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New Mexico | because actual per day of age is actual.
No sense in adjusting back or forwrd on adj, because you may wean em at 150 days, you may wean at 240 days. Actual IS actual.
Furthermore, the calves do not HAVE to be weighed the day you pull em.
Niether do the cows.
If it works best to weigh say a week after..then weigh a week after.
Some folks work calves and cows say 3 weeks before weaning ( preg cows, give calves another round of shots etc.. )
Relative cow efficiency is just that, relative.
Also on BW's, does not have to be exact, you can rate ( for your herd ) as those calves as born say small, mid, or large.
Diff between a small and a large is generally 25 to 30 lbs at Birth. ( 65 lbs vs 95 lbs ).
Thus factor the afore.
If your 10 lbs off on one, your 10 lbs off on all of em so it's still fairly accurate.
( also a 15 lb varient in bw is not much of a factor when spread from 150 to 240 days )
ALSO. BULLS used.
Keep in mind some bull groups are fairly EVEN genetically, some NOT.
You will see cow efficiency diffs due to the calf which is more bull attributed at times.
Cow efficiency ratings work great to sort bulls ( after the fact )...if you know who they're out of, and say 20 cows are not measuring up so to speak....it's likely the bull causing low ww calves, and NOT the cow.
Generally takes 3 years of ratings for a cow to establish her long term "baseline."
( variations from her base from then on are generally NOT the cow, moreso enviro, maybe a bull change etc )
Only takes 1 year though for you to establish your "cut offs."
Reason is a herd avg is a herd avg., thus easy to sell a lesser cow and keep a better hiefer out of a better cow.
Also keep in mind...some cattle lines LACK on weaning, put pick more than that up as converted to yearlings too.
Folks tend to select for what they need.
If it's easier for you to use software for the deal fine.
Generally though, it's your NOTES that might tell you ( why this, or why that etc., on your annual readings )
Keep in mind that weather has alot to do with range conditions ( can hurt or help say + / - 50 lbs of calf weight average )..can be good one year...can be bad too.
Whole issue is just another tool if a person decides that is pertinent and wants to develop said for their deal.
Some folks ( generally it's the ones that live with their cows and go thru em every 3 to 4 days year around )can run totally on notes too....those generally really KNOW their cows, know each family line for 20 years back etc.. | |
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beef cow efficiency
