Extraction Of IgG From Swine Blood And Influence Of IgG On Performance And Blood Parameters In Piglets

Three parts were included in this study:1. Procedure of salting out in ammonium sulfate and procedure of caprylic acid depositting were used to extract IgG from porcine blood respectively in order to compare two methods and offer the foundation for making the better into practice. The results suggest that IgG extracted by procedure of caprylic acid deposition and purified by improved technique is more practical and feasible for its high concentration and activity and low production cost.2. Eighty one-day-old piglets from 10 litters were randomly divided into four groups fed with different doses (0mg, 300mg, 600mg and 900mg) of IgG extracted respectively. Each animal's average-day-gain(ADG), diarrhoea days, serum Alkline phosphatase (AKP) activity and total protein and IgG, and percentage of T-lymphocyte cells of blood were measured on day 5, 10, and 15 after feeding. The experiment aims at evaluating newborn piglets' ability to absorb exogenous IgG and estimate exogenous IgG's influence on piglets' performance and immune capacity. The results showed that the group fed with high dose IgG (900mg) are higher than the contrast group in ADG between day 0 and 15, both serum AKP activity and total protein on day 5 and 10, and serum IgG concentration on day 5 significantly(p<0.05). At the same time, the high dose IgG can decrease the number of diarrhoea piglets and the diarrhoea duration of piglets. It can be concluded that one-day-old piglets have high ability to absorb exogenous IgG and feeding newborn piglets with 900mg IgG on the basis of nature lactation can improve their performance and boichemical and immune parameters of blood.3. Eighty 21-day-old piglets from another 10 litters were evenly divided into four groups injected with different doses (Omg, 300mg, 600mg and 900mg) of IgG extracted respectively, and the same parameters as part 2 were measured. The results showed that the group injected with high dosage of IgG (900mg) are better than the contrast group in ADG between day 21 and 30 and serum total protein significantly (p<0.05). Meanwhile, the number and duration of diarrhoea piglets are less than that of the contrast. Conclusion can be made that 21-day-old piglets injected with 900mg IgG from porcine blood have high performance and immunity.According to results of part 2 and 3, quantity of AKP in piglets' blood has a decline trend with days increasing. On the contrary, T-lymphocyte cells show an increasing trend, which provide an important experimental data for future study on immune system development of piglet.