Synchronisation - Is it an option?

There are many possibilities when using synchronisation in the suckler herd, including tightening the calving pattern and producing enhanced genetics through the use of AI. The technology has been around for decades, yet uptake remains poor.

The low use of AI in commercial and pedigree herds has stifled genetic progress, especially concerning traits such as milk production and fertility. Using highly reliable maternal AI sires on the suckler herd will generate a reliable source of replacement heifers and in turn speed up genetic progress.

Figure 1 outlines one of the recommended synchronisation protocols for suckler cows. This regime is based on three separate interventions, including a PRID or CIDR inserted for seven days and injecting with prostaglandin at time of PRID or CIDR removal. This is required to insure corpus luteum regression and the onset of heat.

The use of GnRH at the start of the progesterone treatment is recommended to induce follicle wave emergence – important for high pregnancy rates following AI.

For fixed-time AI, inseminate 72 hours post-CIDR or PRID removal and inject with GnRH at time of insemination (day 10 of protocol).

Recent research results

A recent synchronisation trial led by Teagasc and funded by the Department of Agriculture and Food demonstrated encouraging results. This project involved 74 autumn-and-spring-calving beef herds, with a total of 2,205 cows used as part of the research.

The trial used a number of synchronisation protocols and the results showed overall pregnancy rates from 54-57% to first service. The highest pregnancy rate was achieved using a low dose of eCG at the time of insert removal. This increased the conception rate for anoestrous cows.

As one part of the study a stock bull was introduced 10 days after fixed-time AI to monitor fertility at subsequent repeat heats. The results were impressive and showed that by implementing this strategy 78% of cows could be pregnant after 23 days of breeding.

Other important points

Before deciding to synchronise a herd of cows, a couple of important factors need to be addressed in relation to your own situation:

Nutrition: Nutrition plays a very important role in resumption to cycling. To achieve best results it is important that cows are on the correct diet pre-and-post-calving. It is recommended that cows should have a body condition score (BCS) of 2.5-3 at the time of treatment and be on a good plane of nutrition for at least 30 days prior to synchronisation

Facilities: There is a greater demand on handling facilities and calving facilities if using these programmes. Farmers should be mindful of this when deciding to opt for a synchronisation programme.

Synchronisation in action – David Holland, Co Laois

David Holland runs the Cairnmor Herd of pedigree Aberdeen Angus cattle on a commercial basis at Cullohill, Co Laois.

David’s breeding policy has developed through the use of AI and pedigree bulls – he now supplies breeding heifers for export and pedigree bulls are sold from the farm for breeding purposes. He runs the 90 strong herd on a strict commercial basis, cows calve in the autumn with all replacements being home-bred.

“We focus on a tight calving pattern on this farm, I have to, as I manage the herd myself with some help from my sons. when they are free to give me a hand. The heifers are calved down at two-years-old and some heifers would be 540kg in weight at 18 months,” remarks David.

David was approached to take part in the Teagasc/UCD trial in 2015 to look at fixed-time AI synchronisation within the herd. A group of his cows were selected for the trial and they were body condition scored and scanned pre-breeding.

“For the trial they used fixed-time AI, where we had just three handlings, this made the process quite easy and I was able to select a choice of AI straws that I could match with the cows,” says David.

“The results were excellent and I found the process took a lot of pressure off my bulls and was labour saving in terms of heat detection and managing calving.

“Since the trial I have continued to use synchronisation on a batch of approximately 30 cows each season. In consultation with my vet Michael Bergin, I have used the same protocols used in the trial with conception rates of over 60% to first service, without any heat detection. My average three year calving interval was 366 days but last season I was at 347 days, with over half of my herd calving in two weeks.

“Calving spread has been a major benefit, it has reduced my calving interval and this year I have only two cows left on their due date. Most calved in prior to their date without problems. The programme has reduced the pressure on my bulls when dealing with any repeat breeders and has allowed me to use more AI to improve the genetics within the herd.

“This year 84% of my herd is scanned in-calf to calve down in four weeks, this makes my life easier.”

“For a part-time farmer or a farmer who would like to compact his/her calving system the use of synchronisation is a cost-effective measure that can help in the management of the farm.”

Advantages

Disadvantages