The Effect Of Cold Stress And Different Energy Levels On Production And Sex Biochemical Indexes In Laying Ducks

The experiment was designed to study the effect of cold stress and dietary energy levels on theJin-ding ducks in cage. In the experiment, 144,13-week-old Jin-ding ducks were assigned to sixgroups randomly with six replicates of four ducks, in 2×3 factors. They were fed in coldtemperature(2±1℃) or (18±1℃). The metabolizable energy of diets are 10.68MJ/kg, 11.36MJ/k and 12.04 MJ/kg, and the additive is vegetable tallow. The experiment was to study theproduction, sex development and serum biochemical indices.The results of feeding experiment showed that in cold temperature, feed intake and feedconversion ratio increased, while daily weight gain decreased (P＞0.05). In cold temperature, asthe dietary level increased, feed intake and feed conversion ratio was tending downwards, anddaily weight was tending upwards.The results of slaughter showed that the development of ovary and oviduct slowered (P＞0.05)in cold temperature, as the dietary level increased, the develop of ovary and oviduct was tendingupwards.The results of serum biochemical indices showed: (1) in cold temperature, the concentration ofserum T₃,progesterone and the T-AOC decreased (P＞0.05), but serum T₄ increased (P＞0.05), asthe dietary level increased, serum T₃,T₄,progesterone and T-AOC were tending upwards. (2) incold temperature, serum total protein significantly decreased (P＜0.01), and serum albumin andglobulin slightly decreased (P＜0.05), as the dietary level increased, serum total protein andalbumin were tending upwards. (3) in cold temperature, serum natrium and calcium had significantdifference (P＜0.01), and serum chlorine and magnesium had difference (P＜0.05), but serum kaliumhad no difference (P＞0.05), but except serum chlorine, the concentration of serum ions of lowtemperature group is lower than warm temperature group. In cold temperature, as the dietary levelincreased, serum natrium,kalium magnesium and calcium were tending upwards. (4) in coldtemperature, ALT,LDH and CK had no difference (P＞0.05), and AST had significant difference(P＜0.01), but the activity of enzymes of low temperature group is higher than warm temperaturegroup. In cold temperature, as the dietary level increased, the activity of ALT and LDH weretending upwards, but the activity of AST and CK were tending downwards. (5) in cold temperature,serum CRE, glucose significantly decreased (P＜0.01), the concentration of TG, CHOL and BUNhad no difference (P＞0.05). In cold temperature, as the dietary level increased, BUN were tendingdownwards, and TG and serum glucose were tending upwards, but CRE and CHOL had no significant variety trend.In all, in low temperature, increasing the energy of feeding can bate the bad effect of lowtemperature.