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Managing Systemic Disease Stress in Commercial Pig Production: Cost and Possible Nutritional Practices to Reduce Performance Loss
This paper presents estimated cost to growth, feed efficiency and financial outcome for pigs that have been naturally challenged by viral diseases. A second purpose is to provide evidence that certain nutrients or bioactive components dampen the severity of response to immune stress. Finally, we discuss how this knowledge is applied in practice. Specific ingredients are utilized to manage disease stress in practice; fish meal and animal plasma are among the most noted. Our portfolio has enlarged to include soybean meal (SBM). Ingredients bring nutrients that are important to modulate disease effects, but also bioactive substances such as anti-inflammatory components and immunoglobulins. We measured G:F deviation during a 55 d period in pigs challenged with Influenza. We estimated feed cost to be increased by at least $1.50/pig (Boyd et al. 2010), however, this could double depending on ingredient price, how late the infection occurred, and how long it remains. Although mortality and medical treatment accompany disease stress, they are beyond the scope of this paper. In an earlier study, we observed that a mix of pro-inflammatory viruses (PRRS, PCVAD, S. suis), during the finish phase, severely reduced rate and efficiency of growth. Mortality and morbidity was 6 times normal for a 16 week period. Growth and G:F ratio were depressed in a 21 d test, but growth was much improved if pigs were fed a relatively high level of SBM (HI-SBM) compared to LO-SBM. Respective whole-body (WB) and carcass growth was observed (LO-SBM: 902, 608 g/d vs HI-SBM: 989, 686). G:F ratio also improved on a WB and carcass basis (0.337, 0.215 vs 0.365, 0.240). The modulating effect of SBM was evident when CP level was equal for LO- and HI-SBM (16.0%) treatments, but relative improvement appeared to increase as the difference in SBM content (and CP) progressively diverged.
The modulating effect of SBM on systemic disease may be due to non-nutritive, anti-inflammatory isoflavones (Greiner et al. 2001), but CP level may be additive to bioactive components. Proof of concept has been extended to weaned pigs (Rochell et al. 2013). Immune modulation with high quality fish meal was an early innovation for weaned pigs. Commercial application through feeding requires intervals of weeks not days, however precise timing is improved if water administered.
Keywords: Immune Stress, Growth, Soya