PSVI-14 - Effects of scent and vocal sensory stimuli to ease piglet stress during weaning phase

Abstract: In the pig industry, weaning stress is a major factor in early production losses due to reduced weight gain, increased disease incidence, and aggressive behavior. Challenges piglets face during this time include maternal separation, abrupt diet change, and social stress due to comingling. Previous research demonstrated sensory stimuli can impact pig behavioral responses and growth. Artificially providing the sow’s scent and nursing call vocalizations may help piglets more quickly adjust to the changes in the post-weaning environment to resume normal behavioral patterns, improve health outcomes, and increase daily gain. The objective of this study was to investigate the effects of providing own-mother scent and vocal sensory stimuli on piglet behavior and growth. During weeks 2 to 3 of lactation, individual sow grunting was recorded while piglets were nursing. These audio files were combined into a single loop of 20 minutes sow grunting followed by no sound for 60 minutes. A 100% cotton cloth was firmly rubbed along the ventral midline of each sow’s udder to collect scent, then immediately vacuum packed and sealed. At weaning, 8 piglets (4 male and 4 female) from each of 12 litters were selected and assigned randomly to one of four treatment groups: NoVocal_NoScent (C), NoVocal_Scent (S). Vocal_NoScent (V), and Vocal_Scent (VS) as a 2x2 factorial arrangement. At weaning, piglets were weighed, transported to nursery, placed in 12 pens with 4 piglets per pen, and provided ad libitum access to water and standard nursery grower diet. The Vocal treatment groups were exposed to the recorded loop of sow grunting for 7 days. The Scent treatment groups were exposed to the cloths with their own mother’s scent for 2 days. The No Scent groups were exposed to cloths with no scent. Behavior was monitored with continual video recording of all pens for 7 days. Behaviors of interest were selected as Approached Feeder, Feeding, Scent – curious, Scent – Interested, and Fighting. Weights were recorded on days 1, 3, 5, 7, 14, 21, 28, and 42. Data was analyzed using GLIMMEX Mixed Model procedure SAS (Cary, NC). Whole plot treatment factor was voice; subplot treatment factor was scent. Results suggested providing own-mother vocalizations to piglets in the immediate post-weaning phase had no effect on weight gain (P > 0.9) and increased incidence of fighting (P< 0.01). Results further suggested the provision of own-mother scent for 2 days resulted reduced fighting (P< 0.01) and increased interest and feeding behavior compared to no scent groups (P< 0.01).