Page 60 - 2020 NZ Hereford Magazine

Industry Focus
Dairy-beef bulls

ticking all the boxes

WORDS / PHOTOGRAPHS BEEF + LAMB NZ GENETICS

LATEST RESULTS FROM THE BEEF + LAMB New Zealand BIRTH WEIGHT AND CALVING EASE
(B+LNZ) Genetics Beef Progeny Test reinforce there are excellent Results reveal many low birth weight beef bulls produce calves
dairy-friendly beef bull options available to dairy farmers – and similar to, or lighter than, calves produced by an average
dollars to be made. Friesian bull, when bred over crossbred cows. Calving ease has
Since 2016, 86 bulls have been assessed through the repeatedly been excellent, with less than 1% of cows assisted
progeny test. The bulls are suited to mating with dairy cows in any season.
– based on their birth weight and gestation length – while also
producing calves suitable for beef finishing. GESTATION LENGTH AND DAYS IN MILK
Research lead associate professor Rebecca Hickson says Bull selection has a big impact on gestation length and therefore
across all of the bulls assessed to date, there was 56kg difference days in milk. The average gestation length EBV of the progeny
between the best and worst bull for yearling weight. “At $3 per kg test bulls was 281 days – slightly better than the dairy breed
live weight, that translates to a $168 difference per head.” average of 282 days.

TOP ALL-ROUND DAIRY BEEF BULLS
BIRTH WEIGHT GESTATION LENGTH YEARLING WEIGHT
AB CODE SIRE BREED n
(kg) (days) (kg)
717054 RISSINGTON C200 Angus 35 32.2 278.7 270

717133 STABILIZER 165303 Stabilizer 33 34.0 278.9 271
717117 GLENSIDE CRUMPY Simmental 36 35.7 279.3 272
717113 BLUESTONE 160022 Hereford 28 35.7 279.9 266
717121 ARDO AJAX 5014 Hereford 37 32.7 281.3 267
Average of progeny-tested bulls 37.1 281.3 263
Range of progeny-tested bulls 32.2 – 44.1 276.8 – 289.1 237 – 293

NB: Calves were weighed up to 10 months of age, so the table’s To find out more information or to see full sire lists, click on the
‘yearling’ weight is actually two months shy of yearling. progeny tests tab on the Beef + Lamb NZ Genetics website
www.blnzgenetics.com.

WHAT ABOUT HEREFORD BULLS?

Drawing on data from the B+LNZ Genetics Beef Progeny Test, quantified the proportion of calves born of various colours
Massey University PhD student Lucy Coleman investigated when crossbred cows were bred with either Angus or Hereford
factors affecting the profitability of using Angus or Hereford bulls. Using 2019 calf sale values for Angus- and Hereford-sired
bulls for follow-up breeding in a dairy herd. calves, each calf was then assigned a value based on whether
The most common follow-up breeding scenario is to run a it displayed overt signs of Jersey parentage or did not.”
Jersey bull in the herd to ensure any cows still not in calf have In the Friesian cow herd, using a Hereford bull resulted in a $50
a final opportunity to conceive. The problem is that Jersey- greater sale price per calf sold, compared with using an Angus bull.
sired calves are of low value and have little potential beyond All Hereford-sired calves were black with a white face. However,
the bobby truck. In contrast, beef-sired calves can be sold for in the crossbred herd, the sale price was only $10 per calf more,
rearing and finishing at a higher price. because many of the Hereford-sired calves appeared brown,
Coleman used computer modelling to compare the striped, speckle-faced or showed other signs of Jersey genetics.
profitability of using Hereford or Angus bulls instead of Jersey The relative cost of bulls was also considered. The additional
bulls, and the profitability of buying a Hereford or Angus bull to cost of a quality recorded bull was justified by the known calving
run with the herd versus artificial breeding to Hereford or Angus ease of such a bull.
genetics. The modelling was run based on a Friesian cow herd Beef bulls in dairy herds typically sire fewer calves per
and also a crossbred herd. season. Coleman identified potential for far superior bulls to be
“I also collected extensive data on calf coat colour and used via artificial breeding. However, the added cost of extended
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