The first Tuesday in November is not only significant for punters! While the Melbourne Cup is a big deal for many people across Australia, in beef production, Melbourne Cup day marks another event for beef producers. In spring calving herds, Melbourne Cup is often the starting point for producers to join bulls into the cow herd.
A November joining sees calving commence in August the following year. Ideally most herds will calve into the spring growth. Calving places huge energy demands on cows. In most cases cows energy requirements double as she commences to produce milk and recover from calving.
Generally, cows lose weight in this period, which can impact on her ability to return to oestrus. It generally takes around 50 days after calving for a cow in average condition (Fat Score 3) to return to oestrus. Cows in lower body condition at calving will take longer to return.
So calving in spring is a strategy designed to match a cows peak energy demands with peak pasture growth. The flush of pasture growth often meets the increased demand for energy and cow weight loss can be a bit more manageable.
But what happens when cows are in a light condition at calving and into joining a few months later? If you are going into joining in November and your cows are lower in condition – Fat Score 2, it’s highly likely many of your cows wont be cycling when the bulls go out.
Often these lighter cows will cycle later and many not go into calf until the middle or end of the joining period.
Length of joining then is an issue for many producers; particularly those struggling to manage lighter conditioned cows and poor seasons. I reckon producers sometimes decide to extend their joining period by a couple of weeks, just to allow some extra time to get these cows in calf.
While that strategy can work to increase your conception rate, I actually think this can be a false economy. Extending joining will result in a big spread of calf ages and weights.
In practical terms there is around 7 kg live-weight differences between calves born a week apart. So Calves born in the first week of joining should be around 7 kilograms heavier than those in the second week. Over a six week calving, its not unreasonable to expect that the calves born in the first week will be about 42kgs heavier than the calves born at the end.
Over 12 weeks, this difference is around 84kgs between youngest and oldest. If you extended joining even longer, the weight differences become larger again.
There is a big difference in managing calves that are so varied in weight. It has implications for your strategies around weaning, marketing, especially if you market weaners and in your choice of heifers to select as replacements.
It can also be hard to bring cows back into line for subsequent joining’s. Late cows generally are always going to be late in re-joining. And they often slip further back over time.
So how do you manage the challenge of joining time and cow condition to maximize conception rates? There are some strategies to consider. Most of these revolve around improving energy supply to your cow herd. Joining on a rising plane of nutrition should always be the goal.
If the season is against you and you have to consider feeding, think trough the most suitable feeding program. Don’t just use the same supplement you always fall back onto! Actually match your supplement to your cows and pastures. It’s also worth considering early weaning to reduce the energy demands on your cow. And it is often more efficient and less cost to feed calves and cows separately.
Don’t forget joining is a pretty physical activity for your bulls, so you need to be out checking regularly on your bulls. They can injure themselves, and you need to pick that up and if necessary replace bulls if they can’t work. Again don’t just leave them out a little longer as this will impact on you for next season.
If you do want to discuss your joining program or have some objective assistance with the program over the next few weeks, I’m always happy to come and have a look. So please feel to get in touch.