Pasture Quality Research Articles

Is the Low Carbon Agriculture Credit Program Impacting Pasture Area and Quality in the Brazilian Northeastern Region?

Is the Low Carbon Agriculture Credit Program Impacting Pasture Area and Quality in the Brazilian Northeastern Region?

Estimating pasture quality of Mediterranean grasslands using hyperspectral narrow bands from field spectroscopy by Random Forest and PLS regressions

Mediterranean grasslands are a cornerstone ecosystem to provide ecosystem services and sustain human societies. The sustainability and provision of ecosystem services by these systems rely on their management. One of the main attributes to perform sustainable and effective management is pasture quality, which is crucial for animal performance in rainfed extensive systems. Remote sensing of grasslands can be an effective tool to inform the management of grasslands. The forthcoming high-priority mission candidate of the European Space Agency, Copernicus Hyperspectral Imaging Mission for the Environment (CHIME) with continuous narrow bands of ≥10 nm spectral resolution could be an asset to provide accurate information on the pasture quality of high-diverse and heterogeneous grasslands. In this study, we investigated the potential of CHIME-like field spectroscopy data at 10 nm resolution to assess the quality of Mediterranean permanent grasslands. The pasture quality indicators used were: crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and enzyme digestibility of organic matter (EDOM). To do so, two machine learning methods commonly used in remote sensing were implemented: Partial Least Squares (PLS) regression and Random Forest (RF) regression. The results using all bands in the 400–2300 nm spectral range and the results obtained by Backward Feature Elimination (BFE) were also compared. Finally, using importance measures of PLS and RF and the BFE approach, the importance and stability of the bands to assess the pasture quality indicators were explored. The results showed that field spectroscopy CHIME-like data at 10 nm of spectral resolution show potential to predict CP at “good” accuracy and NDF at “moderate” accuracy level in Mediterranean permanent grasslands. PLS outperformed RF to predict CP and NDF in terms of accuracy and certainty of the predictions. The BFE approach increased the accuracy of the predictions, especially in PLS, for which a percentage decrease of ΔRMSE = -12.5% was achieved in cross-validation to predict CP. The models built by BFE approach to predict CP using PLS provided a mean R2 value of 0.82 and a range of 0.68–0.90 in bootstrapped predictions. The RMSE was low (mean RMSE = 2.23%) and the mean RPD = 2.47 with values ranging from 1.81 to 3.23. RF models to predict CP produced mean R2 value of 0.68, mean RMSE = 3.00% and mean RPD = 1.82. ADF and EDOM were predicted with poor accuracy and similarly by both, PLS and RF. The bands located in the red-edge and NIR region showed high importance and stability to assess the best-predicted variables. Bands centred at 700, 710, 1160, 1170 and 1180 are highly stable and important to predict CP. The bands from the SWIR region had lower stability. This study provides insightful results on the use of hyperspectral data and future satellite missions such as CHIME to assess the pasture quality of Mediterranean grasslands that can be crucial to inform the management and monitoring of Mediterranean permanent grasslands.

Performance of Bos indicus beef cattle supplemented with mineral or with concentrates in tropical Urochloa decumbens pastures: A meta-regression approach

Models are useful to predict responses of beef cattle to supplementation and its interactions with pasture quality. Therefore, this study was conducted to quantitatively understand variables that influence the performance of cattle under grazing, with or without supplementation, in the tropics by using a meta-analytical approach. The database was composed of individual data of 577 heifers and 194 young bulls from 18 experiments. Information collected included: sex (male or female), total dry matter intake, supplement dry matter intake, forage crude protein (CPforage), forage indigestible neutral detergent fiber (iNDFforage), forage neutral detergent fiber, neutral detergent insoluble protein, crude protein intake from supplement (CPIsupp), metabolizable energy intake from supplement (MEIsupp), initial body weight (BW), final BW and average daily gain (ADG). Additionally, the intakes of rumen degradable protein (RDP), rumen undegradable protein (RUP), and metabolizable protein (MP) from the supplement of each study were calculated. To model animal performance, values within each experiment were divided into two components: ADG-pasture (ADG of non-supplemented animals) and ADG-supplement (differential ADG in relation to non-supplemented animals). Data were evaluated using a meta-analysis approach to estimate fixed and random effects of experiment using linear and nonlinear mixed models. There was no correlation between ADG-pasture and initial BW or final BW. The CPforage was positively correlated, and iNDFforage was negatively correlated with ADG-pasture. Therefore, two equations were developed to predict ADG-pasture, as follows: ADG-pasturemales (kg/day) = 0.007434 × CPforage – 0.001044 × iNDFforage; ADG-pasturefemales (kg/day) = 0.01445 × CPforage – 0.0000642 × CPforage2 – 0.001598 × iNDFforage. There was no correlation between ADG-supplement and total dry matter intake, initial BW, or final BW. The ADG-supplement was positively correlated with CPIsupp and MEIsupp. An exponential model was chosen to fit ADG-supplement. Equations to predict ADG-supplement were composed of three exponential compartments based on ADG-pasture, CPIsupp (or RDP, RUP or MP intakes from supplement), and MEIsupp. The replacement of CPIsupp by RDP, RUP or MP intakes from supplement demonstrated that all protein components could be used to predict the performance of grazing animals. Still, the best fit was observed when RUP intake from supplement was used. The validation process through cross-validation analyses demonstrated that all equations had high accuracy and moderate precision. In conclusion, our results indicate that ADG-pasture can be estimated from CPforage, iNDFforage. The ADG-supplement can be estimated from ADG-pasture, MEIsupp, and protein components intake in grazing heifers and young bulls.

Effect of Amazonian tree species on soil and pasture quality in silvopastoral systems

ABSTRACT With the expansion of livestock in the Amazon region, a high percentage of pasture areas are degraded and unproductive. Novel strategies are needed, including the use of native tree species, to simultaneously achieve economic and ecosystem benefits. This study aimed at assessing the effects of five multipurpose native tree species on soil fertility and forage quality of Urochloa brizantha pastures in the southern Amazon. Soil and forage samples were collected under the crown and adjacent to 25 isolated trees belonging to five species during a dry and a rainy season. The presence of native trees positively affected the level of potassium, calcium and manganese in the soil, as well as the mineral matter and crude protein of the forage, especially in the dry season, suggesting a protective effect against the seasonal drought. The tree species had variable effects on soil fertility and forage quality. Soil under Apeiba tibourbou had higher potassium levels, while the forage under Handroanthus serratifolius had higher protein and fiber content. Our results indicate that it is important to diversify silvopastoral systems in the Amazon through the use of native tree species, contributing to the design of novel silvopastoral strategies in the region. Common multipurpose tree species with widespread natural distribution could be used as a complementary aspect of pasture management to provide a protective effect against drought, contribute to enhanced nutrient cycling and even increase forage quality.

A Research on the Determination of the Botanical Composition of the High Altitudes of Anzer Region (Ikizdere-RIZE)

This study was carried out in 2020 at the pasture areas of high altitudes of the Anzer region in İkizdere district of Rize province of Turkey. In the study, canopy coverage area, botanical composition, pasture quality degree and pasture condition parameters were studied. The vegetation study was carried out in June, when the vegetation reached the climax phase. The vegetation characters of the research area were determined using the "Lup" method. In the research area, 45 taxa belonging to 21 families were identified. Taxa numbers of families; Poaceae (5), Fabaceae (3), Apiaceae (1), Asteraceae (9), Boraginaceae (2), Brassicaceae (1), Caryophyllaceae (3), Crassulaceae (1), Compositae (1), Cyperaceae (1), Gentianaceae (2), Geraniaceae (1 ), Hypericaceae (1), Lamiaceae (2), Liliaceae (1), Onagraceae (1), Orabanchaceae (2), Plantaginaceae (1), Polygonaceae (2), Primulaceae (1), Rosaceae (3) and Urticaceae (1). The canopy coverage rate of pasture area was determined as 72.00%. The botanical composition of the study area was determined as Poaceae 26.32%, Fabaceae 8.92% and other families 64.76%. With a pasture quality degree of 1.95, the condition of the pasture was determined as "Very Weak". Keywords: Botanical composition, canopy coverage, Rize, Anzer region DOI: 10.7176/JSTR/7-10-02

The Known Antimammalian and Insecticidal Alkaloids Are Not Responsible for the Antifungal Activity of Epichloë Endophytes.

Asexual Epichloë sp. endophytes in association with pasture grasses produce agronomically important alkaloids (e.g., lolitrem B, epoxy-janthitrems, ergovaline, peramine, and lolines) that exhibit toxicity to grazing mammals and/or insect pests. Novel strains are primarily characterised for the presence of these compounds to ensure they are beneficial in an agronomical setting. Previous work identified endophyte strains that exhibit enhanced antifungal activity, which have the potential to improve pasture and turf quality as well as animal welfare through phytopathogen disease control. The contribution of endophyte-derived alkaloids to improving pasture and turf grass disease resistance has not been closely examined. To assess antifungal bioactivity, nine Epichloë related compounds, namely peramine hemisulfate, n-formylloline-d3, n-acetylloline hydrochloride, lolitrem B, janthitrem A, paxilline, terpendole E, terpendole C, and ergovaline, and four Claviceps purpurea ergot alkaloids, namely ergotamine, ergocornine, ergocryptine, and ergotaminine, were tested at concentrations higher than observed in planta in glasshouse and field settings using in vitro agar well diffusion assays against three common pasture and turf phytopathogens, namely Ceratobasidium sp., Drechslera sp., and Fusarium sp. Visual characterisation of bioactivity using pathogen growth area, mycelial density, and direction of growth indicated no inhibition of pathogen growth. This was confirmed by statistical analysis. The compounds responsible for antifungal bioactivity of Epichloë endophytes hence remain unknown and require further investigation.

Floristic Composition: Dynamic Biodiversity Indicator of Tree Canopy Effect on Dryland and Improved Mediterranean Pastures

Montado is a characteristic ecosystem of the Mediterranean region. The adequate management of this silvo-pastoral ecosystem requires good understanding of the effect of factors such as tree canopy, fertilization and soil amendment on pasture growth. The main objectives of this work were: (1) to evaluate the effect of tree canopy on soil characteristics and pasture productivity and quality; and (2) to test floristic composition assessment as a bio-indicator of soil improvements (amendment and fertilization) in each study area (under and outside tree canopy). Topsoil was characterized at the beginning of the project (October 2015) and at the end of the experiments (spring 2020). Soil parameters obtained by electronic sensors (soil moisture content, soil cone index and surface temperature) were monitored monthly during the 2017/2018 pasture vegetative cycle. Pasture productivity, quality and floristic composition were evaluated every two years (2016, 2018 and 2020) in the spring flowering period. The results of the floristic inventory were submitted to a multilevel pattern analysis (Indicator Species Analysis, ISA). Pasture biodiversity was evaluated based on the calculation of richness indices. This study showed a positive effect of tree canopy on soil fertility and pasture quality (e.g., CP). Pasture productivity, on the other hand, was higher in areas outside tree canopy. The great potential of ISA as a tool for identification of bio-indicator species was also demonstrated. Pasture species were identified as ecological and dynamic attributes characteristic of each study area, before and after soil amendment and fertilization.

Real-Time Quantification of Crude Protein and Neutral Detergent Fibre in Pastures under Montado Ecosystem Using the Portable NIR Spectrometer

The Montado is a Mediterranean agro–forestry–pastoral ecosystem. Knowledge of pastures’ nutritional value is critical for farm managers’ decision-making. Laboratory determinations are very expensive, destructive and costly, in terms of time and labour. The objective of this experimental work was to calibrate and validate a portable near-infrared spectrometer (micro-NIR) to predict the nutritive value (neutral detergent fibre, NDF and crude protein, CP) of pastures in the peak of spring 2021. Thus, a total of 87 pasture samples were collected at eight experimental fields located in the Alentejo, Southern region of Portugal. The results show good correlations between in-situ micro-NIR measurements and pasture NDF reference values (R2 of 0.73 and 0.69 for calibration and validation models, respectively), and a moderate correlation between micro-NIR measurements and pasture CP reference values (R2 of 0.51 and 0.36 for calibration and validation models, respectively). These results show the potential of this tool for the quick evaluation of pasture quality and constitute a starting point for future work, which should include the monitoring of temporal variability (throughout the entire vegetative cycle of the pasture) and spatial (with geo-referenced information) diversity of pastures characteristic of the Montado ecosystem in the Mediterranean region.

Attributes of resilient pasture for achieving environmental outcomes at farm scale

Pasture resilience commonly refers to a pasture’s ability to withstand or rebound from pressures to maintain production and quality of sown species. We suggest that a broader definition of pasture resilience is needed that also includes environmental responses, thus ensuring that productivity and environmental outcomes are considered together. Key attributes of resilient pastures to minimise soil erosion and nutrient, greenhouse gas and soil carbon losses are summarised based on current understanding of environmental losses from pastoral systems. These attributes include maintaining consistent pasture cover, high energy and/or low nitrogen species and species diversity that provides complementary root morphology and/or growth seasonality; all are likely to have positive benefits for production and productivity. There is a potential tension, however, between productivity and methane emissions, as methane production increases with increased feed intake. Increasing pasture quality is therefore also an important consideration for pasture resilience as it can maintain animal productivity at lower levels of feed intake. From a farm systems perspective, the choice of pasture species should reflect the desired attributes for both productivity and environmental outcomes, and ensure that the sown species persist in the sward. Finally, we note that none of the environmental attributes/benefits are likely to deliver major farm-scale improvements on their own; progress will likely be incremental improvements upon implementing a range of attributes.

Plant diversity with species drilled in the same or alternate rows enhanced pasture yield and quality over 4 years

This paper reports on the effects of plant species diversity and sowing method on pasture yield and quality. Nineteen seed mixtures of perennial ryegrass (PR), plantain (Pl), white clover (WC) and red clover (RC) were sown on 26 March 2015 at Lincoln University. Four mixtures of PR, Pl and WC were repeated with species separated in alternate drill rows. Plots were grazed by sheep and irrigated. After 4 years, a mixture with 25% of each species based on seed count – equivalent to 7.5 kg PR, 5.6 kg Pl, 1.9 kg WC and 4.4 kg RC (19.4 kg total seed)/ha – produced an optimal balance of increased total yield (17.44 t DM/ha/yr), weed suppression (0% of total yield), metabolisable energy (11.4 MJ/kg DM) and crude protein (19% of DM). Sowing method had no effect. Plant diversity enhanced pasture production through positive interactions and identity effects among the legumes (WC and RC) and non-legumes (PR and Pl). The strength of interactions between species depended on the identity and relative abundances of the species involved. The diversity effects occurred alongside shifts in species relative abundances over time. This study demonstrated an experimental basis for the evaluation of multi-species pasture mixtures.

Effect of fertilizer inputs on productivity and herbage quality of native pasture in degraded tropical grasslands

AbstractThe practice of applying fertilizer inputs on an unimproved natural pasture is limited in tropical grasslands. A study was conducted to evaluate the response of degraded natural pasturelands in terms of species composition, forage yield, and quality to the application of different types of fertilizer. The study was conducted in two districts in the central Rift Valley of Ethiopia with contrasting agroecologies. The treatments were control (no application of fertilizer), commercial fertilizer (50 kg urea ha–1 and 100 kg diammonium phosphate [DAP] ha–1), cattle manure (7.5 t ha–1), wood ash (3 t ha–1), and lime (7.5 t ha–1). Soil physical properties were not altered following application of the treatments, but chemical properties, including soil pH (P < .01), electroconductivity (EC) (P < .001), total nitrogen (TN), and P (P < .001) were affected. Soil TN increased from 0.11 to 0.32% following the application of cattle manure. The pH increased from 5.9 to 7.3 with wood ash application. Herbage dry matter (DM) yield increased (P < .001) from 1.88 to 6.65 t ha–1 with chemical fertilizer. The herbage crude protein content increased (P < .01) from 96 to 157 g kg–1 with manure application. On the other hand, the neutral detergent fiber tended to decrease (P < .05) following manure application. Partial cost‐benefit analysis indicated a positive economic gain from the direct sale of pasture hay for all treatments except for lime. The results indicated that fertilizer inputs offer feasible options to improve pasture productivity and enable rural farmers to benefit from their land resources.

The Relationship between Satellite-Derived Vegetation Indices and Live Weight Changes of Beef Cattle in Extensive Grazing Conditions

The live weight (LW) and live weight change (LWC) of cattle in extensive beef production is associated with pasture availability and quality. The remote monitoring of pastures and cattle LWC can be achieved with a combination of satellite imagery and walk-over-weighing (WoW) stations. The objective of the present study is to determine the association, if any, between vegetation indices (VIs) (pasture availability) and the LWC of beef cattle in an extensive breeding operation in Northern Australia. The study also tests a suite of VIs along with variables such as rainfall and Julian day to predict the LWC of breeding cows. The VIs were calculated from Sentinel-2 satellite imagery over a 2-year period from a paddock with 378 cattle. Animal LW was measured remotely using a weighing scale at the water point. The relationship between VIs, the LWC, and LW was assessed using linear mixed-effects regression models and random forest modelling. Findings demonstrate that all VIs calculated had a significant positive relationship with the LWC and LW (p < 0.001). Machine learning predictive modelling showed that the LWC of breeding cows could be predicted from VIs, Julian day, and rainfall information, with a Lin’s Concordance Correlation Coefficient of 0.62 when using the leave-one-month-out cross-validation. The LW and LWC were greater during the wet season when VIs were higher compared to the dry season (p < 0.001). Results suggest that the remote monitoring of pasture availability, the LWC and LW is possible under extensive grazing conditions. Further, the use of VIs and other readily available data such as rainfall can be used to predict the LWC of a breeding herd in extensive conditions. Such information could be used to increase the productivity and land management in extensive beef production. The integration of these data streams offers great potential to improve the monitoring, management, and productivity of grazing or cropping enterprises.

Does grass-legume intercropping change soil quality and grain yield in integrated crop-livestock systems?

In sustainable tropical agriculture, grass-legume intercropping can increase productivity, enhance the nutritional quality of the crop and affect soil microbiological activity, leading to higher yields in succession crops. This study evaluated the impact of grass-legume intercropping, during the pasture phase of integrated crop-livestock systems under no-tillage (ICLS–NT), on soil microbiota, pasture quality, and soybean productivity in the Brazilian Cerrado. We evaluated the effect of intercropping on total soil contents of organic carbon and nitrogen, soil microbial activity, animal and soybean productivity (2017 and 2018 crop seasons), and pasture production and quality. The experiment consisted of twelve treatments under grass-legume intercropping in the pasture phase of ICLS–NT. The grasses Urochloa ruziziensis ‘Kennedy’, U. brizantha ‘Paiaguás’, Panicum maximum ‘Tamani’ and U. brizantha ‘Piatã’ were grown in monoculture and intercropped with cowpea (Vigna unguiculata) ‘Tumucumaque’ or pigeon pea (Cajanus cajan) ‘Mandarin’. A randomized block design, with three repetitions, was used in a split-plot arrangement, considering the grasses as plots and the legumes as subplots. The results showed that ICLS–NT improved the activity of soil microbial biomass when compared to monoculture systems. Grass-legume intercropping during the pasture phase, mainly with cowpea (Vigna unguiculata), increased soybean productivity, and grass dry matter. Total organic carbon (TOC), carbon management index (CMI%), microbial biomass carbon (MBC), soil basal respiration (BR), and metabolic quotient (Qmic) are the most sensitive markers when it comes to the effects of intercropping on soil microbiological activity and soybean productivity in ICLS–NT. Identifying the best grass-legume combinations allows the establishment of more productive crop-livestock integration systems under no-tillage better adapted to the bio-edaphoclimatic conditions of the Brazilian Cerrado.

Effect of supplement crude protein concentration on milk production over the main grazing season and on nitrogen excretion in late-lactation grazing dairy cows

The objectives of this study are to evaluate the effects of (1) a potential interaction between supplement crude protein (CP) concentration and differing cow genotypes on milk production, (2) differing cow genotypes on milk production, and (3) decreasing the supplement CP concentration on milk production and N excretion during the main grazing season within a spring-calving herd. A 2 × 2 factorial arrangement experiment, with 2 feeding strategies [14%; n = 30 (lower CP; LCP) and 18%; n = 28 (higher CP; HCP) CP concentrate supplements] offered at varying levels according to pasture availability and days in milk (DIM) was conducted over the main grazing season from April 3 to September 3, 2019, at University College Dublin Lyons Farm. Cows were also grouped into 2 genotype groups: lower milk genotype; n = 30 [LM; milk kg predicted transmitting ability (PTA): 45 ± 68.6 (mean ± SD); fat kg PTA: 10 ± 4.9; and protein kg PTA: 7 ± 2.3] and higher milk genotype; n = 28 [HM; milk kg PTA: 203 ± 55.0; fat kg PTA: 13 ± 3.8; and protein kg PTA: 10 ± 2.4]. A total of 46 multiparous and 12 primiparous (total; 58) Holstein Friesian dairy cows were blocked on parity and balanced on DIM, body condition score, and Economic Breeding Index. Cows were offered a basal diet of grazed perennial ryegrass pasture. The N partitioning study took place from August 25 to 30, 2019 (187 ± 15.2 DIM). No interactions were observed for any milk production or milk composition parameter. No effect of supplement CP concentration was observed for any total accumulated milk production, daily milk production, or milk composition parameter measured. The HM cows had increased daily milk yield (+1.9 kg), fat and protein (+0.15 kg), and energy-corrected milk (+1.7 kg), compared with the LM cows. Furthermore, HM cows had decreased milk protein concentration (-0.1%) compared with LM cows. For the N partitioning study, cows offered LCP had increased pasture dry matter intake (PDMI; +0.9 kg/d), dietary N intake (+0.022 kg/d), feces N excretion (+0.016 kg/d), and decreased N partitioning to milk (-2%), and N utilization efficiency (-2.3%). In conclusion, offering cows LCP had no negative influence on milk production or milk composition over the main grazing season where high pasture quality was maintained. However, any potential negative effects of offering LCP on milk production may have been offset by the increased PDMI. Furthermore, offering cows LCP decreased N utilization efficiency due to the higher PDMI and feed N intake associated with cows on this treatment in our study.

Supplementation of crossbred cows with maize and urea in tropical pasture

ABSTRACT This research article aims to evaluate the effect of total replacement of corn by soybean meal and urea on intake and apparent digestibility of dry matter and its components, production and composition of milk and feeding behavior of lactating cows grazing, with intermittent stocking Mombaça grass (Megathyrsus maximus cv. Mombaça). Twelve milking cows were distributed in a triple 4 x 4 latin square. Experimental treatments consisted of four soybean meal replacement levels by corn more urea (0; 33; 66; 100%). The grass has an average content of crude protein and neutral detergent fiber of 19% and 59%, respectively. The replacement of soybean meal by corn and urea did not affect the intake and digestibility of nutrients. A linear reduction of milk production was observed, but there was no change in milk production corrected to 4.0% of fat. The milk components (g/kg) of fat, protein, lactose, and total solids were not altered, as well as feeding behavior. Under the conditions of this study, the replacement of the diets is suitable for crossbred dairy cows in lactation third medium, producing in average of 12.5 kg/day-1 when kept in quality pastures.

Forage mass and nutritional value of elephant grass intercropped with forage legumes1

Forage-legume systems are a sustainable and competitive alternative for improving pasture yield and quality because of the symbiotic nitrogen fixation capacity and high nutritional value of legumes. This study aimed to evaluate the forage mass, nutritional value, and nutrient export rate in three forage systems (FS): FS1, with elephant grass (Pennisetum purpureum) (EG), annual ryegrass (Lolium multiflorum) (AR), and spontaneous growth species (SGS); FS2, with EG + AR + SGS + arrowleaf clover (Trifolum vesiculosum); and FS3, with EG + AR + SGS + forage peanut (Arachis pintoi ). The experiment was arranged in a completely randomized design, with three replicates, and repeated measures over time. Results of pre-grazing forage mass were 3.5, 3.8, and 3.9 t/ha, and crude protein export were 1.4, 2.1, and 2.3 t/ha, for the treatments FS1, FS2 and FS3, respectively. Highest crude protein, in situ dry matter digestibility and total digestible nutrients, and lowest neutral detergent fiber were found in the intercropping system with forage peanut, especially in winter. Nutritional values were also better in legume-systems than the non-legume system.

Factors associated with small lungworm infections in heavily infected sheep in southeast South Australia

This field observational study describes the seasonal pattern of small lungworm infections under different grazing managements from August 2018 to March 2019. Live weight, lungworm and gastrointestinal nematode infection, as well as pasture type grazed and snail density, were measured at 5 farm visits. Across all visits and mobs, about one quarter to one half of sheep were positive for small lungworm, although prevalence was as low as 0% and as high as 78%. The density of the intermediate host molluscs was greater than 1600 snails/m2 in irrigated perennial lucerne pasture when it was grazed ('Pasture A'), but was low (<300) in non-irrigated perennial pasture ('Pasture B') and non-irrigated forage crop ('Pasture C'). Overall, non-infected lambs had a similar live weight compared with the small lungworm infected lambs (mean difference -0.6 kg; 95% CI -1.6 to 0.2; P=0.1). The odds ratio of small lungworm infection associated with a twofold increase in worm egg count was 1.7 (95% CI 1.1 to 2.7; P=0.02). Rather than a distinct seasonal pattern of infection, we found that small lungworm can occur throughout the year, with prevalence most influenced by pasture type (irrigated vs dryland), grazing management and the population density of the intermediate hosts. Importantly, this study suggested that small lungworm infection did not reduce lamb live weights. It reinforced that to improve sheep productivity, well-established determinants of production, such as correct grazing management to optimise pasture quality and strategies to reduce infections with gastrointestinal nematodes, should be the priority of farm managers.

Spatiotemporal Patterns of Pasture Quality Based on NDVI Time-Series in Mediterranean Montado Ecosystem

The evolution of dryland pasture quality is closely related to the seasonal and inter-annual variability characteristic of the Mediterranean climate. This variability introduces great unpredictability in the dynamic management of animal grazing. The aim of this study is to evaluate the potential of two complementary tools (satellite images, Sentinel-2 and proximal optical sensor, OptRx) for the calculation of the normalized difference vegetation index (NDVI), to monitor in a timely manner indicators of pasture quality (moisture content, crude protein, and neutral detergent fiber). In two consecutive years (2018/2019 and 2019/2020) these tools were evaluated in six fields representative of dryland pastures in the Alentejo region, in Portugal. The results show a significant correlation between pasture quality degradation index (PQDI) and NDVI measured by remote sensing (R2 = 0.82) and measured by proximal optical sensor (R2 = 0.83). These technological tools can potentially make an important contribution to decision making and to the management of livestock production. The complementarity of these two approaches makes it possible to overcome the limitations of satellite images that result (i) from the interference of clouds (which occurs frequently throughout the pasture vegetative cycle) and (ii) from the interference of tree canopy, an important layer of the Montado ecosystem. This work opens perspectives to explore new solutions in the field of Precision Agriculture technologies based on spectral reflectance to respond to the challenges of economic and environmental sustainability of extensive livestock production systems.

Working with dairy farmers to improve their pasture management skills through better understanding the principles of ryegrass growth

The relationships between leaf regrowth stage, pre- and post-grazing pasture covers, and grazing rotation length are complex. Despite the existence of well-documented grazing guidelines for managing these relationships, implementation on-farm is highly variable indicating that skill levels are often inadequate and/or farmers are not convinced of the benefits. Twenty dairy farm managers and assistant managers from the Hopkins Farming Group in the lower North Island engaged in structured observation and discussion with experts to test the potential of the 3-leaf grazing technique for increasing pasture production and reducing imported supplement use from mid-spring to mid-autumn. The farmer members of the study group initially had little knowledge of the principles of ryegrass growth at the plant level, and how their management influences pasture production and persistence. Grazing management skills developed by group members during the process included: identification of pasture species within the sward, including perennial ryegrass; identification of leaf morphology, tillers, tiller buds and daughter tillers; pasture health checks to understand when new tillers appeared and their grazing and nutrient needs; and the importance of grazing residuals for future pasture quality. Pasture productivity, as measured by the amount of silage conserved, increased by approximately 0.45 t DM/ha during the 6 months of study through the application of this grazing management technique. Managing grazing using the 3-leaf technique requires a greater depth of knowledge than previous, simple, rotation length-based systems. Many farmers are concerned about the lack of persistence of new ryegrass cultivars, whereas it may be their management practices that have a greater influence.

Effect of fungal endophytes on plant growth and nutrient uptake in Trifolium subterraneum and Poa pratensis as affected by plant host specificity

The introduction of well-adapted species, such as Trifolium subterraneum (subclover) and Poa pratensis (Kentucky bluegrass), might enhance the forage yield and quality of dehesa pastures for feeding livestock. However, the climatic hardness and poor soils in these agrosystems may limit plant establishment and development. Since fungal endophytes have been found to alleviate the environmental stresses of their host, the aim of this study was to assess the effect of five isolates on forage yield, nutritive value, and plant mineral uptake after their inoculation in the two abovementioned plant species. Two experiments were established (under greenhouse and field conditions) using plants inoculated with two isolates in 2012/2013 (Epicoccum nigrum, Sporormiella intermedia) and three isolates in 2013/2014 (Mucor hiemalis, Fusarium equiseti, Byssochlamys spectabilis). Fusarium equiseti (E346) increased the herbage yield of T. subterraneum under greenhouse conditions, and B. spectabilis improved the forage quality of T. subterraneum by reducing fiber content and of P. pratensis by increasing crude protein. S. intermedia increased the mineral uptake of Ca, Cu, Mn, Pb, Tl, and Zn in subclover, and M. hiemalis increased the uptake of K and Sr in Kentucky bluegrass. These results evidence the potential of the studied fungal endophytes to enhance herbage yield and nutritional value of forage, although further studies should include all of the target forage species as certain host specificity in the effect was observed.