Performance to 7 weeks on target, but keep an eye til weaning
The lowland flocks in the Teagasc BETTER farm sheep programme have collected the 7 week lamb weights in recent weeks. Frank Campion, Sheep Researcher presents a summary of the weights saying "While performance to 7 weeks is on target, it's important to keep eye on the ball all the way to weaning"
The lowland flocks in the Teagasc BETTER farm sheep programme have collected the seven week lamb weights in recent weeks and a summary of the weights are presented in Table 1. Target average daily gain (ADG) for the flocks is for twin born lambs to be achieving an ADG of > 280 g/day from birth to 7 weeks for lambs being reared on ewes receiving no concentrate supplementation post lambing. As can be seen from the table the most of the flock’s lamb performance to 7 weeks is on target and indeed has exceeded that in some cases.
Table 1. Mean lamb performance from the lowland flocks from birth to 7 weeks of age with range in brackets
The 7 week weight is an important measure of flock performance
7 week weight indicator
The 7 week weight is an important measure of flock performance as not only does it give an indication of how the lambs are performing but also an indication of ewe performance. Up to 6 to 8 weeks of age lambs are getting most of their nutrient requirements from their ewes milk and poor performance to this point can indicate ewes that are not producing enough milk to meet lamb requirements. As a result, where possible, these weights will be used not only to identify underperforming ewes but also when selecting replacement ewe lambs later in the year to try and identify ewe lambs from ewes that had the best litter growth rates to 7 weeks post lambing.
Grassland management
Grassland management has been a key element to the good performance figures recorded at 7 weeks and will become even more important up to weaning as the lambs begin to rely more on grazed grass to meet their nutritional requirements. As lambs grow older and are become more reliant on grass to drive their performance ensuring that the flock has good quality grass in front of it is vital to keeping performance levels on target up to weaning time. Weaning will take place approximately 100 days (14 weeks) from the mean lambing date. Target performance from birth to weaning will be an ADG of >260 g/ day but this can fall below this quickly if lambs do not have good quality grass in front of them.
Grass growth for the Teagasc BETTER sheep farms has been variable during the month of May with grass growth rates behind where they would normally be expected to be. As a result some of the flocks had to re-graze ground closed for silage in order to meet grass demand for the flock. Growth rates in the last week are rising back to more typical levels meaning a careful eye will have to be kept on grass quality ahead of the flocks. The flocks will be targeting 10 grazing days ahead from early June and the days ahead has risen quickly in recent days requiring the flocks to take action to maintain control.
Take action to maintain control. This will mean dropping out paddocks with heavy covers from silage and sub-dividing paddocks as necessary to keep to this days ahead target which will help maintain good quality grass in front of the flock and ultimately help to optimise performance of the flock. Post-grazing heights will also be increased to approximately 5 cm so that lambs are not being forced to clean out swards. It will be important that these swards are grazed out fully either by dry hoggets following behind the ewes and lambs or else by the ewes after weaning during the next rotation.
Find out more about the BETTER Farm Sheep Programme here
The Teagasc Sheep Specialists issue an article on a topic of interest to sheep farmers every second Tuesday here on Teagasc Daily. Find more on Teagasc Sheep here