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Calf Growth Rate Targets – What They Should Be And How to Achieve Them
Achieving optimal calf growth rates is key to maximising returns for a suckler herd. Not only does this ensure a calf reaches the target carcase specification within a desirable timescale, it also means it does it with the most efficient use of rations.
But with the different rearing methods and different calves, how do you achieve and measure this to make sure you’re running the most profitable suckler herd you can? In this blog, we take a look at calf growth rate targets and what management decisions you need to take to optimise them.
Feed Conversion Ratio (FCR)
The rate at which a suckler calf gains weight is measured by the Feed Conversion Ratio (FCR). It equals the weight of feed intake by an animal divided by the weight gain of the animal. Lower values indicate a higher feed efficiency and typically these should be between 6 and 10 for beef cattle.*
An important aspect of FCR to understand, however, is that it is at its most efficient in young animals that are growing quickly, and tails off in older animals. This is because younger animals use more of the energy and protein in their ration to grow rather than to maintain their weight, and it is the reason suckler calves start out on grass when they are young and fast growing, and are finished on higher energy rations.
FCR and DLWG targets are different depending on the type of calves being raised – bulls, steers, or heifers – as well as the rearing system utilised. As a result, we could not cover every different scenario in one article. However, what follows is a general guidance plan that is designed to produce the best returns for moderately-sized, finished suckled calves from spring calving herds.
Finishing Bulls
Of the three types of calves raised for meat, finishing bulls is the most time critical. This is because it is imperative they reach target market specification by 14 months of age. With steers and heifers, there is a bit more leeway.
Once a bull reaches 14 months old, FCR declines significantly and the tenderness of the meat is impacted as testosterone levels rise. Also, bulls beyond 14 months often grow too heavy for market specifications.
Bulls should be weaned around seven to eight months of age and it is not uncommon to creep feed at this point to help acclimatise them to a concentrate diet. This can also reduce finished time by two to three weeks, which can be critical in reaching that 14 month deadline.
Calves should be weighed at weaning as this enables the producer to calculate the DLWG needed to produce the target weight.
Stabiliser bulls tend to weigh around 300kg at weaning and have a target weight of 630kg at 14 months. This equates to a DLWG of around 1.8kg, the figure you should be aiming for.
Once you know this figure, the next step is to produce a balanced ration that will achieve the required weight gain in the timescale. This might include a ration based on good quality silage, rolled barley, sugar beet pulp, and distillers grains plus minerals as this would most likely achieve the FCR needed for efficient weight gain.
It is false economy in any rearing system to limit intake as this will slow growth rates and extend the period to slaughter, denting the profitability of the animal. Faster growing animals eat more each day, but have a shorter life so use less calories for maintenance and more for growth.
As the finishing period for bulls is short, regular checks must be carried out to ensure bull calves are achieving the target DLWG. They should be weighed at monthly intervals for the first three months after weaning, and then go to a minimum of fortnightly as slaughter weight approaches. If DLWG isn’t being achieved, immediate action in the form of increased rations must be taken to ensure target carcase specification is met.
Finishing Steers
Like bulls, steers should be weaned around seven to eight months of age. However, unlike bulls, they have a significantly longer finishing period, usually from 16 to 20 months.
There are two systems routinely used to finish steers – the housed system and the grazing system – and whereas they both have the same target live weight, around 650kg, the DLWG for each system is different.
In the housed system, where the aim is to reach the target carcase weight in 15 – 17 months, the calves will go through a two-stage growing programme.
In stage one – a period of around six to seven months – they should receive a ration designed to grow frame and support daily growth rates of 1.2kg, gaining 200kg – 220kg throughout the winter months.
This leads them on to stage two which starts when they are yearlings of between 500kg and 530kg. Here a finishing ration should be introduced that produces a daily growth rate of 1.5kg – 1.6kg. A good guide for such a finishing diet would be similar to that of bulls and include 30% forage with a 14% protein concentrate.
The aim under the grazing system is to finish steers in around 20 months, leading to a slightly lower DLWG. Initially, steers raised under this system should be over-wintered for six months on a ration designed to produce a 0.9kg daily weight gain with the aim of gaining 150kg. After this, they should be turned out to well-managed grassland that supports a daily weight increase of 1.2kg until they achieve finishing weight.
Steers should be weighed monthly for six or seven months and then, as with bulls, fortnightly as they approach slaughter weight to ensure they are performing as they need to.
Finishing Heifers
When finishing heifers, it is advisable to check the processor’s carcase specification first, to decide exactly what they expect as this will influence how you finish your calves. But as a guide, the aim with heifers is to achieve a steady growth rate towards the target fat specification at 18 – 20 months old.
As with bulls and steers, spring-born heifers are weaned at seven to eight months old. They are then over-wintered on a ration aimed at achieving 0.7kg of daily weight gain for the following six months.
After this, they should be turned out and the majority of heifers should reach a target weight of between 520kg – 560kg on grass, albeit some supplementation in the field may be required.
Those that don’t make target carcase specification on grass will require a short finishing period on a high energy diet similar to that for steers.
Finishing Stabiliser Calves
Because achieving optimal growth rates for calves is so important to achieving a profitable return on a suckler herd, Stabilisers have been selectively bred to have high growth rates. This brings other advantages too, particularly low birth weights which means few interventions during calving time, more fertile cows, less visits from the vets and more sleep for farmers.
This all adds up to the Stabiliser being the UK’s most efficient and profitable suckler cow producing precisely what the market wants for the least possible input, and the advice and guidance in this article will lead to the production of first class Stabiliser calves that generate high returns for farmers regardless of the finishing system they use.
To find out more about Stabilisers and what makes them the UK’s most profitable suckler cow, get in touch on (01377) 227790 or email us at info@stabiliser.co.uk.
