The Effect Of Low Temperature And Selenium On Growth And Biochemical Indexes Of Breeding Ducks In Cage

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.