Effects Of Vitamin D₃on Growth Performance,Slaughter Performance,Calcium-phosphorus Metabolism And Immune Function In Goslings

One experiment was conducted to research the effect of dietary vitamin D3levels on growth performance slaughter performance,calcium-phosphorus metabolism and immune function of Yangzhou goslings through the methods of feeding trial, slaughter test and biochemistry analysis, and got the requirement of vitamin D3to lay the foundation for in-depth study of the mechanism of vitamin D3, provide the theory basis for goose healthy breeding, provide the reference for the perfection of goose feeding standard, and accumulate the material for immune nutrition regulation of vitamin D.This study was conducted with simple factor experiment arrangement.Three hundred5-week-old healthy male Yangzhou geese with similar body weight were randomly allocated into5treatments.There were6replicates per group of10geese each per replicate.The control group was fed with basal diet, while the treatment groups were fed with basal diet supplemented with500IU/kg、1000IU/kg、2000IU/kg and4000IU/kg VD3respectively for6weeks.Then measured the growth performance slaughter performance, serum biochemical index,tibial index,the level of immunoglobulin IgG interleukin-2(IL-2),interleukin-4(IL-4) in serum.The results as follows:1. Effects of dietary VD3addition levels on growth performance of goslings:(1)Supplementation of VD3in diet could very significantly increase body weight of Yangzhou geese at the age of10weeks(P<0.01), and it reached the maximum at1000IU/kg,while there were no significant differences among other groups (P>0.05). (2)Compared with the control group,adding1000IU/kg vitamin D3significantly increased average daily feed intake of goslings;more VD3did not effect the average daily gain significantly (P>0.05).(3)Supplementation of VD3in diet significantly increased average daily gain of goslings(P<0.01).and ADG in1000IU/kg VD3group and2000IU/kg VD3group was significantly higher than that in4000IU/kg VD3group(P<0.05).(4)Supplementation of VD3in diet effected feed/gain of goslings(P<0.05),and it reached a very significant level at the level of2000IU/kg vitamin D3(P<0.01).2. Effects of dietary VD3addition levels on slaughter performance of goslings:(1)Adding1000IU/kg vitamin D3significantly increased the percentage of eviscerated yield (P<0.05) and decreased the percentage of abdominal fat(P<0.05) of10-week-old Yangzhou geese,and there was a trend to increase dressing percentage(P=0.091).(2)The significant effects on half-eviscerated yield percentage,breast muscle percentage,leg muscle percentage,cardiac index,liver index and gizzard index of Yangzhou geese at the age of10weeks were not foud among all groups(P>0.05).3. Effects of dietary VD3addition levels on metabolism of calcium and phosphorus of goslings:(1) When the supplementation of VD3in diet was increased from500IU/kg to1000IU/kg,the content of calcium in serum was increased significantly(P<0.05);the serum calcium content in2000IU/kg VD3group was significantly higher than that in500IU/kg VD3group(P<0.05).very significantly higher than that in control group(P<0.01);continue to increase VD3content to4000IU/kg,there was not significant effect to be foud at serum calcium content(P>0.05).There were no significant effects on phosphorus content and alkaline phosphatase(ALP) activity in serum with different vitamin D3supplemental levels(P>0.05).(2) When the supplementation of VD3in diet was increased from500IU/kg to1000IU/kg,tibia calcium content and tibia strength was improved significantly(P<0.05);more VD3content did not effect them significantly(P>0.05).The contents of tibia ash and phosphorus in experimental groups were higher than control group,but the effect was not significant(P>0.05).3. Effects of dietary VD3addition levels on immune function of goslings:(1)Adding2000IU/kg vitamin D3significantly increased thymus index(P<0.05),and there were not significant different about spleen index and bursal index among all groups(P>0.05).(2)Adding1000IU/kg vitamin D3significantly significantly increased serum immunoglobulin IgG content(P<0.05);compared with control group and500IU/kg VD3group, adding2000IU/kg vitamin D3significantly significantly increased serum interleukin-4(IL-4)content(P<0.05);and when the VD3level was2000IU/kg,there was a trend to decrease serum interleukin-4(IL-4)content(P=0.061). Based on the results of growth performance,slaughter performance,calcium-phosphorus metabolism and immune function,we concluded that the optimal diet vitamin D3supplementation for Yangzhou goslings is1000～2000IU/kg.