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Item Identification and cultivation of methyllycaconitine degraders from wild ruminants to protect against larkspur poisoning in range cattle(Montana State University - Bozeman, College of Agriculture, 2021) Grace, Savannah Gray; Chairperson, Graduate Committee: Carl Yeoman and Craig Carr (co-chair); Joanna-Lynn C. Borgogna, Craig A. Carr, Lance B. McNew, Brian Bothner and Carl J. Yeoman were co-authors of the article, 'Degradation of toxic alklaoids in Delphinium occidentale species occurs within the gastrointestinal tract of Montana's wild ruminants' submitted to the journal 'American Society of Animal Science' which is contained within this thesis.; Joanna-Lynn C. Borgogna, Mostafa Elshahed, Lance B. McNew, Brian Bothner, Craig A. Carr and Carl J. Yeoman were co-authors of the article, 'Degradation of the toxic alkaloid, methyllycaconitine by wild ruminant species is predominantly mediated by rumen fungi' submitted to the journal 'American Society of Animal Science' which is contained within this thesis.Tall larkspur (Delphinium spp.) in the western United States present a serious toxicity danger to rangeland cattle. Consumption of Methyllycaconitine (MLA), the toxic alkaloid in larkspur plants, can cause annual losses of 5-15% of range cattle in grazing pastures with sufficient larkspur. With the wide distribution and abundance of larkspur, wild ruminants in Montana likely encounter tall larkspur while foraging; however, no evidence suggests they are negatively affected by MLA's toxic effects. Therefore, we evaluated: i) whether alkaloids in Delphinium spp., and MLA specifically degraded within ruminal specimens collected from Montana's wild ruminant species over 48 h using in vitro incubations; ii) whether observed degradative activities were abiotic, or mediated by either the fungal or non-fungal (mostly bacterial) residents of the ruminal microbiota in wild ruminant specimens; and iii) if representative microbial isolates individually possessed the ability to degrade MLA within in vitro incubations. Rumen samples were collected from wild ruminant species during the 2019 and 2020 hunting seasons using legal methods by volunteer hunters. In all assays, total alkaloid was measured spectrophotometrically, and MLA by High-Performance Liquid Chromatography Mass Spectrometry (HPLC) from initial and final incubations. Our results demonstrated that, with the exception of white-tailed deer, all wild ruminant species exhibited variable degradative abilities in both total alkaloid (P< 0.001) and MLA (P< 0.001) assays and that such degradation was predominantly mediated by ruminal fungi. Additionally, screening of 15 fungal isolates, representing 10 known genera and 2 isolates of unknown taxonomic identity each obtained from herbivorous hosts, determined all were capable of degrading MLA to some extent. Fungal isolates obtained from wild ruminants exhibited greater degradative activity, with Aestipasuomyces R5 isolated from wild sheep degrading 71% of MLA (P<0.001). Overall, our results indicate that degradation of both total alkaloid and MLA-specifically occurs within the gastrointestinal tract of Montana's wild ruminants and that it is largely influenced by fungal activity. Additionally, fungal strains isolated from wild ruminants are capable of degrading MLA and have the potential to be further used as a direct fed microbial to rangeland cattle as an optimal way to mitigate larkspur toxicosis.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 Influence of starch digestion rate on feedlot performance and site of starch digestion in beef steers fed high concentrate diets of corn or barley(Montana State University - Bozeman, College of Agriculture, 2000) Milner, Timothy JamesItem An in vitro digestion of selected starches(Montana State University - Bozeman, College of Agriculture, 1966) Davis, Ronald LyleItem Monensin effects on digestion of corn or barley high concentrate diets(Montana State University - Bozeman, College of Agriculture, 1995) Surber, Lisa Marie McKinleyItem Effects of alfalfa variety and nitrogen status on pasture bloat in ruminants(Montana State University - Bozeman, College of Agriculture, 2001) MacDonald, Charles DonaldItem Effect of supplemental enzymes on the utilization of energy and phytate phosphorus in wheat by broiler chicks(Montana State University - Bozeman, College of Agriculture, 1994) Ramachandran, RagothamanItem Influence of amino acids and branch chain organic acids on ruminant fiber fermentation(Montana State University - Bozeman, College of Agriculture, 1986) Clark, Connie KayItem Characterizating low-quality forage utilization : feed value of a solid stem straw & effects of an abrupt switch from corn-containing to forage-only diets(Montana State University - Bozeman, College of Agriculture, 2010) Voigt, Lindsey Ann; Chairperson, Graduate Committee: Rachel L. Endecott.Two separate studies were conducted to characterize low-quality forage utilization. The objective of the first trial was to evaluate the suitability of common small grain straws as efficient roughage sources in livestock diets, specifically comparing a solid-stem winter wheat variety (Bynum) to hollow-stemmed varieties of winter wheat (Norris and Willow Creek) and a barley variety (Geraldine). This was a two-part trial involving an in vitro dry matter disappearance (IVDMD) experiment and an individual lamb feeding trial. The IVDMD kinetics trial was conducted using a Daisy Wheel TM incubator, with replicated straw samples removed after 0, 6, 12, 24 48 and 96 hours. In a feeding trial, 16 crossbred wether lambs were randomly assigned to one of four diets containing chopped straw. The solid-stem characteristic of Bynum did not affect the feeding value of the straw compared with barley straw and other winter wheat varieties. The objective of the second trial was to characterize how quickly the rumen adapts to a forage-only diet after an abrupt switch from a concentrate-containing diet. Twelve ruminally-cannulated Hereford-cross heifers were randomly assigned to 3 individually-fed, pre-experiment diets (4 heifers/diet). Diets were: 1) all forage, 2) 35% concentrate, and 3) 70% concentrate. Heifers were fed the diets for ~100 d before the start of the trial. Pre-experiment diets consisted of grass-alfalfa hay, corn, and soybean meal-urea supplement added to make the diets isonitrogenous at 13% CP. On d 0, diets were abruptly switched to grass hay. In situ digestibility runs were conducted starting on d -8 and ran continuously (d 1, 4, 7, 10, 13, 16, 19, 22) after the diet switch. Duplicate sample bags filled with 5 g of grass hay and a blank bag were incubated for 0, 24, 48, and 96 h. Organic matter and NDF digestibilities in subsequent in situ runs were similar (P > 0.10), regardless of pre-experiment diet. Rate of digestion was not influenced by pre-experiment diet (P = 0.74; avg 4.3 ± 0.002%/h). Forage digestibility was depressed when heifers were fed a high-concentrate diet; however, this effect disappeared within 48 h of feeding 100% forage.