Bioactive nutrients for improved metabolic function of dairy cattle by KATIE E. OLAGARAY B.S., California Polytechnic State University - San Luis Obispo, 2014 A THESIS submitted in partial fulfillment of the requirements for the degree MASTER OF SCIENCE Department of Animal Sciences and Industry College of Agriculture KANSAS STATE UNIVERSITY Manhattan, Kansas 2017 Approved by: Major Professor Barry J. Bradford Copyright © Katie E. Olagaray 2017. Abstract Dairy cows undergo many homeorhetic adaptations during the transition to lactation. Although many of the physiological processes - including increased lipolysis and postpartum inflammation - are adaptive, exaggerated responses can contribute to metabolic disease and reduced milk production. L-carnitine has been shown to increase hepatic oxidation of fatty acids and reduce hepatic lipid accumulation in early lactation cows; however, L-carnitine is degraded in the rumen. An experiment using 4 ruminally-cannulated Holstein heifers in a split plot design demonstrated that the relative bioavailability of L-carnitine was greater when delivered abomasally than ruminally. There was a dose × route interaction and a route effect for increases in plasma carnitine above baseline, with increases above baseline being greater across all dose levels (1, 3, and 6 g L-carnitine/d) when infused abomasally compared to ruminally. A second experiment used 56 lactating Holstein cows in a randomized complete block design to evaluate 2 rumen-protected products (40COAT and 60COAT) compared to crystalline L-carnitine at doses targeting 3 and 6 g/d carnitine. Although crystalline and 40COAT were effective in linearly increasing carnitine concentrations, only subtle responses were seen for the 60COAT, which were less than that for crystalline carnitine in plasma, milk, and urine. Ineffectiveness of rumen- protected products to increase carnitine concentrations beyond crystalline may have been due to over-encapsulation that hindered liberation of the carnitine and its absorption in the small intestine. Although L-carnitine has the potential to reduce postpartum hepatic lipidosis, effective rumen protection of L-carnitine while maintaining intestinal availability needs further investigation. Plant polyphenols have anti-inflammatory properties and when administered during the transition period, have been shown to increase milk production. An experiment used 122 multiparous Holsten cows in a randomized block design to determine the effect of short term (5-d; SBE5) and long term (60-d; SBE60) administration of Scutellaria baicalensis extract (SBE)on whole-lactation milk yield, 120-d milk component yield, and early lactation milk markers of inflammation. Whole-lactation milk yield was increased for SBE60 compared to control, but was not different for SBE5 compared to control. Greater total pellet intake, milk lactose yield, and reduced SCC during wk 1-9 for SBE60 compared to control, all could have contributed to the observed sustained increase in milk yield. Milk production parameters were not different for SBE5 compared to control. No treatment effects were observed for BCS or milk markers of inflammation (haptoglobin) and metabolic function (β-hydroxybutyrate). Overall, long term administration of S. baicalensis effectively increased milk production, however the mechanism by which this was achieved is unknown. Although routes of administration to effectively achieve their physiological responses were different between L-carnitine (abomasal delivery) and SBE (feeding), both bioactive nutrients can improve the metabolic function of early lactation dairy cows. Table of Contents List of Figures .............................................................................................................................. viii List of Tables ................................................................................................................................. ix Acknowledgements ......................................................................................................................... x Chapter 1 - Literature review .......................................................................................................... 1 Plant Polyphenols in Ruminants ................................................................................................. 2 Bioavailability ......................................................................................................................... 3 Preruminant calf .................................................................................................................. 3 Ruminal degradation effect on bioavailability .................................................................... 5 Polyphenols for Young Stock ................................................................................................. 7 Polyphenol impacts on calf metabolism ............................................................................. 8 Calf Health .......................................................................................................................... 8 Growth .............................................................................................................................. 11 Fermentation ......................................................................................................................... 12 In vitro ............................................................................................................................... 13 In vivo ............................................................................................................................... 16 Transition Cows .................................................................................................................... 18 Feed intake and milk production....................................................................................... 18 Insulin Resistance ............................................................................................................. 21 Metabolic Parameters........................................................................................................ 23 Endoplasmic reticulum stress ........................................................................................... 24 Hepatic Inflammation and Lipid Accumulation ............................................................... 25 Oxidative and Antioxidative status ................................................................................... 28 Mastitis .................................................................................................................................. 29 Conclusion ............................................................................................................................ 32 REFERENCES ......................................................................................................................... 33 Chapter 2 - Relative bioavailability of carnitine delivered by ruminal or abomasal infusion or by encapsulation in dairy cattle .................................................................................................. 42 ABSTRACT .............................................................................................................................. 43 INTRODUCTION .................................................................................................................... 45 v MATERIALS AND METHODS .............................................................................................. 47 Experiment 1 ......................................................................................................................... 47 Experiment 2 ......................................................................................................................... 48 Cows and treatments ......................................................................................................... 48 Data collection and sampling procedures ......................................................................... 49 Sample Analyses ............................................................................................................... 50 Statistical Analyses ........................................................................................................... 51 RESULTS AND DISCUSSION ............................................................................................... 52 Experiment 1 ......................................................................................................................... 52 Feed and water intake ....................................................................................................... 52 Plasma Carnitine Response ............................................................................................... 52 Experiment 2 ......................................................................................................................... 54 Feed intake and milk production....................................................................................... 54 Metabolic Parameters........................................................................................................ 56 Plasma Carnitine Response ............................................................................................... 57 Excreted carnitine ............................................................................................................. 58 CONCLUSION ........................................................................................................................