分娩限位栏经历丰富度对陌生环境的母猪行为和内分泌的影响

In modern intensive swine industry, traditional farrowing crate causes poor health and welfare in farrowing sows, bad maternity and high crushing mortality for preweaning piglets. With the enhancement of animal welfare consciousness in public, farrowing pen is modified and perfected continuously to improve welfare, recover maternity and increase production efficiency for farrowing/lactating sows. It can be predicted that traditional farrowing crate will be displaced by perfect alternative farrowing systems in the near future. However, alternative farrowing system is an unfamiliar farrowing enviroment for farrowing sows, possiblly causing enveronmental stress. Environmental experience enrichment of earlier stage takes impact on adaptation capacity of unfamiliar environment for farrowing sows, but the mechanism is not clear. Based on animal behaviour and endocrine, the project will analyze the impact of environmental experience enrichment of earlier stage in crate for farrowing sows on adaptation capacity in unfamiliar farrowing environment, and analyze the effect of the accumulation of experience in unfamiliar environment on sow behaviour and endocrine in the next parity. Based on environmental experience enrichment of earlier stage and welfare, the project will build a new pattern to evaluate the level of sow welfare. The research will offer theoretical guidance to recover sow maternity and decrease mortality for preweaning piglet through designing a suitable farrowing environment.

在现代集约化养猪生产中，传统分娩限位栏母猪的健康与福利水平低下，母性退化和仔猪压死问题十分严重。随着国际社会民众动物福利意识的不断提高，多年来人们一直试图改进和完善母猪分娩猪栏，以提高母猪福利水平、恢复母性，并提高分娩母猪的生产效率。可以预测，传统的分娩限位栏将逐步被其理想的替代系统所取代。然而对于母猪而言，替代系统属于陌生的分娩环境，容易引起母猪的环境应激。前期环境经历丰富度对母猪陌生环境的适应能力有影响，但尚不明确其影响机制。本项目拟从动物行为和内分泌角度，探讨前期分娩限位栏环境经历丰富度对母猪陌生分娩环境适应能力和内分泌的影响，分析陌生分娩环境经历的积累对后续胎次母猪的内分泌和行为的影响。本研究将前期分娩环境经历丰富度与母猪福利相结合，建立母猪分娩环境福利水平评价的新模式，为优化生存环境，改善分娩母猪的健康与福利化水平，从环境角度恢复母猪母性和降低哺乳仔猪死亡率提供理论指导。

项目在相同产房条件下，以相同规格分娩限位栏作为分娩陌生环境，持续跟踪测定了具有0-6次分娩限位栏分娩经历大约克母猪的行为、生理、血液内分泌和产仔哺育性能指标。研究初步明确，母猪前期分娩限位栏环境经历丰富度的增加，可通过行为、生理、内分泌等多种途径调控，缓解其再次进入陌生分娩环境的不利应激，更好地适应陌生分娩环境，产程缩短，产仔哺育性能改善。. 1. 前期分娩限位栏经历丰富度增加可减少陌生分娩环境中母猪的异常行为.对试验母猪产仔前后15个行为指标的分析结果显示，母猪前期分娩限位栏分娩经历次数增加，其在陌生分娩环境内的运动步数显著减少，异常行为的发生频率和持续时间显著降低。前期分娩限位栏经历丰富度的增加，有助于母猪通过行为模式调整来更好地适应陌生分娩环境。. 2. 前期分娩限位栏经历丰富度的增加有利于陌生分娩环境内母猪生理和内分泌调控，更好地适应陌生分娩环境.对试验母猪产仔前后的3项生理指标和15项血液内分泌及生化指标的分析结果表明，随着前期分娩限位栏分娩经历次数的增加，再次进入分娩限位栏的母猪体表温度和心率逐渐降低，血液中的胰岛素水平由低位逐渐上升，血糖由高位逐渐下降，皮质醇、促肾上腺皮质激素、乳酸脱氢酶水平由高位逐渐降低。前期分娩限位栏环境经历丰富度的增加有助于母猪的生理、内分泌调控，从而更好地适应陌生分娩环境。. 3. 前期分娩限位栏经历丰富度的增加可缩短母猪产程，改善产仔哺育性能. 对试验母猪产程及产仔哺育性能指标的分析结果显示，随着前期分娩限位栏分娩经历次数的增加，母猪产程缩短，产死仔数减少，泌乳力（仔猪21日龄窝重）和哺乳成活率改善。. 本研究系统揭示了陌生分娩环境下母猪前期分娩限位栏经历丰富度对其行为模式、生理和内分泌指标、产仔哺育性能的影响，对进一步探讨母猪陌生分娩环境适应机制，构建和完善分娩母猪生存环境的福利水平评价新模式，优化分娩母猪管理和提高母猪产仔哺育性能具有重要意义。