(P30-023-23) Vasoactive Intestinal Polypeptide (VIP) May Suppress Inflammation in Lambs Fed a Corn Grain-Based Diet

Objectives: Grain-based diets are commonly fed to finishing ruminants to maximize growth and efficiency of nutrient utilization. However, feeding grain-based diets can result in acidosis-associated inflammation challenges that can adversely impact growth performance. Providing the anti-inflammatory mediator, vasoactive intestinal polypeptide (VIP), could help to decrease the adverse effects associated with ruminal acidosis. The objectives were to determine the effects of providing VIP to lambs fed a corn grain-based diet on serum cytokine concentrations.

Methods: Sixteen Wether lambs (69.6 ± 1.9 kg) were housed in individual pens, adapted to a corn grain-based diet containing no added forage, and randomly assigned into two treatment groups. The treatment period occurred over 28 days and consisted of intraperitoneal injection of a saline (0.9% NaCl) solution containing VIP (1.3 nmol/kg BW; n = 8) or no VIP (n = 8) every other day. Blood samples were collected once a week throughout the treatment period in the morning before fresh feed was offered and serum was obtained by centrifugation. Using multiplex technology, serum concentrations of anti-inflammatory, pro-inflammatory, and pleiotropic cytokines were analyzed using the Milliplex ovine cytokine/chemokine immunology panel. Data were analyzed as repeated measures using the MIXED procedure of SAS 9.4 (SAS Inst Inc., Cary, NC, USA).

Results: The anti-inflammatory cytokine, IL-10, and IL-36RA, were greater (P = 0.006) in VIP-treated lambs than in 0.9% NaCl-treated lambs. The measured pro-inflammatory cytokines (IL-1α, IL-1β, IL-8, MIP-1β, IP-10, TNFα and IL-17A) were not influenced (P ≥ 0.06) by treatment. For the measured pleiotropic cytokines, MIP-1α was greater (P = 0.001) in VIP-treated lambs and IL-6, INFγ, and VEGF-A were not influenced (P ≥ 0.1) by VIP treatment.

Conclusions: These data suggest that VIP could potentially reduce inflammation in lambs fed corn grain-based diets.

Funding Sources: This research project was funded by the State Board of Agricultural Research and Education (SBARE) grant.