I calve my cows as 2yr olds and have been doing so since 1989. Initially using Angus bulls, ½ bred daughters were retained and graded up to bring in new polled blood lines. Since 2007 I have only used purebred bulls over yearlings .I keep a close eye on the 2yr olds at calving time, only needing to assist one breech birth out of 24 last season .The second calving and older cows calve on river bed country that is interspersed with willows and broom . They have to calve unassisted meaning problems are buried. I drive around them once a day if the weather is fine, every 2 -3 days if not, to get a birth date. I don’t weigh calves at birth and while I commend those that do I feel that a successful birth is a successful birth and leave it at that.
I want a medium framed herd of cows as I believe the top growth rate bulls bring too much birth weight and are too lean and late maturing to fit into a one year commercial fatting system in southland. Wintering in southland is very expensive as fatting cattle have to be feed ether crop or baleage, preferably both, and it is more economic to have a weaned calf rather than a 400- 500kg rising 2yr animal that requires 10 – 12kg DM/day simply to maintain itself over winter. Also excessively high growth rate cows struggle to get back in calf as rising 3yr olds. A cow’s toughest year under a 2yr old calving regime.
I am aiming for bred average milking ability rather than high so that calves get off to a good start but don’t put too much stress on the cow’s ability to rebreed. Mating time at Wainuka is the 15th of November which coincides with peak feed demand on the property (14,000 sheep including lambs and 400 cattle including calves all needing grass to eat!)
My immediate aim is to produce sale bulls that scan an EMA of 100cm plus, IMF of 4 plus and RIB of 3-5mm at 550kg to 650kg live weight at the time of scanning. I’m already achieving this in part. I use raw scanning data rather than EBV’s to select sires at this stage as I have only been scanning since 2013 and the EBV’s on my young bulls have low accuracy as well as a lag time on them. They aren’t meaningful until after scanning their progeny, by then a bull will be at least a rising 4yr old and could’ve had up to 3 mating’s. More of a score keeper than a predictor of performance!
I measure EMA: The more the better providing that it doesn’t negatively impact on other important traits such as fertility, calving ease and IMF
RIB FAT: Important for female reproduction and carcass grading. Rib fat has a very high correlation to yearling in calf rates up to a certain level. Processing companies in NZ place a great deal of importance on rib fat through their schedules with heavy discounts for too much or especially too little rib fat. Unlike Australia our cattle are not graded on rump (P8) fat so I see no economic or genetic reason for measuring this trait. So I don’t!
IMF: Important indicator of carcass quality increasingly recognised by processing companies through their grading systems. As a British breed I believe it is South Devon’s big advantage over the European breeds along with temperament.
Polling is definitely the way of the future particularly as animal welfare codes and work safety practices become stricter. The emphases at Wainuka is for polled cattle but having taken 15 years to grade up to purebred I refuse to “throw the baby out with the bath water” in a single minded crusade to become a fully polled herd. I will still use superior horned genetics when the opportunity presents itself until suitable polled animals are available. Don Goodall a well-respected Hereford breeder once said that his “best polled bulls had between a ¼ to a 1/8 horned blood in them”. I agree with his view point and am following a similar policy.