Dietary factors affecting tissue profiles of long chain polyunsaturated fatty acids in cattle

Doctor of PhilosophyDepartment of Animal Sciences and IndustryJ. S. DrouillardThe main goal of this dissertation was to evaluate different methods to protect polyunsaturated fatty acids (PUFA) against biohydrogenation by ruminal microorganisms. The first chapter is a review of literature pertaining to fat and fatty acid metabolism by ruminants and why these fats are relevant in human nutrition. The second chapter discusses effects of supplementing high concentrations of dietary copper to feedlot cattle to assess impact on PUFA profiles in tissues. Two levels of copper (10 or 100 mg/kg) were supplemented to diets with or without flaxseed during the finishing period for beef heifers. Added copper did not affect performance (P > 0.15). Final body weights were similar for cattle fed with or without flaxseed (P > 0.05), but cattle fed diets with flaxseed consumed less feed (P 0.1). The in situ study of L-flaxseed revealed a 2-fold increase in resistance of ALA to ruminal biohydrogenation, and the concentration in plasma after 14 d on feed was more than 4 times that observed in cattle fed ground flaxseed, suggesting the dolomitic lime hydrate was effective as a protective matrix. Chapter 4 evaluated performance, carcass traits, and meat quality of finishing beef heifers in response to feeding diets containing L-Flaxseed. Animals were blocked by weight, randomly assigned to individual pens, and pens to 6 dietary treatments: Control (high concentrate finishing diet), ground flaxseed fed at 3 or 6% of diet DM, L-Flaxseed fed at 2, 4, or 6%. Concentration of ALA in meat increased linearly in response to the level of flaxseed fed (P < 0.05); Moreover, transfer of dietary ALA to tissues increased by 47% when flaxseed was encapsulated within the dolomitic lime matrix. Cattle that were fed diets with 4 or 6% L-Flaxseed consumed less feed than other treatments (P < 0.05), which adversely affected feedlot performance and carcass traits

Performance and carcass characteristics of steers fed with two levels of metabolizable energy intake during summer and winter season

Climate change is producing an increase on extreme weather events around the world such as flooding, drought and extreme ambient temperatures impacting animal production and animal welfare. At present, there is a lack of studies addressing the effects of climatic conditions associated with energy intake in finishing cattle in South American feed yards. Therefore, two experiments were conducted to assess the effects of environmental variables and level of metabolizable energy intake above maintenance requirements (MEI) on performance and carcass quality of steers. In each experiment (winter and summer), steers were fed with 1.85 or 2.72 times of their requirements of metabolizable energy of maintenance. A total of 24 crossbred steers per experiment were used and located in four pens (26.25 m2/head) equipped with a Calan Broadbent Feeding System. Animals were fed with the same diet within each season, varying the amount offered to adjust the MEI treatments. Mud depth, mud scores, tympanic temperature (TT), environmental variables, average daily gain, respiration rates and carcass characteristics plus three thermal comfort indices were collected. Data analysis considered a factorial arrangement (Season and MEI). In addition, a repeated measures analysis was performed for TT and respiration rate. Mean values of ambient temperature, solar radiation and comfort thermal indices were greater in the summer experiment as expected (P\u3c 0.005). The mean values of TT were higher in steers fed with higher MEI and also in the summer season. The average daily gain was greater during summer v. winter (1.10 ± 0.11 v. 0.36 ± 0.06) kg/day, also when steers were fed 2.72 v. 1.85 MEI level (0.89 ± 0.12 v. 0.57 ± 0.10) kg/day. In summer, respiration rate increased in 41.2% in the afternoon. In winter, muddy conditions increased with time of feeding, whereas wind speed and rainfall had significant effects on TT and average daily gain. We conclude that MEI and environmental variables have direct effects on the physiology and performance of steers, including TT and average daily gain, particularly during the winter. In addition, carcass characteristics were affected by season but not by the level of MEI. Finally, due to the high variability of data as well as the small number of animals assessed in these experiments, more studies on carcass characteristics under similar conditions are required

Effects of flaxseed encapsulation on biohydrogenation of polyunsaturated fatty acids by ruminal microorganisms: feedlot performance, carcass quality, and tissue fatty acid composition

Citation: Alvarado-Gilis, C. A., Aperce, C. C., Miller, K. A., Van Bibber-Krueger, C. L., Klamfoth, D., & Drouillard, J. S. (2015). Effects of flaxseed encapsulation on biohydrogenation of polyunsaturated fatty acids by ruminal microorganisms: feedlot performance, carcass quality, and tissue fatty acid composition. Journal of Animal Science, 93(9), 4368-4376. doi:10.2527/jas2015-9171The objective of this study was to evaluate the efficacy of protecting PUFA within ground flaxseed against ruminal biohydrogenation by encapsulating them in a matrix consisting of a 1:1 blend of ground flaxseed and dolomitic lime hydrate (L-Flaxseed). Crossbreed heifers (n = 462, 346 +/- 19 kg) were blocked by weight and randomly assigned to pens. Pens were assigned to 1 of 6 dietary treatments in a randomized complete block design. Treatment 1 consisted of a combination of 54.6% steam-flaked corn (SFC), 30.0% wet corn gluten feed, 8.0% roughage, and supplement (0% flaxseed). In treatments 2 and 3, a proportion of SFC was replaced with 3 and 6% flaxseed, respectively; in treatments 4, 5, and 6, SFC was replaced with 2, 4, or 6% L-Flaxseed, respectively. Cattle were fed for 140 or 168 d and then harvested in a commercial abattoir where carcass data were collected. Approximately 24 h after harvest, carcasses were evaluated for 12th-rib fat thickness, KPH, LM area, marbling score, and USDA yield and quality grades. Samples of LM were also obtained for determination of long-chain fatty acid profiles. Cattle that were fed diets with 4 and 6% L-Flaxseed consumed less feed than other treatments (P 0.05). Supplementation with flaxseed increased (P 99%; increases for Flaxseed and L-Flaxseed of 0.095 and 0.140 mg of ALA/g of tissue for each percentage of flaxseed added). This study indicates that a matrix consisting of dolomitic lime hydrate is an effective barrier to ruminal biohydrogenation of PUFA; however, adverse effects on DMI limit the amounts that can be fed

Individualising Chronic Care Management by Analysing Patients’ Needs – A Mixed Method Approach

Background: Modern health systems are increasingly faced with the challenge to provide effective, affordable and accessible health care for people with chronic conditions. As evidence on the specific unmet needs and their impact on health outcomes is limited, practical research is needed to tailor chronic care to individual needs of patients with diabetes. Qualitative approaches to describe professional and informal caregiving will support understanding the complexity of chronic care. Results are intended to provide practical recommendations to be used for systematic implementation of sustainable chronic care models. Method: A mixed method study was conducted. A standardised survey (n = 92) of experts in chronic care using mail responses to open-ended questions was conducted to analyse existing chronic care programs focusing on effective, problematic and missing components. An expert workshop (n = 22) of professionals and scientists of a European funded research project MANAGE CARE was used to define a limited number of unmet needs and priorities of elderly patients with type 2 diabetes mellitus and comorbidities. This list was validated and ranked using a multilingual online survey (n = 650). Participants of the online survey included patients, health care professionals and other stakeholders from 56 countries. Results: The survey indicated that current care models need to be improved in terms of financial support, case management and the consideration of social care. The expert workshop identified 150 patient needs which were summarised in 13 needs dimensions. The online survey of these pre-defined dimensions revealed that financial issues, education of both patients and professionals, availability of services as well as health promotion are the most important unmet needs for both patients and professionals. Conclusion: The study uncovered competing demands which are not limited to medical conditions. The findings emphasise that future care models need to focus stronger on individual patient needs and promote their active involvement in co-design and implementation. Future research is needed to develop new chronic care models providing evidence-based and practical implications for the regional care setting

Effects of crystalline menthol on blood metabolites in Holstein steers and in vitro volatile fatty acid and gas production

Citation: Van Bibber-Krueger, C. L., Miller, K. A., Aperce, C. C., Alvarado-Gilis, C. A., Higgins, J. J., & Drouillard, J. S. (2016). Effects of crystalline menthol on blood metabolites in Holstein steers and in vitro volatile fatty acid and gas production. Journal of Animal Science, 94(3), 1170-1178. doi:10.2527/jas2015-8779Fifty-two Holstein steers (573 +/- 9.92 kg BW) were used to determine if oral administration of crystalline menthol would induce changes in endogenous secretions of IGF-1 and circulating concentrations of glucose, lactate, and plasma urea nitrogen (PUN). Steers were blocked by BW and assigned within block to treatment. Treatments consisted of 0, 0.003, 0.03, or 0.3% crystalline menthol (DM basis) added to the diet. Animals were housed in individual, partially covered pens equipped with feed bunks and automatic water fountains. On d 1 of the experiment, blood samples were obtained via jugular venipuncture at 0, 6, 12, 18, and 24 h after feeding. Treatment administration commenced on d 2, and blood samples were again drawn at 0, 6, 12, 18, and 24 h after feeding. This blood-sampling schedule was repeated on d 9, 16, 23, and 30. Plasma was analyzed for PUN, glucose, and lactate concentrations. Serum was used to analyze IGF-1 concentration. Body weights were measured on d 1, 9, 16, 23, and 30. To accompany the live animal phase, in vitro fermentations were performed using ruminal fluid cultures. Measurements included VFA concentrations and fermentative gas production for cultures containing crystalline menthol at 0, 0.003, 0.03, or 0.3% of substrate DM. Addition of menthol to the diet of steers resulted in a treatment x day interaction (P 0.21). In conclusion, menthol supplementation minimally affected blood parameters associated with growth or ruminal fermentative activity

Performance and carcass characteristics of steers fed with two levels of metabolizable energy intake during summer and winter season

Climate change is producing an increase on extreme weather events around the world such as flooding, drought and extreme ambient temperatures impacting animal production and animal welfare. At present, there is a lack of studies addressing the effects of climatic conditions associated with energy intake in finishing cattle in South American feed yards. Therefore, two experiments were conducted to assess the effects of environmental variables and level of metabolizable energy intake above maintenance requirements (MEI) on performance and carcass quality of steers. In each experiment (winter and summer), steers were fed with 1.85 or 2.72 times of their requirements of metabolizable energy of maintenance. A total of 24 crossbred steers per experiment were used and located in four pens (26.25 m2/head) equipped with a Calan Broadbent Feeding System. Animals were fed with the same diet within each season, varying the amount offered to adjust the MEI treatments. Mud depth, mud scores, tympanic temperature (TT), environmental variables, average daily gain, respiration rates and carcass characteristics plus three thermal comfort indices were collected. Data analysis considered a factorial arrangement (Season and MEI). In addition, a repeated measures analysis was performed for TT and respiration rate. Mean values of ambient temperature, solar radiation and comfort thermal indices were greater in the summer experiment as expected (P<0.005). The mean values of TT were higher in steers fed with higher MEI and also in the summer season. The average daily gain was greater during summer v. winter (1.10±0.11 v. 0.36±0.06) kg/day, also when steers were fed 2.72 v. 1.85 MEI level (0.89±0.12 v. 0.57±0.10) kg/day. In summer, respiration rate increased in 41.2% in the afternoon. In winter, muddy conditions increased with time of feeding, whereas wind speed and rainfall had significant effects on TT and average daily gain. We conclude that MEI and environmental variables have direct effects on the physiology and performance of steers, including TT and average daily gain, particularly during the winter. In addition, carcass characteristics were affected by season but not by the level of MEI. Finally, due to the high variability of data as well as the small number of animals assessed in these experiments, more studies on carcass characteristics under similar conditions are required

Potentials of Mean Force for Protein Structure Prediction Vindicated, Formalized and Generalized

Understanding protein structure is of crucial importance in science, medicine and biotechnology. For about two decades, knowledge based potentials based on pairwise distances -- so-called "potentials of mean force" (PMFs) -- have been center stage in the prediction and design of protein structure and the simulation of protein folding. However, the validity, scope and limitations of these potentials are still vigorously debated and disputed, and the optimal choice of the reference state -- a necessary component of these potentials -- is an unsolved problem. PMFs are loosely justified by analogy to the reversible work theorem in statistical physics, or by a statistical argument based on a likelihood function. Both justifications are insightful but leave many questions unanswered. Here, we show for the first time that PMFs can be seen as approximations to quantities that do have a rigorous probabilistic justification: they naturally arise when probability distributions over different features of proteins need to be combined. We call these quantities reference ratio distributions deriving from the application of the reference ratio method. This new view is not only of theoretical relevance, but leads to many insights that are of direct practical use: the reference state is uniquely defined and does not require external physical insights; the approach can be generalized beyond pairwise distances to arbitrary features of protein structure; and it becomes clear for which purposes the use of these quantities is justified. We illustrate these insights with two applications, involving the radius of gyration and hydrogen bonding. In the latter case, we also show how the reference ratio method can be iteratively applied to sculpt an energy funnel. Our results considerably increase the understanding and scope of energy functions derived from known biomolecular structures

Knowledge-based energy functions for computational studies of proteins

This chapter discusses theoretical framework and methods for developing knowledge-based potential functions essential for protein structure prediction, protein-protein interaction, and protein sequence design. We discuss in some details about the Miyazawa-Jernigan contact statistical potential, distance-dependent statistical potentials, as well as geometric statistical potentials. We also describe a geometric model for developing both linear and non-linear potential functions by optimization. Applications of knowledge-based potential functions in protein-decoy discrimination, in protein-protein interactions, and in protein design are then described. Several issues of knowledge-based potential functions are finally discussed.Comment: 57 pages, 6 figures. To be published in a book by Springe

Early prevention of diabetes microvascular complications in people with hyperglycaemia in Europe. ePREDICE randomized trial. Study protocol, recruitment and selected baseline data

Objectives To assess the effects of early management of hyperglycaemia with antidiabetic drugs plus lifestyle intervention compared with lifestyle alone, on microvascular function in adults with pre-diabetes. Methods Trial design: International, multicenter, randomised, partially double-blind, placebo-controlled, clinical trial. Participants Males and females aged 45-74 years with IFG, IGT or IFG+IGT, recruited from primary care centres in Australia, Austria, Bulgaria, Greece, Kuwait, Poland, Serbia, Spain and Turkey. Intervention Participants were randomized to placebo; metformin 1.700 mg/day; linagliptin 5 mg/day or fixed-dose combination of linagliptin/metformin. All patients were enrolled in a lifestyle intervention program (diet and physical activity). Drug intervention will last 2 years. Primary Outcome: Composite end-point of diabetic retinopathy estimated by the Early Treatment Diabetic Retinopathy Study Score, urinary albumin to creatinine ratio, and skin conductance in feet estimated by the sudomotor index. Secondary outcomes in a subsample include insulin sensitivity, beta-cell function, biomarkers of inflammation and fatty liver disease, quality of life, cognitive function, depressive symptoms and endothelial function. Results One thousand three hundred ninety one individuals with hyperglycaemia were assessed for eligibility, 424 excluded after screening, 967 allocated to placebo, metformin, linagliptin or to fixed-dose combination of metformin + linagliptin. A total of 809 people (91.1%) accepted and initiated the assigned treatment. Study sample after randomization was well balanced among the four groups. No statistical differences for the main risk factors analysed were observed between those accepting or rejecting treatment initiation. At baseline prevalence of diabetic retinopathy was 4.2%, severe neuropathy 5.3% and nephropathy 5.7%. Conclusions ePREDICE is the first -randomized clinical trial with the aim to assess effects of different interventions (lifestyle and pharmacological) on microvascular function in people with prediabetes. The trial will provide novel data on lifestyle modification combined with glucose lowering drugs for the prevention of early microvascular complications and diabetes