Foreword 7; Part I: Rumen fermentation; Characterisation and quantification of the microbial populations of the rumen 19; J.L. Firkins and Z. Yu; Abstract 19; Introduction 19; Enumerating and characterising prokaryotic and protozoal populations by culture-based and microscopic methods 21; Characterising bacterial populations by molecular biology techniques 24; Observations from cloning and sequencing studies for bacteria 26; Quantitative issues influencing the interpretation of bacterial clone libraries 30; Quantification of microbial populations in the rumen 32; Protozoal ecology 36; Protozoal interactions with Bacteria and Archaea 42; Conclusions 45; Acknowledgements 46; References 46; The role of thermodynamics in the control of ruminal fermentation 55; E.M. Ungerfeld and R.A. Kohn; Abstract 55; Introduction 55; Background 58; Thermodynamics and kinetics of H sinks 64; Thermodynamics and kinetics of VFA interconversion 72; Conclusions 80; References 81; Digestion and passage of fibre in ruminants 87; P. Huhtanen, S. Ahvenjarvi, M.R. Weisbjerg and P. Norgaard; Abstract 87; Introduction 87; Site of digestion 89; Digestion kinetics 92; Parameter estimates of intrinsic rate and extent of digestion 92; The in situ method 93; Effect of intrinsic characteristics on digestion kinetics 98; Effect of extrinsic characteristic on digestion kinetics 100; Validity of digestion kinetic methods 104; Passage kinetics 105. Methodology 106; Particle dynamics 110; Intrinsic and extrinsic factors influencing passage kinetics 114; Integrated models of cell wall digestion in the rumen 119; Conclusions 125; References 126; Part II: Absorption mechanisms; Transport systems in the epithelia of the small and large intestines 139; G. Breves and S. Wolffram; Abstract 139; Introduction 139; Carbohydrate digestion and monosaccharide absorption 140; Rate of flow of starch into the small intestines 140; Enzymatic hydrolysis 141; Epithelial transport of sugars 141; Gastrointestinal absorption of amino acids and peptides 143; Absorption of amino acids 144; Absorption of tri- and dipeptides 147; Intestinal phosphate (Pi) absorption 149; Concluding remarks 150; References 151; Urea transporters and urea recycling in ruminants 155; J.C. Marini, J.M. Sands and M.E. Van Amburgh; Abstract 155; Introduction 155; Urea excretion and its regulation by the kidney 156; Urea entry into the gastrointestinal tract 161; Future work and summary 163; Acknowledgements 164; References 164; Ruminal SCFA absorption: channelling acids without harm 173; G. Gabel and J.R. Aschenbach; Abstract 173; Introduction 173; Quantitative aspects of intraruminal acid production and their final fate 174; Intraruminal proton release and buffering 174; Mechanisms of acid elimination from the ruminal content 174; Intraepithelial metabolism of SCFA 176; Disadvantages vs. advantages of intraepithelial SCFA breakdown 177; Acid-base balance in the ruminal epithelial cell 180; pHi regulating mechanisms and extracellular conditions 180. Systemic vs. luminal release of protons and acids 183; Functional adaptation of the ruminal epithelium can stabilise the whole system 186; Conclusions 188; Acknowledgements 189; References 189; Part III: Splachnic metabolism; Splanchnic metabolism of long-chain fatty acids in ruminants 199; J.K. Drackley and J.B. Andersen; Abstract 199; Introduction 199; Role of PDV in absorption of dietary LCFA 200; Role of splanchnic organs in coordination and use of LCFA 201; Secretion of TAG as VLDL vs. TAG accumulation in liver 205; Control of hepatic ss-oxidation of NEFA 208; Cellular partitioning of hepatic NEFA metabolism 211; Can hepatic capacity for NEFA ss-oxidation be manipulated? 214; Do PDV adipose tissues influence liver metabolism of LCFA? 216; Conclusions and future perspectives 217; References 217; Splanchnic amino acid metabolism in ruminants 225; C.K. Reynolds; Abstract 225; Introduction 226; Measurement of splanchnic amino absorption and metabolism 227; Metabolism of amino acids by the portal-drained viscera 228; Liver metabolism of amino acids 234; Metabolic impact of nonprotein nitrogen metabolism 241; Conclusions 243; References 244; Splanchnic metabolism of short-chain fatty acids in the ruminant 249; N.B. Kristensen and D.L. Harmon; Abstract 249; Introduction 249; Low first pass sequestration of acetate and propionate by ruminal epithelium 250; Large first pass sequestration of butyrate and valerate by the ruminal epithelium 252; Is the ruminal epithelium a specialized butyrate scavenger? 253; Hepatic SCFA metabolism 254; Acyl-CoA synthetases in SCFA metabolism 258; Perspectives 260; Acknowledgements 260; References 260. Part IV: Lactation and reproduction physiology; Patterns and putative regulatory mechanisms of high-affinity glutamate transporter expression by ruminants 269; J.C. Matthews and G.L. Sipe; Abstract 269; Introduction 269; Glutamate transport systems 271; System X-AG transport proteins 271; Importance of system X-AG transport capacity in support of tissue function 272; Characterized and putative regulatory mechanisms of system X-AG transporter expression and function 277; Modulation of chlortetracycline on cattle carcass quality and expression of system X-AG transporters and glutamine synthetase 284; Conclusions 286; Acknowledgements 286; References 286; Characterisation and nutritional regulation of the main lipogenic genes in the ruminant lactating mammary gland 295; L. Bernard, C. Leroux and Y. Chilliard; Abstract 295; Introduction 295; Origin of milk fatty acids 296; Characterisation of the main lipogenic genes and tools for studying gene expression and regulation 298; Effect of dietary factors on lipogenic genes expression in the mammary gland 303; Molecular mechanisms involved in nutritional regulation of gene expression 310; Conclusions and perspectives 316; Acknowledgements 318; References 318; Roles of growth hormone and leptin in the periparturient dairy cow 327; Y.R. Boisclair, S.R. Wesolowski, J.W. Kim and R.A. Ehrhardt; Abstract 327; Introduction 327; Growth hormone 328; Leptin 330; Conclusions 336; Acknowledgements 336; References 336. Part V: Lactation and reproduction physiology; Prenatal nutrition, fetal programming and opportunities for farm animal research 347; B.H. Breier; Abstract 347; Introduction 348; Maternal and fetal responses to reduced maternal nutrition 349; Influence of early life nutrition on postnatal growth and metabolism 350; Animal models of nutritional programming 351; Interactions between prenatal and postnatal nutrition 352; Endocrine and metabolic mechanisms 354; Fetal programming - opportunities for research in farm animals 355; Conclusion 357; Acknowledgements 357; References 358; Mammary cell turnover: relevance to lactation persistency and dry period management 363; A.V. Capuco, E. Annen, A.C. Fitzgerald, S.E. Ellis and R.J. Collier; Abstract 363; Introduction 363; Concept of cell turnover 364; Identification of progenitor cells 365; Population dynamics during lactation 368; Population dynamics during a 60-day dry period 373; Implications of cell turnover to shortened dry periods 376; Conclusions and perspectives 383; References 383; Milk fat depression: concepts, mechanisms and management applications 389; J.M. Griinari and D.E. Bauman; Abstract 389; Introduction 389; Milk fat depression 390; The effect of trans-10, cis-12 CLA on milk fat synthesis 396; Nutritional challenges of cows in early lactation 401; Milk fat reduction and associated lactation responses 403; Conclusions 408; References 409. Part VI: Nutrition and immunology; Endocrine effects on immune function: defining opportunities based on knowledge from growing calf and periparturient animal models 421; T. Elsasser, K.L. Ingvartsen, S. Kahl, and A.V. Capuco; Abstract 421; Introduction 421; Brief overview of the periparturient phenomenon 422; Hormonal maintenance of pregnancy and the impact of fetal-maternal tolerance on natural immunosuppression 423; Somatotropic axis modulation of immune function 425; Temporal, state-dependant, and inter-animal variability factors in the endocrine control of immune function 427; Newer findings on the impact of GH on localized immune function/nitric oxide production 431; The endocrine - immune gradient and integration of priority signals 437; Adrenomedullin - a novel bridge in the endocrine regulation of immune system function 441; Conclusions 445; References 446; Energy and protein effects on the immune system 455; M.E. Kehrli, Jr., J.D. Neill, C. Burvenich, J.P. Goff, J.D. Lippolis, T.A. Reinhardt and B.J. Nonnecke; Abstract 455; Introduction 455; Immune function status of periparturient dairy cattle 456; Energy and protein status of periparturient dairy cattle 459; Energy and protein requirements of the immune system 460; Influence energy and protein status on immune function 462; Conclusions 465; References 465; Vitamin and trace mineral effects on immune function of ruminants 473; W.P. Weiss and J.W. Spears; Abstract 473; Introduction 473; Factors affecting immune response to vitamin and mineral supply 474; Chromium 475; Copper 477; Selenium and vitamin E 480; Vitamin A and B-carotene 483; Zinc 485; Other minerals and vitamins 486; Conclusions 486; References 487. Part VII: Nutrition and stress physiology; Feeding management and stress in calves 499; A.M. de Passille and J. Rushen; Abstract 499; Introduction 499; Deprivation of sucking behaviour 499; Milk quantity 505; Individual versus group housing 507; Conclusions 508; Acknowledgements 508; References 509; Effects of nutrition on stress reactivity 511; L. Munksgaard, M.S. Herskin, P. Lovendahl and J.B. Andersen; Abstract 511; Introduction 511; Changes in HPA-axis activity induced by feeding and fasting 512; Baseline cortisol levels in relation to diet composition and total energy intake 513; HPA-axis reactivity to acute stress is modulated by energy intake 514; Diet composition may affect serotonin at CNS level 516; Can changes in the level of serotonin and CRF regulation at the CNS level affect behavioural responses to stress? 516; How do diet composition and energy intake affect behaviour? 517; Effects of composition and energy density of the diet on time budgets 517; Conclusion 520; Acknowledgements 521; References 521; Part VIII: Human health aspects; Milk fatty acids and human health: potential role of conjugated linoleic acid and trans fatty acids 529; D.E. Bauman, A.L. Lock, B.A. Corl, C. Ip, A.M. Salter and P.W. Parodi; Abstract 529; Introduction 529; The biology of CLA 531; Ruminant dimension 533; Use of models to investigate effects of CLA on disease 538; Functional food implications of CLA for disease prevention in humans 544; Conclusion 550; References 551. Does cow's milk enhance linear growth: evidence from developing and industrialized countries 563; C. Hoppe, C. Molgaard and K. F. Michaelsen; Abstract 563; Introduction 563; Populations with marginal or poor nutritional status 563; Well-nourished populations 564; Own studies 565; Breast milk and infant formula 567; Milk and IGF-I in adults 568; Possible mechanisms 568; Linear growth and non-communicable diseases 569; IGF-I and non-communicable diseases 569; Conclusion 569; References 570; Part IX: Workshop reports; The use of ruminants in less developed counties and the priorities within ruminant physiology research to assist in development; Chaired by J. Madsen and T. Hvelplund; Discussion paper - Ruminants in agricultural development: where is the future for animal physiologists? 575; J. Madsen; Methods used for studying particle size and digesta flow; Chaired by D.P. Poppi and A.de Vega; Discussion paper 1 - Use of image analysis for measuring particle size in feed, digesta and faeces 579; P. Norgaard; Discussion paper 2 - Measurement of digesta flow entering the omasal canal 587; S. Ahvenjarvi; Index 591.
