Massey University sheep husbandry professor Paul Kenyon, the head of the school of agriculture and environment in Palmerston North, spoke about increasing efficiency on sheep farms at a diversification opportunities workshop in Ranfurly last week.
A high-producing flock improved efficiency, Prof Kenyon said.
Body condition scoring a flock was important.
If sheep had a body condition score of more than the optimum of 3.5, it had eaten more food than it needed — a cost which would not produce a financial return.
Feeding ewes in poor condition provided "more bang for your buck", he said.
"You want to be targeting your bottom end. It’s not efficient to be feeding everyone in a mob."
A flock should be scored four times a year — weaning, pre-breeding, scanning and set stocking.
If farmers only wanted to score their flock three times a year, they could drop the pre-breeding scoring, he said.
Information on a ewe’s condition and in what cycle it became pregnant, allowed farmers to target how individual mobs of ewes were fed, rather than giving all the flock the same access to the available feed.
Farmers needed to target the ones that needed it most, especially when feed reserves were short, like the dry conditions in some parts of the Maniototo, he said.
When grass supply was limited, a ewe relied on its body condition to produce milk to grow its lambs.
Farmers only made money from a lamb if it lived, and made more if the lamb was as heavy as possible at weaning — "sheep farmers are milk farmers".
Growing lambs for slaughter faster was more efficient because they consumed less feed post-weaning, had fewer health issues, needed less vet care and labour and produced less greenhouse gas.
"As soon as you kill a lamb it stops eating grass and the grass is available to your ewes."
Ewe lambs grown faster would be "bigger, well-grown replacements with a greater lifetime performance".
A small increase in weaning weight would result in lower feed intake to get to a slaughter weight.
Higher-quality feed would mean less of it was required to reach slaughter weight, he said.
Research showed farmers should be using terminal sires to increase profit.
An ongoing study showed as lambing percentages and lamb weaning weights increased, so did a farmer’s cash operating surplus.
"If you are at the lower end of the spectrum, you’ll gain more money by focusing on reproduction for the same amount of feed."
If a farmer wanted a high-performing flock, they needed appropriate animal health plans and management.
Farmers should have high genetic merit animals, "even if it’s just your rams".
The genetics targeted should align to a desired outcome.
"There’s no point getting high-value genetic rams for wool, when you are getting all your income from lamb."
The poor performers in the flock should be culled.
Farmers should target reducing the death of their ewes by ensuring they had a body condition score between 3 and 3.5.
Pasture should be high quality, green and never be grazed by the flock when any lower than 5cm.
If the pasture was lower than 5cm, a flock’s feed intake was being limited and lambs would be finished more slowly.
The more diverse the feed available, the better a sheep performed.
If a farmer used the same amount of feed to produce more product, such as lamb, they increased their greenhouse gas efficiency per kg of product.
However, total greenhouse gas emissions would only be reduced if the efficiencies gained allowed farmers to maintain production with fewer livestock, resulting in less feed consumed and less greenhouse gas produced.
The extra land would need to be used for an alternative system other than farming animals, such as planting native forestry for carbon.
Research on a North Island hard hill country farm suggested planting native trees on the steepest 10% of the farm could be profitable and reduce greenhouse gas production.
When a native shrub was aged between 5 and 12, sheep were able to browse on it under current regulations.
"There’s a lot of ways you can improve efficiency on farm by changing your system."
However, to be more profitable and efficient, a farmer needed high-quality feed, and animals not affected by health issues and able to grow to their genetic merit.
To achieve higher performance, farmers needed to treat their sheep as individuals, run in mobs, rather than in a single flock, he said.
