The protective effects of ButipearlTM Z during heat stress as measured through in vitro studies with swine intestinal epithelial cells and an in vivo swine trial

Abstract Text: Heat stress (HS) is a major issue and negatively impacts the performance and well-being of all animals. Each year, financial losses from HS in production animals is estimated to be more than a billion dollar worldwide. A significant portion of the damage due to HS occurs in the intestine which leads to compromised intestinal integrity, decreased feed intake, decreased nutrient adsorption and poor gut health. Currently, there are few effective products which provide HS protection.  Zinc is an essential trace mineral involved in tight junction formation and butyric acid is an energy source and signaling molecule. Separately, both molecules have been shown to have consistent beneficial effects toward gut health. It was hypothesized that combining zinc and butyric acid together would harvest the benefits of both molecules. A novel formulation containing both zinc oxide and butyric acid was synthesized, encapsulated and is marketed as ButiPEARL^TM Z (BPZ). The effectiveness of BPZ during HS was tested using pig intestinal epithelial cells (IPEC-J2) and a swine HS trial. The in vitro tight junction integrity in cell culture was determined by measuring the transepithelial resistance (TER) of the cells. To determine if BPZ is effective in mitigating HS, IPEC-J2 cells were incubated at thermoneutral (37 °C) or HS (41.5 °C) conditions. A 300 µM dose of BPZ with HS treatment resulted in TER values equivalent to cells grown at thermoneutral conditions (P<0.05). To test the efficacy of encapsulated BPZ on mitigating HS in vivo, a swine trial was conducted with 24 pigs (n=12 pigs/trt). Pigs were supplemented with BPZ or fed a control diet for four weeks.  Pigs were exposed to biphasic HS, 32°C for 8h and 28°C for 16h, for a week after the initial four weeks.  Pigs were euthanized at the end of the HS period.  Fresh ileum and colon samples were collected and studied on Ussing chambers to measure ex vivo intestinal integrity. During the growth phase, there was a trend for higher ADFI and ADG in pigs fed the BPZ treatment (P<0.1). During HS, ADG and Gain:Feed were statistically higher in BPZ group (P<0.05) and ADFI was numerically higher. Additionally, macromolecule permeability in the ileum and colon was numerically lower and villus height and villus height to crypt depth ratio were numerically higher which indicates a more intact tight junction in the BPZ group. The data provides evidence BPZ may mitigate the negative effects of HS.

Keywords: swine, heat stress, zinc