Effect of onion juice on performance, egg quality traits, hematological and biochemical parameters in laying hens

The present study was carried out to determine the effect of different amount of onion juice in drinking water, on the yield, performance, egg quality, hematological, serological and immune parameters in laying hens. A total of 240 Babcock white laying hens (40 weeks old) were divided into 6 groups (36 birds in each) and each group was further subdivided into 4 replicates, containing 9 birds in each subgroup. Total 5 groups were added onion juice at the rate of 0 %; 0.25; 0.5%; 1.0% and 2% respectively for 12 weeks. Water and feed were offered ad libitum. Birds were vaccinated against New Castle virus in initial of trial for antibody determination in blood. The body weights were recorded at the start, mid and end of an experiment. Feed intake was measured weekly. Eggs produced were recorded daily and weekly average egg production was calculated. Eggs were weighed one day in a week. Three eggs from each replicate were collected randomly at the start, mid and end of the trial and analyzed for egg quality parameters like egg weight, eggshell thickness, color index of the yolk, Albumin index and haugh Unit level. At the end of the trial, three birds from each replicate were selected and blood samples were collected from the heart. Blood samples were drawn and placed in anti-coagulant containing tubes and without anticoagulant for serum separation. Complete blood cell count, Lymphocyte, monocyte, blood Glucose, cholesterol, HDL, LDL, total protein, Liver enzymes like AST, ALT and blood Ca-P level were analyzed. Serum anti-ND antibody titer was determined. The results revealed that mean water consumption had increased significantly (P<0,05) in group C supplemented with 0.5% onion juice. However, body weight, feed consumption, egg production, and feed conversion ratio remained non-significant. For egg quality parameters, eggshell thickness, egg yolk color, Haugh unit, egg weight, albumin index, and yolk index also remained non-significant. For immunity, the group supplemented with 2% group E produced higher (P<0,05) IgG during the second and third month of study which indicates significant result (P<0,05) in the immunological response of laying hens vaccinated against the Newcastle virus. For serological parameters, during second-month cholesterol, LDL and Calcium significantly increased (P<0,05) in group E while other parameters such as glucose, HDL, AST, ALT, Total protein, TAS and TOS remained non-significant. However, in the third month only ALT level only significantly increased (P<0,05) in group B over control. For hematological parameters, only hemoglobin (Hb) concentration increased (P<0,05) in group D with 1% onion juice. However, RBC, MCV, MCH, MCHC, platelet, RDWC, and hematocrit level remained non-significant. It is concluded that onion juice showed positive effects (P<0,05) on some performance parameters and immune system of laying hens without any adverse effects on egg traits. Further detailed studies with multiple dose levels need to be investigated.