Exclusion Lamb Feeding Delivers Unforeseen Benefits

Research has shown that introducing lambs to supplementary feed earlier aids in rumen development, which leads to faster weight gain and potentially earlier joining of the ewe lambs. However, to do this effectively, the ewes need to be excluded from the feeders.

Over the past two years, MLA has funded a Producer Demonstration Site exploring the use of exclusion feeders with lambs. NSW farming systems group, FarmLink is running the trial with Anthony Shepherd from Sheepmatters, and a number of producers from around the south-western NSW region.

Matt and Sam Dart manage ‘Felix Farm’, a 1,200ha property just south of Ariah Park. Felix Farm is part of the DB Group, a shared equity model business that was formed through the merger of a number of family-run businesses and individuals. In addition to cropping, Matt runs a mob of Dohne ewes bred to terminal sires.

Weight gain
After two lambing seasons with exclusion feeding, Matt found a slightly higher weight gain in the trial mob compared to the control.

In 2019, trial lambs had an average weight gain of 247g/head/day compared to 209g/head/day in control lambs, resulting in a 2.5kg difference over 64 days (lamb marking to weaning).

In 2020, trial lambs had an average weight gain of 336g/head/day compared to 306g/head/day in control lambs, resulting in a 2.0kg difference in weight gain over 66 days.

In 2019, Matt had little pasture availability, meaning that both mobs needed supplementary grain. Both mobs were trail fed, and the trial mob still had access to the feeder. This created a great comparison to 2020 where pasture growth rates were very high and supplementary feeding was not necessary.

Weight gain differences between trial and control mobs were similar for both years, demonstrating that the higher weight gain is possible in contrasting conditions.

Unforeseen benefits
Matt admits he was skeptical of the idea of exclusion feeding, but after running the trial for successive seasons, he feels it is a great fit for their operation.

“Higher weight gain was the main target. And yes, we have a seen small weight gains, but there have been other advantages that have really proved beneficial in our system,” he says.

His pastures have benefited, because lambs reach targeted weights earlier, resulting in faster turn-off. This means pastures are less run down, ground cover is maintained and there can be better weed control leading back into a cropping rotation.

“Lambs are not competing for feed with ewes,” he says.

“They are able to wean earlier and don’t require as much nutrition.”

This proved beneficial in 2019 when all stock were trail fed and the ewes would often outcompete the lambs for feed. In the exclusion feeder system, the lambs still had access to a feeder, but the ewes did not.

Matt plans to continue the trial in 2021. He has also been setting up an exclusion feeding system on another farm for his pure breeding stock.

“The faster the weight gain in DB Ag’s pure bred Dohne lambs, the faster a target weight can be achieved and we can think about getting the young ewe in lamb herself,” Matt says.

To this end, they have this year trialed joining 40 ewes from their breeding flock at seven months of age. In mid-February, 20 ewes who were raised on the creep feeder and another 20 who weren’t were put in with the rams for a six-week join.

Matt is interested in whether there is a statistically significant difference in conception rate.

“There’s a chance that all will join, or none will, but what we are interested in is the difference,” he says. “If we can bring joining forward from the traditional 18 months, we can get another lamb out of each ewe. Ultimately we are trying to get more lambs for the same amount of feed.”

Time will tell whether the earlier joining strategy is feasible, but Matt is confident.

“Many people will see the time factor involved in exclusion feeding, where you may need smaller mobs and extra infrastructure is required. But if the result is an extra lamb because of earlier lambing, I think it definitely pays off.”