【作者】 李睿；

【导师】 王安；

【作者基本信息】 东北农业大学 ， 动物营养与饲料科学， 2008， 硕士

【摘要】 本试验研究低温和硒水平对0-4周龄笼养蛋雏鸭生产性能及生化指标的影响。本试验采用两因素有重复设计,两因素分别是环境温度和硒水平。设两个温度水平,分别为低温和适温,适温为雏鸭的正常育雏温度。温度控制要求为1-7日龄为30～33℃,8-14日龄为28～30℃,15-21日龄为24～26℃,22-28日龄为21～25℃。低温处理前三天温度与适温舍相同,第四天开始控制为低于适温舍5±1℃,第28天时与适温舍温度相同21℃。在玉米—豆粕型基础日粮中,分别添加硒(亚硒酸钠)0.2mg/kg(适硒)、0.4mg/kg (中硒)和0.8mg/kg (高硒)组成3种试验日粮。将1日龄健康金定母鸭雏216只,按试验设计随机分为6个处理,每个处理6个重复,每个重复6只鸭。饲养试验结果表明:低温使全期日采食量升高,而使日增重降低,在低温环境下提高饲粮硒水平,能使日采食量有所下降,而日增重有上升的趋势。血液生化指标结果表明:(1)不同处理组对血清中K和Na影响显著(P<0.05);温度对血清中K、Na和Cl影响不显著(P>0.05),低温有使血清K上升的趋势;硒对血清中K、Na和Cl影响不显著(P>0.05)。(2)不同处理组对血清中白蛋白、球蛋白和白蛋白与球蛋白之比影响显著(P<0.05);温度或硒对血清中总蛋白、白蛋白、球蛋白、白蛋白与球蛋白之比影响均不显著(P>0.05)。(3)不同处理组对血清中尿酸和肌酐影响显著(P<0.05);温度对血清中尿酸和肌酐影响显著(P<0.05),对血清中尿素氮影响不显著(P>0.05);硒对血清中尿酸、尿素氮和肌酐影响均不显著(P>0.05)。(4)温度或硒对CO2、pH、渗透压和阴离子间隙均没有达到显著水平(P>0.05)。温度和硒的交互作用对CO2、pH、渗透压和阴离子间隙无显著影响(P>0.05)。(5)温度对血清中T3影响极显著(P<0.01),在低温条件下添加硒使血清中T3显著降低(P<0.05)。温度对血清中T4影响不显著(P>0.05),中硒水平显著提高了血清中T4的浓度(P<0.05)。温度对血清中皮质醇影响不显著(P>0.05),低温使血清中皮质醇有增加的趋势;硒对血清中皮质醇影响不显著(P>0.05),但随硒添加量的增加,血清中皮质醇有下降趋势。(6)不同处理组对血清总抗氧化能力影响差异显著(P<0.05),在低温条件下,随硒添加量的增加,血清总抗氧化能力有升高趋势。低温显著增加了血清丙二醛的含量(P<0.05),硒对血清丙二醛没达到显著水平(P>0.05)。综合考虑生长性能、饲料转化率以及血液生化指标等变化情况,表明低温条件下,适当提高饲粮硒添加水平(本试验推荐适宜的添加量为0.4mg/kg)可缓解冷应激对雏鸭所造成的不利影响。更多还原

【Abstract】 The experiment was conducted to study the effect of low temperature and different levels of Selenium diets on the Jin-ding ducks in cage in the period of breeding (0-4weeks). The experiment was designed with two factors, one factor is temperature, another is different levels of Se. The temperature of normal group was controlled at 30～33℃in 1-7 days, at 28～30℃in 8-14days, at 24～26℃in 15-21days and at 21～25℃in 22-28days .The temperature of two groups was controled as the same in 1-3 days, then the temperature of groups lived in cold was controled 5±1℃lower than the normal groups from the fourth day to the end of this experiment. The temperature of the groups lived in low temperature was 21℃the same as the normal groups at the 28th day. Se had three levels, 0.2mg/kg, 0.4mg/kg and 0.8mg/kg. The 216 Jin-ding brooding ducks were assigned to six groups randomly. Every group has six repetitions and every repetition has six ducks.The results of feeding trial showed as the follows:In low temperature, feed intake increased while daily weight gain decreased; In low temperature, as the level of Se increased, feed intake was tending to downwards meanwhile daily weight gain was tending to upwards (P>0.05).The results of serum biochemical indexes showed as the follows:(1) Different treatments had significant effect on K and Na (P<0.05). The effect of temperature on K, Na and Cl was not significant (P>0.05), and K was tending to upwards in low temperature. The effect of Se on K, Na and Cl was not significant (P>0.05)(2) Different treatments had significant effect on ALB, GLB and A︰G (P<0.05). Temperature or Se had no significant effect on TP, ALB, GLB and A︰G (P>0.05).(3) Different treatments had significant effect on URIC and CRE (P<0.05). The effect of temperature on URIC and CRE was significant (P<0.05), while BUN was not changed significantly (P>0.05). The effect of Se on URIC, BUN and CRE was not significant (P>0.05).(4) Temperature or Se had no significant effect on CO2, pH, OSM and AG (P>0.05). The interact effect of temperature and Se on CO2, pH, OSM and AG was not significant (P>0.05).(5) The temperature had significant effect on T3 (P<0.01), and T3 showed significantly declined (P<0.05) with the level of Se increased in low temperature. The effect of low temperature on T4 was not significant (P>0.05).T4 showed significant increased (P<0.05) as the level of Se increased to 0.4mg/kg. The effect of temperature on Cort was not significant (P>0.05), but was tend to upwards in low temperature. Se had no significant effect on Cort (P>0.05),but Se made Cort trending to downwards.(6) Different treatment had significant effect on T–AOC (P<0.05). In low temperature, T–AOC was tending to upwards with the level of Se increased. The effect of low temperature on MDA showed significantly increased (P<0.05), but Se had no significant effect on MDA (P>0.05).Thinking over the changing tendency of growth performance, feed intake/weight gain and biochemical indexes comprehensively, it can be concluded that increase the diet on Se appropriately can alleviate the hurt to breeding ducks who lived in low temperature.更多还原