Manage spring surplus carefully

Having successfully dealt with a tricky start to spring, grass managers have two more challenges ahead: reducing supplements carefully during the mating season and managing a sudden surplus prudently.

Grass growth rates have rocketed over the past 10 days, reports LIC consultant Bess Jowsey. Consequently, herds in a surplus situation are pulling supplements out of the diet. But she reminds everyone to be careful with dietary changes during the breeding period: “Make sure it’s done gradually over a couple of weeks. Reduce by 1 kg/cow every 4–5 days. It is unusual at this time of year, as the transition would normally happen before breeding,” she says.

While on the whole, cow condition is good, with spring-calving herds reporting that cows are cycling well with strong pre-mating heats, Bess points out that any silage of variable quality fed 2–3 months ago, could have a lingering effect on fertility. It takes 90 days to grow a dominant follicle, so it’s still important in the first six weeks of mating not to make any sudden management changes that might rock the boat.

Bess says that it’s important to get as many animals out as possible to eat grass to deal with the sudden grass surplus. Then ensure that you measure it and understand where, and how much, excess grass there really is for silage. However, she also cautions that closing up large areas of the farm can be a risk if the weather turns hot: “Grass mown for silage could take four weeks or more to be ready to graze again. It will all come back at the same length, so you’ll have to work out how to create a wedge again,” she explains.

“Monitor the situation as it develops, using Agrinet or other grazing software to plan ahead. It can all change again within 10–14 days. Keep walking the paddocks and check you have made the right decision. It’s not too late to pull paddocks back in for grazing – you have until the day you cut.”