Author: Dr Enoch Bergman, Swans Veterinary Services
If you raise livestock for a living, it is pretty obvious that your pay check is intimately linked to the value of your produce. As such, it is a common perception that the bigger the calves are at weaning, the more profit available to reinvest. However, this is an assumption that may require a bit more consideration.
ASHEEP in conjunction with Swans Veterinary Services and Meat & Livestock Australia is running a Producer Demonstration Site (PDS) project to illuminate some of the benefits of weaning calves earlier than typical for the district.
A number of producers have agreed to remove half of their calves from their dams two months earlier than they traditionally wean. At that time, all cows and calves will be weighed, and the cows will be both wet/dried and have their body condition score estimated. Any dry cows will be excluded from the PDS (their data disregarded). The weaned calves will be managed separately. Those remaining on their dams will be weaned approximately two months later, everything will be weighed again, the cows body condition scored, and the cows will again be wet/dried to ascertain which ones were more likely to have had their calf weaned previously. The body condition score and weights of the wet vs. dry cows will be compared (excluding the cows that were dry at the first round of weaning).
What exactly are we trying to demonstrate? Cows use considerable energy to produce milk, but only approximately only 40% of the energy derived from the food they eat which ends up being invested into milk production ends up staying in the milk as energy available for the calf to attempt to digest. Sadly, there is no way around the significant energy outlay, as milk is simply an expensive product for the cow’s liver to produce. However, once it is created, we should endeavour to ensure that none of that precious resource is wasted! Mother nature has helped in that endeavour, as 90% of the energy from milk is absorbed by a newborn calf… until the calf becomes a ruminant! Once a calf weighs over around 150 kgs, their rumen develops and they lose some of their ability to digest milk… however, if left on their mothers they will continue to hit the milk bar as long as we (and their mother) let them.
To put it in perspective, it has been calculated that a cow with a calf at foot needs 15.5 kgs of dry matter to maintain her own body condition and feed her calf. If you were to separate the pair, so that they fend for themselves, only 9.6 kgs of dry matter in total is needed to maintain the cow and grow her weaned calf to the same extent.
So… in a nutshell… you can budget on reducing your animal’s feed requirements by as much as 38% once you wean your calves!
By getting calves off their mothers a bit earlier and before the season finishes, better feed resources can be partitioned to go down the throats of your calves whilst simultaneously allowing you to protect the body condition of your breeding females with far less resources, having dropped the dam’s dry matter requirements from 15.5kgs to a mere 6 kg! No wonder cows which fail to raise a calf struggle to fit through the crush!
Keen to know more? Keep your ear to the ground! We have eight local producers scheduled to be involved in the project this year. We will let you know how they go!
Contacts:
Dr Enoch Bergman (Swans Veterinary Services) 08 9071 5777
Sarah Brown (ASHEEP) 0409 335 194
