Breeding, closing silage ground and heifer synchronisation

In this week's beef management notes Adam Woods takes a look at breeding plans, how much silage ground to close up and heifer synchronisation.

Adam Woods

9 April 2025

Breeding, closing silage ground and heifer synchronisation

One way of reducing the labour requirement around using AI is synchronisation and this can be used very successfully in heifers.

Breeding: Many farms are gearing up for breeding in the next few weeks. For farms starting to calve in mid-February 2026, cows will need to be bred in the first week of May 2025. If you are using AI, cows should be tail-painted at this stage and heats should be recorded for ease of detection three weeks later. Tail painting will also mean you can investigate cows which haven’t been in heat before breeding commences. Some may require a wash-out or have other issues.

Breeding: Many farms are gearing up for breeding in the next few weeks. For farms starting to calve in mid-February 2026, cows will need to be bred in the first week of May 2025.

If you are using AI, cows should be tail-painted at this stage and heats should be recorded for ease of detection three weeks later. Tail painting will also mean you can investigate cows which haven’t been in heat before breeding commences. Some may require a wash-out or have other issues.

Time is of the essence, as a suckler cow can have a non-cycling period after calving for as long as 60 days, which leaves a short time to get cows back in calf inside 365 days. Some farmers suck calves twice a day to break the maternal bond and bring cows into heat quicker.

While this sounds like a huge amount of work, when cows and calves get used to the system, it can work quite well. When breeding does commence, make sure to keep accurate records, especially if you are using a stock bull to monitor fertility. Have you got a plan B if a stock bull gets hurt and is unable to serve cows?

Breeding heifers: Ideally, heifers should be bred to calve one to two weeks before the main herd, or at the very latest the first week of calving. Because of a heifer’s higher fertility, they provide an excellent opportunity to use AI and give you options to use eg high index replacement bulls on the herd.

One way of reducing the labour requirement around using AI is synchronisation and this can be used very successfully in heifers. A simple programme developed by Teagasc is outlined on pages 46-47 of this week’s special breeding Focus. Attention to detail is very important with any synchronisation programme and if the programme says something has to be done at 10am, it needs to be done at 10am.

Silage budget: While it may be at the back of many people’s minds, now is probably the right time to do a silage budget for winter 2025/2026. Completing a budget next November when not much can be done about it is of little use.

Completing one now will mean you can take action over the coming months to boost supply. Use the guidelines below and just multiply by the number of months you usually have animals housed for.

Suckler cows: 1.4t/month.

Store cattle: 1.3t/month.

Weanlings: 0.7t/month.

First-cut will generally yield 7-10t/acre and second-cut will yield 5-7t/acre. Have you got enough area closed up for first-cut silage? If you are stocked at 2.3 L.U/ha, which is a pretty high stocking rate, it’s recommended that you should close 50% of the farm for first-cut and 20% for second-cut.

We are entering into the highest grass growth period of the year so make sure you capitalise on this by having the grazing area stocked high enough to manage grass correctly and make sufficient silage.

Some farmers are saying it’s too early to spread silage fertiliser, but if the weather turns it could be a while before you get back out again. Planning an early cut could also help reduce the amount of concentrates you have to feed next winter.