181 Effect of Temperature and Humidity on Daily Feeding Behavior in Swine

Abstract Heat stress has negative impacts on pork production, particularly during the grow-finish phase. During heat stress events, swine alter feeding behavior to reduce heat production, which can negatively affect performance. Recent technology advancements in feed management systems allow for individualized data recording of feeding behavior for group housed pigs during the finishing phase. The objective of this study was to utilize an RFID-based feed management system to determine feeding behavior patterns of finishing pigs during heat stress conditions and identify changes in behavior due to heat stress events. Data included one pen of 29 Duroc boars reared in a mechanically ventilated facility in north central North Carolina. Feed Intake Recording Equipment (FIRE) pig feeders (n = 3; Osborne Technologies) fed individual pigs in the group housed setting using RFID technology and recorded the number of visits, feed intake of each visit, visit duration, and body weight of each pig during each visit. Feeders were calibrated once per week to ensure accuracy of feed intake and body weight measurements. On day 1 of the study, pigs were placed in the experimental pen and body weights were recorded (37.4 kg ± 4.9 kg) using the FIRE feeders. Air temperature, humidity, and dew point data were collected continuously every 5 minutes from day 13 until the end of the finishing period. Pigs exited finishing (134.5 ± 8.6 kg) on day 83. Feeding behavior traits (number of visits and feed intake) were summarized by day. Temperature, humidity, and heat index were summarized by a maximum, minimum, and mean value for each day. Average temperature, humidity, feeder visits a day, and average daily feed intake across the trial was 26.3 ± 1.6 º C, 75.8 ± 6.7%, 6.1 ± 1.0 visits, 2.66 ± 0.39 kg. Models were used to associate feeding behavior traits with the quadratic effects of day and the linear effects of average temperature and humidity and the interaction of temperature and humidity. Temperature and humidity were associated (P < 0.01) number of feeder visits and average daily intake per day. Further, there was an interaction (P < 0.01) between temperature and humidity in relation to number of feeder visits and average daily feed intake. Results suggest substantial variation in feeding behaviors can be explained by temperature and humidity.