Consider a meat-producing flock: The output is meat. Ewes producing the best and most meat are the ones contributing most to the overall flock profit margin.
How is this measured?
In Northern Ireland, the Department of Agriculture a number of years ago began to encourage breeders to record total weaned weight of lamb per ewe.
Quite a simple exercise really: Lambs are linked to mothers at birth (easiest done using electronic ID tags for both ewes and their newborn lambs), using software in a handheld device.
George Megarry gets data fast using a wand-type electronic reader.
At weaning, if lambs are weighed using the handheld device, Select Sheepware links weaning weights to the mothers. At the season’s end, the total weaning weight of lamb(s) from each ewe goes into a report format.
After a few years the software averages these data, giving average lamb wean-weights per lamb crop over the lifetime of the ewe. Ewes producing say, 35-pound lambs on average at weaning, are culled. Those producing say, 70-pound lambs at weaning (average over a 3 year period) are kept. But importantly, their offspring are considered as replacements.
It’s not that simple, of course.
Some lambs wean at 90 days and some at 110 days, so adjustments are needed to get a calculated 100-day wean weight so all measure against a consistent standard.
Now look at those offspring: The Select Sheepware user runs a sire performance report to see which sires did best in terms of number of lambs born alive per ewe, days from birth to market, etc. On deciding which sires (and possibly which breeds) gave the best results, the data from these two sets of reports may be considered by the breeder in selection of replacements.
Let’s say a Texel ram’s daughters had an average of 1.9 lambs per ewe and Belclare ram’s daughters averaged 1.7. Let’s say the Texel ram’s lambs averaged 182 days from birth to slaughter and the Belclare, 190 days.
Now the user has real concrete data to work with. Based on ewe performance, suppose 100 potential replacements are selected. Based on ram performance, only offspring of the ram with the highest lambing percentage (number of live lambs born per ewe mated) are kept. Now the selection is down to maybe 40 animals.
So the mothers of the lambs kept as replacements all had an average total wean weight of 60 over a three year period and the sires of these replacements averaged 1.9 lambs born per ewe mated.
So the 40 replacements are selected.
At the other end, the reverse logic works: The poorest breeders get culled and their offspring aren’t kept as breeding replacements. This is common sense genetic selection. It does not require hiring specialists in breeding traits and genetic improvement.
Compare the potential improvement using software in this manner with a breeder who uses no software, no record, no tally of lamb wean weights per ewe, incomplete recollections of average lambs alive per sire, etc. We don’t need a statistical survey to see the software is of benefit.
Can this sort of analysis be quantitatively evaluated? Yes, of course.
Having kept the 40 best ewes and culled the poorest, the overall flock performance next year can be compared to this year’s performance. Lambing percentage and total wean weight per ewe will give a clear verdict on benefits.
Here in Ireland, the Department of Agriculture encourages users to consider:
Ease of lambing: Do you really want to continue to breed from animals with significant lambing problems—oversized or malpresented lambs at birth for the last two years?
Lamb viability: “Up-and-suck,” “slow-to-suck,” “needed-help-to-suck,” etc.
About 80 percent of a lamb’s body heat is lost to the ground; 20 percent to the air. The “slow-to-get-up-and-suck” lamb will have more problems than the one on its feet fast. These traits are inherited and can be passed on.
Ireland has low lambing season temperatures. The “slow-to-suck” are off to a bad start; if we hit a snowy spell at lambing time they won’t survive—the mother’s total wean weight per lamb crop is cut dramatically, not a good start.
Good records thus are essential for wise growers who need to better review the many points of data required to more quickly and easily nurture superior sheep that are adapted to their own farms. I’m pleased to report that our software is now helping them do just that, in all types of breeds and all types of environments, all around the world.