Of the health challenges the swine industry face, Porcine Reproductive and Respiratory Syndrome (PRRS) virus is arguably one of the most economically costly viruses to U.S. and world pork production. In addition to mortality losses and costs of interventions, this virus may reduce lean tissue accretion and feed efficiency in growing pigs from weaning to market. Therefore, our objective was to determine the growth performance and tissue accretion of pigs given nutritional supplement via water or feed additive during a PRRSV challenge. Thus, this project aimed to test and identify applied nutritional mitigation strategies for feeding PRRS challenged pigs and to mitigate the decrease in growth and feed efficiency caused by PRRS. One hundred and eight PRRS naïve maternal line barrows were allotted to 1 of 3 treatments, 6 pens per treatment and six pigs per pen. The treatments included: 1) PRRSV Control diet, 2) As #1 + water additive, and 3) As #1 + feed additive. Water and feed additive were produced by TechMix LLC and contained a proprietary combination of proteins, amino acids, carbohydrates and electrolytes which included betaine, soy protein isolates, monosodium glutamate, and high fructose corn syrup. All pigs were inoculated with a field strain of PRRSV at day post inoculation (dpi) 0 and performance monitored weekly for approximately 42 days. Pig sickness behavior and blood metabolites and immune markers were also assessed over the challenge period. The results of this project are:
• As expected, all pigs became PRRSV positive and seroconverted in a time dependent manner. No treatment or treatment by time interaction was observed.
• There was no treatment difference in ADG, ADFI, or G:F during weekly performance or overall performance among treatments. From 0 – 14 dpi, all treatments were on average gaining 37% less and By dpi 28-35, all pigs irrespective of treatment were on average performing similar to predicted performance for pigs 25 – 50 kg (NRC, 2012).
• Pigs whole body, bone mineral content, fat, lean, and protein accretion rates, there was no difference (P > 0.05) among water or feed treatments. All treatments, on average, had protein accretion rates that were 51% less than those predicted for 25-50 kg pigs (NRC, 2012).
• No treatment differences in serum glucose, glucagon, insulin, haptoglobin, NEFA, and BUN were observed.
• No differences in sickness behavior (eating, drinking, and sitting) were observed until 6 dpi (less active and reduced eating and drinking behavior). Furthermore, the nutrient supplement treatments had minimal effect on sickness behaviors of PRRS infected pigs
• These nutritional top-dress strategies during peak PRRS infection did not alter grow-finisher pig performance.