影响母猪瞳孔光反射特征的生理与环境因素的研究

Animals suffering chronic stress should give rise to psychological and mental problems which leads to decline in animal welfare. Existed methods detecting psychological condition of domestic animals are usually indirect, thus it is necessary to explore possible direct method measuring welfare condition. In referring to human's cases that abnormal pupillary light reflex is related to depression. Previous studies showed that sows in farrowing crates performed attenuated PLR characteristic, and also found that its attenuated PLR characteristic was related to psychological stress and physiological condition. If we can can prove the inherent relations. It would be allowed us to establish a new way to evaluate animal welfare, and provide a new way for clinical detection of welfare for domestic animal individual. The purpose of the study is to consider the sows' breed, age, psychological adaptation, physiological and immunological condition and housing environment as the possible influence factors and observe their effects on characteristics of sows' PLR; this can help us theoretically understand the functions of heredity, physiology, environmental conditions on sows' PLR and its modification, and also help us explore the sows' PLR characteristics and the factors leading to psychological problems. It could provide a theoretical basis and technical parameters for establishing a new non-invasive method of detecting chronic psychological stress to evaluate the welfare of sows.

集约化生产中的动物会因长期慢性应激而导致心理疾病或精神异常，是福利水平下降的标志。以往检测家畜心理状况的方法都是间接的，鉴于人类瞳孔反射异常与抑郁症等心理疾病相关的临床有效性启示，有必要开展哺乳类家畜瞳孔反射的基础研究，探索直接检测其心理状态的有效方法。前期研究发现限位饲养母猪存在瞳孔光反射延迟现象，且该现象与异常行为和神经递质、激素水平存在一定联系。如能证实其内在的必然联系，就可以开发一种通过瞳孔检测来评价母猪福利的新方法，为畜禽个体福利状态的临床检测提供新途径，但前提是要明晰母猪瞳孔光反射的基本生理特征。本研究结合母猪品种、年龄、心理适应性、生理与免疫水平、饲养环境等因素，开展母猪瞳孔光反射生理特征的研究，旨在了解遗传、生理、环境对猪瞳孔光反射的影响及修饰，系统的探索母猪瞳孔光反射特征及其影响因素，为确定瞳孔反射能否作为检验动物心理异常或慢性应激提供理论依据及可行的基础技术参数。

本研究以经产繁殖母猪为研究对象，以母猪瞳孔光反射与母猪品种、年龄、饲养环境、规癖行为表现、神经递质、激素、免疫水平的关系为研究内容，探索不同生理基础、心理基础、环境条件对母猪瞳孔光反应的影响。目前已经开展了以下三部分的研究：1.归纳母猪瞳孔反射的生理特征并建立母猪瞳孔反射检测的指标体系。2.瞳孔光反射与母猪心理相关指标的相关性研究。3.瞳孔光反射与限位母猪生理和心理指征的相关性研究。4．丰富环境资源对母猪的福利状况和瞳孔反射的影响。研究结果发现：（1）不同环境、年龄间母猪PLR具有显著差异性，表现为长期的环境限制下母猪的瞳孔收缩能力低于群养环境，长期环境限制和年龄增加均导致瞳孔收缩能力减退。（2）不同饲养环境妊娠母猪的激素、神经递质具有显著差异性，限位环境显著影响母猪的生理状态。（3）比较PLR与行为、神经递质、激素、免疫水平之间的相关关系，表明PLR可以在一定程度上反映妊娠母猪的心理状态。（4）丰富的环境能够提高产后母猪和仔猪的福利状况。综上所述，本研究通过开展母猪瞳孔光反射基础特征的研究，建立母猪瞳孔光反射的生理特征，在此基础上阐明了品种因素、生理条件和环境因素对瞳孔反射的影响，揭示了母猪瞳孔光反射异常现象的标准模型，也表明了瞳孔反射特征尤其是收缩指标能够作为一种检测心理情绪状态的指标，为母猪瞳孔反射异常与慢性应激或抑郁有关提供科学依据，为建立检测母猪抑郁新方法提供证据。