Fast food for lambs
One of the easiest ways to improve efficiency in lamb production systems is to ensure lambs can eat plenty so they can grow quickly, according to Dr Glenn Judson, Animal Nutritionist for Agricom.
Dr Judson was in Australia recently speaking to resellers and lamb producers on ‘paddock to plate’ lamb production. He said part of the challenge for resellers was to encourage producers to optimise stocking rates. “Low stocking rates allow every animal to eat to its full potential, but there are not enough stock to maximise output per hectare and forage quality can be an issue,” he said.
“High stocking rates can also be a problem, because although there can be lots of lambs, they don’t grow very quickly. “We also know that when feed intake is low or close to maintenance, lambs grow more slowly and it takes them longer to reach their target weight, so they consume more feed overall. “Well fed, fast growing animals are more efficient because they reach their target weight in fewer days and so need less feed for their everyday maintenance energy." “Farms have a finite amount of feed, and the faster producers can grow lambs, the less feed they will use in total.”
Dr Judson said there were two key areas to focus on when aiming to improve the feed intake of lambs.
Firstly, producers need to make it easy for lambs to harvest large amounts of forage by helping them to get more in their mouths every time they take a bite. “Bite size is actually the greatest influence on intake,” Dr Judson said.
“By offering pastures and forages which are very erect and have wide leaves, in general, lambs can eat more in a day.” In this respect, resellers should be encouraging graziers to consider feed sources such as brassicas, clover, chicory and plantain, rather than grass-based pastures when high intakes were required. “There are only so many hours in a day and so many bites lambs can take, but there is a lot we can do to improve the harvesting dynamics of the feed source,” Dr Judson said.
“Easy to harvest feed has big leaves and the leaves often sit horizontally, like clover, rather than vertically, like ryegrass.” The second aspect of improving feed intake was the speed of digestion, measured by the fractional degradation rate. “Chicory, plantain and clover clear the rumen much more quickly than perennial ryegrass or kikuyu, so lambs return to grazing faster and eat more in a day,” he said.
Dr Judson said Winfred brassica was a good example of a feed source that was easily harvested and quite quick to clear the rumen to allow lambs to return to grazing sooner. Winfred brassica is a cross between a turnip and kale and has been grown by Australian lamb producers for many years. “Winfred has the potential to be grazed a number of times from autumn through to spring and can tolerate frosts and dry conditions,” Dr Judson said.
Another option is Tonic plantain, a flexible forage herb which offers year-round productivity and the added benefit of supplying minerals to stock. “With appropriate grazing management, these high quality forage options can help producers to meet their production goals,” he said. According to Dr Judson, monitoring of faecal egg counts in sheep and lambs grazing Tonic Plantain showed a consistent picture where worm burdens remained below treatable levels, probably due in part to the improved metabolism and hence the better health of these animals.
He reminded resellers and graziers that it was not the forage crop that paid the bills, but the meat sold after grazing. “Depending on the grazing management, the same brassica crop can cost producers $200/ha or support a return of $200/ha,” he said.
Dr Judson presented the results of a blind tasting of lamb, which showed trained meat tasters could not distinguish between lambs fed on a range of forages which included brassicas, clovers, grasses and herbs. “Forage type does not seem to have any impact on eating quality, so encourage your grazier customers to choose a feed grows well in their environment,” he said. “Getting lambs to eat enough is much more important than what they are eating.” For sowing recommendations to maximise livestock production or the new Tonic Technical Agnote, call Stephen Pasture Seeds (VIC, SA, TAS) on 03 5335 8055 or AusWest Seeds (NSW, QLD) on 1800 224 897.