Grazing in silvopastoral systems: multiple solutions for diversified benefits

Abstract Silvopastoral systems are multifunctional systems that combine herbage, shrub and tree layers with grazing animals in a single site. The multiple possible combinations of components within these systems creates different options that have in common the capacity to deliver positive outcomes related to land productivity and environmental and climatic benefits. This editorial provides a perspective of the diversity of ancient and more recent silvopastoral systems and their main benefits. The major challenges for both systems are different. Ancient silvopastoral systems, which originated on cultural grounds, deal mostly with conservation issues, while intensive silvopastoral systems, founded on technological changes of the grazing livestock production model, are more production driven but also concerned with climatic changes. Both types of system share similar benefits, and in this special issue we look at positive outcomes in the perspective of grazing animals, highlighting production and welfare. The purpose of this special issue is to contribute to gathering and sharing the knowledge emerging from grazing on different silvopastoral systems, promoting a common ground for future integrative research approaches

Pastor.i: a smartphone application to facilitate grazing management

Grazing in extensive beef farming systems is often manage in an empirical way based on past experience and on the visual appreciation of animal behavior and forage potential. Records of entrances and exits of the animals in the paddocks are rare. However, knowing the occupation period and the animal density, when coupled with biomass defines the grazing pressure. This knowledge is essential for planning and making informed decisions, that influence the profitability of the farm. Moreover, adequate grazing pressure is crucial for the sustainability of many SSPs where system maintenance is dependent on the balance between grazing pressure and regeneration or maintenance of trees and shrubs. Pastor.i is a smartphone application (APP) designed to allow pasture data logging to be very simple. The application is synchronized with the website and allows the producer to have in his pocket all the farm, being possible to identify the paddock, calculate the area, record the movements of the animals and consult the occupation history of the paddock. The application calculates the actual stocking rate, that can be associated with the location of the animals, obtained if the animals are using collars with GPS, which allows to know the areas of the paddock that are most grazed, visualized through heat maps. The information enables localized actions, such as fertilizing or sowing, to improve areas that are not grazed. The application also allows you to save photos of the sward. This temporal photographic record provides information on the condition of trees, the botanical composition and on the tendency of grazing to improve or to worsen coverage. The APP is available for download, is compatible with Android and is being tested with focus groups

Tannins in Ruminant Nutrition: Impact on Animal Performance and Quality of Edible Products

Tannins are widespread throughout the plant kingdom, occurring as hydrolysable and condensed tannins and at different levels in several animal feeding sources. Recent years have seen an increasing interest in the use of tannin-rich plants and plant extracts in ruminant diets for improving the quality of their edible products. Some results show that this strategy is effective in improving the fatty acid profile of meat and milk, increasing the level of health-beneficial fatty acids as well as enhancing the oxidative stability of the products. However, the use of tannin-rich feed in animal diets requires great care, due to its possible detrimental effects on animal performance and induction of metabolic disorders. Although promising, the results of studies on the effects of tannins on animal performance and quality of their products are still controversial, probably depending on type and chemical structure of tannins, amount ingested, composition of diet, and species of animal. In this chapter, the current knowledge regarding the effect of dietary tannins on animal performance and the quality of their products (meat and milk), particularly on the fatty acid profile, oxidative stability, and organoleptic properties, is reviewed. The tannin chemistry diversity and its occurrence in ruminant diets, as well as its beneficial and adverse effects on ruminants, will be briefly reviewed, and aspects related to oral cavity physiology, saliva production/composition, and postingestive effects will also be discussed

Overgrazing in the Montado? The need for monitoring grazing pressure at paddock scale

Montados are presently facing the threat of either abandonment or intensification, and livestock overgrazing has been suspected of contributing to reduced natural regeneration and biodiversity. However, reliable data are to our knowledge, lacking. To avoid potential risks of overgrazing, an adaptive and efficient management is essential. In the present paper we review the main sources of complexity for grazing management linked with interactions among pasture, livestock and human decisions. We describe the overgrazing risk in montados and favour grazing pressure over stocking rate, as a key indicator for monitoring changes and support management decisions. We suggest the use of presently available imaging and communication technologies for assessing pasture dynamics and livestock spatial location. This simple and effective tools used for monitoring the grazing pressure, could provide an efficient day-to-day aid for farm managers’ operational use and also for rangeland research through data collection and analysis

Use of point of view cameras for welfare management in extensive grazing systems

Grazing patterns can be a major indicator for welfare assessment in extensive systems. The aim of this study was to test animal-borne video as a method to evaluate sheep grazing behavior. To test the changes in grazing duration, grazing frequency and grazing rate, we used wide angle cameras (Go-Pro and infra-red night vision) to access diurnal and nocturnal grazing activities of ewes in a native sward, during two weeks in late spring, the season with greatest changes in weather and vegetative growth. Three ewes were chosen from a flock of 15 animals for focal observation. The foraging behaviour of the entire flock were recorded by scan sampling with a 10-minute interval. Grazing bout duration increased significantly between the first (44.6 ± 41.4 s) and the second week (94.0 ± 57.0 s) (F = 10.295, P<0.05). Conversely, grazing bout duration differed among grazing hours (F = 4.523, P<0.05), with a peak for the dusk grazing period (128.1 ± 88.8 s). Nocturnal grazing did not differ significantly for any of the grazing parameters, although a general trend for longer grazing duration through time was observed. Sheep spend the hot part of the day lying in shade under trees and use more than one tree as resting areas. A significant correlation was shown to exist between the grazing behaviour estimated from focal sampling with video cameras and the scan sampling (r2=0.83). We concluded that animal-borne video cameras are a method appropriate for assessing sheep variations of grazing behaviour structure allowing to understand differences of adaptive grazing patterns that can be useful for welfare management in extensive systems

Sheep and goat saliva proteome analysis: A useful tool for ingestive behavior research?

Sheep and goats differ in diet selection, which may reflect different abilities to deal with the ingestion of plant secondary metabolites. Although saliva provides a basis for immediate oral information via sensory cues and also a mechanism for detoxification, our understanding of the role of saliva in the pre-gastric control of the intake of herbivores is rudimentary. Salivary proteins have important biological functions, but despite their significance, their expression patterns in sheep and goats have been little studied. Protein separation techniques coupled to mass spectrometry based techniques have been used to obtain an extensive comprehension of human saliva protein composition but far fewer studies have been undertaken on animals' saliva. We used two-dimensional electrophoresis gel analysis to compare sheep and goats parotid saliva proteome. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and liquid chromatography tandem mass spectrometry (LC-MS/MS) were used to identify proteins. From a total of 260 sheep and 205 goat saliva protein spots, 117 and 106 were identified, respectively. A high proportion of serum proteins were found in both salivary protein profiles. Major differences between the two species were detected for proteins within the range of 25–35 kDa. This study presents the parotid saliva proteome of sheep and goat and highlights the potential of proteomics for investigation relating to intake behavior research

Result-based payments as a tool to preserve the High Nature Value of complex silvo-pastoral systems: progress towards farm-based indicators

s shown by the Green Deal's ambition, the European Commission is progressively pushing for an environmental shiftand climate action in Europe. For the Common Agricultural Policy (CAP), this involves a stronger focus on greening policy objectives.For agri-environmental schemes, this entails changes toward performance-based payments, partially replacing traditional activity-basedpayments. The CAP foresees greater flexibility in national programs and tailor-made solutions centered on results (i.e. environmentaloutcomes), benefiting farmers who go beyond the minimum environmental performance required. The environmental outcomes offarm practices must be assessed so that changes can be monitored over time and linked to payment delivery. This requires stakeholdersto collaborate with researchers to identify farm-based indicators that are easily applicable, to achieve environmental results that aredependent on farm practices, and to assess and monitor changes in outcomes over time. The analysis in this paper is based on atransdisciplinary process that began in 2017 in a Natura 2000 site and its surroundings in Southern Portugal, to identify result-basedmeasures for the Montado silvo-pastoral system. Farmers' understanding of how to adapt their practices to reach better environmentalresults was combined with scientific knowledge of the relevant environmental outcomes and how these can be assessed with indicators.Ten field-based visual indicators were defined, which farmers applied in the field, and validated by technical staff. These indicators arerelated to several aspects of the silvo-pastoral system: soil quality, pasture diversity, tree renewal, tree health, singular landscape elements,and biodiversity. The approach used in this process was innovative. We describe each step and present its advantages and drawbacksfor designing and implementing result-based payments. Ultimately, their implementation is expected to lead to higher sustainability inthe Montado. (PDF) Result-based payments as a tool to preserve the High Nature Value of complex silvo-pastoral systems: progress toward farm-based indicators. Available from: https://www.researchgate.net/publication/359442049_Result-based_payments_as_a_tool_to_preserve_the_High_Nature_Value_of_complex_silvo-pastoral_systems_progress_toward_farm-based_indicators#fullTextFileContent [accessed Feb 03 2023]

Effects of grazing pressure on activity and richness of bats in a Portuguese silvo-pastoral system

Background High Nature Value Farmlands (HNVF) harbor species dependent upon habitats maintained by low-intensity farming. Among HNVF, the montado (dehesa in Spain) is a multifunctional system declining due to droughts, pathogens, and increasing grazing pressure. Specifically, grazing pressure leads to compact soils and hinders natural tree regeneration. Regrettably, there is a dearth of information supporting management decisions on the side-effects of high grazing pressure on HNVF-dwelling biodiversity. In particular, little is known about the impact of grazing pressure on bats, a group of species of special conservation concern that may provide key ecosystem services such as biological pest control. Purpose We investigated patterns of activity levels and community composition of insectivorous bats to test the hypothesis that there is a significant relationship between the level of livestock grazing pressure within montado HNVF parcels and patterns of insectivorous bats’ presence and activity. Our specific aims were to (i) assess separately the effects of grazing pressure on bat activity and species composition, (ii) test the predictive significance of key covariates (e.g., insect availability). Methods We conducted this study in 2014 in the Natura 2000 network site “Monfurado”, southern Portugal. This site is specifically acknowledged for its well-preserved montados providing feeding areas for bat species. We quantified acoustically bat flight activity and species richness in farm parcels dominated by cork oak trees. Per parcel, we selected two separate locations (high vs. low grazing pressure) based on landowners’ interviews and grazing pressure indicators, totaling 42 sampling locations. We then used linear mixed-effects modeling to evaluate the effects of grazing pressure and covariates on activity and species richness. Results Bat activity and bat species richness peaked at low grazing pressure locations. Bat activity also increased with tree cover and in locations where livestock grazing signs were old or absent. Conversely, bat activity at low grazing pressure locations decreased with distance to the nearest standing water body. Discussion Our study clearly demonstrated that locations maintained under high grazing pressure within HNVF can have negative consequences for bats, which are acknowledged as good bioindicators of habitat quality. In order to promote better habitat for bats, practitioners should avoid favoring grazing-prone areas (e.g., rotating the location of livestock feeders, drinkers, and gates) across montado HNVF. Broadly, ecosystem services provided by bats for HNVF must be enhanced through sustainability oriented agro-environment schemes under the Economic Community Rural Development Program, including the reduction of stocking density

Sequence analysis of bitter taste receptor gene repertoires in different ruminant species

Bitter taste has been extensively studied in mammalian species and is associated with sensitivity to toxins and with food choices that avoid dangerous substances in the diet. At the molecular level, bitter compounds are sensed by bitter taste receptor proteins (T2R) present at the surface of taste receptor cells in the gustatory papillae. Our work aims at exploring the phylogenetic relationships of T2R gene sequences within different ruminant species. To accomplish this goal, we gathered a collection of ruminant species with different feeding behaviors and for which no genome data is available: American bison, chamois, elk, European bison, fallow deer, goat, moose, mouflon, muskox, red deer, reindeer and white tailed deer. The herbivores chosen for this study belong to different taxonomic families and habitats, and hence, exhibit distinct foraging behaviors and diet preferences. We describe the first partial repertoires of T2R gene sequences for these species obtained by direct sequencing. We then consider the homology and evolutionary history of these receptors within this ruminant group, and whether it relates to feeding type classification, using MEGA software. Our results suggest that phylogenetic proximity of T2R genes corresponds more to the traditional taxonomic groups of the species rather than reflecting a categorization by feeding strategy

Characterization of grazing behaviour microstructure using point-of-view cameras

Grazing patterns, intake structure, and diet selection are dynamic responses to animals’ feeding environment. This study uses video sequences from animal-borne cameras to capture time- and scale-dependent grazing behaviour variables related to sward explanatory conditions. We observed grazing ‘through’ the sheep’s eyes using point-of-view (POV) cameras coupled with event logging software. Time-specific sward features were measured by sampling ‘really’ grazed patches identified by applying a global navigation satellite system (GNSS) precision-grazing approach. Sward variables on a Mediterranean native sward were measured for two years during the active spring plant-growth cycle. Overall, the results demonstrate that POV cameras were able to capture grazing behaviour fine-tuning to changes in sward characteristics. Sheep compensate for the decrease in sward quantity and nutritive value by increasing the size and duration at each behavioural scale (i.e., meal, bout, and station) while increasing the bout rate and decreasing the station rate. Diet composition also changed as sward matured. The proportion of forbs in the diet remained high in early and late spring, and forbs and legumes were preferred to grasses in early spring. Grazing selectivity was more pronounced in late spring, with sheep favouring the middle stratum of the sward’s vertical structure, preferring green vegetative material, while enlarging the feeding niches’ span and spending more time at each niche, consequently reducing the station rate. Although data collected by individual animal-borne POV cameras were representative of the flock behaviour, they may underestimate the total grazing time outside major meals. The results indicate that the use of animal-borne video cameras is suitable for assessing variations in sheep grazing behaviour patterns in complex swards