The decreasing and increasing variance of CSF maternal antibodies in piglets.

Hog cholera maternal antibody in piglets at different ages of 0,1,4,7,10,14,20 and 30 days was detected by Blocking ELISA of IDEXX company.The results showed that the titers of the maternal antibodies in piglets were zero before suckle,arrived the highest level at 1 d age,and then slowly declined.The titers fell sharply at 20 d age of weaning,but the average titers were above 25.9,and were 24.3 at 30 d age.Thus,these results suggested that half-life of hog cholera maternal antibody in piglets is 6.8 d age.