Sam Wyffels

• Doctor of Philosophy
• Assistant Professor and Beef Specialist at Montana State University

Current management paradigms suggest deferring grazing rangeland for two years post-fire to avoid additional stress on native grass species, but there is little research supporting these recommendations. This study was conducted within and adjacent to the burn area of a wildfire to evaluate the differences in diet quality, botanical composition, an...

Dormant forage is generally understood to be low-quality, but how and why it changes over the dormant season have not been well studied. Therefore, this study evaluated the changes in the forage quality of bluebunch wheatgrass (Pseudoroegneria spicata) and Idaho fescue (Festuca idahoensis) over the course of the dormant season and in response to co...

The objectives of this study were to evaluate the levels of supplemental salt on low-quality forage intake, water intake, dry matter digestibility, and rumen fermentation. Six ruminally cannulated, Angus crossbred heifers (14 mo of age; 449 kg ± 24 kg BW) were used in a dual 3 × 3 Latin square design. The heifers were housed in individual stalls wi...

This study evaluated the influences of graded levels of supplemental alfalfa pellets on beef cattle performance during mid-late gestation of multiparous beef cows. Angus based bred cows (n = 120) were used in an 84-d winter grazing experiment that took place on native foothill rangelands. Cattle were stratified by age and body condition and, within...

The objectives of this study were to quantify the change and variation in forage quality of Idaho fescue (Festuca idahoensis) and bluebunch wheatgrass (Pseudoroegneria spicata) over the course of two consecutive winters. Five sites were selected from within a 1064-ha, foothill grassland management unit at Red Bluff Research Ranch in Norris, MT. Beg...

While suitable research has been done on the influence of climatic conditions on feeder cattle welfare, we have seen limited work done that assesses the relationship of hide color and cattle thermoregulation in response to extreme environmental changes, particularly of those seen at northern latitudes. Specifically, there is limited research on the...

Pulmonary arterial pressure (PAP), determines the susceptibility to High Altitude Disease (HAD) of an animal, which causes pulmonary hypertension due to hypoxia. Cattle that reside in elevations greater than 1,500 m are more susceptible to HAD. PAP measures the resistance of blood flow through the lungs and can be used as an indicator of the suscep...

Research has shown that forage quality increases after a fire. Greater crude protein content in forage can be beneficial for livestock, and even attract herbivores to recently burned areas. However, there has been little research into how forage quality changes within the first 2 yr after a fire and how it affects livestock diet quality or composit...

Simple Summary An estimated USD 60 million is lost annually due to High Altitude Disease in the cow–calf industry, and there continues to be a growing concern about heart–lung function in feedlot cattle located at moderate elevations. As the cattle industry puts more emphasis on and focuses on heart–lung function, it is valuable to provide a review...

In the United States, rangelands comprise 30% of the total land cover and serve as a valuable resource for livestock, wildlife, water, and recreation. Rangelands vary in climate and are often subject to disturbances like drought and wildfire. Historic wildfire trends have indicated an increase in wildfire size and frequency, raising societal and ec...

Designing research for applied beef cattle production systems has always presented challenges for Land Grant University and USDA Scientist. Specifically, creating study designs that have enough replication for statistical inference has often prompted scientists to use designs that do not closely replicate actual production systems. Past research ha...

The objectives of this study were to increase the amount of phenotypic data available for enhancing the foot and claw EPDs of Montana sires and evaluate factors that could impact foot angle and claw set scores. Specifically, this study evaluated the interaction of sex and age on claw set and foot angle scores of front or hind legs. Researchers used...

Current management paradigms suggest deferring grazing rangeland for two years after a wildfire to avoid additional stress on native plant species, but there is limited research supporting these recommendations. Therefore, this experiment was conducted within and adjacent to a burn area of an August 2020 wildfire to evaluate the differences in diet...

Angus based bred cows [n = 150; initial shrunk body weight (BW) = 615 ± 6.61 kg; initial body condition score (BCS) = 5.2] were used in an 84-d winter grazing experiment that took place over two consecutive years. Cattle were stratified by age and body condition and, within stratum, randomly assigned to one of three protein supplementation treatmen...

Two studies were conducted to evaluate the influence of graded levels of supplemental protein on the intake, digestion, ruminal fermentation, and metabolism of beef cows consuming low-quality forage base diets (6% CP and 74% NDF). For both studies, 15 ruminally cannulated cows (4/5 yrs age, 803 and 757 kg = avg BW for study 1 and 2, respectively) w...

Simple Summary As the beef industry continues to become more efficient and profitable, structural soundness will be important for the longevity of forage-based beef cattle. This study characterized the effects of age, sex, and sire line on mean foot angle and claw set scores of registered Angus cattle in Montana, USA. In our study, yearling bulls h...

Rangeland wildlife ecology and conservation is strongly influenced by domestic livestock systems. Domestic livestock production on rangelands in North America is dominated by ruminant livestock, with beef cattle being the largest industry. Rangeland ruminant livestock production systems are unique in that land/animal managers develop production sys...

Introduction Limited forage quantity and quality are challenges faced in livestock production systems in semi-arid rangelands of the western United States, particularly when livestock face stressors such as cold weather or have increased nutritional requirements such as during pregnancy and lactation. To meet livestock nutrient requirements, produc...

Simple Summary Due to various selection pressures, beef cattle have been transformed in size and shape over the last seventy-five years. The increased demand for cattle performance has put extra stress on foot and leg structure. While some research has been performed in the dairy sector, little work has been conducted in extensive beef production s...

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Simple Summary This study was conducted to evaluate intake and performance of beef cattle provided different protein supplements on pasture. Protein sources were rumen degradable protein (RDP) and rumen undegradable protein (RUP) supplied as pressed blocks provided in two time periods. Protein supplement was provided before and during the breeding...

The incorporation of cover crops into cropping systems is important for enhancing soil health in agricultural systems. Soil microbes contribute to soil health by supplying key nutrients and providing protection against plant pests, diseases, and abiotic stress. While research has demonstrated the connection between cover crops and the soil microbio...

Simple Summary Selecting replacement beef females is often based on individual producers and their own individual needs. Selection criteria typically vary from producer to producer but generally include productivity of the mother, ability to rebreed and wean a heavy calf. Increased longevity of the dam may be an indicator of potential productivity...

Data used in these studies were part of another project described by Parsons et al. (2021). These studies evaluated heifer post-weaning intake classification on performance measurements of two-, five- and eight-year-old lactating or non-lactating Angus females. We analyzed intake and production data of 57 pregnant, non-lactating (Study 1) and 54 la...

The objectives of this study were to evaluate the impacts of supplement form on supplement intake behavior, body weight (BW), and body condition score (BCS) change of yearling heifers grazing dryland pastures during the summer. In each of the two years, Angus crossbred heifers (14 months of age; Year 1, n = 57, BW = 449 ± 3.60 kg; Year 2, n = 58, B...

Simple Summary The total cost of production for cow-calf producers is increasing; with feed costs accounting for about 65% of total input costs per year. Development and selection of replacement beef heifers is a key factor in improving overall herd productivity and profitability. Selecting for replacement females with greater voluntary feed intake...

Simple Summary Replacement beef heifers represent the future of a herd for many cow-calf producers. Producers must invest significant resources into the development of these females as well as consider their maintenance and production costs as mature cows. As a result, selection focuses on replacement heifers that are more efficient in limited nutr...

This study evaluated the influence of cow age and temperature adjusted for windchill (Twindchill) on supplement intake behavior of cattle winter grazing rangelands. A mixed-age herd of Angus-based cows (291 and 316 in year 1 and 2, respectively) were classified by age (1-, 2-, 3-, 4-, 5-7-, and ≥8-year-old) and grazed rangeland pasture (329-ha) for...

The introduction of cover crops as fallow replacement in the traditional cereal-based cropping system of the Northern Great Plains has the potential to decrease soil erosion, increase water infiltration, reduce weed pressure and improve soil health. However, there are concerns this might come at the cost of reduced production in the subsequent whea...

The introduction of cover crops as fallow replacement in the traditional cereal-based cropping system of the Northern Great Plains has the potential to decrease soil erosion, increase water infiltration, reduce weed pressure, and improve soil health. However, In the Northern Great Plains, there has been hesitation for the adoption of cover crops in...

The objectives of this study were to evaluate the effect of differences in protein type and delivery method on rumen dynamics and nutrient digestion. Cows were allotted to rumen degradable protein (RDP) or rumen undegradable protein (RUP) and self-fed (SF) salt-limited pressed blocks or hand-fed (HF) loose supplement, resulting in four dietary trea...

Designing research for beef cattle production in rangeland environments is an ongoing challenge for researchers worldwide. Specifically, creating study designs that mirror actual production environments yet have enough observations for statistical inference is a challenge that often hinders researchers in efforts to publish their observations. Nume...

Crop-livestock integration has demonstrated that cover crops can be terminated using livestock grazing with minimal negative impacts on soil health, however, provides little information on system-level approaches that mutually benefit soil health and both crop and livestock production. Therefore, the objective of this research was to examine the ef...

Simple Summary Cattle in feedlots are typically fed diets with a high proportion of cereal grains. While feeding high-energy grain-based diets is advantageous for growth and performance, it can also contribute to an increased likelihood of metabolic issues. Different feedstuffs have unique digestive utilization, which may lead to different cattle p...

Two studies were conducted to evaluate the efficacy of sustained release mineral boluses as an alternative nutrient delivery method for beef cattle. For both studies 16 ruminally-cannulated cows were used in a completely randomized design. In study 1, we evaluated degradation rates of two bolus prototypes and cow age (2-yr-old versus 3-yr-old cows)...

Simple Summary Supplemental nutrition for cattle is the greatest operating cost for cow-calf producers, accounting for 65% of the annual expenses. In addition, residual feed intake (RFI) is being used as a selection tool for purchasing and retaining heifers, as well as selecting bulls with the goal of improving feed efficiency and/or reducing suppl...

Simple Summary Feed efficiency is becoming an important selection tool in the beef cattle industry. Traditionally, feed efficiency of beef cattle has been expressed as the ratio of feed intake to body weight gained; however, selection for high growth rates inevitably increases the maintenance requirements, feed requirements, and intake of cattle, w...

Simple Summary Cattle wintered at northern latitudes are often exposed to periods of severe cold. Cattle likely alter feed intake and behavior to combat environmental challenges. This study evaluated the influence of diet and environmental changes on intake behavior and activity (lying time) of feedlot steers. Short-term temperature changes impacte...

This study evaluated heifer post-weaning residual feed intake (RFI) classification on reproductive and performance measurements of first, second and third parity Angus beef females. We analyzed the annual, as well as, cumulative production of 347 Angus females from birth through weaning of their 3 rd calf. Heifer post-weaning RFI was calculated as...

Simple Summary A variety of feedstuffs can be used in beef cattle finishing rations. While corn has traditionally been the most popular feed ingredient in the United States, barley, which is better adapted to the growing and climatic conditions of northern latitudes, can also be utilized. This study evaluated the effects of corn and barley finishin...

This study evaluated the relationships between supplement intake behavior, beef cattle performance, and grazing behavior on dormant northern mixed-grass rangelands. In each of two years, a commercial herd of bred cows grazed a rangeland pasture from November to January. All cattle were managed as one contemporary group. Calf birth date, birth weigh...

This study evaluated the influence of cow age and temperature adjusted for windchill (Twindchill) on supplement intake behavior of cattle winter grazing northern mixed-grass prairie rangelands. A commercial herd of 291 (yr-1) and 316 (yr-2) bred cows were winter grazed on a 329-ha rangeland pasture for 2 years. Cows were assigned to one of six age...

Feeding cattle is one of the largest expenses in beef production systems. Genetic testing has been proposed as a tool to help select livestock that are the most efficient, with greater performance and/or carcass yield or quality. Improved beef cattle performance, increased feed efficiency, and increased carcass value are ongoing goals for beef catt...

Our study was conducted to evaluate the influence of cow age and supplement intake level during gestation on the quality of colostrum at calving, serum IgG levels of the cow at parturition, and serum IgG levels of the calf 3 days post-partum using two on-farm refractometer methods. Forty-five non-lactating multiparous Angus cows were selected from...

The objectives of this research were to determine how daily and hourly distance traveled, grazing time, and resting time of beef cows are influenced relative to the timing of supplementation. Over two winters, a herd of commercial Angus cows grazed in a 645-ha Montana foothill rangeland pasture for 56 days between December and February each year. A...

The objectives of this study were to evaluate Rumax BoviBox versus Rumax BoviBox HM protein supplements on supplement intake behavior, body weight (BW), and body condition score (BCS) change of yearling heifers grazing dryland pastures during late summer. Fifty-nine yearling commercial Angus heifers (428 kg) were stratified by BW and randomly assig...

This study evaluated the effects of barley and corn finishing rations on feedlot performance and feed intake behavior of steer calves. For 2 consecutive years, Angus-based steer calves were fed and finished at the Northern Agricultural Research Center in Havre, MT. Steers averaged 427 kg (n = 48) in year 1 and 407 kg (n = 47) in year 2. Feedlot rat...

behavior of beef cattle winter grazing rangelands in North Central Montana. A herd of non-lactating commercial Angus cows, n = 205 (yr-1) and n = 203 (yr-2), ranging in age from 1 to 9 yr old, grazed rangeland pastures (586 ha) from mid-October to early January of 2018 and 2019. Cows were grouped into 6 age classes to evaluate the effects of RFI an...

Dormant season livestock grazing reduces reliance on harvested feeds, but typically requires protein supplementation to maintain animal performance. Individual variation in supplement intake can impact animal performance; however, it is unknown if this variation leads to individual or herd-level effects on grazing behavior, resource utilization, an...

This study evaluated the influence of cattle stocking density on the use of botanical communities on a native bunchgrass prairie. In each of two years, 192 cow-calf pairs and 48 yearling heifers were randomly selected for the following grazing treatments: 1) control, no livestock grazing; 2) low stocking, 0.36 animal units (AU) • ha-1 ; 3) moderate...

This study evaluated cow age and supplement intake level during gestation on the quality of colostrum at calving, cow serum immunoglobulin G (IgG) levels at parturition, and serum IgG levels of the calf 3-days post-partum using two refractometer methods. Forty-five multiparous Angus cows were selected from a contemporary group of 300 cows that were...

This study evaluated the influence of cow age and temperature adjusted for wind chill (Twindchill) on supplement intake behavior of beef cattle winter grazing northern mixed grass prairie rangelands. A commercial herd of 272 (yr 1) and 302 (yr 2) bred cows (Angus, Simmental x Angus) ranging in age from 1- to 12-yr-old grazed a 329-ha rangeland past...

Grazing dormant forage under low-input heifer development strategies typically exposes cattle to low-quality forage. Protein supplementation while grazing dormant range can enhance heifer growth and reproductive performance. We examined resource utilization of heifers and the effects of dormant season grazing on residual vegetation characteristics...

Dormant season grazing reduces reliance on harvested feeds, but typically requires protein supplementation to be successful during periods of low forage quality. Providing supplements to grazing beef cattle during times of low forage quality may improve animal performance and vegetation utilization across the landscape. However, information relatin...

Clinical and subclinical trace mineral deficiencies can limit productivity in western sheep production systems. The objective of this research was to determine the proportion of ranches that supplemented with trace minerals and to quantify serum trace mineral concentrations in ram lambs after weaning across Montana with particular emphasis on Se an...

We evaluated the influence of vegetation types within mountain Montane habitats of the inland Pacific Northwest. Specifically, we sampled vegetation by most common plant species for four grassland types (riparian grass, riparian sedge/rush, bunchgrass, and scabland) and six forest types that focused on early and late sucessional ponderosa pine, Dou...

We evaluated the influence of habitat type and overstory characteristics on understory vegetation quality within Montane habitats of the inland Pacific Northwest. Specifically, we sampled vegetation by most common plant species for three forest types (ponderosa pine, Douglas fir, and grand fir stands), and, within each forest type, two successional...

This study evaluated the influence of cattle stocking density on the use of different botanical communities on a native bunchgrass prairie. In each of two years, 192 cow-calf pairs (549.27 kg, BCS = 4.89) and 48 yearling heifers (383.34 kg, BCS = 5.02) were stratified by age and body condition, and randomly selected for a randomized block design (f...

Background/Question/Methods Developing sustainable grazing practices for public and private lands depends on a comprehensive understanding of how livestock grazing intensity affects biodiversity and ecological function of many taxa, including invertebrates. Although invertebrates are the most diverse animal group and play significant roles in man...

Background/Question/Methods Livestock grazing is a widespread land use in western North America, which may impact native bees by affecting floral and nesting resources. Native bees are considered to be one of the most important pollinators. However, few studies have investigated how livestock grazing impacts native bees in western North America....

This study evaluated the influence of cattle stocking density on botanical composition of diet, diet preference, and cattle performance on a native bunchgrass prairie. In each of two years, 192 cow-calf pairs (549.27 kg, BCS = 4.89) and 48 yearling heifers (383.34 kg, BCS = 5.02) were stratified by age and body condition, and randomly allotted to a...

An experiment was conducted to evaluate the influence of lactation on diet quality, botanical composition, relative preference, and foraging efficiency of beef cattle grazing at different stocking densities in a bunch grass prairie. A randomized block design was used, with four (160 ha) blocks divided into four (40 ha) pastures. Four grazing treatm...

Graduation date: 2010 This study evaluated the influence of cattle stocking density on botanical composition of diet, diet preference, and cattle performance on the Zumwalt Prairie in Northeastern Oregon. In each of two years, 192 cow-calf pairs (549.27 kg, BCS = 4.89) and 48 yearling heifers (383.34 kg, BCS = 5.02) were stratified by age and body...