Calves: Spring-born calves that are on target to calve down at 24 months old should be 25% of their mature liveweight now. So if the mature liveweight is 580kg, then the calves should be weighing 145kg now. Jersey crossbred calves will have lighter mature weights, probably closer to 500kg, so the target liveweight for these calves is 125kg. There is often some confusion about target weights. In all likelihood, if you weigh a bunch of calves, the average weight will be in or around the target weight. That is not the objective of weighing though. You want to identify the lighter heifers and give them the opportunity to get back on target. Similarly, you don’t want heifers to get too far ahead of target either, as heavy heifers have bad fertility. A lot of farms will have aftergrass coming back from silage over the coming weeks. This is usually the best grass on the farm and should be targeted at milking cows and underweight youngstock. One or two kilos of meal along with the good grass is advised for the calves that are underweight. Give them the best possible chance to catch up – are they OK for minerals and parasite control? What about viruses like IBR or RSV? If you have different breeds of heifers, you will have to use different target weights – there is no one size fits all.

Flies: Now is the time to start fly control on in-calf heifers and dry cows. Flies increase the risk of summer mastitis, as they spread the bacteria. Summer mastitis is a serious disease, usually resulting in the loss of the affected quarter and a sick animal. The easiest method of control is pour-on, which will cover the animal for up to four weeks. Fly tags are another option; these cost €4 to €5 per animal and are said to last up to four months. They contain Cypermethrin, which keeps flies away. Topical treatments like Stockholm tar are also an option, but they need to be used more regularly, at least every fortnight, and are messy to apply. For dry cows, long-acting dry cow tubes and teat sealer will be the best prevention.

Grass: As Stephen Connolly reports this week, grass growth has dropped on some farms over the past fortnight. A combination of a high proportion of the farm recently cut and a drop in air temperatures led to the drop in growth. You really need to be measuring grass regularly to know where you stand and predict what is going to happen. The number of farmers routinely measuring grass is dismal, but those who do find huge benefit from doing it. There are no excuses. The act of measuring is easy and the software for making decisions is easy to use. Pasturebase is available as an offline app, meaning it can be used with limited or no phone coverage. A useful function is to predict ahead to what the wedge will look like next week based on expected growth rate. This can only be accessed using the web version, either on a desktop computer or internet browser on your phone. Higher temperatures this week and plenty of moisture in the soil indicates a return to normal growth rates of 70kg or more over the coming week.