Why the first 48 hours is key to a successful lambing season

The many nutritional challenges facing the ewe during late pregnancy must be managed in order to avoid a detrimental lambing outcome, according to UCD’s Prof. Tommy Boland.

Speaking at the recent Teagasc National Sheep Conference, Boland said a one size fits all approach does not exist, but a range of common principles apply.

“Late pregnancy is one of the key risk periods in the management of the flock and we need to get better at managing that period.

“Really, late pregnancy nutrition is all about setting the flock, the sheep and the farm up for a successful lambing season. We need to meet the energy and protein requirements of our animals. It’s very simple and quite often it’s not achieved at farm level.”

Why is late pregnancy nutrition so important?
  • A correctly fed ewe gives the maximum chance of a successful lambing outcome;
  • In order to produce good-sized lambs and to minimise lamb mortality;
  • For the ewes to produce sufficient quantities of good-quality colostrum;
  • 85% of foetal growth occurs in the final two months of pregnancy;
  • Correct feeding is critical to minimise metabolic diseases.

The importance of colostrum

Along with being critical for lamb birth weight, late pregnancy nutrition is also essential for colostrum production, Boland said.

For ewes to produce adequate supplies of colostrum, he said, it’s important to maintain the mid-pregnancy body condition right through until the point of lambing.

“That body condition is much more valuable to us a sheep farmers in early lactation; the ewe shouldn’t burn it off in late pregnancy.”

He continued: “Colostrum is absolutely crucial to a successful lambing. If you want to have hardship around lambing time have ewes lambing down with no colostrum or milk. That’s a key problem on a lot of farms.”

Key lambing targets:
  • <8% lamb mortality for a flock weaning 1.3-1.4 lambs per ewe;
  • <2% ewe mortality;
  • 6kg single lamb birth weight;
  • 5kg twin lamb birth weight;
  • 4.5kg triplet lamb birth weight.

Touching on the quantities of colostrum required by each lamb, Boland said: “Each lamb will require about 1L of colostrum in the first day of life and at least 0.5L must be available when the ewe lambs down. That’s achievable through good nutrition.

“We give lambs the best chance by having ewes lambing down with high volumes of good-quality colostrum and that’s half of the story.

“The other half is that the lamb must be able to consume that colostrum; both those factors are hugely affected by how we feed our ewes in late pregnancy.

If our lambs don’t have access to good-quality colostrum, it presents us with a huge challenge. 50% of all lamb mortality occurs within the first 48 hours of life.

“The vast majority of that mortality is linked to problems around colostrum; either the lamb doesn’t get enough colostrum to generate heat or the lamb doesn’t get enough colostrum to prevent disease.

“If we get the lamb through the first 48 hours of life, the chances are pretty good that they will make it all the way through to slaughter.”

The timing of lamb mortality. Source: HCC lambing project 2010/2011

Boland also discussed the findings of a recent trial carried out in Lyons Estate, which compared the growth rates of triplet lambs that received or didn’t receive colostrum within the first 24 hours of birth.

Right throughout life, the lambs which received colostrum grew about 60g/day faster than the lambs that didn’t receive colostrum.

“Not only is colostrum essential to lamb survival during the first critical 48 hours, it also primes the digestive tract to make the lamb more efficient at utilising feed for the remainder of its life.

“If we miss that window in the first 48 hours, the lamb is permanently compromised. Interestingly, the differences didn’t manifest pre-weaning; they only came to the fore in the post-weaning period when the lamb is expected to survive on an all solid feed diet,” he said.