How many cows are in the U.S.? The United States is home to approximately **** million cattle and calves as of 2024, dropping slightly from the 2023 value. Cattle farming in the United States There are over ***** times more beef cows than milk cows living in the United States. Raising cattle is notoriously expensive, not only in terms of land, feed, and equipment, but also in terms of the environmental impact of consuming beef. Beef and milk have the highest carbon footprints of any type of food in the United States. U.S. milk market The volume of milk produced in the United States has been steadily increasing over the last several years. In 2023, total milk production in the U.S. was about ***** billion pounds, up from ***** billion pounds in 2010. ********** is the leading producer of milk of any U.S. state, generating approximately ** billion pounds of milk in 2022. Wisconsin came in second, producing about **** billion pounds of milk in that year.

How many cattle are in the world? The global live cattle population amounted to about 1.57 billion heads in 2023, up from approximately 1.51 million in 2021. Cows as livestock The domestication of cattle began as early as 10,000 to 5,000 years ago. From ancient times up to the present, cattle are bred to provide meat and dairy. Cattle are also employed as draft animals to plow the fields or transport heavy objects. Cattle hide is used for the production of leather, and dung for fuel and agricultural fertilizer. In 2022, India was home to the highest number of milk cows in the world. Cattle farming in the United States Cattle meat such as beef and veal is one of the most widely consumed types of meat across the globe, and is particularly popular in the United States. The United States is the top producer of beef and veal of any country worldwide. In 2021, beef production in the United States reached 12.6 million metric tons. Beef production appears to be following a positive trend in the United States. More than 33.07 million cattle were slaughtered both commercially and in farms annually in the United States in 2019, up from 33 million in the previous year.

The US beef cattle production industry is currently marked by tight supply conditions and elevated prices. Over recent years, persistent drought conditions have led to significant herd liquidation, with beef cow numbers falling to historic lows. This contraction has created a bottleneck in calf production and feeder cattle availability, sustaining high cattle prices. In tandem, elevated feed costs have further pressured prices upwards, driving revenue as cattle producers seek to pass on costs and maintain their heightened profit. As herd rebuilding has remained slow, cattle supplies have remained low and kept prices high even as feed, energy and other key agricultural input costs have declined from their highs in 2022. Industry revenue has grown at a CAGR of 6.3% during the current period to reach an estimated $97.3 billion after declining by 1.0% in 2025. Consumer preferences are shifting in the beef cattle production industry. There is an increasing awareness of environmental and health-related concerns associated with beef consumption. Consequently, many consumers are reducing their intake of conventional beef, turning instead towards more sustainable and perceived healthier alternatives such as grass-fed and organic beef. This shift has spurred growth in these segments as consumers look for transparency and ethical farming practices. Retailers and restaurants have responded accordingly by offering more options that align with these consumer preferences. However, these trends also pose challenges, especially for smaller producers who face significant costs associated with transitioning to sustainable practices or achieving certifications like organic or "sustainably raised." Though opportunities for growth will continue to present themselves, the outlook for the industry as a whole does not look as positive in the next five years. Poultry, pork and plant-based proteins will threaten beef demand as they appeal to health-conscious customers, particularly as cattle prices are elevated. Climate change will also continue to introduce environmental pressures, demanding resilience and adaptability from producers. Periods of stable weather could facilitate herd rebuilding, leading to increased cattle supplies and dropping prices, but continued climatic fluctuations and extreme weather events could reduce the consistency of production and increase revenue volatility. Advancements in technology, such as drones and wearable sensors, promise to help optimize cattle management, improving operational efficiencies and animal welfare. These innovations, however, require investment and broader accessibility to ensure equitable adoption across the industry. Additionally, while global trade disruptions remain a concern due to disease outbreaks and geopolitical tensions, US producers will have opportunities in niche market segments to differentiate themselves, counterbalancing some of these pressures. Overall, revenue for cattle producers is forecast to decline through 2030 at a CAGR of 1.5% to $90.4 billion.

In the U.S., there have been approximately three times more beef cows than dairy cows each year since 2001. As of 2024, it was estimated that there were about 28 million beef cows and only about 9.3 million dairy cows. Beef vs. dairy cows Both beef and dairy cows are bred for their respective purposes and farmers often look for different qualities in each. Dairy cows are often bigger, as they can produce a larger volume of milk. Beef cows on the other hand are generally shorter and there is more emphasis on their muscle growth, among other qualities. In 2022, over 28 billion pounds of beef were produced in the United States. U.S. milk production and consumption The United States was among the top consumers of milk worldwide in 2022, surpassed only by India and the European Union. The annual consumption of milk in the U.S. that year was just under 21 million metric tons. To keep up with this level of consumption, milk production in the U.S. has increased by over 60 billion pounds since 1999 and is expected to exceed 228 billion pounds by 2023. California and Wisconsin were the top producing states as of 2022, producing about 41.8 and 31.9 billion pounds of milk, respectively.

Cattle markets, where livestock producers may buy and sell cattle and calves, act as major hubs in the shipment network that connect cattle populations across the United States (U.S.). Cattle markets can then provide insight into the integration of the U.S. cattle industry, thus informing how regional price fluctuations can influence cattle prices nationally. Despite biosecurity measures and regulatory compliance from livestock markets, commingling and re-distribution of animals from multiple sources may elevate the risk of disease spread and make tracing animal movements more complex, which could pose significant challenges if a transboundary animal disease (TAD) were introduced into the U.S. Therefore, knowing the size and location of cattle markets in the U.S. is critical to understanding cattle industry market dynamics and enhancing pandemic scenario modeling efforts. In this article, we present a list of cattle markets, their locations, and estimated quarterly cattle sales. We compiled a list of 1,619 known cattle markets with and without market sales data from 1,131 counties across the U.S. from 2012-2016. To estimate unknown market sales data, we fit a spatial autoregressive lag model to annual county-level market sales data and used the fit to predict annual sales in counties that lacked sales information. County-level sales data provide important insight into the structure of the U.S. cattle industry. The dataset can be used to improve national-scale cattle movement models, livestock disease models, and inform TAD surveillance efforts.

This dataset provides livestock data for US Counties within the contiguous US. Census data of cattle, poultry (fowl), hogs, horses and sheep are provided. These data are estimated counts for 1990 based on an average of 1987 and 1992 census data from US Dept. of Agriculture (USDA) Natural Resources Conservation Service (NRCS) and the US Census Bureau.

EOS-WEBSTER provides seven datasets which provide county-level data on agricultural management, crop production, livestock, soil properties, geography and population. These datasets were assembled during the mid-1990's to provide driving variables for an assessment of greenhouse gas production from US agriculture using the DNDC agro-ecosystem model [see, for example, Li et al. (1992), J. Geophys. Res., 97:9759-9776; Li et al. (1996) Global Biogeochem. Cycles, 10:297-306]. The data (except nitrogen fertilizer use) were all derived from publicly available, national databases. Each dataset has a separate DIF.

The US County data has been divided into seven datasets.

US County Data Datasets:

1) Agricultural Management 2) Crop Data (NASS Crop data) 3) Crop Summary (NASS Crop data) 4) Geography and Population 5) Land Use 6) Livestock Populations 7) Soil Properties

In 2022, Brazil was the leading cattle producer in Latin America and the Caribbean, with an estimate of about 48 million heads of cattle. Ranking second was Argentina, with about 13.7 million heads of cattle, and it was followed by Mexico, where cattle production reached over eight million heads.

The environmental impacts of beef cattle production and their effects on the overall sustainability of beef have become a national and international concern. Our objective was to quantify important environmental impacts of beef cattle production in the United States. Surveys and visits of farms, ranches and feedlots were conducted throughout seven regions (Northeast, Southeast, Midwest, Northern Plains, Southern Plains, Northwest and Southwest) to determine common practices and characteristics of cattle production. These data along with other information sources were used to create about 150 representative production systems throughout the country, which were simulated with the Integrated Farm System Model using local soil and climate data. The simulations quantified the performance and environmental impacts of beef cattle production systems for each region. A farm-gate life cycle assessment was used to quantify resource use and emissions for all production systems including traditional beef breeds and cull animals from the dairy industry. Regional and national totals were determined as the sum of the production system outputs multiplied by the number of cattle represented by each simulated system. The average annual greenhouse gas and reactive N emissions associated with beef cattle production over the past five years were determined to be 243 ± 26 Tg carbon dioxide equivalents (CO2e) and 1760 ± 136 Gg N, respectively. Total fossil energy use was found to be 569 ± 53 PJ and blue water consumption was 23.2 ± 3.5 TL. Environmental intensities expressed per kg of carcass weight produced were 21.3 ± 2.3 kg CO2e, 155 ± 12 g N, 50.0 ± 4.7 MJ, and 2034 ± 309 L, respectively. These farm-gate values are being combined with post farm-gate sources of packing, processing, distribution, retail, consumption and waste handling to produce a full life cycle assessment of U.S. beef. This study is the most detailed, yet comprehensive, study conducted to date to provide baseline measures for the sustainability of U.S. beef. Resources in this dataset:Resource Title: Appendix A. Supplementary Data - Tables S1 to S8 (docx). File Name: Web Page, url: https://ars.els-cdn.com/content/image/1-s2.0-S0308521X18305675-mmc1.docx Direct download, docx.

Table S1. Important characteristics of farms and ranches simulated throughout seven regions of the U.S.

Table S2. Important characteristics of representative finishing facilities simulated in seven regions of the U.S.

Table S3. Important characteristics of dairy farms simulated throughout seven regions of the U.S.

Table S4. Summary of 25 years of weather data (daily solar radiation, daily mean temperature, annual precipitation and daily wind speed)1 used to simulate beef cattle operations in each area of the eastern regions.

Table S5. Soil characteristics used for locations simulated across the U.S.

Table S6. Cattle numbers by state and region as obtained or estimated from NASS (2017).

Table S7. Cattle numbers by state and region divided between traditional beef and dairy breeds as obtained or estimated from NASS (2017).

Table S8. Important resource inputs and emissions from representative cow-calf, stocker / background and feedlot operations expressed per unit of final carcass weight (CW) produced.

India's cattle inventory amounted to about *** million in 2023. In comparison, the global cattle population stood at over ***********, India had the highest cattle population followed by Brazil, China and the United States that year. Where are cattle bred in India? As one of the leading dairy producers and consumers worldwide, cattle in the south Asian country were bred mainly in the rural areas. However, its population was spread unevenly across the vast land. Uttar Pradesh ranked first in terms of milk production, followed by Rajasthan, and Madhya Pradesh in 2023. Contextualizing the holiness of the Indian cow Considered a sacred animal by Hindus in India, the cow is associated with several gods and goddesses. This deep religious and cultural significance has led to communal tensions. In 2014, the government established the Rashtriya Gokul Mission (RGM) to conserve and develop indigenous breeds of cows and buffaloes. While the general goal was well-received, it aligns with the underlying Hindu nationalist narrative of the current government.

Discover the challenges in the U.S. beef supply as cattle numbers reach historic lows, driving up meat prices. Insights from Omaha Steaks' CEO Nate Rempe and future predictions for market recovery.

In 2024, the there were around 14.8 million heads of cattle in Argentina, representing an increase of almost one percent compared to the previous year. It was expected that this number would remain the same in 2025. That year, Argentina was the country with the second highest number of cattle in Latin America.

The global artificial insemination (AI) market for cattle is experiencing robust growth, driven by increasing demand for high-quality genetics, improved herd productivity, and disease control. The market, estimated at $2 billion in 2025, is projected to expand at a Compound Annual Growth Rate (CAGR) of 7% from 2025 to 2033, reaching approximately $3.5 billion by 2033. This growth is fueled by several factors. Firstly, the rising global population necessitates increased meat and dairy production, leading to greater adoption of AI techniques to enhance breeding efficiency and livestock quality. Secondly, advancements in AI technologies, including sexed semen and genomic selection, are enabling farmers to achieve precise breeding goals and improve the overall genetic merit of their herds. Finally, the increasing prevalence of contagious diseases among cattle populations is prompting farmers to utilize AI as a safer and more effective method of breeding compared to natural mating, reducing the risk of disease transmission. The market is segmented by application (family farms and commercial farms) and cattle type (dairy cows and beef cattle), with commercial farms currently dominating the market share due to higher adoption rates of advanced technologies and economies of scale. Regional variations exist, with North America and Europe holding significant market shares, driven by established agricultural infrastructure and higher adoption rates of AI technology. However, developing regions in Asia-Pacific and South America are also witnessing substantial growth, driven by expanding livestock populations and increasing awareness of the benefits of AI. Despite the positive outlook, the market faces challenges. High initial investment costs associated with AI technologies, lack of awareness and skilled personnel in certain regions, and regulatory hurdles in some countries can act as restraints on market growth. Furthermore, the fluctuating prices of livestock and feed, as well as the potential for technological disruptions, could impact market dynamics. However, ongoing research and development efforts focused on improving AI techniques, along with government initiatives promoting the adoption of advanced breeding technologies, are likely to mitigate these challenges and sustain market growth. The leading companies in this sector are strategically investing in research and development, expanding their geographical reach, and forming partnerships to solidify their market positions and cater to the evolving needs of the livestock industry.

Livestock distribution in the United States (U.S.) can only be mapped at a county-level or worse resolution. We developed a spatial microsimulation model called the Farm Location and Agricultural Production Simulator (FLAPS) that simulated the distribution and populations of individual livestock farms throughout the conterminous U.S. Using domestic pigs (Sus scrofa domesticus) as an example species, we customized iterative proportional-fitting algorithms for the hierarchical structure of the U.S. Census of Agriculture and imputed unpublished state- or county-level livestock population totals that were redacted to ensure confidentiality. We used a weighted sampling design to collect data on the presence and absence of farms and used them to develop a national-scale distribution model that predicted the distribution of individual farms at a 100 m resolution. We implemented microsimulation algorithms that simulated the populations and locations of individual farms using output from our imputed Census of Agriculture dataset and distribution model. Approximately 19% of county-level pig population totals were unpublished in the 2012 Census of Agriculture and needed to be imputed. Using aerial photography, we confirmed the presence or absence of livestock farms at 10,238 locations and found livestock farms were correlated with open areas, cropland, and roads, and also areas with cooler temperatures and gentler topography. The distribution of swine farms was highly variable, but cross-validation of our distribution model produced an area under the receiver-operating characteristics curve value of 0.78, which indicated good predictive performance. Verification analyses showed FLAPS accurately imputed and simulated Census of Agriculture data based on absolute percent difference values of < 0.01% at the state-to-national scale, 3.26% for the county-to-state scale, and 0.03% for the individual farm-to-county scale. Our output data have many applications for risk management of agricultural systems including epidemiological studies, food safety, biosecurity issues, emergency-response planning, and conflicts between livestock and other natural resources.

Snapshot img

Cattle Healthcare Market Size 2024-2028

The cattle healthcare market size is forecast to increase by USD 4.47 billion at a CAGR of 8.91% between 2023 and 2028.

The market is experiencing significant growth due to several key factors. The increasing burden of cattle diseases is a major driver for market expansion, as farmers seek effective solutions to maintaIn the health and productivity of their herds. Additionally, the rising shift towards animal farming, particularly in developing countries, is creating new opportunities for market participants. However, challenges remain In the form of problematic disease management practices, which necessitate the development of advanced healthcare solutions. These trends and growth factors are shaping the future of the market, offering potential for innovation and growth.

What will be the Size of the Cattle Healthcare Market During the Forecast Period?

Request Free SampleThe market encompasses a range of products and services aimed at maintaining the health and productivity of bovine livestock. Animal husbandry practices prioritize preventative measures against diseases such as bovine tuberculosis, anthrax, brucellosis, rabies, milk fever, and chronic conditions like mastitis and inflammation of the mammary gland. Clinical mastitis, a common ailment causing inflammation and infection In the mammary gland, significantly impacts milk production and necessitates timely intervention. Drug consumption and medical devices are integral components of cattle healthcare, with a focus on enhancing immunity and mitigating the spread of diseases. The adoption of advanced technologies, including vaccine development, is driving market revenues in this sector.The market is a critical aspect of livestock production, with implications for both milk and meat production industries, as well as poultry production.

How is this Cattle Healthcare Industry segmented and which is the largest segment?

The cattle healthcare industry research report provides comprehensive data (region-wise segment analysis), with forecasts and estimates in 'USD million' for the period 2024-2028, as well as historical data from 2018-2022 for the following segments. TypeBeef cattleDairy cattle ProductPharmaceuticalsFeed additivesVaccinesOthers GeographyNorth AmericaUSEuropeGermanyFranceAsiaChinaIndiaRest of World (ROW)

By Type Insights

The beef cattle segment is estimated to witness significant growth during the forecast period.

Beef cattle healthcare is a critical component of animal farming, focusing on the prevention, diagnosis, and treatment of diseases, as well as the promotion of productivity and animal welfare. Disease prevention is achieved through vaccination programs targeting illnesses like bovine tuberculosis, milk fever, and chronic diseases, ensuring herd health and reducing drug consumption. Proper nutrition plays a significant role in maintaining cattle health and productivity, with balanced diets tailored to various life stages. Regular health monitoring, including parasite control and hoof care, is essential to address potential health issues. Medical devices, such as diagnostic imaging tools like CT scans and magnetic resonance imaging, are used to diagnose and treat conditions affecting the mammary gland, such as clinical mastitis and inflammation.Veterinary services and medications, including vaccines and medicines naturally derived, are crucial in maintaining the well-being of the cattle population. Livestock production, including milk production, poultry production, and dairy industry, relies on effective cattle healthcare practices, with emerging economies investing in initiatives to improve infrastructure, funding, and awareness. Disease control and monitoring are essential for sustainable livestock production, addressing zoonotic diseases like Salmonellosis and ensuring animal welfare.

Get a glance at the Cattle Healthcare Industry report of share of various segments Request Free Sample

The Beef cattle segment was valued at USD 3.7 billion in 2018 and showed a gradual increase during the forecast period.

Regional Analysis

North America is estimated to contribute 37% to the growth of the global market during the forecast period.

Technavio’s analysts have elaborately explained the regional trends and drivers that shape the market during the forecast period.

For more insights on the market share of various regions, Request Free Sample

The North American the market is experiencing significant growth due to several factors. The region's increasing cattle population and heightened focus on animal welfare have fueled the demand for advanced cattle healthcare solutions. Approximately 60% to 65% of US households own cattle, with around 85 million to 87 million homes housing them. To enhance cattle health, veterinary clinics and hospitals are adopting innovative healthcare p

The U.S. Geological Survey (USGS) is developing SPARROW models (SPAtially Related Regressions On Watershed Attributes) to assess the transport of contaminants (e.g., nutrients) through the Pacific drainages of the United States (the Columbia River basin; the coastal drainages of Washington, Oregon, and California; the Klamath River basin; the Central Valley of California, and the west slopes of the Sierra Nevada Mountains). SPARROW relates instream water quality measurements to spatially referenced characteristics of watersheds, including contaminant sources and the factors influencing terrestrial and aquatic transport. The population of livestock within a watershed is a potential factor affecting nutrient delivery to streams. The spatial data set “County-level livestock data for the Pacific drainages of the United States (2012)" summarizes livestock populations and the associated generation of manure nutrients for each county lying partially or fully within Pacific drainages of the United States. This data set was created by combining an existing data set of county-level livestock and manure nutrient data for the United States with regional information on cattle housed in dairies and feedlots.

[NOTE - 11/24/2021: this dataset supersedes an earlier version https://doi.org/10.15482/USDA.ADC/1518654 ] Data sources. Time series data on cattle fever tick incidence, 1959-2020, and climate variables January 1950 through December 2020, form the core information in this analysis. All variables are monthly averages or sums over the fiscal year, October 01 (of the prior calendar year, y-1) through September 30 of the current calendar year (y). Annual records on monthly new detections of Rhipicephalus microplus and R. annulatus (cattle fever tick, CFT) on premises within the Permanent Quarantine Zone (PQZ) were obtained from the Cattle Fever Tick Eradication Program (CFTEP) maintained jointly by the United States Department of Agriculture (USDA), Animal Plant Health Inspection Service and the USDA Animal Research Service in Laredo, Texas. Details of tick survey procedures, CFTEP program goals and history, and the geographic extent of the PQZ are in the main text, and in the Supporting Information (SI) of the associated paper. Data sources on oceanic indicators, on local meteorology, and their pretreatment are detailed in SI. Data pretreatment. To address the low signal-to-noise ratio and non-independence of observations common in time series, we transformed all explanatory and response variables by using a series of six consecutive steps: (i) First differences (year y minus year y-1) were calculated, (ii) these were then converted to z scores (z = (x- μ) / σ, where x is the raw value, μ is the population mean, σ is the standard deviation of the population), (iii) linear regression was applied to remove any directional trends, (iv) moving averages (typically 11-year point-centered moving averages) were calculated for each variable, (v) a lag was applied if/when deemed necessary, and (vi) statistics calculated (r, n, df, P<, p<). Principal component analysis (PCA). A matrix of z-score first differences of the 13 climate variables, and CFT (1960-2020), was entered into XLSTAT principal components analysis routine; we used Pearson correlation of the 14 x 60 matrix, and Varimax rotation of the first two components. Autoregressive Integrated Moving Average (ARIMA). An ARIMA (2,0,0) model was selected among 7 test models in which the p, d, and q terms were varied, and selection made on the basis of lowest RMSE and AIC statistics, and reduction of partial autocorrelation outcomes. A best model linear regression of CFT values on ARIMA-predicted CFT was developed using XLSTAT linear regression software with the objective of examining statistical properties (r, n, df, P<, p<), including the Durbin-Watson index of order-1 autocorrelation, and Cook’s Di distance index. Cross-validation of the model was made by withholding the last 30, and then the first 30 observations in a pair of regressions. Forecast of the next major CFT outbreak. It is generally recognized that the onset year of the first major CFT outbreak was not 1959, but may have occurred earlier in the decade. We postulated the actual underlying pattern is fully 44 years from the start to the end of a CFT cycle linked to external climatic drivers. (SI Appendix, Hypothesis on CFT cycles). The hypothetical reconstruction was projected one full CFT cycle into the future. To substantiate the projected trend, we generated a power spectrum analysis based on 1-year values of the 1959-2020 CFT dataset using SYSTAT AutoSignal software. The outcome included a forecast to 2100; this was compared to the hypothetical reconstruction and projection. Any differences were noted, and the start and end dates of the next major CFT outbreak identified. Resources in this dataset: Resource Title: CFT and climate data. File Name: climate-cft-data2.csv Resource Description: Main dataset; see data dictionary for information on each column Resource Title: Data dictionary (metadata). File Name: climate-cft-metadata2.csv Resource Description: Information on variables and their origin Resource Title: fitted models. File Name: climate-cft-models2.xlsx Resource Software Recommended: Microsoft Excel,url: https://www.microsoft.com/en-us/microsoft-365/excel; XLSTAT,url: https://www.xlstat.com/en/; SYStat Autosignal,url: https://www.systat.com/products/AutoSignal/

The global ruminant feed market, valued at approximately $XX million in 2025, is projected to experience steady growth, exhibiting a compound annual growth rate (CAGR) of 3.20% from 2025 to 2033. This growth is fueled by several key factors. Increasing global demand for meat and dairy products, driven by a rising global population and changing dietary habits, is a primary driver. Furthermore, advancements in feed technology, such as the development of more efficient and sustainable feed formulations, contribute significantly to market expansion. The incorporation of improved nutrient-rich ingredients, like specialized cereals and cakes, aims to enhance animal health and productivity, boosting overall market value. However, challenges remain. Fluctuations in raw material prices, particularly grains, pose a significant constraint, impacting profitability and potentially influencing price points for consumers. Additionally, growing concerns regarding the environmental impact of livestock farming, including greenhouse gas emissions, are prompting stricter regulations and sustainable farming practices, requiring ongoing adaptation within the industry. Market segmentation reveals strong demand across various animal types, with dairy cattle and beef cattle commanding significant shares, followed by other animal types. Ingredient-wise, cereals, cakes, and meals are major components, highlighting the market's reliance on efficient grain utilization and processing technologies. Geographical distribution shows a diverse market landscape. North America, particularly the United States and Canada, are expected to maintain substantial market shares due to advanced agricultural practices and high livestock populations. Europe also presents a significant market, with countries like Germany, Spain, and the UK representing substantial consumer bases. The Asia-Pacific region, driven by growing economies and increasing meat consumption in China and India, is anticipated to witness robust growth throughout the forecast period. South America, with its significant cattle population in Brazil and Argentina, is also an important contributor. Competition among key players, including Cargill Inc., Land O' Lakes Feed, DBN Group, Archer Daniels Midland, and others, is intense, fostering innovation and driving efficiency improvements within the ruminant feed sector. The future growth trajectory of the market hinges on addressing sustainability concerns, optimizing feed formulations, and successfully navigating fluctuating raw material prices. Notable trends are: Government Regulations.

Diagnostic statistics for the proposed model, the model of Wielgus and Peebles [1] and the model of Poudyal et al. [2].