From article

"Research hones in on making more pregnancies",

January 25, 2011 Issue, page 57

Abstract 161: Alternative protocols to presynchronize estrous cycles in dairy cattle before a timed AI program. Since Ovsynch was introduced, researchers have continued to explore various protocols which might improve the number of pregnancies resulting from timed AI. Kansas State researchers compared the effectiveness of five different presynchronization protocols (Figure 1) prior to Cosynch-72 to Cosynch-72 without presynchronization. The first three presynchronization treatments consisted of two prostaglandin injections administered 14 days apart with the second injection 14, 12 or 10 days prior to the initiation of Cosynch-72 (Figure 1). Two additional treatments consisted of progesterone inserts (CIDR) for 7 days with prostaglandins given at CIDR removal either 10 or 3 days prior to beginning the Cosynch-72 protocol. The only difference identified was the number of pregnancies per AI at 60 days after insemination was reduced in the CIDR3 group compared to all other treatments.