Scholarship & Research
Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/1
Browse
12 results
Search Results
Item Supplement intake behavior of heifers grazing late summer dryland pasture(Montana State University - Bozeman, College of Agriculture, 2022) McClain, Tyrell Phillip; Chairperson, Graduate Committee: Timothy DelCurto; This is a manuscript style paper that includes co-authored chapters.Two studies were conducted to evaluate supplement intake and intake behavior of Rumax BoviBox protein supplements. For both studies, individual supplement intake, time spent at the feeder, and frequency of visits was measured using a SmartFeed Pro self-feeder system. In study 1, we examined the effects of free choice loose mineral salt on protein block supplement intake behavior of first-calf heifers. Heifers were stratified by weight, and, within stratum, randomly allotted to one of two supplementation treatments: 1) free-choice access to protein block supplement (30% CP) with access to loose mineral and salt; and 2) free-choice access to protein block supplement (30% CP) with no access to loose mineral and salt for a 42-day performance study. Individual animal was considered the experimental unit. No differences were observed for total supplement intake or supplement intake expressed as grams per kg body weight (BW; P > 0.05). In summary, availability of loose mineral salt did not have an impact on protein block supplement intake. In study 2, we evaluated Rumax BoviBox versus Rumax BoviBox HM protein supplements on supplement intake, intake behavior, body weight (BW), and body condition score (BCS) change of yearling heifers grazing dryland pastures during late summer. Heifers (428 kg) were stratified by BW and within stratum randomly assigned to one of two supplementation treatments: 1) free-choice access to Rumax BoviBox protein block supplement (30% CP, 23% salt; n = 29); and 2) free-choice access to Rumax BoviBox HM high magnesium protein block supplement (28.7% CP, 23% salt; n = 30). Supplement intake rate (g x min -1) displayed a treatment effect (P < 0.01) indicating that heifers in the Rumax BoviBox treatment had lower intake rate compared to Rumax BoviBox HM supplemented heifers. In conclusion, there were only minor differences in intake behavior and animal performance observed in both trials.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 The impacts of supplementing rumen degradable or undegradable protein to heifers and cows on supplement intake behavior, performance, reproduction, and nutrient digestion(Montana State University - Bozeman, College of Agriculture, 2021) Manoukian, Marley Kathryn; Chairperson, Graduate Committee: Megan Van Emon; J.A. Kluth, S.A. Wyffels, T. DelCurto, C. Sanford, T.W. Geary, A. Scheaffer and M.L. Van Emon were co-authors of the article, 'Impacts of rumen degradable or rumen undegradable protein supplement on supplement intake behavior, performance, and reproductive parameters with yearling heifers and cows grazing dryland pastures' submitted to the journal 'Journal of animal science' which is contained within this thesis.; J.A. Kluth, S.A. Wyffels, T. DelCurto, A. Scheaffer and M.L. Van Emon were co-authors of the article, 'Impacts of rumen degradable or rumen undegradable protein supplement with or without salt on nutrient digestion and VFA concentrations' submitted to the journal 'Journal of animal science' which is contained within this thesis.Low-quality forages, often low in protein, are a common feed resource for beef cattle in Montana and the western United States. A supplement intake study, as well as a digestion study were performed to observe the effects of rumen degradable protein (RDP) and rumen undegradable protein (RUP) on supplement intake behavior, performance, reproductive parameters, nutrient digestion, and rumen kinetics. Yearling heifers were used in a completely randomized design and two- and three-year old cows were used in a randomized complete block design for an 84-d supplement intake study. Treatments were: 1) pressed supplement block containing RUP (RUP), and 2) pressed supplement block containing RDP (RDP). Heifer and cow supplement intake displayed (P < 0.01) a treatment x period interaction. Cow intake rate and coefficient of variation displayed (P < 0.01) a treatment x period interaction. The RUP heifers consumed supplement faster (P < 0.01) than RDP heifers. The RDP cows had greater (P < 0.01) average daily gains than RUP cows. The RUP cows had greater final pregnancy rates than RDP cows (P = 0.04). In conclusion, protein type impacted intake behavior in cows and heifers, and RDP cows had ADG, but protein type did not negatively impact final performance or pregnancy success. Eight two-year old and eight three-year old rumen fistulated cows were used in a 2 x 2 factorial design for a 22-d digestion study. Animals were fed an ad libitum low-quality diet. Supplements included either RDP or RUP and were self-fed (SF) salt-limited pressed blocks or hand-fed (HF) the same loose ingredients without salt resulting in 4 dietary treatments: 1) RUP-SF, 2) RUP-HF, 3) RDP-SF, and 4) RDP-HF. There was a delivery x protein type interaction (P ? 0.04) for both NDF digestibility and water intake. There was an effect (P = 0.02) of protein type on fluid flow rate. Ruminal ammonia displayed (P < 0.01) a delivery x protein type x hour interaction. Valerate ruminal concentrations were greater in RDP supplemented animals compared to RUP supplemented animals (P = 0.04). In conclusion, self-fed supplements containing RDP may enhance the use of low-quality forages.Item The effects of L-citrulline supplementation on physical performance(Montana State University - Bozeman, College of Education, Health & Human Development, 2019) Stordahl, Peter Lawrence; Chairperson, Graduate Committee: John G. Seifert; John G. Seifert, Mary Miles and Dawn Tarabochia were co-authors of the article, 'The effects of l-citrulline supplementation on physical performance' submitted to the journal 'Journal of strength and conditioning research' which is contained within this thesis.INTRODUCTION. Recent studies have investigated l-citrulline (CIT) as a possible ergogenic aid. A small number of studies have explored the performance question, with varying methodologies and results. The purpose of this study was to examine CIT influence on cycling time to exhaustion, cardiovascular function, and muscle activity. METHODS. Thirteen healthy subjects volunteered for this study. The first visit was to obtain a maximal power output, where 80% and 50% of maximal power were calculated for the following two visits. Subjects were then randomly assigned into either treatment or placebo groups for the second visit and the opposite treatment for the third visit. Subjects were instructed to drink their treatment 1 hour prior to coming into the laboratory. The treatment drink contained 10g of CIT while the placebo (PBO) was formulated to look and taste like the CIT drink. The second and third visits to the laboratory consisted of EMG from the rectus femoris, vastus medialis, and medial gastrocnemius of the right leg, along with HR monitor and BP. Subjects completed a 40-minute interval ride, consisting of 8 5-minute intervals of 3 minutes at 50% maximal power and 2-minutes at 80% maximal power. After the interval ride, subjects received a second dose of either treatment, 5g of CIT or PBO and were allowed 1-hour rest before the ramped time to exhaustion (TTE) test. RESULTS. There was no significant difference in TTE by treatment (CIT, 20.79 + or - 4.48 and PBO, 20.86 + or - 3.99). There was no significant main effect of treatment on percent of maximum heart rate (p = 0.084), mean arterial pressure (p = 0.714), or muscle activity of the rectus femoris (p =0.300), vastus medialis (p = 0.641), or medial gastrocnemius (p = 0.133) during the TTE test. CONCLUSIONS. There were no differences in cycling TTE between treatments. Further research should investigate the metabolism of CIT under different physiological conditions.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 Medicinal use of herbs : an introductory guide for health care practitioners(Montana State University - Bozeman, College of Nursing, 1999) Hughes, Laine Dean; Chairperson, Graduate Committee: Catherine CaniparoliItem Lymphocyte responses to the polyphenol, oenothein B, and the influence of age on these responses(Montana State University - Bozeman, College of Agriculture, 2014) Ramstead, Andrew Gordon; Chairperson, Graduate Committee: Mark Jutila; Igor A. Schepetkin, Mark T. Quinn, and Mark A. Jutila were co-authors of the article, 'Oenothein B, a cyclic dimeric ellagitannin isolated from Epilobium angustifolium, enhances IFNgamma production by lymphocytes' in the journal 'PLoS ONE' which is contained within this thesis.; Igor A. Schepetkin, Kimberley Todd, James Loeffelholz, Mark T. Quinn and Mark A. Jutila were co-authors of the article, 'Aging influences the response of T cells to stimulation by the ellagitannin, oenothein B' which is contained within this thesis.; Mark A. Jutila was a co-author of the article, 'Complex role of gamma delta T cell-derived cytokines and growth factors in cancer' in the journal 'Journal of interferon and cytokine research' which is contained within this thesis.Innate lymphocytes, such as NK cells, play an important role in a number of human diseases. Therefore, they have become popular target cells for new therapeutics. Studies to identify materials that stimulate these cells have identified a number of molecules from nutritional supplements which can activate and/or inhibit their activity. While the use of nutritional supplements has potential to enhance the activity of innate lymphocytes to help treat and prevent disease, there is still much which is currently unknown about the activity of these compounds. Previous work has identified oenothein B, an ellagitannin isolated from Epilobium angustifolium, to be a stimulant for myeloid cells. In this study, we further examined the immunomodulatory effects of oenothein B and identified that it also stimulates lymphocytes. We found that oenothein B induces the production of IFN gamma by NK cells and both alpha beta and gamma delta T cells. In addition to inducing the production of IFN gamma by NK cells alone, oenothein B also enhances IFN gamma production in response to secondary stimuli, such as IL-18 or a tumor cell line, in a synergistic manner. We also identified a novel effect of aging on the lymphocyte response to oenothein B. The induction of IFN gamma, as well as GM-CSF, production by T cells in response to oenothein B increases in adults compared to young individuals. The predominant producers of IFN gamma in response to oenothein B also shift from the NK cell population in young individuals to the T cell population in adults. The increase in cytokine production in adult T cells correlates with increasing numbers of CD45RO+ T cells, which produce more cytokines in response to oenothein B than CD45RO- T cells. This influence of aging on the immune response to oenothein B may be applicable to numerous nutritional supplements which stimulate innate immunity and could be an important variable in the effectiveness of these compounds in improving human health. In this dissertation, we identify age as an important factor which should be taken into account when examining the effect of polyphenols on innate immunity and could have important implications for optimizing the benefit of immunomodulatory polyphenols.Item Influence of form of supplementary copper and zinc on mineral status and performance of beef heifers during and after mineral antagonism(Montana State University - Bozeman, College of Agriculture, 1999) Bailey, John Denver