Livestock Logic director and veterinarian Dr Andrew Whale has been encouraging clients to use teaser rams, and said last year they vasectomised 500-600 rams for clients, a number that has gradually built up over the last six years.
Mr Whale said the use of teaser rams is suited to those running British-bred sheep, who join out-of-season.
“Sheep don’t naturally cycle very well prior to the summer solstice, the longest day of the year, which is usually on December 22, they improve in conception ability the further we go from that period,” Dr Whale said.
“Depending on the breed of sheep, some will not be cycling well until late February.
“For strongly British bred sheep, like composites, we consider joinings prior to mid February to be out-of-season, and these flocks can really benefit from the use of teasers.”
He said when you initially put rams in with ewes, ewes will have what is called the ‘ram effect’.
“The ewes will only ovulate two to five days after the rams have gone in, but it’s a silent ovulation, so they don’t actually go on heat or seek a ram,” he said.
“They’ll return on heat 19-25 days after the initial ram introduction, which means you get very few conceived in the first 17 days of joining.”
He said without a teaser ram, this will impact the number of ewes that get pregnant if you have a shorter joining period, and can affect the tightness of your lambing period.
“You’d be thinking they’re going to lamb in two weeks, but they’ll lamb in five, and your nutritional management can be impacted by that, making it challenging to have lambing ewes in the right paddocks at the right time,” he said.
He said it also means you are able to sell heavier lambs prior to the end of the growing season, putting more dollars in your pocket.
“You’re able to bring forward the birth date of your lambs by 17 days, and if your lambs are growing at 300 grams a day, which they should be if they’re on their mother, that’s an extra five kilograms liveweight, and 2.5kg carcase weight, that you’re able to sell,” he said.
Fourth generation farmers Andrew and Jane Rentsch, ‘Coolibah’, Penshurst, currently run 8000 composite ewes, and used teaser rams for the first time this year.
“Once a ram is with a ewe, the ram makes her cycle, so we put the teasers out 14 days before the rams, which starts a natural cycle, so once the rams are with them, they’re already cycling and will conceive,” Mr Rentsch said.
“We’re due to lamb on the 1st of July, but nothing normally happens until July 15, so the idea is to squeeze it up so by the 1st of July, the lambs should be coming, and we can scan for earlies and lates, and have them separated and managed accordingly.”
Ms Rentsch said it’s all about making management easier.
“This is the first year we’ve really committed and bought teasers, so by the end of the year, we’ll be really interested to see the result, we’re pretty excited,” Ms Rentsch said.
The Rentschs purchased Merino rams to be their teaser rams, and said while they look “hilarious” in a flock of composites, it makes them easy to identify.
“It also means that they’ll actually give us a fleece worth something, so we can make some money off them, otherwise they’re just boys doing nothing for the majority of the year,” Ms Rentsch said.
Dr Whale said Merinos are a good option to use as teaser rams, but like all animal purchases, you need to consider the biosecurity risks.
He recommended getting in contact with a Merino breeder, to see if they have cull rams available, and then get them vasectomised, or alternatively simply keep male ram lambs yourself.
He said it is important to get in contact with your vet, to see if this process is suited to your operation, which is almost entirely dictated by your joining time.