Frank M. Mitloehner

University of California, Davis | UCD · Department of Animal Science

The development of technologies that promote environmental stewardship while maintaining or improving the efficiency of food animal production is essential to the sustainability of producing a food supply to meet the demands of a growing population. As such, Elanco (Greenfield, IN) pursued an environmental indication for a selective β-modulator (lu...

With a growing global population and increased environmental concerns around animal agriculture, it is essential to humanely maximize animal performance and reduce environmental emissions. The present study aims to determine the efficacy of feeding ractopamine hydrochloride (RAC), an orally active, β1–adrenergic agonist (β1AA), to feedlot steers in...

Many dairy calves in the southwestern regions of the United States are raised in wooden hutches with 1.23 m ² of free space that house 3 calves individually. Producers claim that calves in hutch systems are not ready to wean and be placed in groups at the country-average age of 6 wk. Calves may remain in this individual housing system until as late...

Mathematical models are a useful part of extension and researcher collaboration with producers and policymakers. Although many models of large ruminant production exist, with a wide variety of objectives and users, the range available to small ruminant producers is limited. This review summarizes the current state of models available to small rumin...

We examined the dose‐dependent effects of feeding lactating dairy cows a standard diet supplemented with monensin at 175, 368, or 518 mg cow‐1 day‐1on the rumen microbiota. For each dosage, 3 animals were randomly assigned into groups and fed the same basal total mixed ration diet supplemented with monensin, at the respective dose. After 20 days, r...

While the environmental impacts of livestock production, such as greenhouse gas emissions and water usage, have been studied for a variety of U.S. livestock production systems, the environmental impact of U.S. sheep production is still unknown. A cradle-to-farm gate life cycle assessment (LCA) was conducted according to international standards (ISO...

Vermifiltration is a biological treatment process during which earthworms (e.g., Eisenia fetida) and microorganisms reduce the organic load of wastewater. To infer microbial pathways responsible for nutrient conversion, past studies characterized the microbiota in vermifilters and suggested that nitrifying and denitrifying bacteria play a significa...

Vermifilter design and emission sampling sites. The vermifilter is a concrete enclosure (49 m × 11 m × 1.5 m) filled woodchips inoculated with earthworms and microorganisms to enhance solids and contaminant removal. The large particle size of the woodchips, the bottom layer of gravel, and the exhaust pipes that line the perimeter of the vermifilter...

Rarefaction curves. Rarefaction analysis of the V4 region of the 16S rRNA gene from three replicates (A, B and C) of three dairy wastewater samples (LAG, lagoon water; INF, influent; and EFF, effluent) constructed at 97% sequence similarity.

By 2050, Earth will be home to nearly 10 billion people, a tripled human population during our lifetime. Only 1.8% of the Earth’s surface is arable land that can be used for growing crops, a resource not likely to increase, which means the amount of cropland per person will decline by 20% (1). In the face of finite resources and a changing climate,...

As participants at the Ecosystem Inception Meeting convened by the Global Dairy Platform and held in Chicago in June 2016, we have identified some concepts as central to the study of food systems science. Following the definition developed by the Food and Agriculture Organization for sustainable diets, the food supply needs to provide foods that ar...

This study aimed to evaluate the effect of supplementing biotin (BIO), nicotinamide (NAM) and their interaction on feed intake, milk production, and energy metabolism of transition dairy cows. Forty multiparous Holsteins were assigned randomly within block to 1 of the following 4 treatments: control (no supplementation), 30 mg/d BIO, 45 g/d NAM (ru...

Fodder for feeding pork and poultry requires a large amount of cultivated and processed agricultural crops, which are often related to greenhouse gas emissions from land-use change (LUC). Given the rapid growth in meat production in Brazil for domestic consumption and international export, the link between LUC emissions and consumption of pork and...

Dairy workers experience a high degree of bioaerosol exposure, composed of an array of biological and chemical constituents, which have been tied to adverse health effects. A better understanding of the variation in the magnitude and composition of exposures by task is needed to inform worker protection strategies. To characterize the levels and ty...

Agriculture in California contributes 8% of the state's greenhouse gas (GHG) emissions. To inform the state's policy and program strategy to meet climate targets, we review recent research on practices that can reduce emissions, sequester carbon and provide other co-benefits to producers and the environment across agriculture and rangeland systems....

A partial life cycle assessment (LCA) of a sheep production system in California was conducted to better understand the environmental impacts of sheep production in the United States. This cradle-to-farm-gate LCA analyzed emissions from sheep–lamb, stocker, and finishing stages of lamb production within the same market chain. Our objective was to c...

Simple Summary Fine particulate matter (with less than 2.5 microns diameter; aka PM2.5) are a human and animal health concern because they can carry microbes and chemicals into the lungs. Particulate matter (PM) in general emitted from cattle feedlots can reach high concentrations. When feedlot cattle were given an altered feeding schedule (ALT) th...

Dairy calves in the Southwest regions of the United States are typically raised individually in wooden hutches with 1.23 m2 of space. The objective of the study was to determine if increased space allowance in wooden hutches influences measures of innate immunity and behaviors of Holstein bull calves pre- and postcastration. Calves were randomly as...

Dairy calves in the Southwest regions of the United States are typically raised individually in wooden hutches with 1.23 m(2) of space. The objective of the study was to determine if increased space allowance in wooden hutches influences measures of innate immunity and behaviors of Holstein bull calves pre- and postcastration. Calves were randomly...

Silage on dairy farms can emit large amounts of volatile organic compounds (VOCs), a precursor in the formation of tropospheric ozone. Because of the challenges associated with direct measurements, process-based modeling is another approach for estimating emissions of air pollutants from sources such as those from dairy farms. A process-based model...

Nitrous oxide (N 2 O) is a greenhouse gas with about 300 times the global warming potential (GWP) of carbon dioxide (CO 2). It is emitted from a wide range of sources and is responsible for about 6% of anthropogenic US greenhouse gas emissions. Analytical techniques are needed that can measure concentrations of N 2 O rapidly and inexpensively in so...

Enteric methane (CH4) generated in the gastrointestinal tract of ruminant represents the source of the greatest direct greenhouse gas (GHG) released from the livestock sector. We evaluated the global potential reduction of enteric CH4 emissions released from dairy cattle through amendment of their traditional diets in 183 countries aggregated to 11...

Dairy calves in the western United States are commonly raised individually in wooden hutches with a space allowance of 1.23 m(2)/calf. Recent legislative initiatives in California and across the United States were passed regarding concern over space allowance for farm animals. The objective of this study was to determine if rearing male Holstein ca...

This study was carried out to measure the mass flow and distribution of nutrients (N, C, S, P, and K) as well as solids and moisture in conventional cage (CC), enriched colony (EC), and aviary (AV) laying-hen houses with Lohmann LSL lite hens located on a commercial laying-hen farm in Iowa. The weight of consumed feed and water, and amounts of eggs...

The objective of this study was to compare respiratory health of poultry workers in conventional cage, enriched cage and aviary layer housing on a single commercial facility, motivated by changing requirements for humane housing of hens. Three workers were randomly assigned daily, one to each of conventional cage, enriched cage, and aviary housing...

To assess respiratory exposures and lung function in a cross-sectional study of California dairy workers. Exposure of 205 dairy and 45 control (vegetable processing) workers to particulate matter and endotoxin was monitored. Pre- and postshift spirometry and interviews were conducted. Geometric mean inhalable and PM2.5 concentrations were 812 and 3...

Objective: To assess respiratory exposures and lung function in a cross-sectional study of California dairy workers. Methods: Exposure of 205 dairy and 45 control (vegetable processing) workers to particulate matter and en-dotoxin was monitored. Pre-and postshift spirometry and interviews were conducted. Results: Geometric mean inhalable and PM 2.5...

Individual exposures to particulate matter and endotoxin in dairies have increased as operations have transitioned to larger herd sizes. A cross-sectional study at 13 California dairies and one non-dairy control facility was conducted to determine associations between endotoxin concentrations measured in fine particulate matter (PM2.5) and respirat...

The objective of this study was to compare the personal respiratory exposures of poultry workers in three different types of layer housing under commercial production conditions.Workers were randomly assigned to each of conventional cage, enriched cage, and aviary barns in a crossover repeated- measures design for three observation periods over the...

The objective of this study was to compare the personal respiratory exposures of poultry workers in three different types of layer housing under commercial production conditions.Workers were randomly assigned to each of conventional cage, enriched cage, and aviary barns in a crossover repeated- measures design for three observation periods over the...

Concentrated animal feeding operations (CAFOs) have become a prevalent form of intensive animal production. They are operations that confine livestock for more than 45 days, in an area that does not produce vegetation, and meets size thresholds. CAFOs can have considerable impacts on the environment because greater stocking density is directly asso...

The objective of this work was to evaluate the effects of biological and chemical silage additives on the production of volatile organic compounds (VOC; methanol, ethanol, 1-propanol, methyl acetate, and ethyl acetate) within corn silage. Recent work has shown that silage VOC can contribute to poor air quality and reduce feed intake. Silage additiv...

Airborne particulate matter with aerodynamic size less than 10 mm was collected at a California dairy in fall 2006 using a Rotating Drum Impactor (RDI) sampler in 8 size ranges (i.e., 10e5, 5e2.5, 2.5e1.15, 1.15 e0.75, 0.75e0.56, 0.56e0.34, 0.34e0.26, and 0.26e0.09 mm). The RDI samples were analyzed using synchrotron X-ray Fluorescence (XRF) at the...

Abstract Text: Previous research on nitrate (NO3-) supplementation in dairy cattle diets demonstrated that NO3- is effective in decreasing methane (CH4) production; however, it also induced nitrous oxide (N2O) production under the rumen simulated conditions. One possible strategy to mitigate concomitant N2O emission is by enhancing the activity of...

Abstract Text: Silages have the potential to contribute to poor air quality through emission of volatile organic compounds (VOC), especially ethanol. Silage additives may be useful for reducing VOC production, but few studies have evaluated them for this purpose. The objective of this experiment was to test the effects of a biological and a chemi...

Abstract Text: Feeding nitrate has been proposed as a means to reduce enteric greenhouse gas emissions from ruminants. Nitrate can compete with methanogens for hydrogen in the rumen and therefore reduce methane from eructation. However, increasing the nitrate concentration in the rumen could induce enteric nitrous oxide emissions, potentially nul...

Climate change will pose risks for the world’s food supply in the coming decades; this comes at a time when the global demand for food is expected to soar based on 2050 world population estimates. It is important to recognize that climate change will necessitate temporal and geographical shifts in food production, but will most likely not result in...

In recent years, the livestock production industry has been receiving pressure to assess and improve production practices in two seemingly unrelated areas: environmental quality and animal welfare. In this article, we argue that the nexus of these two areas of study should be a priority for future research and that the integration of these discipli...

Silage, fermented cattle feed, has recently been identified as a significant source of volatile organic compounds (VOCs) to the atmosphere. A small number of studies have measured VOC emission from silage, but not enough is known about the processes involved to accurately quantify emission rates and identify practices that could reduce emissions. T...

Increased animal productivity has the potential to reduce the environmental impact per unit of consumable product and is believed to be the most promising and sustainable mitigation technique to meet increasing demand for high quality protein. The feedlot industry uses ionophores, antibiotics, growth implants, and β2-adrenergic agonists to improve...

Nitrous oxide reductase (N2OR), the enzyme responsible for the reduction of N2O to N2 in denitrification, uses copper (Cu) as its cofactor. Its activity is lowered under conditions of Cu deficiency. In general, high organic matter (OM) soil decreases Cu availability. The present study investigated different Cu forms, namely organic (ORG) v. inorgan...

While research has documented the adverse impact of agricultural work on the respiratory health of farmers, few studies have reported on the respiratory health of dairy workers. Additionally, we are not aware of any published studies addressing the health impacts associated with large dairies in the western United States. The present investigation...

• The human demand for animal protein will double by the year 2050. Food must be produced efficiently considering limited water and arable land. • Livestock production emits carbonaceous and nitrogenous compounds that contribute to air and water pollution as well as climate change. • Animal biotechnologies, including recombinant bovine somatotropin...

Over the past 30 yr, individual California dairy operations have grown in size; however, little is known about the distribution and determinants of particulate matter (PM) concentrations on these dairies. Elevated exposure to PM is associated with respiratory and cardiovascular health effects, particularly in occupational settings. The purpose of t...

Aims: To describe, at high resolution, the bacterial population dynamics and chemical transformations during the ensiling of alfalfa and subsequent exposure to air. Methods and results: Samples of alfalfa, ensiled alfalfa and silage exposed to air were collected and their bacterial population structures compared using 16S rRNA gene libraries con...

This book with eighteen chapters draws together themes on sustainability that have emerged as the most pressing in recent years. The book addresses practical topics such as air quality, manure management, animal feeds, production efficiency, environmental sustainability, biotechnology issues, animal welfare concerns, societal impacts and an analysi...

Monensin is a feed additive used in dairy cattle diets to improve feed efficiency that may reduce methane(CH4) emissions; however, past results have been variable, which could be due to the dose of monensin included in the diet. The objective of this study was to test the short-term dose effects of monensin on eructated CH4 emissions from lactating...

Objective: To study whether dairy workers in California have lower baseline and greater cross-shift decrements in lung function than control employees. Methods: A cross-sectional study of 210 dairy and 47 control workers who completed questionnaires and spirometry before and after the work shift. Results: Dairy work was associated with mean ba...

Endotoxin, found in the cell wall of gram negative bacteria, is an important contributor to the biological activity of agriculture particulate matter (PM). We analyzed endotoxin in PM collected on 13 California dairies and from the breathing zone of 226 workers during the summer months of 2008. Two particle size fractions were measured: PM(2.5) and...

Beef production is a recognized source of greenhouse gas (GHG) and ammonia (NH(3)) emissions; however, little information exists on the net emissions from beef production systems. A partial life cycle assessment (LCA) was conducted using the Integrated Farm System Model (IFSM) to estimate GHG and NH(3) emissions from representative beef production...

Improved animal performance is suggested as one of the most effective mitigation strategies to reduce greenhouse gas (GHG) and ammonia (NH(3)) emissions from livestock production per unit of product produced. However, little information exists on the effects of increased animal productivity on the net emission reduction from beef production systems...

From the point of view of biogeochemis-try, manure is a complex of organic matter containing minor minerals. When manure is excreted by animals, it undergoes a series of reactions such as decomposi-tion, hydrolysis, ammonia volatilization, nitrification, denitrification, fermentation etc., from which carbon dioxide (CO 2), nitrous oxide (N 2 O), me...

Two methods were described to estimate interference in the measurements of infrared (IR) photoacoustic multi-gas analyzer (PAMGA). One is IR spectroscopic analysis (IRSA) and the other is mathematical simulation. An Innova 1412 analyzer (AirTech Instruments, Ballerup, Denmark) with two different filter configurations was used to provide examples th...

The purpose of the present study was to investigate activation of inflammatory markers in human macrophages derived from the U937 cell line after exposure to particulate matter (PM) collected on dairy farms in California and to identify the most potent components of the PM. PM from different dairies were collected and tested to induce an inflammato...

A three-dimensional air quality model with 8 km horizontal resolution was applied to estimate the summertime ozone (O(3)) production from mobile sources and fermented livestock feed in California's San Joaquin Valley (SJV) during years 2000, 2005, 2010, 2015, and 2020. Previous studies have estimated that animal feed emissions of volatile organic c...

Life cycle assessment for livestock: a complex issue Discussions about global climate change have spurred evalua-tions of livestock agriculture's contribution; however, the com-plexity and variation in livestock production systems makes the quantification of greenhouse gas (GHG) emissions difficult. Several recent publications have used Life Cycle...

Simple Summary We describe the construction and operation of a unique system for measuring gaseous emissions that arise from the rumen and metabolism of cattle. This system allows for the collection of high quality data that can be used to improve emission inventories at the regional and national level. Additionally, the system can be used to test...

Objectives To determine whether exposure to particulate matter (PM) including endotoxins on large California dairies is associated with decreased cross-shift respiratory function. Methods Male workers at 13 dairies and one control facility wore personal air samplers collecting total suspended particles (TSP) or PM2.5 over their shift. Pre- and pos...

Large-scale agricultural activities have come under scrutiny for possible contributions to the emission of ozone precursors. The San Joaquin Valley (SJV) of California is an area with intense agricultural activity that exceeds the federal ozone standards for more than 30 to 40 d yr(-1) and the more stringent state standards for more than 100 d yr(-...

To determine the effects of sodium bisulfate (SBS) on the bacterial populations in cattle waste. We applied SBS at 0, 60, 70 or 100 kg week(-1) to cattle waste as it accumulated on the floors of four cattle pens, housing eight cattle each. We observed significant pH decreases in all of the treated wastes on day one; however, the 60 kg week(-1) trea...

Livestock's contributions to climate change and smog-forming emissions are a growing public policy concern. This study quantifies greenhouse gas (GHG) and alcohol emissions from calves and feedlot steers. Carbon dioxide (CO) methane (CH), nitrous oxide (NO), ethanol (EtOH), and methanol (MeOH) were measured from a total of 45 Holstein and Angus ste...

Composting of green waste separated from the disposed solid waste stream reduces biodegradable inputs into landfills, and contributes valuable soil amendments to agriculture. Agencies in regions with severe air quality challenges, such as California’s San Joaquin Valley (SJV), have raised concerns about gases emitted during the composting process,...