Page 43 - Hereford Magazine 2021

Doing dairy

beef better

The 2018-born cohort in the Beef + Lamb NZ Genetics Dairy Beef Progeny Test (taken winter 2020). Photo credit: Anna Boyd.

Increasing use of dairy beef is an important tool in the crossbred cows they were mated to, indicating there is
in our toolbox of on-farm mitigation strategies. a substantial pool of bulls available that could be used with
confidence over dairy cows. It is important to note the same
By associate professor Rebecca Hickson, Massey University cannot be said for first-calving dairy heifers, and only very
easy calving bulls should be used over these heifers.
airy beef has had an interesting year. Prices for For bulls used over the cow herd, the goal should be ‘light
four-day-old and weaner dairy beef calves were enough’ calves so as to not cause calving difficulty, but not
down last spring, in part because of a hangover so light that they do not offer a decent rearing proposition.
of finishing cattle that didn’t make it to slaughter Given hand-reared calves are typically weaned to a fixed
Din the autumn drought. Indications are that weight, the time spent on milk and the associated milk and
fewer people are rearing calves, and the bobby calf kill is up labour costs increase as calves get lighter. Data from the
on previous years. Appetite for good yearling bulls has held, B+LNZ Genetics Dairy Beef Progeny Test at Limestone Downs
so there will be many calves on offer again next spring. indicates an increase of 1kg in birth weight was associated
A recent study comparing the climate footprint of dairy with 1.6kg and 1.5kg additional carcass weight for heifers
beef with traditional beef systems in New Zealand highlighted and steers, respectively.
the potential to reduce the impact of our beef production Dr Lucy Coleman, who completed her PhD examining the
by about 20% by switching to dairy beef. Of course, the dairy farm impacts of using beef bulls in the B+LNZ Genetics
suggestion we could replace our breeding cows with finishing Dairy Beef Progeny Test at Limestone Downs, reported no
cattle fails to recognise the intrinsic value of the beef cow effect on milk production or rebreeding performance for cows
on our sheep and beef farms. On many farms, we couldn’t that calved to different bulls in the progeny test. The caveat
efficiently finish cattle on the same pasture that our beef cows here is that none of the bulls contributed to calving difficulty,
are frequently allocated. Nevertheless, the principle is robust, and this indifference to service sire is unlikely to hold in the
and increasing use of dairy beef is an important tool in our event a bull caused difficult calving. Further research will
toolbox of on-farm mitigation strategies. confirm this result at Pamu’s Renown farm, for the second
The challenge is to get the right genetics for dairy beef; that phase of the progeny test.
involves finding bulls that provide the all-important calving Within the 101 bulls tested between 2016 and 2019, all of
ease on the dairy farm, and produce calves with growth which produced calves that were born without difficulty,
potential for finishing. This is where the Beef + Lamb NZ gestation length had a range of 13 days. This has the potential
(B+LNZ) Genetics Dairy Beef Progeny Test is important. to add value for dairy farmers, especially where the bulls are
A critical pinch point in the dairy beef system is calf-rearing used later in the mating period, and a shorter gestation can
capacity and industry recommendations (based on studies in be used to bring a late calver back towards the main herd,
Friesian bull calves), which advise a minimum live weight for increasing her chance of conceiving in the following season. It
rearing of 40kg. The average birth weight of calves in the dairy is worth noting not all dairy situations call for short gestation
beef progeny test has consistently been about 37.5kg, and beef bulls; for example, if beef semen is used for the lower merit
approximately 75% of beef-sired calves born in the progeny cows during the initial mating period when most cows are bred
test would not meet this minimum requirement. The bulls to dairy semen with the goal of producing replacement heifers,
tested to date have not caused significant calving difficulty short gestation beef semen results in a small number of early

Year 2021 HEREFORD MAGAZINE 41