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Item Impact of increasing NaCl levels in livestock drinking water on the intake and utilization of low-quality forages by beef cattle(Montana State University - Bozeman, College of Agriculture, 2022) Nack, Makae Frances; Chairperson, Graduate Committee: Timothy DelCurto; This is a manuscript style paper that includes co-authored chapters.Water is one of the most important nutrients for livestock production (Petersen et al., 2015) but its quality is often overlooked in western range settings. The western United States and more specifically, Montana, are prone to variable precipitation and droughts, reducing the quantity and quality of livestock drinking water as well as limited forage quality/quantity. Dormant season grazing of rangeland forages often involves utilizing self-fed, salt limited supplements to meet cattle nutrition requirements and better utilize forage. Self-fed supplements commonly add salt as an intake limiter because it is effective, cheap and necessary in beef cattle diets (Cardon et al., 1951). The objective of this study was to evaluate the impacts of increasing NaCl levels in water on low quality forage intake, digestibility, and rumen fermentation of cattle consuming low quality forage. Eight, ruminally-cannulated, Angus crossbred cows were individually stalled and used in two 4 x 4 Latin squares design. One square was hand fed a non-salt supplement; the second square was fed a salt limiting supplement. Two cows (one from each square) were assigned to one of four water treatments per period: 1) control, no added NaCl; 2) 1000 mg NaCl/L; 3) 2000 mg NaCl/L; and 4) 3000 mg NaCl/L. A 14-day adaption period allowed cattle to acclimate to the water; followed by a 6-day total collection period. Rumen fluid samples were collected on day 22 at hours 0, 4, 8, 12, 18 and 24; and on day 23 a total rumen evacuation was conducted to determine total rumen volume and collect rumen content samples. Increasing levels of NaCl did not influence intake in either study (P > or = 0.36). Rumen pH was influenced by water NaCl in study 1 (P = 0.01), however, post hoc analysis revealed no differences. Volatile fatty acids in both studies were not affected by NaCl in either study (P > or = 0.39). Our results suggest the NaCl levels in our study may have little influence on intake, rumen fermentation and liquid kinetics suggesting NaCl levels up to 3,000 are safe for cattle.Item Corn versus barley in beef cattle finishing diets: effect on steer performance, feeding behavior, and ruminal environment(Montana State University - Bozeman, College of Agriculture, 2021) DelCurto-Wyffels, Hannah Margaret; Chairperson, Graduate Committee: Megan Van Emon; Julia M. Dafoe, Cory T. Parsons, Darrin L. Boss, Timothy DelCurto, Samuel A. Wyffels, Megan L. Van Emon and Janice G. P. Bowman were co-authors of the article, 'Corn versus barley in finishing diets: effect on steer performance and feeding behavior' in the journal 'Animals' which is contained within this dissertation.; Julia M. Dafoe, Cory T. Parsons, Darrin L. Boss, Timothy DelCurto, Samuel A. Wyffels, Megan L. Van Emon and Janice G. P. Bowman were co-authors of the article, 'The influence of environmental conditions on intake behavior and activity by feedlot steers fed corn or barley-based diets' in the journal 'Animals' which is contained within this dissertation.; Hannah M. DelCurto-Wyffels, Julia M. Dafoe, Cory T. Parsons, Darrin L. Boss, Timothy DelCurto, Samuel A. Wyffels, Megan L. Van Emon and Janice G. P. Bowman were co-authors of the article, 'Diurnal ruminal pH and temperature patterns of steers fed corn or barley-based finishing diets' in the journal 'Animals' which is contained within this dissertation.While corn is the most common feed ingredient in the United States, barley, which is more suitable for the growing and climatic conditions at northern latitudes, can be a common feed alternative to corn. The different digestive utilization of unique feedstuffs coupled with extreme environmental conditions can pose challenges to efficiently feeding cattle in different climates. Thus, to further our understanding of the use of barley in feedlot diets at northern latitudes this study evaluated the effects of barley and corn finishing rations on feedlot performance, feeding behavior, and ruminal environment. For two consecutive years, Angus-based yearling steer calves were fed in a feedlot trial (427.3 + or - 3.7 kg; n = 48 in year 1, and 406.8 + or - 3.4 kg; n = 47 in year 2). Steers were randomly assigned to one of two primary basal grain dietary treatments: 1) Number 2 feed corn or 2) Hockett barley. Steers were fed in a GrowSafe system to measure individual animal intake and behavior throughout the duration of the study. Twelve steers per treatment group for each year of the study were also fitted with a HOBO pendent G accelerometer to measure activity and a SmaXtec ruminal bolus for continuous rumen monitoring of temperature and pH. Limited differences were observed in regard to performance and eating behavior of steers fed corn or barley-based diets. The steer's diet interacted with short term environmental changes to influence animal feeding behavior, but diet had limited impact on cattle lying activity. Continuous ruminal monitoring revealed average daily ruminal pH and temperature were not impacted by diet; however, diet did affect daily variation in ruminal pH and temperature. Intake patterns were also different between corn and barley-fed steers in which corn-fed steers consumed more feed the first 6 hours directly after feeding while barley-fed steers consumed more feed later in the day. Presumably, these intake patterns could be influenced by differences in diurnal patterns of ruminal pH between corn and barley. Depending on cost and production year, both barley and corn can be high quality feedstuffs to use in beef cattle finishing rations.Item Evaluation of sustained release mineral boluses as a long-term nutrient delivery method for beef cattle(Montana State University - Bozeman, College of Agriculture, 2021) Carlisle, Tanner Jay; Chairperson, Graduate Committee: Timothy DelCurto; Samuel A. Wyffels, Steve D. Stafford, Anna R. Taylor, Megan L. Van Emon and Timothy DelCurto were co-authors of the article, 'Evaluation of sustained release mineral boluses as a long-term nutrient delivery method for beef cattle' in the journal 'Animal feed science and technology' which is contained within this thesis.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) over an 87-d study period. In study 2, we evaluated two bolus types (90-d degradation target versus 180-d degradation target), as well as two diet qualities contrasting low-quality high-fiber forage (> 65% NDF and < 8% CP) and high-quality low-fiber forage (< 55% NDF and > 15% CP). For both Studies intake and digestion periods were conducted to evaluate cow age (study 1) or diet quality (study 2) effects on intake and rumen/reticulum function. In study 1, models containing an asymptotic effect of day and an interaction between day and bolus type received virtually all support of candidate models for bolus degradation rate. Cow age did not affect bolus degradation rates (Beta = -0.81 + or - 1.13; P= 0.48) and degradation rates were greater for bolus prototype B compared to bolus A (Beta prototype B = -20.39 + or - 1.13; Beta prototype A = -9.64 + or - 0.81; P < 0.01). In study 2, models containing a linear effect of day and an interaction between day and diet received virtually all support of candidate models for the degradation rate of the 90-d and 180-d prototype. In addition, both bolus protoypes displayed a diet quality + or - time interaction (P < 0.01) for bolus degradation rate. Cattle treated with the 90-d bolus and fed a high-quality diet had greater degradation rates (Beta High-quality = -2.64 + or - 0.08; Beta Low-quality = -1.97 + or - 0.10; P < 0.01) than the cows that were fed a low-quality diet. In contrast, cattle treated with the 180-d bolus expressed greater degradation rates (Beta Low-quality = -0.09 + or - 0.007; Beta High-quality = -0.04 + or - 0.005; P < 0.01) with cows on the low-quality diet versus the high-quality diet. Across both studies, two of four bolus prototypes met target release rates at 90 days. However, bolus degradation characteristics varied and were influenced by diet quality.Item Salt limited intake: impacts of salt level and form of supplement on intake, nutrient digestion, and variability of supplement intake in beef cattle(Montana State University - Bozeman, College of Agriculture, 2021) White, Hayley Christina; Co-chairs, Graduate Committee: Megan Van Emon and Timothy DelCurto (co-chair); M. L. Van Emon, H. M. DelCurto-Wyffels, S. A. Wyffels and T. DelCurto were co-authors of the article, 'Impacts of form of salt-limited supplement on supplement intake behavior and performance with yearling heifers grazing dryland pastures' submitted to the journal 'Journal of feed science & technology' which is contained within this thesis.; M. L. Van Emon, H. M. DelCurto-Wyffels, S. A. Wyffels and T. DelCurto were co-authors of the article, 'Impacts of increasing levels of salt on intake, digestion, and rumen fermentation with beef cattle consuming low-quality forages' submitted to the journal 'Journal of animal science' which is contained within this thesis.For centuries, salt has been used as a cost effective intake-limiter of supplements for ruminants. Beef cattle production in the western United States relies on self-fed, salt-limited supplement to offset seasonal nutrient deficiencies which, in turn, may improve performance and increase forage intake. However, research has found high variation in individual supplement intake among animals and across days. If cattle are over consuming high-salt diets, this may result in negative impacts on animal performance and additional cost for the producer. Two studies were conducted to evaluate the effects of form of supplement on supplement intake behavior, body weight, and body condition change and the impacts of supplemental salt levels on forage intake, water intake, dry matter digestibility, and rumen fermentation of yearling heifers consuming low quality forages. During a two-year summer grazing trial, individual supplement intake, time spent at the feeder, and frequency of visits was measured. It was found that supplementation and form of supplement did not influence heifer weight gain or intake CV (P = 0.26), but heifers in the pelleted treatment consumed more supplement (grams/kg BW), and at a faster rate compared to heifers fed the loose supplement form (P < 0.01). In study 2, six ruminally cannulated heifers were assigned to treatments to determine the effect of salt levels on digestibility and rumen parameters. Salt treatments consisted of: 1) control, no salt (CON), 2) 0.05% of BW salt (LOW), and 3) 0.1% of BW salt (HIGH). Forage and water intake, digestibility, and rumen parameters were measured. Supplemental salt tended to decrease forage intake (grams/kg BW; P = 0.06) and tended to increase DM fill (P = 0.07). Both water intake and liquid fill increased with increasing level of salt (P < 0.01). Ruminal pH and ammonia levels decreased with increasing salt (P < 0.01) while acetate concentration increased (P < 0.01). Digestibility was not influenced by salt levels (P > 0.05). Our results suggest that pelleting salt-limited supplements has a masking effect on the intake regulation of salt. Additionally, increasing levels of salt modifies rumen fermentation and digestion suggesting lower efficiency of intake and use with high-salt diets.Item A comparative approach to refine molecular mechanisms impacting meat quality and carcass characteristics(Montana State University - Bozeman, College of Agriculture, 2021) Schumacher, Madison Lee; Chairperson, Graduate Committee: Jennifer Thomson and Jane A. Boles (co-chair)Fat deposition is important to both producers and consumers. Producers decide when to harvest animals based on a fat endpoint while consumers equate marbling to tenderness. USDA quality grade is determined by physiological age and marbling. While quality grades help provide insight about product palatability, there is too often variation within the same quality grade. The control of fat deposition is important to determination of carcass endpoint and efficiency of production. The purpose of this study was to increase our understanding of the regulation of fat deposition and muscle growth in relation to USDA quality grade, and to utilize a species comparison to highlight genes and pathways regulating these tissues in multiple meat producing species. Fifteen wethers and fifteen steers from the Red Bluff Research Center were fed to end points that represented Standard, Select, and Choice quality grades endpoints for steers while sheep were fed to fat thicknesses typical to industry endpoints. Subcutaneous adipose tissue and muscle samples were collected for gene expression analysis. Loin were removed from each animal for shear force analysis. Shear force analysis showed a significant reduction in shear force values as quality increased in beef (p < 0.05). RNA extracted from the adipose and muscle tissue was sent to Novogene for RNAseq analysis. The largest difference observed in this study was found within the ovine muscle tissue. Comparing Class 3 to Class 1 muscle tissue resulted in 723 genes down regulated and 1,853 genes up regulated. Class 3 to Class 2 showed 1,127 genes down regulated and 2,272 genes up regulated. When comparing bovine samples, there was an equal distribution of up and down regulated genes. Differentially expressed genes were associated with fat metabolism, cellular signaling, and inflammation in beef. Poor annotation limited the functional analysis of differentially expressed genes in sheep. This study emphasized the need for additional studies evaluating the relationship between gene expression and fat deposition.Item The use of nuclear magnetic resonance spectroscopy and measures of cattle temperament to predict feedlot perfromance of commercial beef cattle(Montana State University - Bozeman, College of Agriculture, 2021) Bouffiou, Jesse James; Chairperson, Graduate Committee: Jennifer ThomsonThe objective of this study was to identify small molecule metabolites in a serum sample taken at entry into the feedlot that can predict performance, and animal health. One-hundred and thirty-one Angus x Simmental steers from a single ranch were sampled at a commercial feedlot. Blood samples for metabolite analysis, chute score, exit velocity, and blood lactate concentration for temperament classification were collected in addition to feedlot performance data and carcass quality measurements. The GLM and LSM procedures of SAS were used to evaluate differences between temperament classifications. Steers were divided into three exit velocity classifications with fast animals having exit velocity greater than one standard deviation from the mean and slow animals having exit velocities lower than one standard deviation from the mean. Forty metabolites were quantified using 1H NMR Spectroscopy from serum. Metaboanalyst was used to analyze serum metabolites and phenotypic values using one way- ANOVA, PCA, PLS-DA, and a permutation test to cross validate. Data was normalized and scaled. No metabolites were predictive of any of the animal health metrics collected. Five metabolites were different in exit velocity class at p < 0.01 (methanol, isopropanol, lactate, isobutyrate, and pyruvate). Similarly, 7 metabolites were different between chute score classes at p < 0.01 (methanol, isobutyrate, creatinine, dimethyl sulfone, hippurate, isopropanol, and succinate). Furthermore, several metabolites in serum at entry in the feedlot were related to carcass quality metrics: back fat (urea and 2-hydroxyisobutyrate at p < 0.01), a trend for prediction of quality grade at p = 0.068, carcass value p = 0.085. The relationship between serum metabolites, feedlot performance traits, and eventual carcass quality warrants further research to elucidate the roles these metabolites play during the feedlot period and in predicting carcass merit.Item Dormant season grazing of northern mixed grass prairies: effect of supplementation and winter environmental conditions on beef cattle grazing behavior, residual vegetation conditions and variation in supplement intake(Montana State University - Bozeman, College of Agriculture, 2019) Wyffels, Samuel Aaron; Chairperson, Graduate Committee: Lance McNew; Janice G. P. Bowman (co-chair); Lance B. McNew, Janice G.P. Bowman, Mark K. Petersen, Darrin L. Boss and Bok F. Sowell were co-authors of the article, 'Dormant season grazing of northern mixed grass prairies: the effect of supplementation strategies on heifer resource utilization and vegetation use' submitted to the journal 'Rangeland ecology & management' which is contained within this thesis.; Lance B. McNew, Janice G.P. Bowman, Mark K. Petersen, Darrin L. Boss and Bok F. Sowel were co-authors of the article, 'Dormant season grazing on northern mixed grass prairie agroecosystems: does protein supplementation and individual animal variation impact beef cattle resource use, vegetation and residual cover for wildlife' submitted to the journal 'Rangeland ecology & management' which is contained within this thesis.; Lance B. McNew, Janice G.P. Bowman, Mark K. Petersen, Darrin L. Boss and Bok F. Sowell were co-authors of the article, 'The influence of age and environmental conditions on supplement intake by beef cattle winter grazing a northern mixed-grass rangeland in Montana' submitted to the journal 'Rangeland ecology & management' which is contained within this thesis.Dormant season grazing reduces reliance on harvested feeds, but typically requires protein supplementation to maintain animal performance and vegetation utilization across the landscape. However, information relating supplementation strategies and supplement intake behavior to individual grazing behavior and resource utilization on dormant forage is lacking. Thus, the intent of this research is to examine cattle resource utilization, supplement intake behavior, residual cover of vegetation and utilization on rangelands grazed during the dormant season. One hundred weaned heifer calves were randomly selected and placed into one of two supplementation treatments in each of 2 years (50 heifers/treatment/year); one receiving a free access 62% crude protein self-fed mineral/protein concentrate, and the other receiving a daily hand-fed 20% crude protein cake while grazing December through March. Additionally, a commercial herd of 300 bred cows ranging in age from 1- to 12-yr-old were provided a 30% crude protein self-fed supplement with 25% salt to limit intake in a SmartFeed Pro self-feeder system to measure individual animal supplement intake from November to January in each of 2 years. In both grazing trials, transects were randomly located within each pasture for measuring vegetation composition, production and quality, canopy cover and visual obstruction readings pre and post grazing. Grazing locations were monitored for individuals with Global Positioning System collars containing head position sensors that record daily space use and location of grazing activities. Data sets were used to quantify space use with generalized linear models to assess cattle resource utilization and supplementation behavior. Cattle provided the hand-fed cake selected grazing location near supplement delivery sites and spent less time grazing per day than self-fed supplemented cattle. Substantial amounts of herd-level variability in both studies suggests individual attributes are major drivers in cattle resource use. Supplement treatment and grazing intensity had little impact on residual vegetation conditions, however, the timing of grazing and year did affect the response of residual vegetation to grazing. Younger cattle consumed more supplement with less variability than older aged cattle. This research provides multidimensional insight to stakeholders concerning grazing behavior and the ecological impacts of late season use on Montana rangelands.Item Grazing, feed intake, and milk production differences in beef cows of varying efficiency classification and size(Montana State University - Bozeman, College of Agriculture, 2018) Williams, Alyson Rose; Chairperson, Graduate Committee: Timothy DelCurto; C.T. Parsons, J.G.P. Bowman, D.L. Boss and T. DelCurto were co-authors of the article, 'The influence of weaning weight ratio and cow size on feed intake behavior, milk yield, and milk constituents' submitted to the journal 'Journal of animal science' which is contained within this thesis.; S.A. Wyffels, C.T. Parsons, J.G.P. Bowman, D.L. Boss and T. DelCurto were co-authors of the article, 'The influence of weaning weight ratio and cow size on winter grazing and supplement intake behavior' submitted to the journal 'Journal of animal science' which is contained within this thesis.Metrics that identify beef cow efficiency in extensive rangeland environments has long been desired in both beef cattle research and production settings. However, research is limited relative to matching cattle metrics to western production systems. Previous research has suggested the ratio of calf weight weaned to cow weight, or weaning weight ratio, is an accurate estimate of cow efficiency. Furthermore, milk production has been attributed to influence calf pre-weaning average daily gain. Few studies have evaluated how cow type or cow characteristics influence grazing distribution and supplement consumption on native landscapes. The objectives of this study were to assess cow feed intake, grazing behavior, supplement intake, and milk production differences between cows of differing weaning weight ratio and body weight classification. Individual cow average daily feed consumption, average daily feeding bout duration, number of visits per day, and total time spent eating per day were collected during a feed intake period and a supplement intake period. Total distance traveled and time spent grazing were collected on individual cows with global positioning system collars. Milk samples were analyzed for fat, solids not fat, total solids, protein, and lactose content, and milk yield was calculated as the change in calf weight following a weigh-suckle-weigh procedure. High weaning weight ratio cows consumed more feed when expressed on a g/kg bodyweight basis (P < 0.001) but did not differ in supplement consumption (P > 0.10). High weaning weight ratio cows produced more milk both in total kg (P < 0.03) and when expressed as /kg bodyweight (P < 0.001). Heavy bodyweight cows tended to consume more feed than light bodyweight cows (P < 0.09) but neither bodyweight group ate more supplement than the other (P > 0.10). High weaning weight ratio cows spent an hour longer grazing per day than low weaning weight ratio cows (P < 0.02). Total distanced traveled per day did not differ (P > 0.10). Results suggest weaning weight ratio and cow size are not accurate metrics of cow efficiency and the use of weaning weight ratio may unintentionally favor cows with higher milk production and higher feed requirements.Item Evaluation of molecular mechanisms impacting beef quality and carcass characteristics(Montana State University - Bozeman, College of Agriculture, 2018) Blatter, Sarah Anne; Chairperson, Graduate Committee: Jennifer ThomsonTenderness has been stated as being one of the most important traits for consumers with regards to purchasing steak. However, too often there is much variation in tenderness in steaks that grade the same quality. Research in the past has done little to expand on the impact that genetics has on meat tenderness. This study was designed to attempt to illuminate this question by looking at the genes being differentially expressed between quality grades, and the pathways they impact. Angus crossbred steers (15) were fed to the end points of Standard, Select and Choice. Intermuscular and subcutaneous adipose tissue and muscle samples were snap frozen for gene expression analysis, as well as a loin kept from each animal for shear force analysis. Shear force analysis showed a significant difference between Choice and Standard graded animals (P<0.05), showing that the Choice animals in this study were more tender than Standard. RNA extracted from the adipose and muscle samples were sent to Novogene for RNAseq analysis. The results of the gene expression analysis showed 4 genes down regulated and 29 up regulated in the comparison of Select to Standard adipose tissue, with 8 genes down regulated and 15 up regulated with Select to Choice adipose tissue. The largest difference occurred between Standard to Choice adipose tissue with 49 genes down regulated and 113 up regulated. With regards to the muscle, 15 genes were down regulated while 20 were up regulated in the Standard to Choice. In the Select to Choice, 1 gene was down regulated with 4 up regulated. When comparing Select to Standard, there was not a large enough difference in genes being expressed. This study emphasized the need for additional functional studies on the impacts of gene expression on marbling deposition.Item Utilizing sugar beets in steer backgrounding, sheep nutrient metabolism, and silage(Montana State University - Bozeman, College of Agriculture, 2017) McGregor, Ian Robert; Chairperson, Graduate Committee: Megan Van Emon; C. M. Page, W. C. Stewart and M. L Van Emon were co-authors of the article, 'Effects of sugar beets on steer backgrounding performance, sheep nutrient metabolism, and ruminal characteristics' submitted to the journal 'Journal of animal science' which is contained within this thesis.; J. G. P. Bowman, C. M. Page, A. R. Hubbard, M. Manoukian, W. C. Stewart, and M. L Van Emon were co-authors of the article, 'The effect of ensiling sugar beets on preservation characteristics, nutrient profile, and in situ disappearance' submitted to the journal 'Journal of animal science' which is contained within this thesis.Non-harvested sugar beets are an abundant yet underutilized feedstuff for producers in Montana and Northern Plains region. A performance and metabolism study were performed to observe the effects of sugar beets on steer backgrounding performance, sheep nutrient metabolism, and rumen fermentation characteristics. Both experiments utilized four dietary treatments where sugar beets replaced 0% (0SB), 15% (15SB), 30% (30SB), and 45% (45SB) of barley on a dry matter (DM) basis. Forty eight Angus steers were used in a completely randomized design to conduct the 50 d performance study. Average daily gain (ADG), feed efficiency (G:F), and dry matter intake (DMI) weren't affected by treatment (P > or = 0.06). A 4 x 4 replicated Latin Square design was used to observe the effects of increasing dietary inclusion of sugar beets on nutrient metabolism and rumen fermentation characteristics of eight growing wethers. Crude fiber, DM, and nitrogen (N) digestibility weren't affected by treatment (P > or = 0.10), while N balance demonstrated a cubic effect (P = 0.04). Butyrate concentration demonstrated a treatment x time effect (P = 0.01), where butyrate concentrations increased with increasing sugar beets in the diet at 1300. The acetate to propionate ratio demonstrated a linear increase (P = 0.03) with increasing sugar beets in the diet. Overall, we concluded that sugar beets can be included up to 45% of the diet without inducing any deleterious effects on steer performance or sheep nutrient metabolism. However, the moisture content of sugar beets creates difficulty when storing this feedstuff, and we hypothesized that sugar beets may ensile well with other feedstuffs. Therefore, we carried out a study to test this hypothesis using a 3 x 2 factorial design. Treatments were hay (H), or sugar beets mixed with either hay (SBH) or soybean meal (SB) were ensiled at a rate of 50:50 (as fed) with or without a mold inhibitor. The pH of all treatments fell below 5.0 before d 90 (P < 0.01). All treatments increased in crude fiber and crude protein over time (P < or = 0.03). With these results, we conclude that sugar beets can be effectively ensiled with hay or soybean meal.