Sward quality key to lamb growth rates in June

A slow down in lamb growth in June is due to sward quality, according to Pat McCambridge, from the College of Agriculture, Food and Rural Enterprise (CAFRE).

His latest management notes show that once sheep farmers see grass starts heading, dry matter digestibility decreases from about 75D in mid-May to about 60D in mid-June.

Importantly he also notes that: “This happens at a time when lambs become more dependent on grass.”

To counter this problem McCambridge advises farmers to maintain good grass covers and good sward management during June (rotational system). This means entering grazing swards at 2200 kg dry matter per hectare (6-8cm) and grazing down to 1600 kg dry matter per hectare (3-4 cm).This type of management helps cut out seed head production and maintains a leafy sward.

Take out excess grass in the system through cattle grazing or for silage. Sheep grazing pastures can carry a high worm burden during June. It is normally recommended to dose all lambs with a suitable wormer. However, it is worthwhile checking for worm egg counts from the lambs before dosing. This can be arranged through your Vet, who can also provide advice on a worm control strategy.