Classification of behavior at the signs of parturition of sows by image information analysis

영상정보에 의한 모돈의 분만징후 행동특성 분류

Abstract

The aim of this study is to predict the exact time of parturition from analysis and classification of preliminary behavior based on parturition signals in sows. This study was conducted with 12 crossbred sows (with an average of 3.5 parities). Behavioral characteristics were analyzed for duration and the frequency of different behaviors on a checklist, which includes the duration of the basic behaviors (feeding, standing, lying down, and sitting). The frequency of specific behaviors (investigatory behavior, shame-chewing, scratching, and bar-biting) was also recorded. Image information was collected every two minutes for 24 hours before the first piglets were born. As a result, the basic behavior of a sows' standing time (22.6% of the time after 24 h, 24.9% after 12 h) and time lying down (55.9% after 24 h, 66.3% after 12 h) increased over the 12 h period before parturition, compared with the 24 h period before parturition (p<0.01). Feeding (13.42% after 24 h, 4.38% after 12 h) and sitting (8.2% after 24 h, 4.5% after 12 h) tended to decrease during the 12 h before parturition (p>0.05). The sows' investigatory behavior ($11.44{\pm}1.80$ after 24 h, $55.97{\pm}6.13$ after 12 h), scratching ($3.75{\pm}1.92$ after 24 h, $20.99{\pm}5.81$ after 12 h), and bar-biting ($0.69{\pm}0.15$ after 24 h, $3.71{\pm}1.53$ after 12 h) increased in the 12-hour period before parturition, compared with the 24-hour period before parturition (p<0.01). On the other hand, shame-chewing ($2.20{\pm}1.67$ after 24 h, $0.07{\pm}0.01$ after 12 h) decreased compared to the 12-hour period before parturition (p>0.05). Thus, standing, investigatory behavior, scratching, and bar-biting could be used as behaviors indicative of parturition in sows.

본 연구는 모돈의 분만징후에 따른 예비행동특성 분석 및 분류를 통하여 정확한 분만시점을 예측하고자 본 실험을 진행하였다. 모돈 12마리(평균 3.5 산차)에서 분만전 징후의 행동특성으로 측정된 행동은 지속시간에 따라 분석된 기본행동(섭식, 서기, 눕기, 앉기)과 빈도로 분석된 특이행동(탐색, 저작, 긁기, 스톨물기)으로 나뉜다. 분만 24시간 전부터 첫 태아가 나오는 시점까지 시간대별 2분 간격으로 영상정보를 녹화 및 수집하여 분석하였다. 그 결과 모돈의 기본행동 중 서기시간(22.6%; 24H, 24.9%; 12H)과 횡와시간(55.9% ;24H, 66.3% ;12H)은 분만 24시간 전의 빈도가 유의적으로 낮게 나타났다(p<0.01). 섭식시간(13.42% 24H, 4.38% 12H)과 앉기시간(8.2% 24H, 4.5% 12H)은 분만 12시간 전부터 감소하는 경향을 보였다(p>0.05). 모돈의 특이행동 중 탐색행동($11.44{\pm}1.80$ 24H, $55.97{\pm}6.13$ 12H), 바닥을 긁는 행동 ($3.75{\pm}1.92$ 24H, $20.99{\pm}5.8$ 12H) 및 스톨물기 행동($0.69{\pm}0.15$ 24H, $3.71{\pm}1.53$ 12H)은 분만 24시간 전 보다, 분만시간이 점점 다가오는 12시간 전부터 점진적으로 빈도가 증가하였다 (p<0.01). 반면 저작행동 ($2.20{\pm}1.67$ 24H, $0.07{\pm}0.01$ 12H)은 분만 12시간 전부터 감소하는 경향을 보였다(p>0.05). 결과적으로 분만시점이 다가갈수록 서기 탐색 긁기 스톨물기 행동이 높게 발현되는 것으로 나타났다.

Fig. 1. Basic behavioral characteristic of sows captured by CCTV camera (Measure of time budget, min./h)

Fig. 2. Specific behavioral characteristic of sows captured by CCTV camera (Measure of frequence (no./h.)

Fig. 3. Association between time and measure of time budget to basic behavior.

Fig. 4. Frequency of behavioral change (n=12 sows, ** from paired-sample Wilcoxon signed-rank test). ns, not significant.

Table 1. The percentage of time spent in basic behavior for different 12h vs. 24h

Table 2. The count of frequency in specific behavior for different 12h vs. 24h