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Earth’s tropical savannas typically support high biomass of diverse grazing herbivores that depend on a highly fluctuating resource: high-quality forage. An annual wet–dry cycle, fire and herbivory combine to influence forage quality and availability throughout the year. In the savannas of northern Australia, a depauperate suite of large native (marsupial) herbivores (wallaroos [Osphranter spp.] and the agile wallaby [Notamacropus agilis]) compete for resources with non-native large herbivores introduced in the late nineteenth century, particularly bovines (feral and managed cattle [Bos spp.] and feral water buffalo [Bubalus bubalis]) that now dominate the landscape. Anecdotal reports of recent population declines of large macropods and negative impacts of bovines highlight the need to better understand the complex relationship between forage, fire and abundance of native and introduced large herbivores. The pyric herbivory conceptual model, which posits complex feedbacks between fire and herbivory and was developed outside Australia, predicts that native and introduced large herbivores will both respond positively to post-fire forage production in Australian savannas where they co-occur. We used grazing exclosures, forage biomass and nutrient analyses and motion-sensor camera-trapping to evaluate the overall robustness of the pyric herbivory model in the Australian context, specifically whether forage quantity and quality are impacted by herbivory, season and fire activity, and which forage attributes most influence large grazing herbivore abundance. Forage quantity, as measured by live, dead and total herbaceous biomass and proportion of biomass alive, was higher inside herbivore exclosures, even at relatively low densities of herbivores. Forage quality, as measured by fibre content, was not affected by herbivory, however, crude protein content of live herbaceous biomass was greater outside herbivore exclosures. Recent fire was an important predictor of all measures of forage quantity and quality. Recent fire occurrence decreased overall quantity (biomass) but increased quality (decreased fibre content and increased crude protein content); late dry season fires resulted in forage with the highest crude protein content. The predictions of the pyric herbivory conceptual model are consistent with observations of the feeding behaviour of introduced bovines and some large macropods in northern Australian savannas, lending support to the global generality of pyric herbivory in fire-prone grassy biomes.

Forage crops have the potential to serve multiple functions, providing an ecological framework to sustainably intensify food production, i.e., ecological intensification. We review three categories of forages (annual forages, perennial forages, and dual-use perennial crops/forages) we believe hold the greatest promise for ecologically intensifying food production. Annual cover crops can provide additional forage resources while mitigating nutrient losses from agricultural fields when they are intercropped with, interseeded into, or following an annual crop, for instance. The integration of perennial forages either temporally, such as annual crop rotations that include a perennial forage phase, or spatially, such as the intercropping of perennial forages with an annual cash crop, provide weed suppression, soil quality, and yield and crop quality benefits. Dual-use crops/forages can provide forage and a grain crop in a single year while providing multiple ecological and economic benefits. However, tradeoffs in balancing multiple functions and limitations in reducing the risks associated with these practices exist. Advancing our understanding of these systems so we can overcome some of the limitations will play a critical role in increasing food production while promoting positive environmental outcomes.

Aims Intensive dairy regions have an opportunity to enhance recycling of manure nutrients within forage rotations improving the system sustainability. This study investigated the combined effect of winter double crops and tillage on nutrient uptake, yield, and forage quality under annual manure applications with silage corn ( Zea mays ). Methods The 2 × 4 split block study consisted of conventional (CT) vs minimal (MT) tillage, and combinations of manure (M) vs synthetic fertilizer (S) and winter triticale (x Triticosecale ) (D) vs fallow (F) for each tillage type. Plant tissue was collected for annual forage yield, nutrient concentrations, and forge quality. Results In soils, M significantly increased SOC, TN, Olsen P, K, Na, and Zn (20–96%) along with multiple enzyme activities (45–75%) and decreased NH 4 -N and Ca (9–26%) compared to synthetic fertilizers, regardless of tillage and winter crop. Manure increased tissue N, P, and K for both corn silage (12–39%) and triticale (31–45%) regardless of tillage. However, tillage effects were seen for corn Na and triticale Mg, Na, Zn, Ca, and Mn. Triticale removal of all nutrients was significantly greater with manure application (77- 97%) regardless of tillage. While inclusion of winter double crop removed 1.1 – 1.8 times as much NPK as winter fallow, triticale tissue K exceeded maximum concentrations for feed forages. Manure increased crude protein for both forages; however, M also increased triticale fiber content and reduced feed energy compared to synthetic fertilizer. Conclusion Winter triticale can increase forage production and enhance manure nutrient utilization in forage rotations.

The availability and quality of forage on the landscape constitute the foodscape within which animals make behavioral decisions to acquire food. Novel changes to the foodscape, such as human disturbance, can alter behavioral decisions that favor avoidance of perceived risk over food acquisition. Although behavioral changes and population declines often coincide with the introduction of human disturbance, the link(s) between behavior and population trajectory are difficult to elucidate. To identify a pathway by which human disturbance may affect ungulate populations, we tested the Behaviorally Mediated Forage-Loss Hypothesis, wherein behavioral avoidance is predicted to reduce use of available forage adjacent to disturbance. We used GPS collar data collected from migratory mule deer (Odocoileus hemionus) to evaluate habitat selection, movement patterns, and time-budgeting behavior in response to varying levels of forage availability and human disturbance in three different populations exposed to a gradient of energy development. Subsequently, we linked animal behavior with measured use of forage relative to human disturbance, forage availability, and quality. Mule deer avoided human disturbance at both home range and winter range scales, but showed negligible differences in vigilance rates at the site level. Use of the primary winter forage, sagebrush (Artemisia tridentata), increased as production of new annual growth increased but use decreased with proximity to disturbance. Consequently, avoidance of human disturbance prompted loss of otherwise available forage, resulting in indirect habitat loss that was 4.6-times greater than direct habitat loss from roads, well pads, and other infrastructure. The multiplicative effects of indirect habitat loss, as mediated by behavior, impaired use of the foodscape by reducing the amount of available forage for mule deer, a consequence of which may be winter ranges that support fewer animals than they did before development.

Substantial improvements in access to food and increased purchasing power are driving many people toward consuming nutrition-rich foods causing an unprecedented demand for protein food worldwide, which is expected to rise further. Forage legumes form an important source of feed for livestock and have potential to provide a sustainable solution for food and protein security. Currently, alfalfa is a commercially grown source of forage and feed in many countries. However, soybean and cowpea also have the potential to provide quality forage and fodder for animal use. The cultivation of forage legumes is under threat from changing climatic conditions, indicating the need for breeding cultivars that can sustain and acclimatize to the negative effects of climate change. Recent progress in genetic and genomic tools have facilitated the identification of quantitative trait loci and genes/alleles that can aid in developing forage cultivars through genomics-assisted breeding. Furthermore, transgenic technology can be utilized to manipulate the genetic makeup of plants to improve forage digestibility for better animal performance. In this article, we assess the genetic potential of three important legume crops, alfalfa, soybean, and cowpea in supplying quality fodder and feed for livestock. In addition, we examine the impact of climate change on forage quality and discuss efforts made in enhancing the adaptation of the plant to the abiotic stress conditions. Subsequently, we suggest the application of integrative approaches to achieve adequate forage production amid the unpredictable climatic conditions.

Guinea grass ( Megathyrsus maximus ) is a common tropical forage crop valued for its high biomass yields, nutritional quality, and adaptability to diverse abiotic stresses. However, the genetic basis of its key agronomic traits remains poorly understood. In this study, we conducted genome-wide association studies (GWAS) using whole genome sequencing (WGS) data from 124 diverse M. maximus genebank accessions, yielding a high-density single-nucleotide polymorphism (SNP) data set of 1,261,156 SNPs after mapping to a related reference genome. Population structure analysis revealed three major genetic subgroups within the collection. Using three complementary GWAS models (Bayesian-information and Linkage-disequilibrium Iteratively Incorporating Knowledge (BLINK), the Fixed and Random Model Circulating Polynomial Unification (FarmCPU), and the Multiple Loci Mixed Model (MLMM)), we identified 25 significant marker-trait associations (MTAs) spanning three major trait categories: (i) phenological and plant-architecture; (ii) nutritional and digestibility; and (iii) productivity and nitrogen-use traits, evaluated under wet-season, dry-season, and greenhouse conditions. Several MTAs were associated with genes related to plant growth and development, lignin biosynthesis, and nitrogen-cycling (including nitrogen uptake and biological nitrification inhibition). Notably, two SNPs were pleiotropic, with one associated with both nitrogen uptake and shoot biomass production, and another shared between crude protein and in vitro dry matter digestibility. Although a complete reference genome is not yet available for M. maximus , our results provide valuable information for future marker validation and breeding. This study highlights the potential of GWAS as a powerful tool for trait dissection and genetic improvement in tropical forage crops. The research represents a step forward in developing more resilient and productive M. maximus cultivars.

The viability of organic dairy operations in the United States (US) relies on forage production. The objectives of this study were to (1) assess producer and farm information regarding current forage production practices and producer knowledge gaps and (2) identify forage research and educational needs of organic dairy producers across the US. A survey was distributed to 643 organic dairy producers across the US, with 165 respondents (26% response rate). A focus group consisting of extension professionals, university researchers and staff, consultants, dairy industry representatives and organic dairy producers was also consulted for forage research needs. Results showed that approximately half (51%) of surveyed producers were somewhat satisfied with their forage production systems and sometimes experienced negative weather-related impacts on forage yield and quality. A majority (64%) of producers felt their knowledge to meet farm goals was adequate but they reported a lack of resources to implement this knowledge especially for balancing high-forage diets and selecting soil amendments. This study revealed that 54% of producers rely on peer experiences as information resources to make decisions on forage programs. Producer knowledge gaps included pasture renovation with reduced or no-tillage, forage mixtures that match their needs, and forage management practices aiming for high-quality forage. Based on the survey and focus group findings, forage research and educational activities should foster climate change resilience regarding forage diversity adapted to local and regional climatic conditions, improve forage quality, enhance economic returns from soil fertility amendments and pasture renovation, and introduce new forages and forage mixtures that suit economical, agronomical, and environmental needs.

Annual screenings of forage grasses and legumes for shade tolerance were conducted from 1996 to 2001 in the outdoor Shade Tolerance Screening Laboratory at the Horticulture and Agroforestry Research Center, University of Missouri. Forty-three forages were grown under non-shade (100% of full sunlight), moderate shade (45%), and dense shade (20%) without competition for water and nutrients. Annual forage yield (g pot−1) was equal to or higher under moderate shade for all 43 forages and under dense shade for 31 forages than the non-shade control. Relative distance plasticity index (RDPI), a measure of a species’ adaptability to different environments, ranged from 0.104 to 0.567. Cool season grasses had the lowest RDPI (0.183), followed by warm season grasses (0.252), warm season legumes (0.274), and cool season legumes (0.314), indicating grasses tend to be more shade tolerant than legumes in terms of forage yield. Overall, most grass and legume forages have the potential to produce equivalent or higher yields in agroforestry practices featuring light to moderate shade than forages in open pastures when competition from tree roots is minimized.

The forage maturation hypothesis (FMH) proposes that ungulate migration is driven by selection for high forage quality. Because quality declines with plant maturation, but intake declines at low biomass, ungulates are predicted to select for intermediate forage biomass to maximize energy intake by following phenological gradients during the growing season. We tested the FMH in the Canadian Rocky Mountains by comparing forage availability and selection by both migrant and nonmigratory resident elk (Cervus elaphus) during three growing seasons from 2002—2004. First, we confirmed that the expected trade-off between forage quality and quantity occurred across vegetation communities. Next, we modeled forage biomass and phenology during the growing season by combining ground and remote-sensing approaches. The growing season started 2.2 days earlier every 1 km east of the continental divide, was delayed by 50 days for every 1000-m increase in elevation, and occurred 8 days earlier on south aspects. Migrant and resident selection for forage biomass was then compared across three spatial scales (across the study area, within summer home ranges, and along movement paths) using VHF and GPS telemetry locations from 119 female elk. Migrant home ranges occurred closer to the continental divide in areas of higher topographical diversity, resulting in migrants consistently selecting for intermediate biomass at the two largest scales, but not at the finest scale along movement paths. In contrast, residents selected maximum forage biomass across all spatial scales. To evaluate the consequences of selection, we compared exposure at telemetry locations of migrant and resident elk to expected forage biomass and digestibility. The expected digestibility for migrant elk in summer was 6.5% higher than for residents, which was corroborated with higher fecal nitrogen levels for migrants. The observed differences in digestibility should increase migrant elk body mass, pregnancy rates, and adult and calf survival rates. Whether bottom-up effects of improved forage quality are realized will ultimately depend on trade-offs between forage and predation. Nevertheless, this study provides comprehensive evidence that montane ungulate migration leads to greater access to higher-quality forage relative to nonmigratory congeners, as predicted by the forage maturation hypothesis, resulting primarily from large-scale selection patterns.

Plastic pollution is an anthropogenic stressor in marine ecosystems globally. Many species of marine fish (more than 50) ingest plastic debris. Ingested plastic has a variety of lethal and sublethal impacts and can be a route for bioaccumulation of toxic compounds throughout the food web. Despite its pervasiveness and severity, our mechanistic understanding of this maladaptive foraging behaviour is incomplete. Recent evidence suggests that the chemical signature of plastic debris may explain why certain species are predisposed to mistaking plastic for food. Anchovy (Engraulis sp.) are abundant forage fish in coastal upwelling systems and a critical prey resource for top predators. Anchovy ingest plastic in natural conditions, though the mechanism they use to misidentify plastic as prey is unknown. Here, we presented wild-caught schools of northern anchovy (Engraulis mordax) with odour solutions made of plastic debris and clean plastic to compare school-wide aggregation and rheotactic responses relative to food and food odour presentations. Anchovy schools responded to plastic debris odour with increased aggregation and reduced rheotaxis. These results were similar to the effects food and food odour presentations had on schools. Conversely, these behavioural responses were absent in clean plastic and control treatments. To our knowledge, this is the first experimental evidence that adult anchovy use odours to forage. We conclude that the chemical signature plastic debris acquires in the photic zone can induce foraging behaviours in anchovy schools. These findings provide further support for a chemosensory mechanism underlying plastic consumption by marine wildlife. Given the trophic position of forage fish, these findings have considerable implications for aquatic food webs and possibly human health.