间歇光照对肉鸡体内脂质过氧化作用和抗氧化酶活性的影响

Effects of intermittent lighting schedules on incidence of ascites and lipid peroxida-tion and enzymatic antioxidant activity in broilers

低温诱发肉鸡肺动脉高压综合征(PHS),动态观察限制光照对肉鸡PHS发病率及体内脂质过氧化作用的影响。将320羽1日龄肉鸡随机分为4组。常温组按常规饲养,24 h连续光照。3个低温组从14日龄起逐步降温诱发PHS,并于9～30日龄分别在夜间停止光照0、35、h。结果,低温组PHS发病率、右心全心比(RV/TV)、肺厚壁末梢血管百分率(%TWPV)和丙二醛(MDA)水平显著升高,而血浆超氧化物歧化酶(SOD)活性降低。限制光照组SOD活性升高而PHS发病率、RV/TV、TWPV和MDA显著降低。间歇光照组早期生长速度减慢,后期体质量得到补偿性增长,并在44日龄与连续光照组差异不显著。这一结果表明,减轻体内脂质过氧化作用,提高机体抗氧化酶活性并减轻以非肌型肺动脉肌型化为特征的肺血管重构,可能是限制光照使肉鸡PHS发病率降低的机理之一。

The purpose of the present study was to examine the efficacy of intermittent lighting schedules at night in reducing the incidence of ascites induced by cool environment and to test its effect on the lipid peroxidation and activity of enzymatic antioxidant in broilers. A total of three hundred and twenty 1-day-old Avian-2000 mixed-sex commercial broilers were allocated randomly to four rooms at 9 days of age. In one room,the continuous lighting（CL） schedule of 24 h light：0 h dark was maintained,and ambient temperature was kept normal temperatures（ maintained at 20℃ ）. While in other three rooms CL schedule of 24 h hght：0 h dark and intermittent lighting（IL） schedules of 21 h light：3 h dark and 19 h light：5 h dark were imposed respectively during the night from 9 to 30 days of age. Chickens in the later three rooms were subjected to a low temperature to induce pulmonary hypertension syndrome（PHS）. The results showed that low temperature increased significantly RV/TV and the ascites morbidity, so were the plasma MDA concentration and the percentages of TWPV. Whereas the plasma SOD activity decreased. IL schedule had successfully prevented PHS in broilers. The values of RV/TV and the plasma MDA concentration reduced significantly, whereas the activity of the plasma SOD promoted significantly. Body weights were reduced significantly by light restriction at 20 days. However,/L broilers exhibited compensatory growth during the finisher period in such a way that at day 44（market age） ,a similar BW as that of their CL counterparts was attained. The results indicated that alleviated the lipid peroxidation, enhanced the enzymatic antioxidant activity and reduced the percentages of the TWPA may be the part mechanism of IL schedule prevent ascites of broiler.