The Research Of Retained Placenta Of Dairy Cow

Retained Placenta(RP)is one of the most important diseases in dairy cows. It could cause endometritis,reduce reproduction performance and increase the economy loss badly.The causative agents of RP is stills unknown.To find out some blood biochemical parameters which can be used to anticipate the occurrence of RP,a reseach on the dynamic changing characters of some blood biochemical parameters in 18 Holstain dairy cows around parturition was conducted from 2006 to 2007,the effects of dietary cation anion balance(DCAB)on the metabolic disease incidence and the effects of RP on the reproduction performance after parturition were investigated in two dairy farm.The results shown as follows:1.We firstly found that BUN/Crea ratios in RP cows was higher than that in NRP cows from the day 14 prepartum to the calving day,and BUN/Crea ratios in RP cows was significantly higher than that in NRP cows at Day 0,7 postparturition(P＜0.05).2.The activity of GSH-Px in the RP cows was always lower than that in the NRP cows from day 28 prepartum to das 21 postpartum.The activity of GSH-Px at day 14 prepartum, day 0 postparturition day in RP cows was significantly lower than that in NRP cows(P＜0.01,P＜0.05 respectively).3.The contents of plasma Calcium and phosphorus from day 21 prepartum to day 0 postparturition in RP cows was lower than that in NRP cows,they were significantly lower in RP cows than that in NRP cows at day 0 postparturition(P＜0.05).4.The levels of plasma E₂ and P₄ in RP cows was lower than that in NRP cows at day 0 postparturition.It is suggested by above results that the parameters of BUN/Crea,GSH-Px,Ca,P in blood plasma may be use as predictive indicators of retained placenta in dairy cows.5.In the similar breeding condition,the disease:incidence of RP,mastitis and endometritis was lower in dairy farm which used low DACB than that in dairy farm which used high DACB.6.The number of breeding and conception days in RP cows was higher than that in NRP cows.