Effects Of Vitamin B₂ On Growth Performance And Biochemical Indexes Of Laying Ducklings Reared In Cages

The experiment was conducted to study the effects of vitamin B₂ (VB₂) on Growth Performance and Biochemical Indexes of of Laying Ducklings Reared in Cages of ducklings in cages.Two hundred and eighty-eight one day old Jin-ding ducks, with an average of (43.13±1.19) g, were randomly allotted into six treatments. each group with eight ducks. VB₂ were added 0, 4, 6,10, 20 or 50mg/kg diet, Experimental period was four weeks.In the experiment, the laying ducks were weighted at the beginning and the end. For each replicate group, ducks weight and surplus feed were recorded weekly to calculate daily gain and feed conversion ratio. In the fiveth day and fourth week, one was randomly taken out and taken blood from wing vein.and randomly killed to take out the spleen,bursa of fabricius for mensuration.The results of feeding experiment showed that the levels of Vitamin B₂ had significant effect on daily gain,feed intake and feed conversion ratio, and 10 mg·kg^-1 can notablely increase daily gain and improve feed conversion ratio. More or less Vitamin B₂ level couldn't develop the production of laying ducks well.The results of antioxidant capacity showed that the levels of Vitamin B₂ had significant effect on the activities of T-AOC,SOD,GSH-Px and CAT. while with the increasing of Vitamin B₂ level, the activity antioxidant capacity were at first increased and subsequently decreased, while with the increasing of Vitamin B₂ level, At 1-7 days add VB₂ 10mg/kg-20mg/kg the antioxidant indicators to achieve the greatest; At 8-28 days add VB₂ 10mg/kg the antioxidant indicators to achieve the greatest; At 1-7 days add VB₂ 10mg/kg Concentration of MDA to achieve the smallest; At 8-28days add VB₂ 20mg/kg Concentration of MDA to achieve the smallest;The results of blood sampling experiment showed that VB₂ added 10.0 mg/kg-20.0 mg/kg diet, the activities of GLB and IL-2 in liver were significantly affected (P<0.05), At 1-7 days add VB₂10mg/kg-20mg/kg the activities of GLB and IL-2 in liver were significantly affected (P<0.05); At 8-28 days add VB₂ 10mg/kg-50mg/kg the activities of GLB and IL-2 in liver were significantly affected (P<0.05);The results of Hormone experiment showed that, Concentration of T3 and GH were significantly affected with the increased levels of VB₂ (P<0.05), Add VB₂ 10mg/kg Concentration of T3 and GH achieve the greatest. Concentration of T4 were significantly affectedwith the increased levels of VB₂ (P<0.05). Add VB₂ 10mg/kg Concentration of T4 achieve the smallest.The results of Serum Anions and Cations Content showed that, Concentration of Na was significantly affected with the increased levels of VB₂(P<0.05),with the increased levels of VB₂ Concentration of K,Ca,Cl,P had no significant role (P＞0.05).The results of slaughter experiment showed that At 1-7 days add VB₂ the bursa of fabricius index had no significant role (P＞0.05), spleen index and thymus index were significantly affected (P＜0.05); With the increasing of Vitamin B₂ level, spleen indexes were at first increased and subsequently decreased,Add VB₂ 10mg/kg spleen indexes to achieve the greatest; At 8-28 days add VB₂ the bursa of fabricius index,spleen index and thymus index were significantly affected (P＜0.05); Add VB₂ 10mg/kg spleen indexes to achieve the greatest.According to growth, serum biochemical,indexes slaughter experiment and the immunity indexes variety analysis of the same term, it is suggested that the optimal supplement amount of Vitamin B₂ was from 10mg-kg^-1to 20 mg·kg^-1 under cage condition at the stage of young laying ducks.