张苏楠 田建艳 菅垄 姬政雄

摘要： 在集约化养殖过程中，生猪打斗行为是影响生猪福利养殖的重要因素之一。针对复杂养殖环境下传统方法识别圈养生猪打斗行为准确率低的问题，提出1种基于帧间差分法（Frame difference， FD）-单点多框检测器（Single shot MultiBox detector， SSD）的生猪打斗行为识别方法。首先，利用帧间差分法提取生猪连续视频帧中的移动像素，排除光照度变化、地面水渍及尿渍等环境因素以及静止生猪对打斗行为识别的干扰。然后，以连续视频帧中的移动像素为样本，采用MobileNet_v2、焦点损失函数、网络参数迁移学习对单点多框检测器进行改进，用于检测发生剧烈运动的生猪个体，提高SSD对运动生猪个体的检测精度与速度。最后，针对生猪发生打斗行为时的特点，设计精准的生猪打斗行为判别方法，以识别生猪是否发生打斗行为。试验结果表明，该方法对生猪打斗行为的识别准确率、查准率、查全率分别达到93.75%、96.79%、90.50%，可以有效识别圈养生猪的打斗行为，为饲养员判断生猪异常状况提供依据。

关键词： 生猪;打斗行为;帧间差分法;单点多框检测器;判别方法

中图分类号： TP391.41  文献标识码： A  文章编号： 1000-4440（2021）02-0397-08

Abstract： Aggressive behavior of live pigs is one of the most important factors influencing welfare breeding of live pigs in the process of intensive breeding. Aiming at the problems of low accuracy rate of traditional methods in detecting aggressive behaviors of live pigs in pigpens under complex breeding environment， an identification method for porcine aggressive behaviors was proposed based on frame difference （FD）-single shot MultiBox detector （SSD）. Firstly， FD method was used to extract the moving pixels in continuous video frames of live pigs to eliminate the interference of environmental factors such as illuminance change， surface water stain， urine stain and static pigs on the detecting of aggressive behaviors. Secondly， using the moving pixels in continuous video frames as samples， the SSD was improved by using MobileNet_v2， focal loss function and transfer learning of network parameters to detect the violently moving live pigs and improve the detection accuracy and speed of SSD. Finally， according to the characteristics of live pigs with aggressive behaviors， accurate discriminative method for live porcine aggressive behavior was designed to recognize aggressive behaviors. The experimental results showed that， the accuracy rate， precision rate and recall rate of the proposed method in recognizing porcine aggressive behaviors reached 93.75%， 96.79% and 90.50% respectively. The method can effectively recognize the aggressive behaviors of live pigs in pigpens and provide judgment basis for breeders.

Key words： live pig;aggressive behaviors;frame difference;single shot MultiBox detector;discriminant method

福利養殖是指在养殖过程中满足动物最基本的自然需求，使动物免于不必要的痛苦，在现代化养殖系统中，打斗行为是影响生猪集约化养殖福利水平的重要因素之一[1]。在集约化养殖过程中，当生猪摄取的膳食纤维含量低、猪群构成发生变化或活动空间有限时，都可能导致生猪发生打斗行为[2]。……