COMPARISON OF PRODUCTION AND NUTRITIONAL VALUE OF TWO SEED SOURCES OF WINTERFAT A Thesis Submitted to the Faculty ofGraduate Studies and Research in Partial Fulfilment ofthe Requirements for the Degree of Doctor of Philosophy in the Department ofAnimal and Poultry Science University ofSaskatchewan by Michael P. Schellenberg August 2005 © Copyright Michael P. Schellenberg, 2005. All rights reserved. In presenting this thesis in partial fulfilment ofthe requirements for a postgraduate degree from the University ofSaskatchewan, I agree that the libraries of this University may make it freely available for inspection. I further agree that permission for copYing ofthis thesis in any manner, in whole or in part, for scholarly purposes maybe granted by the professor or professors who supervised my thesis work or, in their absence, by the Head ofthe Department or the Dean ofthe College in which my thesis was done. It is understood that any copYing, publication, or use ofthis thesis or parts thereoffor financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Saskatchewan in any scholarly use which may be made ofany material in my thesis. Requests for permission to copy or make other use ofmaterial in this thesis in whole or part should be addressed to: Head ofthe Department ofAnimal and Poultry Science University ofSaskatchewan Saskatoon, Saskatchewan S7N 5A8 1 ABSTRACT Winterfat, Krascheninnikovia lanata (Pursh) A.D.J. Meeuse & Smit, a native shrub that exhibits ecotypic variation, has been recommended for extending the grazing season into the fall, when protein levels are low in other plants ofthe northern Great Plains. A series ofstudies was established in 2001 and 2002 at Swift Current, SK to examine developmental and nutritional differences between a northern seed source (Ducks Unlimited Canada ecovar™, DU) and a southern seed source (New Mexico, NM). Additionally, winterfat's nutritional contribution to mixtures containing alfalfa and western wheatgrass was examined. For the first experiment, plants were clipped once, at 50% ofplant height, between June and snow fall. New Mexico winterfat was 8.7 % taller in 2002 than DU, but DU plants were more productive (P < 0.05) on a g m-2 basis (15% in 2002, 110% in 2003) than NM with more primary branches (40 % in 2002,20% in (2003), higher fibre (4% in 2003) and decreased digestibility (7% for 3 year old plants) than NM. NM and DU plants had different (P < 0.05) crude protein, Ca, P, K, Na, Mn, Zn, Fe, Co, and Cd concentrations in 2002 and 2003. Supplementation of Ca, Cu, Co and Se for both seed sources and Zn for older NM plants would be required, to meet nutritional requirements ofa medium framed British breed replacement heifer in its first trimester. Sulfur, Mg and Fe were in excess ofanimal requirements and may decrease Cu availability. In a study examining seed production ofboth seed sources as affected by fertilization and irrigation, DU plants produced seed in potentially commercial potential quantities while NM plants remained vegetative. Fertilizer and water had no effect on seed production (P > 0.05). The third study examining seeding mixtures ofwinterfat with alfalfa and western wheatgrass indicated that the mixtures provided adequate crude protein for a medium framed British breed heifer. Two in sacco experiments modelled a) digestion ofthe two winterfat types compared to alfalfa and western wheatgrass; and b) digestion ofthe same species as poly- or mono-cultures. 11 Alfalfa and NM winterfat, were similar, and had greater (P < 0.05) effective degradability than DU winterfat or western wheatgrass. The poly-culture feed mixture degradability ofcrude protein was greater (P < 0.05) than DU winterfat or Western wheatgrass. A positive synergy was observed for effective degradability ofCP in mixtures. The studies overall demonstrate 1) northern and southern winterfat ecotypes have different growth and nutritional characteristics and 2) inclusion ofalfalfa in mixtures with winterfat could provide adequate crude protein with a proportion (390 g kg- 1 CP) being in the form ofrumen undigestible crude protein. 111 ACKNOWLEDGEMENTS The author wishes to express his gratitude and appreciation to Dr. Roger Cohen and Dr. Paul Jefferson for their guidance, constructive criticism and advice throughout this period ofstudy. The author wishes to thank Dr. J. Waddington for planting the seed literally and conceptually which has produced the research project for this thesis. Recognition is also extended to Drs. John McKinnon, Yuguang Bai and Bernard Laarveld who served as members ofmy advisory committee. Appreciation is extended to Dr. Peiqianq Yu for his time explaining the modelling process and the help he provided the author for the modelling component of the thesis. Special appreciation is expressed to Jacqueline Bolton for her dedicated help collecting the data for this thesis as well as ongoing research projects. A special thanks is expressed to the Forage Research team, located at Agriculture and Agri-Food Canada's Semiarid Prairie Agricultural Research Centre in Swift Current, for their assistance in the field, laboratories and bams, and their support throughout this study period. Gratitude is extended to the Saskatchewan Agricultural Development Fund and Agriculture and Agri-Food Canada Research Branch for funding. Gratitude is also extended for access to the facilities at Agriculture and Agri-Food Canada's Semiarid Prairie Agricultural Research Centre. Finally, I would like to dedicate this thesis to Vivian, Rachel and Adam Schellenberg for support and sacrifices made during this period ofstudy. tV TABLE OF CONTENTS PERMISSION TO USE......................................................................................... i ABSTRACT............................................................................................................ ii ACKNOWLEDGEMENTS iv TABLE OF CONTENTS ~ v LIST OF TABLES................................................................................................. x LIST OF FIGURES............................................................................................... XVII LIST OF ABBREVIATIONS xviii APPENDIX TABLES xx APPENDIX FIGURES ~ ~ xxii 1. INTRODUCTION............................................................................................... 1 1.1 Why Shrubs? 1 2. LITERATURE REVIEW.................................................................................. 5 2.1 Geographic Range............. 5 2.2 Ecotypic Differences... 6 2.3 Growth......... 7 2.4 Mixtures........................... 9 2.5 Nutritional Characteristics............................. 11 2.6 Utilization. 16 2.7 Seed Availability.................................................................................... 17 2.8 Hypotheses to be Tested......................................................................... 18 2.9 Objectives to Test Hypotheses..................... 18 v 3. PHENOLOGICAL DIFFERENCES BETWEEN DUCKS UNLIMITED AND NEW MEXICO SEED SOURCES....................................................................... 21 3.1 Introduction............................................................................................ 21 3.2 Materials and Methods.. 23 3.2.1 Experiment 1........................................................................... 23 3.2.2 Experiment 2........................................................................... 25 3.2.3 Meteorological Data. 25 3.2.4 Statistical Analyses.................................................................. 25 3.3 Results and Discussion............ 26 3.3.1 Meteorological Data 26 3.3.2 Canopy Structure and Biomass............................................... 27 3.3.2.1 Experiment 1............................................................ 27 3.3.2.1.1 First Year ofHarvest 2002 27 3.3.2.1.1.1 Seed source 27 3.3.2.1.1.2 Clipping date 27 3.3.2.1.2 Second Year ofHarvest 2003.................... 32 3.3.2.1.2.1 Seed source 32 3.3.2.1.2.2 Clipping date.............................. 35 3.3.2.2 Experiment 2............................................................ 40 3.3.2.2.1 First Year ofHarvest 2003 40 3.3.2.2.1.1 Seed source 40 3.3.2.2.2.1 Clipping date.............................. 40 3.3.2.3 General Results and Discussion for Canopy Structure and Biomass...................................................................... 41 3.3.3 Stage ofGrowth 43 3.3.3.1 Experiment 1............................................................ 43 3.3.3.1.1 First Year ofHarvest 2002 43 3.3.3.1.2 Second Year ofHarvest 2003 44 3.3.3.2 Experiment 2............................................................ 44 VI 3.3.3.1.1 First Year ofHarvest 2003 44 3.3.3.3 General Results and Discussion for Stage of Growth................................................................................ 44 3.3.4 LeafStem Growth................................................................... 44 3.4 Conclusions.. 48 4. SEED PRODUCTION POTENTIAL AS AFFECTED BY SEED SOURCE, FERTILIZATION AND IRRIGATION........................................... 50 4.1 Introduction.. 50 4.2 Materials and Methods......................................................................... 52 4.3 Results and Discussion.......................................................... 54 4.3.1 Production.............................................................................. 54 4.3.2 Climatic Conditions.............. 61 4.4 Conclusions.......................................................................