Does synchronisation have a role to play on dairy farms?

The use of synchronisation protocols has been widely adopted worldwide and the success rate – in terms of conception rates – continues to grow through research and product development.

Speaking at a recent Interchem fertility seminar, Dr. Federico Randi discussed the potential of synchronisation to maximise labour efficiency and improve six-week calving rate.

The technical manager with CEVE Santé Animale said: “Synchronisation was initially developed as a tool for year-round calving and TMR (total mixed ration) systems – predominately in the US.

“In these systems, synchronisation has a great role because it is able to control breeding after the voluntary waiting period.”

However, the uptake of synchronisation has been slow in compact-calving, seasonal, grass-based herds.


Synchronisation has been proven to improve herd fertility, Randi explained, and the newest programmes were found to achieve better results in terms of conception rates.

100% submission rates were also achieved, which are otherwise not possible. No matter what type of technology we use, the ability to catch animals in heat is still about 70-75% because you are dealing with silent heats.

“For a seasonal system like Ireland’s, synchronisation can have a massive impact. It’s able to maximise submission rate; increase the number of pregnancies achieved through AI; and it can potentially allow us to shorten the breeding period, which is beneficial for compact calving.”

The study

A comprehensive study in the use of timed artificial insemination (TAI) synchronisation was carried out by UCD and Teagasc – in collaboration with CEVA – in 2015. The research work aimed to explore the benefits of this process in a seasonal, Irish dairy system.

As part of the study, Randi examined over 1,400 cows across four farms; two herds were pure Holstein and two were crossbred. Despite the management systems differing slightly, high grass utilisation was a key feature of all four of the spring-calving enterprises.

Randi explained that a control group with natural observation / tail painting was compared against two specific Ovsynch + PRID protocols to determine fertility performance figures.

“There were about 470 cows in each of the treatments. All of the cows were ultrasound scanned and body conditioned scored (1-5 scale) by the same operator on all of the farms across the two years.

“We randomly assigned the cows to the three treatments on the basis of days in milk and parity. They were equally distributed across the three groups,” he said.


Randi stated that the results obtained showed positive trends for practical application; 100% of the synchronised cows were submitted to AI on the first day of the breeding season, while 88% of the control group were submitted within the first 21 days.

When it came to the conception rates achieved, he said: “There was absolutely no difference in the chances of getting pregnant for a single artificial insemination between the three groups.”

However, the synchronised cows calved 12 days earlier than the control group.

With 100% of cows submitted, you end up with a greater chance of getting your cows pregnant within your [specified] time frame. In fact, the pregnancy rate at 21 days was 52% for Ovsynch + PRID and 47.2% for the Ovsynch + PRID + EcG group.

Continuing, he said: “What’s important is that the interval from mating start date to conception was significantly changed with the use of synchronisation.”

The outstanding benefit was the fact that the cows in the synchronisation groups became pregnant far earlier. On average, he said, they conceived 12 days earlier than the control group.

Calving spread was another factor that was examined. The trial worked showed that no more than 9% of cows in the synchronised groups –  that held to first service – calved on the one day.


In terms of cost, Randi said the protocol costs about €33/head. He said: “We gained 12 days in milk with synchronisation because the cows conceived earlier.”

At a yield of 20kg/day and a milk price of 33c/L, he estimated that farmers would generate an additional €79 in milk sales through the use of a synchronisation programme.

Overall, it’s about €46 that the farmers saved by using these oestrus synchronisation programmes.