Healthy chickens, healthy children? Exploring contributions of village poultry-keeping to the diets and growth of young children in rural Tanzania by Julia de Bruyn A thesis submitted fulfil requirements for the degree of in ment Doctor of Philosophy of the 201 8 School of Life and Environmental Sciences Faculty of Science University of Sydney Statement of originality This thesis is submitted to he University of Sydney in fulfilment of the requirements for the degree of Doctor of Philosophy.t The material presented has not been submitted for a degree at this or any other institution. I certify that the intellectual content of this thesis is the product of my own work, and that all sources and assistance received in preparing this thesis have been acknowledged. Julia de Bruyn December 2017 i Abstract One in three Tanzanian children under five years of age is affected by stunting: an outcome of chronic undernutrition and an indication of impaired physical and cognitive development. The potential for livestock-keeping to contribute positively to children’s growth, including by providing nutrient-dense animal-source foods and household income to enable other nutritious food purchases, has been well-described but poorly demonstrated. Village chickens are an accessible and versatile form of livestock, kept in small free-ranging flocks by many households in resource-poor settings and often managed by women. This mixed methods research was undertaken in villages of Manyoni District in central Tanzania, alongside a project establishing a community-based vaccination service against Newcastle disease in village chickens. Significantly larger chicken flock sizes were identified as an outcome of vaccinating in a given campaign and of continuing to vaccinate at four-monthly intervals, compared to vaccinating less often or not at all. Chicken meat and eggs were infrequently eaten during the study period, with eggs more commonly hatched to increase chicken numbers and chickens retained for sale in times of need. Consumption of poultry products by mothers and their young children was closely linked and no gender-based differences in children’s consumption frequency were found. Analysis of national and regional food composition tables highlighted the need for recent and locally-derived data on the nutrient content of animal-source foods, to better reflect the products of indigenous livestock in low-input management systems. This thesis did not identify a significant impact of chicken-keeping on the height-for-age of children over a two- year period; however, importantly, it found no negative health or growth impacts which would undermine a continued focus on poultry interventions as a strategy to sustainably enhance nutrition at a household level. ii Acknowledgements While the final months spent writing this thesis have seemed a solitary venture, the underlying body of work has involved a team which has spanned several countries, languages and research disciplines. My entry into the field of international food and nutrition security in late 2013 marked an abrupt shift from a career as a clinical veterinarian. The learning curve which has followed would not have been possible without the guidance, support and opportunities provided by many people. I owe a great deal to my primary supervisor, Professor Robyn Alders, who has instilled in me the value of consultative field-based research. I continue to be inspired by Robyn’s commitment to tackling the issues which matter to smallholder farmers in resource-poor settings, and working towards sustainable outcomes. My co-supervisor Professor Ian Darnton-Hill’s generosity in sharing his experience in international public health nutrition research and policy has been much appreciated, as has his diplomacy and eye for detail. Time spent with my social anthropologist advisor, Dr Brigitte Bagnol, in our study sites and in discussions, has been both enjoyable and invaluable in developing my skills and appreciation of qualitative and cross- cultural research. I have also benefited greatly from the support and endless patience of my statistics advisor, Associate Professor Peter Thomson, in helping me to navigate rich and complex datasets to reach valid conclusions. I am very grateful to our project coordinator in Tanzania, Wende Maulaga (“Mama Wende”), whose compassion, commitment and ability to bring people together has made this work the success it has been. Thank you to all my Tanzanian colleagues, especially Elpidius Rukambile, Msafiri Kalloka, Geofrey Kiswaga, Deorinidei Mng’ong’o and Sospeter Mwingira. This research has been facilitated by strong partnerships at the Tanzania Veterinary Laboratory Agency, Tanzania Food and Nutrition Centre and Sokoine University of Agriculture, and the continuing support of the Government of Tanzania. The key role of community leaders, local enumerators and chicken vaccinators in implementing this project cannot be overstated. Thanks especially to our “Community Assistants”: Robert Delisa, Theresia Mathias, Jeni Zacharia, Simon Beatus, Johnson Mkuyu, Rosemary Ackley, Esther Kapande, Moses Joseph, Selafina Maloda, Amos Maloda, Angelina Masiaga, Laurent Charles, Suzana Joseph, Happiness Cassian, Marino Alphonce, Agnes Joseph, Mandela Gabriel, Modesta Martin and Yohana Joseph. iii Thank you to the broader Nkuku4U team at he University of Sydney (Professor Robyn McConchie, Professor Mu Li, Professor Judy Simpson,t Dr Siobhan Mor and Dr Floris van Ogtrop), with whom I have greatly enjoyed working and who have contributed to my early experiences of interdisciplinary research. Funding for this project has been provided by the Australian Centre for International Agricultural Research (ACIAR). Opportunities afforded to me through both ACIAR and The Crawford Fund have helped me to build networks within the international agricultural research community. Financial support through he University of Sydney’s Postgraduate Research Support Scheme has also facilitated tmy participation in three international conferences during my candidature. It is hard to imagine the last three-and-a-half years without my friend and ally Johanna Wong. Our chats, discussions and debriefs (from our respective field sites, loitering by the office photocopier, and over dinner) have made the transition to this new subject area and the highs and lows of PhD student life a far greater experience. Thanks also to Dr Darryl Stellmach for the pep-talks, Friday writing sessions, and for broadening the diversity of our female-veterinarian- dominated research group. Thanks to my family and friends, for their love and belief in the many moments of self-doubt. And finally, thank you to the women and children of Sanza and Majiri Wards in Tanzania. iv Table of contents Statement of originality ......................................................................................................................................................... i Abstract ......................................................................................................................................................................................... ii Acknowledgements ............................................................................................................................................................... iii Author contributions to published papers ................................................................................................................. x Authorship attribution statement ................................................................................................................................ xii Additional publications and presentations ............................................................................................................ xiii Abbreviations and acronyms ........................................................................................................................................ xvii Glossary ...................................................................................................................................................................................... xx List of tables ....................................................................................................................................................................... xxviii List of figures ........................................................................................................................................................................ xxx References .......................................................................................................................................................................... xxxiv Chapter 1. Background, introduction and research aims .......................................................................... 1 1.1 Introduction ....................................................................................................................................................................... 2 1.2 Undernutrition .................................................................................................................................................................. 2 1.2.1 Stunting ................................................................................................................................................................... 3 Stunting levels in Tanzania ..........................................................................................................................