HOW AI ADDS UP AT WAVE HILLS
FOR Devan Robertson the decision to swap to a 100 per cent AI program on Wave Hills, Tahara West, via Hamilton, Victoria, was a no-brainer after his experience working with dairy herds.
Putting 800 cows through two joinings – with 650 in the spring – Devan said there were several reasons why AI now rules at Wave Hills.
And first and foremost is cost.
“We have estimated it cost us about $120 to put a calf on the ground conceived via a natural mating program,” Devan said.
“For a calf conceived through AI that cost is between $45 and $48,” he said.
“Even using back-up bulls on the 30-40 per cent still showing heat after the first round of AI, there’s no way they are going to get them all in calf, and the same would apply for the third round.”
Devan said the other set of numbers that appealed to him were the conception rates.
He said his target for the 2018 AI spring joining had been 90 per cent.
“We got 89.5 per cent – and I know where I stuffed up so that won’t happen again,” he admitted.
“This year we are hoping for 92-93 per cent for spring, but the autumn AI result was 86 per cent, due to tight seasonal conditions.”
Use of pregnancy scanning to check for empties throughout the joining period has also improved the herd conception rates – and the herd’s genetic profile.
We are using early detection pregnancy scanning to detect those cows who have not shown a heat during the second and third rounds. Those cows then receive another opportunity to get AI’d rather than risk running through the rest of the program and having to be culled. 28 days after a major insemination period we will preg check the cows again and within 7 days those who have been detected empty will receive another insemination.
Devan said while they are ruthless with culling unproductive females, last spring, he took the opportunity with eight 14-month-old heifers who did not conceive to try a different program. This resulted in five pregnancies.
“If maiden heifers and first calvers are empty and not in saleable condition we are prepared to have another go with them. Having split calvings enables this to occur without too much ill effect of keeping unproductive females.”
As a Team Te Mania member Wave Hills also has access to next-generation genetics and Devan said in the current joining they are using semen from Te Mania Nebo; Te Mania Nolan, Te Mania Meteor, Te Mania Maguire and Te Mania Legend.
Through this management program, Devan has accelerated the herd’s genetic profile. His aim is a tight 7 week joining program for the cow herd, however a small number receive a third insemination to a low gestation length bull, with the aim of bringing their calving forward for next year.
“The rising plane of nutrition pre-joining is all off grass for spring joining – and we are lucky to have had plenty of feed this year but the autumn joiners, which we feed a lot of hay to may also require pellets prior to joining to help their conceptions,” he explained.
Our breeding programme focuses on high growth rates (600D), marbling (IMF%) and high eye muscle area (EMA). Additionally, the main considerations are heifers weighing 320-360kg receive a lower birth weight bull at joining, heifers >360kg receive a moderate to high birthweight bull, and all cows being AI’d in the third round receive a lower gestation bull.
- Team Te Mania members since 2005
- Accreditations – EU | Beef Only | PCA (Pasturefed Cattle Assurance System)
- Calving Period – Feb-Mar & Aug-Sep