| The feeding trial, digesting experiment, xylose absorption test and the test of serum antibody (IgG) litres to the soybean allergens were conducted to study the anti-nutritional mechanism of main soybean antigens on calf, Twelve newborn calves were randomly divided into 3 groups(Group A, B and C )with each group involved 4 replicates, each group of the calves were fed on the diets contained raw soybean flour, heated soybean flour or whole milk, respectively. The experiment was conducted through 3 phases, 0-3 day of age: colostrums was offered to all calves; 4~10day of age: Group A and B were fed on experiment diets contained 16.4% raw soybean flour or heated soybean flour(based on DE); ll~42day of age: Group A and B were fed on experiment diets contained 24.6% raw soybean flour or heated soybean flour(based on DE). The calves of group C were fed on whole milk from 4 to 42 day of age. During the period of trial. At the age of 1 day, 5ml jugular blood was sampled before received the colostrums. Al day 3, 7, 10, 14, 18, 22, 26, 30, 34, 38, 42 of age, 5ml jugular blood was sampled in the morning before calves feeding. An ELISA procedure was used to measure serum IgG specific to the immunogenic soy allergens; Calf weights were recorded weekly before feeding in the morning. And the rations were adjusted according to the body weight; The faeces were collected from 28 to 34day of age to determine the apparent digestibility of the nutrients; Xylose absorption test was performed at the 38days of age, the jugular blood was sampled at 0,l,2,3,4and 5h after ingestion of xylose, to measured the concentration of the xylose in serum of calves.The result showed, all calves of group A and B begun to diarrhea at the age of 10 day, the calves of group A were more severe than that of group B, and the desquamate intestines mucous were observed in the faeces of group A at the age of 20day ,But no diarrhea was found in the faces of the group C.The apparent digestibility of the CP and EE of the group A were significantly lower than that of group B and C (P<0.01), at the same time, the apparent digestibilityof these nutrients were significantly lower than that of group C either(P<0.01). The weight gain of the calves of 3 groups were similar to the apparent nutrition digestibility. Group A was significantly lower than group B (P<0.01) and group B was significantly lower than group C too(P<0.01). At the same time , there was difference about the degree of the digestibilities' decrease . The degree of decrease in CP digestibility was more than EE's.In the test of antibody(IgG) to glycinin , P -conglycinin, the second peak of 7S fraction and the second peak of US fraction, The conclusion could be drown that all of the four kinds antigens could lead to calf's immunoreaction, Antibodies to soybean antigens were detected in serums of all calves, but the calves receiving the raw soybean flour(group A) and heated soybean flour(group B) appeared to have higher serum litres than those receiving the whole milk (group C). With the growth of age and the increase of received dietary antigens, all the antibodies specific to soybean antigens maintained the tendency of increasing until to the age of 42day.But the hnmunogenicity of lour kinds of antigens were different, The second peak of 7S fraction of raw and heated soybean have higher immunogenicity than other antigens. In raw soybean, the immunogenicity of P -conglycinin (the first peak of 7S fraction) to calves was higher than the immunogenicity of 11S fraction before the 30day of the age, however, the it would be lower than 1 IS fraction after 30day of age. In heated soybean, before the age of 26day, P -conglycinin's immunogenicity was higher than 11S fraction's, but it would be lower than the first peak of 11S's after 26 day of the age.The result of the xylose test showed that the concentration of the calves serum xylose of group A was significantly lower than those of group B and C(P<0.01). furthermore, those of group B was also significantly lower than those of group C(P<0.01)...
|
PDF Full Text Request