Establishment And Preliminary Application Of Hybridomas Secreting Monoclonal Antibodies Against Clostridium Perfringens Enterotoxin

An experiment was conducted using 768 New Lohmann Layers aged 35 weeks to study the effect of alfalfa meal on production performance, egg quality, egg yolk color, yolk cholesterol, content of lipid and hormone levels. Layers were randomly divided into eight treatments according to a 2×4 factorial arrangement, each treatment represented by three replicates of 32 birds each . Layers were fed corn-soybean based diet with 0%, 3%, 5%, 7% alfalfa meal and 1.6%, 2.4% fat during the phrase of 60 days. The results showed that:(1)Layers added alfalfa meal and fat had no significant difference of laying rate, average daily feed intake, egg weight and feed/egg ratio(P＞0.05)than that of no meal treatment. Alfalfa meal at 5% in diet was optimum according to the production performance of layers. (2)Addition of alfalfa meal and fat had no significant difference of egg shape index, egg yolk index, eggshell relative weight(P＞0.05). There were significant higher(P＜0.05) of eggshell thickness, haugh unit compared with that of no alfalfa meal. Effect of alfalfa meal on egg quality was better than that of fat(P＞0.05).(3)Egg yolk color added alfalfa meal was significant higher(P＜0.01)than that of no alfalfa meal and its color reached a steady level at the 30th day of experiment. Fat had no significant effect on egg yolk color(P＞0.05). (4)Layers added alfalfa meal and fat had no significant difference of yolk relative weight(P＞0.05)than that of no meal treatment. Yolk weight was increased according to the increasing of alfalfa meal additive, addition of alfalfa meal cholesterol concentration, Eggs given the diets at 7% diet extremely significantly increased(P＜0.01)in the low fat treatment, the others had no difference. Addition of alfalfa meal significantly decreased(P＜0.01)egg yolk added with alfalfa meal had a lower(P＜0.01)egg cholesterol concentration than those given no alfalfa meal diets. During the interaction, alfalfa source had more effect on egg yolk cholesterol concentration and egg cholesterol concentration that fat source.(5)Egg yolk cholesterol concentration and egg cholesterol concentration decreased with alfalfa meal increasing, egg yolk cholesterol concentration decreased sharply in the former 30d, then reached a steady level at the 45th day of experiment. (6)Serum TC,TG,LDL had decreased compared with no alfalfa meal added treatment(P＜0.05),(P＜0.01), serum HDL had increased compared with no alfalfa meal added treatment(P＜0.05).(7)Serum FSH,LH,P4,E2 had increased with the increasing of alfalfa meal. There were significant higher(P＜0.05) of FSH,LH compared with that of no alfalfa meal. Addition of alfalfa meal and fat had no significant difference of P4,E2(P＞0.05).(8)Economic profit of layers fed diets with alfalfa meal was improved significantly.The research suggested that there were no significant difference of production performance, egg quality of layers, but it can improve the egg quality in some degree; Egg yolk color increased and egg yolk cholesterol decreased with the increasing of alfalfa meal and it was significant higher compared with that of no alfalfa meal addition treatment. Combined all index, it recommend that addition of alfalfa meal at 5% was optimum in layer diet.