Effects of feed removal during acute heat stress on the inflammatory response and short-term growth performance in grow-finish pigs

Authors: KPODO, KOUASSI - Purdue University; DUTTLINGER, ALAN - Purdue University; MASKAL, JACOB - Purdue University; MCCONN, BETTY - Orise Fellow; Johnson, Jay

Submitted to: Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2021
Publication Date: 1/15/2021
Citation: Kpodo, K.R., Duttlinger, A.W., Maskal, J.M., Mcconn, B.R., Johnson, J.S. 2021. Effects of feed removal during acute heat stress on the cytokine. Animals. 11(1). https://doi.org/10.3390/ani11010205.
DOI: https://doi.org/10.3390/ani11010205

Interpretive Summary: Extreme heat events put pigs at a greater risk for acute heat stress and reduces intestinal health and producer profitability. To combat the negative effects of heat stress, a quick return of body temperature to normal is necessary. However, the return of body temperature to normal can be delayed by feed access during recovery, which may have detrimental effects on intestinal health and future pig performance. Therefore, the study objective was to determine whether feed removal during and after an acute heat stress event would improve short-term growth performance and reduce biomarkers associated with intestinal damage and inflammation in grow-finish pigs. We hypothesized that feed removal during an acute heat stress event would result in a faster return of body temperature to normal, reduce the inflammatory response, and improve short-term growth performance in grow-finish pigs. Although body temperature and some inflammatory biomarkers were altered by heat stress and feeding treatments, overall, few beneficial effects of feed removal during acute HS were detected in grow-finish pigs in the present study.

Technical Abstract: The study objective was to evaluate the effects of feed removal during acute heat stress (HS) on the systemic inflammatory response and its short-term effect on growth performance in grow-finish pigs. Thirty-two pigs (93.29 ± 3.14 kg initial body weight; 50% barrows and 50% gilts) were subjected to thermoneutral (TN; 23.47 ± 0.10°C; n = 16 pigs) or HS (cycling 25 to 36°C; n = 16 pigs) conditions for 24 h. Within each temperature treatment, 50% of the pigs were provided feed (AF; n = 8 pigs/temperature treatment) and 50% of the pigs had no feed access (NF; n = 8 pigs/temperature treatment). Following the 24-h temperature and feeding treatment (TF) period, all pigs had ad libitum access to feed and water and were maintained under TN conditions for 6 d. During the first 12 h of TF, gastrointestinal (TGI) and skin (Tsk) temperatures were recorded every 30 min. Serum cytokines were determined at 0, 4, 8, 12, and 24 h during the TF period and on d 3 and 6 of the post-TF period. Average daily gain (ADG) and average daily feed intake were measured on d 1, 3, and 6 of the post-TF period. Behavioral data were collected from d 1-6 of the post-TF period. Heat stress increased (P < 0.02) TGI and Tsk. During the post-TF period, IL-1a was greater (P < 0.01) in HS+NF compared to HS+AF and TN+NF pigs. From d 1 to 2 of the post-TF period, ADG was reduced (P < 0.01) in TN+AF compared to HS+AF, HS+NF, and TN+NF pigs. In conclusion, feed removal during an acute HS challenge did not reduce the systemic inflammatory response or improve short-term growth performance in grow-finish pigs.