Holistic vitamin strategy to improve the robustness of pigs

One of the United Nations' 21st Century Protein Sustainable Development Goals refers to the provision of universally accessible, affordable, safe and sustainable proteins. It is an urgent problem that intersects with systemic challenges, such as consumption, the environment, food security, health and the economy. One of the pillars of sustainability is the reduction of antibiotic resistance. Porcine reproductive and respiratory syndrome virus (PRRS) is one of the most important diseases in the pig industry (1,2). Its impact is estimated at US $ 664 million per year in the United States (3), with death rates of up to 100% in the most extreme cases of emerging highly pathogenic strains. It is important to note that PRRS will induce a depression of the immune system favoring co-infections (4) by other viruses as well as bacteria and parasites, among which, influenza, Mycoplasma hyopneumoniae, porcine circovirus, E post-weaning coli and bacterial septicemia. (Strep suis, H. parasuis). In order to have a disease model close to what is observed in the field, PigGen Canada in collaboration with the Center de Développement du Porc du Québec (CDPQ) developed in 2015 a Natural Disease Challenge Model (NDCM) for weaning at slaughter (5). Their aim was to mimic the disease pressure caused by many pathogens common to commercial pig production, in particular PRRS. This model is unique in the world. and represents a real lever for designing strategies aimed at reducing morbidity and the use of antibiotics while improving the welfare, global competitiveness and sustainability of Canadian pork production. Thus, the objective is to use the NDCM to test a strategy put forward during the COVID-19 pandemic (6.7) to improve the health of pigs, namely, the increase of vitamins D and the possible boost of the effect of D through its association with vitamin C (8). The impact of the strategy will be tested in terms of growth performance, mortality, morbidity, eating and drinking behaviors, incidence of PRRS, vitamin and mineral status and bone mineralization. Specifically through: 1) the evaluation of vitamin strategies to maximize growth performance and improve health status, robustness and disease resistance during a health challenge using the NDCM, 2 ) monitoring the timing and acuity of PRRS infection based on dietary treatments, 3) assessing the impact of vitamin supplementation on vitamin status and immune response, and 4) assessing vitamin strategies to maximize growth performance and bone mineralization during the first few weeks after weaning in a clean environment.