Grey literature is research resources that have not gone through the formal journal peer-reviewed process. Examples include: white papers (reports from governments or organisations), research from non-governmental organisations (NGOs) or non-profits, dissertations/theses, and pre-print research. While peer review is useful tool to find quality information, this does not mean that grey literature is not a valid and necessary form of research/resources.
You may also want to look at the web resources page.
Pre-prints:
VetSciRN: The Veterinary Science Research Network on SSRN is an open access preprint server that provides a venue for authors to showcase their research papers in our digital library, speeding up dissemination and providing the scholarly community access to groundbreaking working papers, early-stage research, and clinical research.
BioRxiv: (pronounced "bio-archive") is a free online archive and distribution service for unpublished preprints in the life sciences. It is operated by Cold Spring Harbor Laboratory, a not-for-profit research and educational institution.
MedRxiv: (pronounced "med-archive") is a free online archive for complete but unpublished manuscripts (preprints) in the medical, clinical, and related health sciences.
MarXiv
A free preprint repository for the ocean and marine-climate research.
Government:
Government of Prince Edward Island - Department of Agriculture
The Department of Agriculture oversees both animal health/welfare, and veterinarians in PEI.
Canada Food Inspection Agency : Canadian federal government food safety regulations and publications.
US Animal & Plant Health Inspection Service (APHIS): Publications from US Department of Agriculture Department on biotechnology, animal disease, animal welfare and related trade issues.
NGOs/non-profits:
Food Agriculture Organization of the United Nations: Publications from UN agency dealing with most aspects of food including livestock production and health, food security and aquaculture
World Organization for Animal Health Publications (formerly OIE): statistics from international agency dealing with animal disease, veterinary services, animal welfare and related trade issues
General:
OpenGrey: Includes technical or research reports, doctoral dissertations, some conference papers, some official publications, and other types of grey literature.