Using Accelerometers to Determine the Cessation of Activity of Broilers

In recent years, the threat of a pandemic outbreak of avian influenza has become a global issue. The existence of zoonotic strains, causing cases of human infection throughout Eastern Asia, has increased interest in the prevention and containment of avian influenza outbreaks. Research has led to the development of a mass emergency depopulation method utilizing water-based foam for turkeys and chickens. Birds undergoing foam depopulation cannot be easily observed to determine time to death. As a result, a means to monitor birds and to determine time to death was needed to be developed in parallel to the new depopulation method. In this study, the use of an accelerometer for determination of the cessation of reflex reactions during the procedure was validated by comparing muscular cessation on external limbs to cardio-relaxation detected by an electrocardiogram. Electrocardiogram and accelerometer readings were taken from trials in which birds were euthanized by cervical dislocation and compared with other experiments in which water-based foam and CO₂-polyethylene tent treatments were used. Statistical analysis indicated that accelerometers are valid sensors for the detection of the cessation of terminal convulsions in broilers.     

A comparison of uniaxial and triaxial accelerometers for the assessment of physical activity in dogs

The present study compares the outputs of uniaxial accelerometer (UA) and triaxial accelerometer (TA) to determine whether UAs can be used instead of TAs in estimating physical activity (PA) in domestic dogs (N = 79). The PA of the dogs was measured simultaneously by a UA and a TA attached to regular collars under 3 different conditions: unstructured activity in the kennels (kennel activity); and 2 structured on-lead activities of different intensities on a designated pathway (walking and trotting). The study finds that UA consistently detected significantly more steps. Kennel activity showed the largest differences between the accelerometers, and trotting showed the least. Dogs in the heaviest body weight category showed the best correlation between the devices and the least differences between the accelerometers across the 3 activities. The limits of agreement were wide in all activities. Significantly higher agreements were associated with lower step counts in kennel activity and higher step counts in walking and trotting. The results show that these 2 types of accelerometers cannot be used interchangeably. Confounding factors, such as body weight, must be considered in future analysis of accelerometer outputs and selection of devices for different contexts. Optimal interpretation of objectively measured PA is paramount in supporting future dog fitness, health, and welfare studies.     

牛磺酸对肉仔鸡生产性能、养分利用率及脂肪酶活性的影响

本研究旨在探讨牛磺酸对肉仔鸡生产性能、养分利用率及脂肪酶活性的影响。选用240只1日龄AA肉仔鸡,随机分为5组,每组3个重复。对照组饲喂玉米-豆粕型基础日粮,试验组在基础日粮中添加0.05%,0.10%,0.15%和0.20%的牛磺酸,试验期42 d。结果表明:日粮中添加0.10%牛磺酸,能够显著提高肉仔鸡平均日增重和饲料转化率(P<0.05),显著提高18~21日龄粗蛋白利用率(P<0.05);0.15%水平的牛磺酸能够显著提高18~21日龄肉仔鸡的表观代谢能和粗脂肪利用率(P<0.05)及21日龄胰脏和小肠内容物脂肪酶活性(P<0.05);添加牛磺酸对39~42日龄肉仔鸡的养分利用率及42日龄胰脏和小肠内容物脂肪酶活性均无显著影响(P>0.05)。说明牛磺酸对肉仔鸡促生长作用与提高养分利用率有关,且粗脂肪利用率的提高与胰脏和小肠内容物脂肪酶活性提高有关。     

不同蛋白源日粮对肉鸡生长性能、酶活及胫骨特征的影响

文章旨在评估肉鸡在不同生长阶段饲喂不同蛋白源日粮对其生长性能、小肠酶活和胫骨特征的影响。试验将平均初始体重为（43.55±0.36）g的400只商品肉仔鸡随机分为5组,每组4个重复,每个重复20只。试验分为1～14?d和15～28?d两个试验阶段,T1组肉鸡在1～28?d饲喂鱼粉型日粮,T2组肉鸡在1～14?d饲喂豆粕型日粮,15～28?d饲喂鱼粉型日粮,T3组肉鸡在1～14?d饲喂菜粕型日粮,15～28?d饲喂鱼粉型日粮,T4组肉鸡在1～14?d饲喂鱼粉型日粮,15～28?d饲喂豆粕型日粮,T5组肉鸡在1～14?d饲喂鱼粉型日粮,15～28?d饲喂菜粕型日粮。结果：T3和T4组肉鸡1～14?d平均日增重和采食量显著高于T1和T2组,而T1和T2组肉鸡1～14?d料重比最低（P＜0.05）。T1和T5组肉鸡小肠胰蛋白酶活性显著高于其他组（P＜0.05）,T3和T4组肉鸡小肠脂肪酶活性显著高于其他组（P＜0.05）,T1组肉鸡小肠糜蛋白酶活性最低（P＜0.05）。T2组胫骨灰分含量较其他组分别显著提高了9.65%、13.64%、15.74%和17.92%（P＜0.05）。结论：在本研究条件下,肉鸡在生长初期（1～14?d）饲喂菜粕型日粮可以显著改善采食量和日增重。 [关键词]蛋白源饲料|肉鸡|生长性能|酶活|胫骨特征