Effects Of Selenium On Production Performance And Biochemical Indexes Of Primiparous Laying Ducks In The Low Temperature Environment

The experiment was conducted to study the effects of selenium levels on growth performance and biochemical indexes in early laying period ducks (18～22w) in the low temperature environment(T<7.29℃). Two hundred and sixteen18-weeks-old jinding ducks were assigned randomly to6selenium levels (0.00mg/kg、0.08mg/kg、0.12mg/kg、0.20mg/kg、0.41mg/kg、0.71mg/kg, six replicates for each treatment,6ducks for each replicate). Basal diet for test was corn-soybean meal diet. The group I was considered as the control group. The period of experiment was5weeks.The results of feeding experiment showed as the follows:In the low temperature environment, the effect of different levels of selenium had no significant effect on feed intake and average daily gain (P>0.05), laying rate, average egg weight and the ratio of feed to egg were significantly influenced (P<0.05). Laying rate and average egg weight of group IV were64.54%、8.13%higher than the control group, and the ratio of feed to egg was39.62%lower (P<0.05).The results of slaughter experiment showed as the follows:In the low temperature environment, addition of0.20mg/kg selenium had significantly improved spleen, thymus and ovarian relative weight(P<0.05), the relative weight of spleen, thymus and ovarian of group Ⅳ were30%,81.25%,67.65%higher than the control group. The effect of different levels of selenium had no significant effect on Oviduct relative length and number of follicles at all levels (P>0.05).The results of blood sampling experiment showed as the follows:In the low temperature environment, different levels of selenium had no significant effect on T-AOC, MDA in hepar(P>0.05). Addition of0.20mg/kg selenium had significantly improved the concentration of T-AOC and MDA in serum(P<0.05).Addition of0.20mg/kg selenium had significantly improved levels of CAT, T-SOD and GSH-PX.(P<0.05). In addition, Addition of0.12mg/kg,0.41mg/kg selenium could significantly improved levels of CAT, GSH-PX in serum and T-SOD, GSH-PX in hepar. Addition of0.20mg/kg selenium had significantly improved the concentration of FSH, P4and IL-2in serum (P<0.05), significantly reduced the concentration of T3and Cort in serum(P<0.05). Addition of0.20mg/kg,0.41mg/kg selenium had significantly improved the concentration of LH and E2in serum (P<0.05), significantly reduced the concentration of BUN and TC in serum (P<0.05). Different levels of selenium had no significant effect on T4, Ig and TG in serum (P>0.05).Addition of0.20mg/kg selenium had significantly reduced the concentration of ALP in serum (P<0.05). Addition of0.12mg/kg,0.20mg/kg,0.41mg/kg selenium had significantly reduced the concentration of TP, ALB, GLB in serum (P<0.05). Different levels of selenium had no significant effect on LDH in serum (P>0.05).