Late calving cows: cull them or breed them?

The vast majority of suckler cows calve in a suckler to weanling production system in Ireland.

Cows calve in spring and weanlings are sold in October. Achieving a 365 day calving interval on suckler farms is key to profitability in that you are not feeding an empty cow that isn’t pregnant for too long.

This is a challenge in a spring calving system especially where you want to keep calving to a tight 12-14 weeks.

Once the cow calves the clock starts and if a cow has a 286 day gestation period, that means she has to get back in calf within the next 79-days. Suckler cows have a longer anoestrous period where they don’t come in heat.

This can last up to 55 days so that means the window is even tighter to get her back in calf.

If you take away the 55 days that means you are left with 24 days to get the cow back in calf, or two cycles at best.

Big challenge

A difficult calving or C-section would mean the 55 days could extend out to 80-100 days so it really is a big challenge to get a suckler cow to calve every 12 months.

Spring 2024 was a tough battle and fodder ran tight on a lot of farms. In some cases poorer quality forage was fed to calved suckler cows and condition was let run a little lower than many would have liked. This has had an impact on the resumption to cycling on some farms especially where concentrates weren’t fed during that time. In a weanling production system weight and quality are the two big determinants in weanling price.

If we take weight, calving date has a big impact on this.

If you have a suckler cow that calves on 1 February in 2024 but doesn’t calve until 1 April in 2025, this will have a big impact on the sale price of the calf. There are 28 days in February and 31 in March so that’s 59 days of lost weight gain for that calf. If it was a bull calf we could put the weight gain down at 1.2kg/day for those two months. That means this calf has lost a potential 71kg of weight when it comes to sale time in October.

If we put a price of €3/kg on that weight, that’s €213 less than that weanling will sell for due to the later calving date and lost weight gain. If five cows slipped in a small suckler herd that’s €1,065 so it’s worth taking a look at.

Here are three options to deal with late calving cows.

1 Cull

It’s the nuclear option but it could be the right one in some cases especially where cows are calving very late. The temptation with very late cows is to let them run around to autumn but that is a false economy and the chances are they will end up spring calving again in a short number of years.

Cull cow prices are high at the moment and instead of struggling with them to get them back in calf you could take the option of culling them. A well fleshed 700kg cow is crossing €3/kg in some marts in the last few weeks. The cull value of €2,100/head would go a long way to bringing back in an in calf heifer into the system and you could focus on selecting a heifer that is going to calve at the beginning of the calving season. If you do select cows for culling these cull cows could be grazed in a separate group and fed some meal. Calves could also be creep fed so that they can be weaned early. Consistent late calving cows or cows that continue to slip a few weeks every year should be culled.

2 Restricted suckling

This is more of an option when cows and calves are still indoors but can work when cows are out grazing as well. It sounds like a lot of work but when cows and calves get into a routine it can be completed quite quickly in the mornings and evenings. It will work best where there are fields around sheds that cows can graze on.

Calves can be kept indoors and cows let out to graze. Cows then come back into the yard/shed in am and pm to allow them suckler their calves. This reduces the cow calf bond and has a positive effect on the hormone profile in the cow and can help to bring them back in heat. Farmers who have tried this method say that you need to stick with it for at least 10-14 days to see any affect on heat activity. It is more labour intensive but very cost effective.

3 Synchronisation

The 3rd option is synchronisation and this option can also work where you have late calving cows. It also has the benefit of being able to use AI. Cows need to be calved at least 30 days for a synchronisation programme to work in suckler cows.

Table 1 outlines an example of a programme that can be used with late calving suckler cows.

There is some work involved with cows coming into the yard for treatment on 5 occasions. It is also quite expensive with this programme costing in the region of €32/head. That is made up of €11/each for the PRIDs, €14 for the shots of receptal and €7 for the shot of estrumate. If an artificial insemination is added at €34/insemination that brings the cost to €66/cow. You could expect 60% conception rate but this will depend on a number of factors.