Nutrient supplementation effects on pig performance and sickness behavior during a porcine reproductive and respiratory syndrome virus infection

Abstract

Objective: Investigate how nutrient additive inclusion impacts performance and sickness behavior in pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV). Materials and methods: At 10 weeks of age, 108 PRRSV naïve barrows (mean [SD] body weight: 31 [1.4] kg) were allotted into 18 pens in a commercial barn and enrolled in a 35-day PRRSV challenge study. After a 5-day acclimation period, all pigs were inoculated intranasally and intramuscularly with a field strain of PRRSV and began nutrient supplement treatments. Treatments included no nutrient supplement (control; n = 6 pens), water nutrient supplement (water; n = 6 pens), and water and feed nutrient supplement (water+feed; n = 6 pens). Pen performance was recorded weekly at 0, 7, 14, 21, 28, and 35 days post inoculation (dpi). Pig homepen behavior was recorded on -1, 3, 6, 9, 12, 15, and 18 dpi. Results: Over the 35-day challenge, no significant differences in pig viremia or performance were reported due to treatment. Compared to control, water+feed additive increased sitting in pigs; however, no other sickness behavior treatment differences were observed. Decreased activity was observed 6 and 9 dpi. Eating was decreased 6 dpi whereas drinking was decreased from 6 dpi throughout the rest of the behavioral observation period at 18 dpi. Implications: The addition of a nutrient additive in water and water+feed had minimal effect on sickness behavior and no observed effect on viremia or performance of PRRSVinfected pigs. Decreased activity, eating, and drinking may help caretakers identify healthchallenged pigs.