By Poppy Frater, sheep and grassland specialist, SAC Consulting

The performance of the ewe and the lamb is exceptional during lactation. The ewe is able to utilise her fat reserves and consume great amounts of feed to satisfy the growing lamb demand.

The lamb is growing more efficiently than it ever will as it converts milk, grass and, possibly, creep feed into frame, muscle and, latterly, fat. Lactation really sets the scene to ensure lambs get away quickly, so consider the changes in performance drivers as we move from early to mid to late lactation to make this period the most productive for the business.

Peak lactation occurs three to four weeks post lambing. A ewe with twins will produce 2-3 litres of milk at this time. Ewe condition and nutrition dictate this the extent of peak production. Body condition score targets of 2.5-3 at lambing time will go a long way but we also have the opportunity to improve what feed is in front of them.

Fortunately, for many, lactation nicely coincides with fresh spring grass which is often measured at around 11.5-12.5MJ ME/kg DM and 18-20% crude protein. This year, with plentiful spring grass production, the nutrition of the ewe is taken care of for most farmers. However, when grass height is below 4cm, they will benefit from additional feed such as sugar beet pulp, lifted fodder beet or concentrates.

Mid-lactation (from four weeks post lambing), the lamb’s performance is increasingly influenced by grass. Maintaining grass height in the 5-7cm sweet spot with high clover content will keep them going as their milk intake declines. This is where manipulating stocking pressure can be useful by bringing in cattle to keep the pasture under control or reducing their area.

When grass height exceeds 7cm, there will be a decline in quality, which can knock lamb growth rates in the short term, but also impacts grazing quality later in the season. Some farmers rotationally graze at this time. This is particularly useful if, like 2018, grass is in short supply as it reduces the grass wastage and gives greater control.

In the final 30 days of lactation, lamb performance is driven by feed quality, gut worms and, to a lesser extent, minerals (mainly cobalt). If grass is short, earlier weaning is beneficial because the ewe and lamb will be more efficient independently than together.

Health planning and monitoring comes into play more significantly here but good nutrition is always the best starting point. Read a summary from the SAC Consulting Live Lambs meeting at Graham Lofthouse’s farm here: where we discussed supplementing grass and condition scoring amongst many other topics.