Effects of Mixing on the Aggressive Behavior of Commercially Housed Pigs

• Published in: Animal bioscience Vol. 28; no. 7; pp. 1038 - 1043
• Main Authors: Rhim, Shin-Jae, Son, Seung-Hun, Hwang, Hyun-Su, Lee, Jae-Kang, Hong, Joon-Ki
• Format: Journal Article
• Language: English
• Published: Korea (South) Asian - Australasian Association of Animal Production Societies 01.07.2015; Asian-Australasian Association of Animal Production Societies (AAAP) and Korean Society of Animal Science and Technology (KSAST); Asian-Australasian Association of Animal Production Societies; 아세아·태평양축산학회
• Subjects: Aggressive Behavior; Aggressiveness (Psychology); Behavior; Dominance Index; Health aspects; Interaction; Mixing; Pig; Swine; 축산학; Mixing; Aggressive Behavior; Interaction; Dominance Index; Pig
• ISSN: 1011-2367; 2765-0189; 1976-5517; 2765-0235
• DOI: 10.5713/ajas.14.0907

In this study, we investigated the effects of mixing on the aggressive behavior of commercially housed pigs. The behavioral patterns of 36 groups of pigs (a total of 360 animals) were observed over 3 consecutive days directly after weaning (25±1.2 days of age), and 25 and 50 days later with the aid of video technology. Fight latency and total duration and frequency of fighting were significantly different among the age groups. The aggressive behaviors decreased in 75-day old pigs if compared to 25- and 50-day old animals. Moreover, dominance index (DI) was higher in 25-day old and lower in 75-day old pigs. A comparison of dominant (DI>0) and submissive (DI<0) pigs showed significant differences (p<0.05) for major aggressive behaviors in all age groups. Dominant pigs were involved in more aggressive interactions, had longer fights, and initiated more fights than submissive pigs. Post-mixing aggressive behavior was altered by previous experience of mixing. Aggressive behavior and DI are suitable methods for analyzing the effects of mixing on commercially housed growing pigs.