By Robert Ramsay, senior beef consultant, SAC Consulting

With suckler margins under real pressure and the changing shape of the industry, now is the time to take a good look at the efficiency of your suckler system.

When you think about inputs in a livestock enterprise, it is easy to get drawn into thinking about fertiliser, compound feed, vet costs and so on. However, there is one fundamental input to a beef system that affects efficiency more than any other – dry matter.

When compared to other livestock systems, the suckler cow is a relatively inefficient animal. She is good at converting low value forage into high value protein but when you compare her body weight to the body weight of her calf at weaning, it is hard to deny there are inefficiencies in the system.

In order to really improve things, we need to take a step back and look at what we are trying to achieve from suckler systems. The traditional approach was to try to maximise the number of kilogrammes of saleable product leaving the farm. While this approach works well on high output systems like dairying, in suckler beef systems, the business has to focus on the efficiency of the production system itself, as well as the number of kilogrammes sold.

If you’ve never done it before, weighing cows is an interesting thing to do. Without weighing, using an educated guess, most people think their cows are 650kg, but more often than not, cows are between 50 and 150kg heavier than expected. Why is this important? Because the bigger the cow, the more she will eat and therefore the higher her maintenance burden will be on your business.

A 600kg cow will eat about 12kg of dry matter per day, or about 48kg of grass silage (at 25% DM) or about 70kg of grazed grass, while an 800kg cow needs about 16kg of dry matter, to meet her requirements, which equates to 46kg of the same silage or 95kg of grazed grass. Neither the silage, nor the grass are free, so on a dry matter basis, bigger cows are more expensive to run.

That’s not the end of the story, there are also calves from each of these cows. For simplicity and assuming a birth weight of both calves is 40kg – if the first calf (out of the smaller cow), achieves a weaning weight of 300kg, then the cow will have weaned 50% of her body weight, with the calf growing at around 1.3 kg per day to achieve this.

To achieve the same 50% weaning ratio, the calf out of the larger cow would need to be 400kg and achieve a daily live weight gain of 1.8 kg from birth to weaning – something that is very unlikely to be achieved. While a cow efficiency of 50% across the whole herd would be great, it is probably unrealistic and a target of 40% in the interim would be something to work towards.

Everyone likes to look at big strong cows, but it is important to consider the efficiency and the true cost of running these 'good cows'.

And for those that would argue a higher cull value justifies keeping a bigger cow, remember, that cow’s higher dry matter consumption is unavoidable and will have been a burden on your business for many years, while the improved cull value will benefit your cash flow only once at the end of the cow’s life.