The best way to finish lambs is to provide them with high-quality feed and plenty of water, according to Reid Redden, North Dakota State University sheep extension specialist. Lambs also need to be free from disease and parasites to maintain health, and predators need to be controlled, Redden said.
Most lambs are finished in a feedlot, but grass-finished lambs are gaining popularity. Feedlot lambs are fed a high concentrate ration to grow quickly, while grass lambs mainly consume forages and have a variable rate of gain depending on the quality of forage provided.
"Lambs that are finished on grass won't have as high of gain as a feedlot-finished lamb," Redden said.
Grass-finished lambs require an energy dense, highly digestible and highly palatable ration, he continued. Forages like young tender grass and fall regrowth are ideal for grass-finished lambs. Crop regrowth and young, immature weeds can also provide some good feed, he added.
"The ewes will train the lambs which grasses to eat first," Redden explained. "When you buy a set of young lambs, you need to have a high-quality grass available for them to utilize."
In a grass situation, Redden cautions producers against grazing forages shorter than four inches. Grass-finished lambs can be susceptible to parasites, he explained.
"Lambs on grass need a lot of protein, and grass has a lot of water. Lambs need enough dry matter to fight off parasitic infections," he explained. "Young, short grasses have the most parasites."
If producers suspect a parasite problem, Redden encourages them to drench lambs and hold them in a drylot until they shed the parasites, then rotate animals to a new pasture and graze only areas taller than four inches.
In a feedlot, lambs can be finished by consuming grain from a bunk or a self feeder.
"Bunkline feeding is high maintenance, high output and has variable feed costs," Redden said. "Self feeders are low maintenance, provide good production, and have higher feed costs."
The advantage of bunkline feeding is the ability to use a variety of feeds in the finishing ration if a mixer wagon is available. Grain, silage, chopped hay, a mineral package and byproducts like distillers grain or beet pulp can all be mixed together and fed in the bunk.
Lambs consuming grain from a self feeder are more restricted to grains like corn, with a pellet added. In a self-feeder, the final diet is typically 80-90 percent concentrate, and 10-20 percent pellet. Redden recommends Parker Pellet because of its crude protein, mineral and vitamins.
"Ionophores can also be added to help improve health and gain," he said.
If producers are using a self-feeder, Redden said the "Rule of Ten" applies. Start with 10-20 percent concentrate. For every 10 pounds consumed, concentrate increases 10 percent.
When determining the amount of crude protein in the diet, Redden said sheep require an amount, not a percentage. He shared a study comparing efficient and non-efficient eaters consuming alfalfa hay and alfalfa pellets. At first glance, the sheep consumed more alfalfa pellets than coarse alfalfa hay, but feed conversion told the full story. Lambs consuming alfalfa pellets had a feed conversion of 10 to 1, compared to sheep eating coarse alfalfa at 40 to 1.
"If a lamb is efficient, the feed efficiency is considerably better feeding them a pellet," he explained. "They have better feed conversion eating the pellet than consuming and digesting coarse alfalfa hay."
Energy, vitamins and mineral content in a feed affects the intake of finishing lambs. They will also consume different amounts of feed depending upon what type of feed they are offered, what breed they are, and the type of environment they are living in.
"Rambouillets aren't big eaters like Hampshires, Suffolks and Columbias," he said. "Lambs also won't eat as much when it's hot outside, but they will consume more when it's cold."
When developing a balanced ration for lambs, Redden encourages producers to seek advice from experienced professionals like feed nutritionists, extension specialists or other lamb feeders. Producers can also refer to a Montana State University site where they can utilize a free ration formulator at www.msusheepration.montana.
Editor's Note: For more information about finishing lambs, Redden can be reached at 701-231-5597.