha), and low stocking rate (LSR; 10 goats/ha), on gastrointestinal (GI) nematode infections and productive responses of Cashmere goats grazing such pastures. Treatments were replicated twice on 6 paddocks sown with and and with a high presence of the native grass . The experiment lasted 3 grazing seasons (from spring to autumn). Pastures were sampled for sward height and botanical and proximate composition. Body weight and BCS changes of goats were monitored and GI nematode infections were assessed by fecal egg counts (FEC). The established treatments resulted in lower mean sward height in the HSR than in the MSR and LSR (9.6, 11.5, and 14.4 cm, respectively; < 0.001). Pasture botanical composition and nutritive quality did not differ between treatments. The mean FEC of does across the 3 grazing seasons were greater ( < 0.05) in the HSR than in the LSR. spp., , and were the most prevalent nematode species identified in coprocultures. Does showed more favorable ( < 0.001) BW and BCS changes in the LSR than in the MSR and HSR (-14, -30, and -52 g/d and -0.1, -0.3, and -0.7 BCS units [scale 1 to 5], respectively). Greater ( < 0.001) kids' BW gains were observed in the LSR and MSR (average 94 g/d) compared with the HSR (70 g/d). Inversely, kid output per unit land area was greater in the HSR than in the MSR and LSR (320, 258, and 192 kg∙ha∙yr, respectively; < 0.001), whereas daily kids' BW gains per hectare were greater ( < 0.001) in the HSR and MSR (average 1.37 kg∙d∙ha) compared with the LSR (0.98 kg∙d∙ha). A medium stocking rate of 15 goats/ha could represent the best compromise between animal health, performance, and productivity per unit land area in this type of upland pastures, but stricter controls of parasite levels during the grazing season would be necessary to avoid production losses, unless alternative nutraceuticals are provided.

Hill country pastures, botanical composition and productive capacity

Botanical composition of pastures is indicative of their dry matter production and nutritive value and so capacity for animal production. Two previous national pasture surveys were conducted in 1935/1940 and in 1987/1988, and one regional survey in 1967/1968, to assess the state of this resource across all land classes. Among many purposes, results from these surveys were used to assess the outcomes of technological advances such as aerial topdressing and oversowing in hill country from the 1950s onwards, and to record changes in the abundance of particular species such as C4 grasses that could indicate effects of climate change, and identify research needs and opportunities. In the 28 years since the most recent survey, there have been many changes in the farm operating environment. This is particularly so in hill country, where other sectors such as forestry and dairy have encroached on traditional sheep and beef land, and poor profitability has forced variable and often sub-maintenance applications of phosphate (P) and sulphur (S) fertilisers. However, the low use of P and S has been partly offset by increased use of nitrogen (N) fertiliser. The declining number of beef cows, substituted by growing dairy and dairy-beef cattle, and the remarkable increase in the per head productivity of sheep are probably the biggest changes shifting the feed demand profile and the ratio of mature: young livestock. These changes affect pasture utilisation. This paper will consider the possible effects of those changes over the 28 years since the most recent national survey of pasture botanical composition, and the future capacity and resilience of this important resource to cope with continuing farm system change, emerging pressures for productivity growth, and regulatory and compliance requirements. Keywords: hill country pasture, botanical composition, resource status, survey

Species Diversity and Botanical Composition of Permanent Grassland as a Response to Different Grazing Management Practices

The effects of different levels of grazing utilization (two, three and four grazing cycles per year) and mineral fertilization (nil-fertilization; N100P30K60) on the botanical composition of permanent grasslands were studied in the locality of Rapotín (Czech Republic, 332 m a.s.l.) from 2003–2010. The vegetation of the experimental pasture was classified as Cynosurion. It was found that moderate treatment (three grazing cycles per year) without mineral fertilization showed the highest value of diversity index (DI = 6.08), and maximum dominance of legumes (Dmax = 9.1%), particularly Trifolium repens. The highest dominance of grasses (Dmax = 77.7%), mainly Dactylis glomerata and Elytrigia repens, was achieved with the fertilized treatment utilized in two grazing cycles per year. Based on RDA results, tested management treatments explained 26% of species composition variability, where effect of number of grazing cycles per year was five-times higher than effect of fertilization. We recommend grassland utilization in three grazing cycles per year as the most suitable way from the objective of both species diversity and botanical composition of pastures in similar site conditions. Pasture fertilization should be more controlled by careful consideration of individual pasture goals, actual nutrient status of the soil and possible environmental risks.

Impact of cultivation method on productivity and botanical composition of a kikuyu–ryegrass pasture

Kikuyu (Pennisetum clandestinum)–ryegrass (Lolium spp.) cultivated pastures form the base for dairy production in the southern Cape region of South Africa. The impact of various methods and implements used to over-sow ryegrass on the productivity and botanical composition of the pasture is unknown. The study aimed to assess the impact of cultivation along a soil disturbance gradient on the productivity and botanical composition of kikuyu-based pastures. Five tillage treatments were assessed, namely kikuyu over-sown with ryegrass using a minimum till planter, eradication of kikuyu with herbicide and ryegrass sown with a minimum-till planter, shallow (<150 mm) and deep (>150 mm) disturbance with a rotavator or conventional tillage, respectively, and a control. The autumn, spring, summer and annual productions of treatments with the least soil disturbance were the highest (P ≤ 0.05). Shallow or deep tillage resulted in intermediate annual productions and the lowest (P ≤ 0.05) was recorded for the herbicide treatment. Differences in production caused by different tillage methods were significant (P ≤ 0.05) and changed the botanical composition. Kikuyu over-sown with ryegrass using a mulcher and minimum-till planter was the most viable option to manage cultivated pastures.

Animal performances, pasture biodiversity and dairy product quality: How it works in contrasted mountain grazing systems

The interactions between botanical composition of pasture, quality of herbage grazed, performances of dairy cows and sensory and nutritional properties of dairy products were investigated using an integrated system approach. Two contrasting grazing systems were evaluated from May to September in two years. The treatments included a continuous grazing system (DIV) managed at a lenient stocking rate (1.0LUha−1) on a botanically-rich permanent pasture, and a rotational grazing system (PROD) set up at a higher stocking rate (1.7LUha−1) on a former temporary grassland presenting moderate biodiversity. DIV aimed to maximize biodiversity and obtain high sensory and nutritional quality cheese, whereas PROD was oriented towards milk production and herbage quality. In each system, 12 non-feed-supplemented Montbéliarde cows were used. The DIV system led to higher milk production per cow in the early grazing season than the PROD system (22.2 vs. 19.9kgd−1). At the beginning of summer, this milk production pattern was inverted following a decrease in grass nutritive value in the DIV system. In parallel, DIV cows showed a more marked loss of body condition than PROD cows over the season. In terms of milk fatty acid profile, the DIV system proved very interesting early in the grazing season but lost its value over time as the herbage matured. Cheese sensory properties differed between systems only after a long ripening period (6 months). Regarding the ecological performances, the DIV plot showed greater botanical and entomological biodiversity than the PROD plot. This study provides evidence that the balance between animal performances, dairy product quality and biodiversity in dairy systems is more complex than previously thought, since the expected benefits of each system vary markedly over periods. The evolution of herbage vegetation stage during the grazing season combined with the botanical composition of the pasture is a key component for understanding these variations.

Effect of Sicilian pasture feeding management on content of α-tocopherol and β-carotene in cow milk

This study was performed to evaluate α-tocopherol and β-carotene contents of pasture milk under ordinary Sicilian farming conditions. Fourteen dairy farms were allocated into 2 balanced groups on the basis of cultivated (CULT) or spontaneous (SPO) pasture type feeding. Bulk milk per farm was collected 4 times from February through April at 3-wk intervals. Pasture botanical and diet composition, diet nutritional quality, milk yield and composition were estimated each time. Pasture intake levels were calculated based on feed analyses, hay and concentrate amounts fed, and milk yield and chemical composition. According to pasture intake, the farms were split into low pasture intake (LPI; <29.5% of dry matter) and high pasture intake (HPI; >29.5% of dry matter) groups. Milk samples per farm were analyzed for α-tocopherol and β-carotene contents by HPLC. The SPO group had higher levels of α-tocopherol and β-carotene in milk (0.7 and 0.3mg/L, respectively) and milk fat (19.0 and 7.5mg/kg fat, respectively) compared with the CULT group in milk (0.5 and 0.2mg/L, respectively) and milk fat (14.6 and 4.9mg/kg, respectively). High pasture intake compared with LPI increased α-tocopherol in milk fat (18.0 and 16.0mg/kg of fat, respectively). However, only in the SPO (not in CULT), HPI compared with LPI increased milk α-tocopherol (0.8 vs. 0.6mg/L, respectively), milk β-carotene (0.3 vs. 0.2mg/L, respectively), and milk fat β-carotene (8.4 vs. 6.6mg/kg, respectively). Results may be related to the different botanical composition of the respective pasture types and pasture intake. Spontaneous pasture compared with CULT contained a higher mass proportion of Asteraceae, Fabaceae, Cruciferae, Euphorbiaceae, and Malvaceae plants. Milk and milk fat α-tocopherol levels were higher on test-days (TD)-1, TD-2, and TD-4 compared with TD-3. For HPI farms, milk fat β-carotene content was higher on the first 2 TD compared with the last 2 TD. These differences could be related to plant biological stage. On Sicilian dairy farms, the highest milk α-tocopherol and β-carotene contents may be obtained feeding high levels of SPO pasture in the spring.