Maiden heifers

Getting maiden heifers in calf as early as possible in the breeding season is one of the most effective ways of improving the six week calving rate next spring. Furthermore, by getting these animals calved early, they will have a much greater chance of remaining in the herd for longer.

Heat detection is critical to achieve high submission rates. They need to be watched at least three times per day in addition to using a heat detection aid. Scratch cards tend to work better than tail paint on heifers. The lighter frame of the heifers rubs off scratch cards easier than tail paint.

Heifers by their nature can be more inquisitive than cows and I’ve seen them lick and bite off scratch cards, so make sure they are well stuck on by using carpet glue in addition to the glue on the card.

Most farmers will AI to standing heat for seven days, before giving a shot of prostaglandin to heifers not yet served.They will then wait for them to come in over the next two to five days before letting off bulls.

It’s not recommended to rely on just one bull to get either cows or heifers in-calf because if that bull becomes sub-fertile or infertile during the season, then that carries a massive risk and cost. Fertility testing bulls is good practice but it’s still no guarantee that the bull will work.


Grass supply is tight enough on most farms. Growth was very slow earlier in the week, but in the last few days seems to have turned the corner. Even though temperatures aren’t expected to rise massively over the coming days, the time of the year is on the farmers’ side with longer daylight hours playing a big role as we move into May.

The lower than normal nitrogen rates this year are also likely to be having some effect on growth rates. The main job over the next while is to walk the farm every five or six days to be in a position to make decisions early. Feeding silage or additional meal at this time of year carries a massive cost, particularly when that feed could be replaced by grass.

From now on, low protein ration can be fed. Some farmers are feeding as low as 12% protein nuts and cows are milking well. Make sure when ordering nuts that magnesium, to be fed to prevent grass tetany, is included at a rate which gives tetany cover even at low feeding rates such as 1.5-2kg.

Some farmers have cut meal out completely and are just supplementing minerals in the water. Some level of mineral feeding in addition to the magnesium is necessary on most farms. Looking at the forecast, the weekend could be high risk for grass tetany.


With so much flux in the fertiliser market, it’s important not to forget about applying sulphur. It’s needed in lighter soils, with deficiencies presenting themselves in a similar way to a nitrogen deficiency. It’s an important nutrient for grass growth and yield, particularly for silage.

It’s also an essential nutrient for clover as it plays an important role in nodule formation, which is where nitrogen is fixed. If topping up silage fields with nitrogen, consider spreading a product such as ASN which is 26% nitrogen and 14% sulphur, if available locally.