Grass supplies are touch and go for the Athenry research demonstration flocks. Weaning, which took place two weeks ago, provided a short-term reprieve and allowed aftergrass swards to be prioritised to lambs.
Last week’s growth rate dropped to less than 30kg DM/ha, with growth in paddocks that have been recently grazed and have no cover of grass practically stalling.
Researcher Philip Creighton says that growth rates this week are likely to be even lower, with growth in many swards in single-digit figures, while a few paddocks grazed tight by ewes post-weaning are showing no signs of regrowth.
Philip explains: “Ewes bagged up well after weaning and with the high temperatures we were mindful of a higher risk of mastitis. Ewes were tightened up for a few days with access to water and shelter and this worked well in drying them off without any issues. We have reduced the pressure on them this week and they will start grazing after lambs to clean out swards.”
The quality of grass on offer to lambs is poorer than desired, but is not too bad when you consider the stress that swards are under. “Swards are being hit on two fronts. We applied nitrogen, but the plant did not get a chance to take it in before the dry spell hit, so along with the plant being under stress for nitrogen, it has also had to cope with a growing moisture deficit. This has led to grass going to stem and heading out quicker. Quality is not too bad compared with other parts of the country that have gone without rain for longer,” he said.
Lower performance
The lower-quality grass on offer and higher temperatures altering normal grazing behaviour is negatively affecting performance and is adding to lower pre-weaning performance.
The average weight of lambs at weaning was about 2kg to 3kg below normal, with a range of 28kg to 30kg in the medium and high stocking rate and prolificacy groups.
Philip said: “Lambs got off to a difficult start, with performance in the first four to five weeks hit by weather. There was a short period of normal performance in mid-lactation before returning to lower levels of performance as temperatures increased in the leadup to weaning and post-weaning.
“We had a spell of higher than normal temperatures in 2013 and daily performance fell by 40g to 50g as lambs spent longer taking shelter and resting during peak daytime temperatures. Lambs look good, but they are not weighing well. It will be interesting to get a weight next week to see how weather is hitting current performance.”
While performance is lower, lambs achieved a level of compensatory growth when daily performance was curtailed in recent years.
With no signs of rain and supplies falling to dangerous levels, steps will need to be taken in the coming week to keep lambs on track and avoid higher numbers competing for autumn grass supplies.
Days ahead is running at 13 to 15 days and will be monitored closely. At this stage, it looks like concentrates will need to be introduced next week at a rate of 0.5kg per head, with feeding levels reviewed in the context of available grass supplies.
The farm has met its target for winter feed and has a small reserve. If conditions continue to worsen, then there will be no option but to also supplement ewes with forage to avoid any body condition loss.
Health concerns
Faecal egg counts are being used to determine the need to treat lambs, while lambs are being run through a footbath solution every time they are handled to keep on top of lameness, which has been a greater concern in recent weeks.
The other health treatment is regular cobalt supplementation.