Drafting lambs

The kill-out percentage of lambs will generally drop by 1% to 2% post weaning. This should be taken into account in drafting decisions. It may be possible to drop down in the drafting weight for the final draft pre-weaning and still achieve a favourable carcase weight. This decision will depend on the target carcase weight and grass supplies available. The degree of the reduction in kill-out will be influenced by the age of lambs, quality of grass and aspects such as creep being offered. It is normal for grass-fed lambs to drop from a kill-out of 45% to 47% in the weeks pre-weaning back to 43% to 45% kill-out post-weaning. It is also important to note that there is typically a 1% difference in kill-out between male and female lambs with this increasing to 1.5% to 2% for ram lambs versus wether and ewe lambs as the season progresses. The weight is only one part of drafting criteria, with fat cover equally important. Reports indicate ewe lambs are killing with a good fat cover so it may be necessary to select these at a lower liveweight.

Selecting replacements

Weaning is taking place in greater frequency in mid-season lambing flocks. For farmers selecting their own replacements it is important to identify suitable replacements early in the season so that better performing lambs are not missed out on through drafting for slaughter. Aim to select maternal-type sheep that have good length and do not possess excessive terminal traits. Initially selecting a higher number of replacements than will be required is a good option as it allows for further drafting down the line and selection of lambs that excel on grass. The ideal situation is where performance can be linked back to dams so that progressive flock improvement can be achieved.

Tagging procedure

Wraparound tags appear to be a popular choice for lambs presented at marts. Tag manufacturers advise applying the tag in a way that leaves room between the edge of the ear and the tag. This ensures tags do not become too tight as animals mature and ears grow. The general recommendation is to allow 4mm to 5mm for ear growth and again more may be necessary for breeds with large or thick ears.

Replenishing nutrients

A lot of meadows have been cut in the last week. The recovery time in swards will be influenced by soil fertility and sward quality. Along with normal fertiliser recommendations for a given soil index swards will require in the region of 20kg P/ha and 120kg K/ha to replenish nutrients removed in silage / hay making. Strategic use should also be made of slurry. Cattle slurry of 7% dry matter has a phosphorus content of 5 units P/1,000 gallons and 30 units K/1,000 gallons. Diluted cattle slurry at 3.5% dry matter will be half this level. The nitrogen content of cattle slurry is listed at six units and five units nitrogen / 1,000 gallons, respectively, but this will be lower at this stage of the season and may be negligible if applied in unsuitable weather. Thought should also be given to addressing any pH deficit in the coming weeks but avoid applying lime on ground which may be harvested for another cut.