Grass supplies

Grass growth rates remain hugely variable across the country. Some farms along the western half of the country that received significant rainfall about 10 days ago recorded growth rates on well-fertilised swards of 70kg DM/ha to 120kg DM/ha. These farms are in a good position for grass supplies and here management is focusing on maintaining quality and ensuring swards are identified to have sufficient supplies of highly digestible grass available for lambs post-weaning.

There are pockets within this region though that did not receive this rainfall, while the soil moisture deficit continues to worsen for farms along the eastern coast and in parts of the midlands. Here growth has reduced to 25kg DM/ha to 40kg DM/ha and this is expected to continue to fall with no significant rainfall in the forecast.

Highly stocked farms have seen grass reserves diminish quickly and are now at a stage of having to act quickly to retain sufficient supplies in front of lambs. A number of options are being utilised. Some farms where infrastructure allows are creep-grazing lambs ahead of ewes and also in cases offering creep feed to conserve supplies, while others with lambs aged 11 to 12 weeks old on average are weaning early.

The latter approach is significantly reducing demand, with grass demand for ewes falling from 2.3kg to 2.5kg DM/day down to 1kg DM/day. These ewes are being used to graze out paddocks while if this is not an option ewes can be supplemented with hay or silage at grass. As mentioned last week if cull ewes are being sold immediately to reduce demand you may need to check if this will affect compliance with the Sheep Welfare Scheme reference number of ewes that must be maintained.

The other complication on some farms that utilise forage crops for finishing lambs is that crops are struggling badly with no moisture. Crops and grass swards should achieve a level of compensatory growth when rain does arrive but in the meantime steps will need to be taken to keep lambs moving.

The general level of creep being offered to lambs to underpin performance ranges between 0.3kg and 0.5kg per head daily. Where offering higher volumes, the economics will be greatly enhanced by batching heavier lambs for a short feeding period. Remember to build feeding levels gradually and ensure a fresh water supply is available.

Drafting lambs

Factory agents report an increase in the number of leaner lambs coming on stream over the last week. It is important that lambs are assessed on a combination of fat cover and liveweight. Lambs that are poorly covered will also achieve a lower kill-out percentage and this increases the risk of lighter lambs falling below the lower carcase weight cut-off in most plants of 17kg. These lambs should be delayed from drafting as significant penalties are imposed, with a low level of supplementation where required going a long way to improve fat cover.

Safety risks

It is easy to overlook safety concerns when applying pour-ons to treat and prevent external parasites. However, there is a significant risk of inhaling chemicals through aerosol mist of liquid particles. As such, a respiratory mask with appropriate chemical filters should be used along with correct protective clothing to prevent absorption through the skin.