2017 Rustici Science Symposium – Speaker Highlights & Poster Session

The goal of the 4th Rustici Rangeland Science Symposium is to engage ranchers, land managers, researchers, and policymakers in co-developing actionable science, policy, and management to sustain rangelands. The symposium will focus on partnerships surrounding a variety of topics, including: sustaining water resources; coping with drought; habitat conservation; and enhancing ranch profitability. Click here for more details and to register. 

Speaker Highlight –
Collaborative Adaptive Rangeland Management in Semiarid Ecosystems

Dana Bowman, Rancher and member of the Crow Valley Livestock Cooperative, Inc.

Justin Derner, Rangeland Scientist, USDA-Agricultural Research Service

Social and biophysical barriers exist for implementing management strategies to achieve desired outcomes of sustained livestock production, grassland bird populations, and vegetation structural heterogeneity in the shortgrass steppe of Eastern Colorado. Dana Bowman and Justin Derner will discuss the processes associated with the Collaborative Adaptive Rangeland Management (CARM) experiment, initiated in 2012, which is a novel effort where an 11 person Stakeholder Group comprised of ranchers, non-government conservation organizations and federal/state land management agencies make ranch-scale adaptive rangeland management decisions. Stakeholders and scientists co-produce defensible, science-based management recommendations for multiple rangeland objectives, and build trust and collaborative relationships. For more information on this research project, please see www.ars.usda.gov/rrsr/agm

Poster Session –
The poster session is a great opportunity to showcase your work to ranchers, researchers, land managers, agency representatives, conservationists, and policy makers.The broad focus for the combined mixer and poster session includes any activities related to sustainable rangeland research, management, conservation, and policy.

To submit your poster abstracts (250 words maximum) please contact Grace Woodmansee at gwoodmansee@ucdavis.edu.

Submissions are Due Friday, March 17, 2017.

2017 Rustici Science Symposium – Speaker Highlights & Poster Session

The goal of the 4th Rustici Rangeland Science Symposium is to engage ranchers, land managers, researchers, and policymakers in co-developing actionable science, policy, and management to sustain rangelands. The symposium will focus on partnerships surrounding a variety of topics, including: sustaining water resources; coping with drought; habitat conservation; and enhancing ranch profitability. Click here for more details and to register. 

Speaker Highlight –
Sediment and Salmon: Ranch Management Strategies to Conserve Habitat

Dina Moore, Rancher and Member of the Yager/Van Duzen Environmental Stewards (YES)

​David Lewis, Advisor, UC Cooperative Extension

With the Endangered Species Act listing of the coho salmon on California’s north coast, landowners, conservation organizations, regulatory agencies, and scientists were charged with finding solutions to in-stream habitat degradation by erosion and sediment. Potential sediment producing activities on private ranches in the region include timber production, livestock grazing, and the road networks allowing access to these rugged lands. The region is also known for high natural erosion potential, and the legacy sediment contributed to stream channels from historic logging and mining activities. Dina Moore and David Lewis will discuss the partnerships between landowners, water resource protection agencies, and scientists to identify the sources of sediment in these watersheds and implement practices to reduce erosion and protect this endangered species.

Poster Session –
The poster session is a great opportunity to showcase your work to ranchers, researchers, land managers, agency representatives, conservationists, and policy makers.The broad focus for the combined mixer and poster session includes any activities related to sustainable rangeland research, management, conservation, and policy.

To submit your poster abstracts (250 words maximum) please contact Grace Woodmansee at gwoodmansee@ucdavis.edu.

Submissions are Due Friday, March 17, 2017.

2017 Rustici Science Symposium – Speaker Highlights

Managing Livestock Grazing on Watersheds Supplying Drinking Water

Tim Koopmann, Water Resource Specialist and Manager Emeritus, San Francisco PUC

Ken Tate, Professor and CE Specialist in Rangeland Watershed Sciences, UC Davis

About 80% of California’s surface water supply is either derived from, or stored on grazed rangeland watersheds. Concerns about linkages between livestock as a source of the waterborne pathogen Cryptosporidium parvum, contamination of drinking water, and risks to public health began to arise in the 1990s – following a series of epidemics across the nation. Most municipal water treatment systems do not completely remove this tiny parasite from source waters, making proactive watershed management to prevent pollution essential.  Tim Koopmann and Ken Tate will discuss the partnerships between watershed managers, researchers, municipal water providers, and water quality protection agencies that have led to practical, effective, science-based grazing strategies to safe-guard public health.

Click here for more details and to register

Annual Grasslands as Working Landscapes

Download fact sheet here

California’s annual rangelands include open grasslands and woodlands dominated by an understory of herbaceous annual plants in the state’s valleys and low elevation mountains and foothills. These largely privately owned lands span 10 million acres and produce nearly 70% of the state’s livestock forage base. Therefore, annual rangelands provide a critical economic foundation for California’s rangeland livestock production1—annual gross value of cattle and sheep production exceeds $3 billion.
Through active stewardship and conservation, rangeland owners can manage for agricultural production and a diversity of other ecosystem services across these working landscapes. Managers can use prescribed grazing (the controlled implementation of timing, frequency, and intensity of grazing) as a tool to support and enhance multiple agricultural and conservation goals2—including biodiversity, wildlife habitat, and watershed health (Table 1).


Invasive Plant Management

Figure 1. Invasive weeds like medusahead are a major threat to California’s annual rangelands. Optimal timing of grazing for medusahead control is late spring, when plants are in the late vegetative to seed head emergence stages.

Large-scale weed invasion is a major threat to both conservation and agricultural goals on annual rangelands. Invasive weeds can significantly reduce rangeland health by inhibiting biodiversity, depressing forage productivity and quality for both livestock and wildlife, and depleting soil water resources3. Proper grazing management can maintain or enhance grassland diversity and productivity.
Prescribed grazing can be used to target specific weeds, particularly as part of a long-term integrated pest management program. The most critical components of a prescribed grazing program for weed management are timing and intensity of grazing. Target weeds must be grazed during their most biologically susceptible stages (Fig. 1). Using appropriate grazing timing and intensity can reduce undesirable weeds, such as medusahead and yellow starthistle, and increase desirable plants, such as forbs like clover, while maintaining production3.

Biodiversity and Habitat

Annual rangelands are one of the world’s major biodiversity hotspots, supporting thousands of plant and animal species. California’s rangelands provide habitat connectivity, which is critical for annual migration of many wildlife species. These lands also support important foraging and nesting habitat for wild pollinator populations, which provide crop pollination for many agricultural crops4. Loss of ranching as a land use can impact habitat connectivity and restructure the landscape matrix of ecosystems, often with negative consequences for native flora and fauna4.
Livestock grazing, via appropriate management strategies, can be used to maintain or enhance herbaceous plant diversity. Long-term studies have found that managed cattle grazing can be used as an effective tool to mitigate climate change and anthropogenic nitrogen deposition impacts on annual rangelands4. For example, grazing has been shown to enhance California’s unique vernal pool habitats by controlling exotic annual plants and enhancing herbaceous plant diversity, which can lead to longer pool inundation periods benefiting a diversity of aquatic species, including endangered species such as the California tiger salamander5.


Ecosystem Services Example Services from Annual Rangelands
Provisioning Livestock production, Forage production, Water supply, Timber/Fuel wood production, Genetic resources
Regulating Climate regulation, Water/Nutrient cycling, Pest control,  Pollination, Moderation of extreme events, Resistance to weed invasion
Habitat Plant and animal diversity, Migratory corridors, Genetic diversity
Cultural Aesthetic, Recreation/tourism, Sense of place, Heritage

Table 1. Examples of ecosystem services (the wide range of benefits humans obtain from the environment) provided by California’s annual rangelands.

Watershed Health

More than two-thirds of surface waters used for municipal and crop production in California are derived from rangeland watersheds. Microbial pollution from improperly managed livestock can threaten water quality. Fortunately, researchers and managers have widely demonstrated that prescribed grazing management—used in concert with the natural capacity of rangelands to mitigate microbial pollutants—provides for clean water6-8. Recent scientific literature syntheses have documented a large tool box of effective rangeland and livestock management options that minimize risks of direct deposition or hydrologic transport of viable microbial pollutants from cattle fecal material to surface waterbodies of concern2,9. These collective findings have been integrated into educational materials supporting on-ranch water quality protection10.

Key Points
  • California’s annual rangelands span approximately 10 million acres.
  • Annual rangelands support cattle production, the state’s 4th most valued commodity, and the 2nd largest sheep herd in the US.
  • Managers can use prescribed grazing to support and enhance agricultural and conservation goals, including production and biodiversity.
  • California rangelands provide habitat connectivity, which is critical for the migration of many species.
  • Proper grazing management maintains rangelands’ capacity to attenuate waterborne pollutants and supply clean water.
Further Reading
  1. Roche, L et al. 2015. Sustaining working rangelands: insights from rancher decision making. Range Ecol Manage. 68:383-9.
  2. Briske, DD (ed). 2011. Conservation Benefits of Rangeland Practices: Assessment, Recommendations, and Knowledge Gaps. Lawrence, KS: Allen Press.
  3. DiTomaso JM. Invasive weeds in rangelands: Species, impacts, and management. Weed Sci. 2000. 48:255-65.
  4. Huntsinger, L and JL Oviedo. 2014. Ecosystem services are social-ecological services in a traditional pastoral system: the case of California’s Mediterranean rangelands. Ecol and Soc 19 (1): 8.
  5. Pyke, C and J Marty. 2005. Cattle grazing mediates climate change impacts on ephemeral wetlands. Cons Biol 19:1619-1625.
  6. Roche, L et al. 2013. Water quality conditions associated with cattle grazing and recreation on national forest lands. PLOS ONE 8(6): e68127.
  7. Li, X et al. 2005. Seasonal temperature fluctuation induces rapid inactivation of Cryptosporidium parvum. Env Sci Tech. 39:4484-4489.
  8. Tate, KW et al. 2006. Significant E. coli attenuation by vegetative buffers on annual grasslands. J. Env Q. 35:795-805.
  9. Atwill, ER et al. 2012. Introduction to waterborne pathogens in agricultural watersheds. USDA NRCS. Tech Note No. 9. 90 pp.
  10. George, MR et al. 2011. California’s rangeland water quality management plan: an update. Rangelands. 33:20-24.

Just Published! Coping with Drought via Adaptive Rangeland Decision-Making

Grazinglands support the livelihoods of millions of people around the world. These working landscapes include livestock-grazed rangelands and pasturelands and occupy an estimated one-quarter to two-fifths of the world’s land surface—making them the largest and most biologically and physically diverse land resources in the world. Severe and widespread droughts pose substantial and recurrent economic and ecological stresses to these systems—particularly for rangelands, which are largely rain-fed. Drought also brings substantial uncertainty and stress into the lives of people that depend upon these landscape for their livelihoods.


Using the California Rangeland Decision-Making Survey, this study examined responses of 479 ranchers to better understand the in-place strategies that have been adapted by ranchers over time in response to severe drought.


Results in a nutshell –

  • There were 4 types of on-ranch drought strategies identified. The 4 strategies spanned a gradient of increasing management intensity, ranging from low adoption of drought management practices to high use of both reactive and proactive  drought practices.
  • Ranch operation variables driving drought strategy selection included experience with drought, classes of livestock, grazing system, and land ownership types. For example, operations with both privately leased lands and public lands were most likely to have the greatest flexibility in drought strategies.
  • Information resource networks (education, quality and number of information sources, generations in ranching), goal setting for sustainable natural resources (e.g., forage production), and management capacity (number of practices/conservation programs actively used, diversity of land ownership types in operation) all enhanced individual capacity to cope with drought.


Read the newest publication here!


Flexibility in management is a key component of ranchers’ ability to adapt to and cope with drought. Drought policy planning should take into account the diversity of strategies that have been developed by ranchers over multiple generations and within the context of their unique operations, as well as support these working landscapes via a suite of information, management, and policy options to reduce vulnerability across all types of ranching operations. Given the clear importance of information networks, UC Cooperative Extension continues to work with stakeholders to share new tools for peer-to-peer learning, public education, and extending knowledge to larger audiences to increase outreach impact (read more here and here).


This rangeland drought research and extension program was collaboratively funded by the US Department of Agriculture National Institute of Food and Postdoctoral Fellowships Program, the UC Agriculture and Natural Resources Competitive Grants Program, and the UC Davis Russell L. Rustici Rangeland and Cattle Research Endowment.

These efforts were made possible through partnership with the California Cattlemen’s Association, California Farm Bureau Federation, California Wool Growers Association, UC Cooperative Extension, UC Davis, USDA Natural Resources Conservation Service, California Rangeland Conservation Coalition, and USDA Agricultural Research Service.

UC Rangelands Fall 2016 Newsletter

Save the Date!rusticisciencesymposium

You are invited to participate in the 4th Rustici Rangeland Science Symposium scheduled for March 23-24, 2017 at the UC Davis campus. The goal of this event is to engage ranchers, land managers, researchers, and policymakers in co-developing actionable science to sustain grazinglands. The symposium will address multiple challenges across grazinglands, including sustaining water resources, coping with drought, habitat conservation, and enhancing livestock production and profitability. Check out UC Rangelands for upcoming details!


Rangeland Drought Hub

Announcing the launch of UC Rangeland’s Drought Hub for assisting ranchers and land managers in drought preparation and management! The drought hub is a compilation of dashboard indicators, drought related social media, and a variety of resources covering economics, forage management, alternative feeds, government programs, and research.


Rangeland Weed Workshop Seriesmedusaehead_hand

This fall, UC Cooperative Extension and partners have been hosting a workshop series on novel research and effective weed management strategies. Workshops are selling out quickly, so register soon!

Upcoming workshops:

December 13, 2016 – Eureka

December 14, 2016 – Susanville


Rangeland Research Archives

Check out the new UC Rangelands Research & Education Archive, which provides access to rangeland and pasture information, including more than 700 archived publications and reports.

Like us on Facebook!

You can also stay update on research project highlights, outreach and extension events, and blogs on Facebook.

Interested in issues of herbicide-resistant weeds on rangelands and other working landscapes?

Help wanted: participation in herbicide-resistant weeds workshop

Adapted from UC ANR blog

By Brad Hanson

Requesting growers and ag industry members to contribute to the national conversation on herbicide-resistant weeds

As part of a national effort on developing research and regulatory priorities related to the challenging problems of herbicide-resistant weeds, the Weed Science Society of America is sponsoring a series of half-day regional workshops to discuss the issues, potential solutions, and technical and economic barriers related to resistant weeds.

To date, much of the conversation about herbicide resistance at the national level has been dominated by the large acreage row crops of the Midwest, East, and South. These cropping systems, particularly the glyphosate-based no-till corn, soybean, and cotton production systems have been tremendously affected by resistance.  In the West, however, our challenges with (and solutions for) herbicide resistance are likely to be very different than in the rest of the country.

California, New Mexico, and Arizona are combining to hold a

Southwest US Herbicide Resistance Listening Session

on February 15, 2017 in Tulare, California

during the World Ag Expo. The format of this workshop will be a facilitated half-day (morning) discussion session and will lead to a more formalized and defined understanding of herbicide resistance at both the regional and national level.

Our goal with the Southwest listening session is to gather a group of people representing the diverse cropping systems, working landscapes, natural ecosystems, as well as the mosaic of urban, suburban and infrastructure areas where weeds are managed. Some of these areas are highly impacted by herbicide resistance while others are virtually unaffected.  We’d like to ensure that the challenges of resistant weed in the Western US are represented in the national level conversation so we are seeking participation from a broad spectrum of growers, retailers, consultants and pest control advisors, and other private and public sector weed managers to participate in the discussion.

If you are interested in contributing to this conversation from your perspectives as: growers, commodity leaders, ag suppliers, pest control consultants, local/state/federal land managers, right-of-way managers, etc, please go to the web address below to provide your contact information and answers to a few simple categorization questions.

In a few weeks, we’ll use this list to invite workshop attendees that balance among the view points, regions, and sectors representing the diversity of Southwestern weed management viewpoints.


Thank you

Brad Hanson, University of California

Brian Schutte, New Mexico State University

Ranchers, environmentalists and policy makers unite to protect water quality on California rangeland

Common Ground

Ranchers, environmentalists and policy makers unite to protect water quality on California rangeland

(Adapted from UC Davis Magazine Online)

Volume 29 Number 4 (Summer 2012)

By Diane Nelson


Grazing and water quality?

Over half of California’s 57 million acres of rangeland is privately owned and managed for livestock production – and that holds big implications for the food we eat and the water we drink. Some 80 percent of the state’s irrigation and drinking water passes through or is stored on rangeland. All the water and all those animals raise a serious concern:


Can microbial pollutants in cow manure be transferred to the water that runs off these ranges, tainting the food we eat and the water we drink?


The short answer: Yes, but it takes a herculean effort for a bad bug to survive the journey from cow to human, and there are ways to manage cattle to make the journey highly improbable. Rangelands, in fact, provide some of the state’s healthiest watersheds.


That short answer was a long time in the making, a journey that continues to this day. UC Davis researchers and UC Cooperative Extension specialists have been central to the process, helping turn foes into friends committed to a common goal — protecting rangelands in order to meet society’s need for open space, habitat for plants and wildlife, and healthy watersheds delivering clean water for us all.


A thirsty state

People don’t like the thought of cow manure near their drinking water. “In the late 1980s, grazing was being blamed – wrongly in many cases – for any number of environmental and wildlife conservation issues,” says Mel George, UC Cooperative Extension Rangeland Specialist Emeritus. “So we knew it was important to get out in front of grazing and water-quality issues. We wanted to know, what was the risk of pathogens in water runoff from rangeland? Where there ways to mitigate it?”


In the early 1990s, George helped spearhead the UCCE Rangeland Watershed Program, which used education and applied research to answer those questions and more. Collaborating with local water districts, the U.S. Environmental Protection Agency, and several state and federal natural resources agencies and associations, the rangeland watershed team went to work.


The program really started making headway in 1995, with the birth of a new research partnership. Rangeland hydrologist Ken Tate joined UC Davis as a UCCE Rangeland Watershed Specialist. He joined forces with Rob Atwill, a newly hired UCCE Specialist at the School of Veterinary Medicine and an expert on waterborne infectious diseases. Their teams conducted groundbreaking experiments with “waterborne zoonotic pathogens,” bugs that are shed by animals, transmitted by water and can make people sick. Some common culprits include Cryptosporidium parvum, Giardia, E. coli and Salmonella.


“Their science helped us find that balance, helped us make smart land-use decisions.” Tim Koopmann, a watershed resource specialist with the San Francisco Public Utilities Commission.




It takes a toolbox

Conditions vary from ranch to ranch – soil, slope, climate, vegetation, etc. – so when it comes to rangeland watershed management, one strategy does not fit all.


“Our goal is to build a tool box, a range of methods to reduce the risk of microbial pollutants,” says Tate. “We don’t tell ranchers and regulators what tools to use. We identify what works and what doesn’t work, so they can design a water-quality and grazing management plan that’s feasible and sustainable.”


The biggest threat to human health from cow manure is from the youngest in the herd – most pathogens found in cows live within calves less than 4 months old. (Ten percent of adult cows shed Cryptosporidium but only 0.5 percent of them shed a strain that is infectious to humans. And most Giardia shed by cows of any age is not infectious to humans.) Accordingly, early fall or spring calving is better than winter calving. Strategic fencing can help keep livestock away from running water, as well as providing water and feed in spots away from creeks.


Pathogens in cow dung die quickly in warm weather, thanks to solar radiation. And even in cold, wet weather, pathogens tend to stay trapped in the fecal pat. By timing grazing in critical watershed areas to occur during spring, summer or early fall, all Cryptosporidium can be inactivated before winter rainfall and runoff occurs.


Take care of your rangelands and riparian areas, and they will take care of you. Researchers say that well-vegetated hill slopes, riparian areas and buffers function as kidneys, trapping and holding pathogens. “For each additional yard pathogens have to travel through vegetation, there is another 30-99.99 percent reduction in potential transfer of pathogens from fecal pat to stream or lake,” Tate says.


There’s no silver bullet, and management can’t reduce the risk to zero. But when ranchers keep cows from loafing near running water, give pastures a rest before irrigation, care for the buffers and protect their soils, they minimize the threat. Even during the wettest winter, rangeland runoff is generally safer than runoff from urban areas, with its full suite of pollutants like gasoline, garbage, motor oil, heavy metals, fertilizers and pesticides.


Next steps

Building on the common ground established over that past 20 years, this team of stakeholders is working today to establish the California Grazing Water Quality Partnership as a forum to ensure collaborative, proactive grazing land water quality protection for the next 20 years.

UC Rangelands Blog – Tina Saitone

Saitone_thumbThis week’s blog post features Dr. Tina Saitone, new UC Cooperative Extension Specialist in Livestock and Rangeland Economics.

My name is Tina Saitone, and on June 1 of this year I began an appointment as a Cooperative Extension Specialist focusing on livestock and rangeland economics. While my “home” is in the Agricultural and Resource Economics Department at UC Davis, I am proud to be an affiliated faculty member working with the UC Rangelands team. I grew up in Sonoma County riding horses (hunters and jumpers) and was an active member of the Petaluma FFA. After attending Sonoma State University and completing my undergraduate degree in economics, I came to UC Davis to complete both my Masters and Ph.D. in agricultural and resource economics. After finishing my graduate studies, I worked in the field of litigation consulting for several years before returning to UC Davis.

To give you an idea of my research interests, I would like to briefly describe a couple of my current projects. The first project (with Larry Forero and Josh Davy) is geared toward providing cattle ranchers in California with information on auction prices and market trends in the State and nationally. I will be approaching local auctions throughout California and asking them to share their sales data with me so I can provide real time analysis of prices for cattle of different ages, weights, etc. sold in different geographic areas throughout California. In other states, USDA Market News Reporters provide this service—but that has not been done in California. So, I am looking to fill this void and provide California ranchers with the tools and information that are available to ranchers elsewhere. Each month, I will produce a market outlook newsletter that summarizes the sales data from the previous month and provides insights into market trends based on my economic analysis. If you would like to receive this letter or recommend auctions to be included in this project, please contact me (saitone@primal.ucdavis.edu)!

Another immediate focus of my research efforts is on livestock predators, both coyotes and wolves. The coyote project is a joint effort with Kimberly Rodrigues and focuses on the benefits and costs associated with non-lethal depredation efforts undertaken to protect the sheep herd at the Hopland Research and Extension Center. The wolf project, which is a new collaboration with UC Rangelands and several northern UCCE county offices, will focus on the potential production-level impacts (e.g., reduced feed conversion, reduced weaning weights, etc.) associated with predator pressures of expanding wolf populations in California. This is a long-term project that will be based upon surveys of cattle ranchers in areas where wolves are present or anticipated to be present in the future. If you are interested in participating in this new project, please contact Dan Macon at dmacon@ucdavis.edu.

Considerations for Feeding Rained on Hay

HayStackJosh Davy, Tehama County Cooperative Extension Farm Advisor and Peter Robinson, Cooperative Extension Nutrition Specialist


This blog post was adapted from the UCCE Tehama – Livestock and Rangeland News – April 2016*


The series of storms this spring across Northern California was welcome on rangelands during the continuing drought.  Although these storms helped rangeland managers, the rains made for some risky decisions on timing hay cuttings – resulting in a lot of rained-on hay. As every rancher knows, this can lead to a lot of hay on the market with various levels of mold.


Although moldy hay can be inexpensive to buy, it may result in expenses later. Mold that grows on rain damaged hay can cause feed avoidance (and so wasted $ spent on purchasing the hay), sub-acute toxicity (sick livestock) and even acute toxicity (death). Here are some important points to consider about moldy hay….


  1. Horses should never be fed moldy hay, while cattle can consume some moldy hay.


Generally the mold itself does not make cattle sick.  It is the toxins created by some types of molds that are the culprits.  Molds that do not create toxins are not particularly dangerous to cattle, although they may still result in feed avoidance. While drying hay in the sun stops mold growth, the toxins and not impacted and can still be a threat to cattle if consumed.


  1. Cattle will naturally avoid consuming most moldy hays.


This is presumably due to learned behavior that mold makes them sick. In the case of bales with moldy exteriors, they will generally avoid exterior hay in favor of the center of the bales. The center is less moldy due to a lack of oxygen and moisture. 


  1. When you combine hungry cattle and moldy hays there is potential for disaster.


Hunger may overcome the cattle’s’ learned avoidance behavior and result in overconsumption of mold and toxins.


  1. Including moldy hay in a total mixed ration can also create risk.


This is because animals can no longer easily avoid moldy hay and thus toxins. However, this can also reduce risk by diluting the molds in the total diet consumed. 


  1. Bottom-line it is the mold count in the whole diet that determines risk.


It is not difficult or expensive to send hay samples to the lab for mold count analysis. There are guidelines (see below) on how much risk is associated with feeding moldy hay based on these counts. It is assumed that the higher the mold count the greater the likelihood that there will be toxins. While the actual mold species can be identified this is expensive and may only identify some of the dangerous molds.  In other words if the molds are identified that are known toxin producers it does not mean that they produced molds and a toxin producing mold could be missed and so its toxins could be present.


Below is a 6 tier risk scoring system based on mold counts. This is useful when feeding total mixed rations where cattle selectivity is very limited. It is also useful when the diet is primarily hay.


Risk Tier Mold Count So What?
1 <500,000 Suggests low mold levels and no threat
2 <1,000,000 Safe to feed
3 <2,000,000 Caution is advised
4 <3,000,000 Closely observe cattle for abnormal symptoms
5 <4,000,000 Dilute prior to feeding with mold free feed to reduce levels in the diet
6 >5,000,000 Do not feed unless at very low levels and in a very well mixed ration


If abnormal symptoms are observed, then access to the feed by the cattle should immediately be stopped.


You can read more details on feeding rained on hay here, here or find a forage testing lab here.

Also, more recent news about hay found here!