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Video 32 Fertility in the suckler herd

We have seen a lot of research in dairy herds looking at fertility over the last decade. With suckler herds, fertility is also a key driver for overall efficiency and profitability. We can focus on some key areas to improve fertility on our beef farms.

More suckler herds should consider using A.I (artificial insemination) to speed up the genetic gains in their herds. One challenge is your suckler cow will take longer to begin cycling after calving, this is down to the negative impact of suckling of the young calf on oestrus and ovulation.

This can be overcome in beef herds by breeding for fertility as part of your herd plan.

On suckler farms, we are in the business of weight production in a yearly cycle. A great metric is weight in kg weaned per cow per year.

This means that the more calves born alive and weaned the more profitable the farms can be.

Fertility plays a huge role in this with the aim of (0.95-1.0) calves reared per cow per year. Also, we need to have a compact calving (80% of cows calved in 60 days) and a 365-day calving interval.

We need to aim to have low culling rates for fertility and each cow to average 5-6 calves in their lifetime. I know its easy in print.


While many factors outside the farm gate will negatively impact on price. If you want to be in suckler farming then fertility is one key area to improve. While I’m not suggesting this is easy or not without effort it is one area where improved performance and effort will be rewarded

Here are some very simple steps you can take

  1. Nutrition

Body condition and nutrition are the biggest drivers in good fertility management. This, of course, presumes that we chase fertility through the use of better genetics as well.

A suckler cow has a voluntary waiting period of 45 days before we consider them eligible for breeding.

If cows are in poor body condition or have lost a lot of body condition between calving and breeding they will not be cycling. Heifers also need to be at the right weight and size for their age. All breeding animals should be on a rising plane of nutrition coming into breeding.

This may be a naturally occurring cycle on pasture-based systems with the flush of grass in April/May/June. However, we must ensure this is happening and not make any presumptions. This is why grass measuring and looking at intakes are very important for beef enterprises.

Very thin cows at breeding time will take longer to come cycling.

With late calvers and thin cows, some people will use restricted suckling to try and encourage them along. This will have some success but is very labor-intensive. With calves separated but not out of sight and allow twice-daily suckling for 2-3 weeks. Cows should be calved at least 30 days and following this restricted suckling and heat detection (BREEDING) restricted suckling can be stopped.

My preference for breeding would be managing body condition and focus on genetics particularly with heifers coming through. I will discuss hormone treatments a little later.

  1. The male effect

While we can improve genetic gains using AI the stock bull is still a very important guy on the farm. There are some key things we need to focus on with the bull.

  • You can never have enough bulls. You need to be mindful of young bulls that 12 empty cows is a lot for them. While a mature bull will handle 25-30 empty cows (breeding cows). Using AI will also reduce the need for numbers of stock bulls
  • With stock bulls, calving ease is so important. Hard calvings mean more risk for the calf, the cow and also impacts heavily on cows’ ability to even go back in calf.
  • Remember when buying in bulls we could be buying in disease. They need to be also assessed after arrival and there will be the time needed to settle into a new diet and facilities. Every bull should receive relevant vaccines, minerals and run through a footbath at least twice before joining the herd. They should receive all relevant dosing especially fluke if the farm is fluke free,
  • One of the most important jobs prebreeding for all bulls is a prebreeding exam. Feeling the testicles and taking a sperm sample to check fertility. 1:8 bulls in my experience can be infertile or certainly be subfertile. Too often we see issues where cows are repeating and the bull is the problem. With teams of bulls, an infertile bull can be an issue as we have lower conceptions but it takes longer to realize we have issues.

Get your vet to perform a full prebreeding MOT on all bulls before breeding.

  • Bulls are sexual athletes and their feet after their testicles are the next vital tools in seeing out a successful breeding season. Lame bulls won’t mount and have a high risk of being infertile. Any bull which goes infertile takes 6 weeks or more to start producing sperm again.

So any bull with a temperature (sickness) or lame should be considered a risk of going infertile.


When using A.I timing is critical, at the end of standing heats or in the 12 hours after.

  1. Heifers

If we can get heifers mated at 15 months and calving down at 24 months we can improve efficiency. Some people say this is too young but it can be done.

For this, we need to get early nutrition right. At breeding time they must be at the right weight and size. Fat heifers are more difficult to get in calf and may not be cycling.

We want to calve them in early so consider synchronization and utilize AI with them. Where synchronizing any animals if you have large numbers cycling at the one time you risk wearing out bulls.

Prostaglandins can work well or some more advanced hormonal treatments using CIDRs or PRDIDs along with hormone injections.

  1. Maximize the eligible players

We want to maximize the number of cows eligible for breeding. We do this by ensuring that as many cows are cycling once breeding commences.

Pull out the problem cow’s early and get them checked. This is a well-established practice in dairy farms where we look at examining cows prebreeding not seen in heat or had issues between calving and breeding.

Any cow with a hard calving, twins or has been sick should be examined before breeding. Get your vet to scan the womb and the ovaries. You can also metricheck these ladies to check for any uterine infections. Uterine infections respond well to an antibiotic washout before breeding time.

This is a great time to scan thin cows also or calved greater than 50 days and no signs of heat or bulling.

  1. Heat detection

If using a stock bull then they become your heat detection. Ensure that they are serving cows properly and have good libido. Where A.I is being used you must try and use heat detection aids. If you increase heat detection you will improve or tighten your first 6 weeks of breeding.

It is the most important area to focus on during breeding when using A.I.

Utilize any detection aids necessary like tail paint. Clip the rumps before applying tail paint and try and top up regularly. With heifers, scratch cards and crayons work well.

Time must also be set aside for heat detection. Cows will show signs of bulling more often in the early morning and late evening. Vasectomized bulls also offer a wonderful tool for heat detection in smaller herds using AI. Be very careful not to wear them out too early though. They come into their own when the number of empty cows gets smaller and heat detection becomes harder.

With margins tight on beef farms we haven’t seen the same uptake in technological aids. These can be worth the investment where time is limited and possibly in part-time farms along with the use of synchronization.

  1. Vaccination and dosing

Ensure the main infectious disease are vaccinated against in your herd. BVD and leptospirosis are the two big ones.  With our national eradication program nearing completion, the risk of BVD is going down but when some PIs remain it also is a risk for immunoniave herds.

Ensure all fluke and worming is up to date in heifers and cows post-winter have had fluke control or dosing. Don’t forget the bulls when we talk about vaccines and dosing.

  1. Minerals

The main minerals to focus on during the breeding time in suckler herds are copper, selenium, and iodine. Ensure good and regular supplementation is being carried out.

For farms, you can assess the risk as I covered it here in this video blog https://youtu.be/qqYWmIHmKWs

Minerals do play a role in fertility but are often blamed for poor fertility too often.

We need to focus on the main areas of fertility first and then ensure good mineral supplementation to complete our fertility planning.


  1. Synchronization

With a very narrow window in suckler cows to maintain the tight calving interval of 365 days. We also have a period of 45 days where the beef cow is unlikely to begin cycling again. We can use hormones to help us in this process.

Particularly for cows not seen bulling or calved late, we can use these hormone programs to help cows come around and start bulling.

With heifers, they are also an excellent way of synchronizing them when using Artificial Insemination.

With problem cows also we can use hormone programs to help bring them around quickly. When using AI make sure you don’t overwork the workload for the stock bull with large numbers coming bulling.

Remember that prostaglandins work well when there is CL so there is a narrow window in the cycle between day7-16 days.

Fixed time AI also allows farmers who want to save on labor and improve efficiency with part-time farmers.


Good beef fertility can improve your bottom line, overall herd efficiency, and profitability.


Thought of the day

We rarely like someone who is too confident but it is important to have self-belief. Self-doubt can eat away at you. So step up and step out, believe in yourself.


Huge thanks to Nettex for their support in developing this #50in50 series for more information click here  https://www.rumenco.co.uk/


Happy safe farming

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