Milk EPD - Clarification

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Chap

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I have read several comments about cows that carry low milk epds that actually milk quite well.  I had posted this in the Hereford thread below and thought it would benefit some members as a stand alone thread.  The jist is that the Milk EPD is not a direct expression of how a cow will milk but rather the genetic potential of her daughters to milk as compared to daughters of other cows or bulls.

When talking about milk epd, we need to remember that those figures represent the daughters of those animals ability to milk expressed in lbs of calf at weaning attributed to milk.  obviously with any EPD, there will be differences in progeny, including outliers.  so a bull or cow with a +5 milk epd would be expected to produce daughters whose calves weigh 5 lbs more at weaning , due to milk and morthering ability, than another cow or bull's daughter that had a 0 milk epd.

From Angus.org
Maternal Milk EPD (Milk), is a predictor of a sire's genetic merit for milk and mothering ability as expressed in his daughters compared to daughters of other sires. In other words, it is that part of a calf's weaning weight attributed to milk and mothering ability. 
 

Bawndoh

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I dont think that it represents the daughter of the cows' ability to milk.  Bulls eps's would represent their daughters ability to milk, but not a cow!  Dont cows epd's relate directly to thier own abilities?? 
Ulitmately, no, it does not seem that a cow ever milks according to her epd...I think it may have something to do more so with milk quality.  I think overall, the Total Maternal epd is something much more important than the milk epd.  Ultimately I think great calves could be produced by mating a high growth epd with a high milk epd. 
Ever wonder why the bulls with +30 milk epds have a measly weaning weight of their own...me too?  There is even more proof to look at the TM numbers, and the entire pedigree and potential of the bull versus a set of numbers.  Some days i dispise epd's!  Some days...
 

SSIMMENTALS

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I agree with Bandowh. It is somewhat ironic that the cattle with the lower milk #s end up with high growth #s. I have found at my house that the milk epd isn't as accurate as what I know about the "real world milk" that different cow families produce. For example, we have two cows. One is at 3 for milk and up high into the 30 and high 60s for ww and yw. (Simm) then, we have a cow that 13 fr milk and high 20s and low50s for ww yw. The cow w/ the lower milk score keeps her udder full and is weaning a much heavier calf than the "milk" cow. The cattle who have the genetic potential for more milk dont always end up on top at my house. They seem to be the harder doing ones that get thin really fast if they are not babied. This I conclude is b/c they are trying to produce much more than their environment allows them to. I like the more moderate milking cattle who still give enough milk and end up raising a heavier calf due to more growth potential. They keep weight more easilly and breed back more quickly. At my house that's the goal. This is JMO, but it is a hard lesson that we had to learn from the long road.

Sarah
 

Chap

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by definition an epd is Expected PROGENY Difference.  I understand your statements but the EPD is a statement of that animal's progeny's ability to perform.  To clarify, cows with high Milk EPD's are the result of parents that had a combined high maternal milk value and the opposite is also true, so you could assume from that that cows with higher EPD's are more likely to milk better than cows with low epds, but it is not necessarily true in every instance.    You must keep in mind that epds are a tool to be used in the aggregate and don't necessarily translate lb for lb on every animal.  Outliers are part of every equation.  Over time and with adequate reporting EPDs will become more accurate. Proving the necessity of accuracy when using EPDs.  As an example look at Dream On's initial EPD profile as a yearling bull compared to what they are today.  You will be astonished to see how much they have changed.  CE, BW and milk have all improved, while his growth numbers have moderated with large numbers of progeny reported.
In addition I would submit that most simmental and angus cows are not hurting for milk.  a -1 milk epd in the simmental herd would probably milk as good as she needs to in order to express the genetic potential of her calf.  In the simmentals we don't see the huge spreads in milk epds that we do in other breeds.  Negative is not necessarily a terrible thing as it may only be 5 or 6 lbs under breed average, whereas an Angus with a +4 milk epd would be about 18 lbs under the breed average.  An example of why it is important to look at breed average and percental rankings when using EPDs.    Weaning weight epd are a much better representation of calf weight at weaning than milk, as the milk epd only represents the difference in progeny at weaning due to milk and mothering ability, while the weaning weight EPD is direct expression in pounds of calf at weaning due to growth factors.  a bull with a +30 ww epd would be expected to produce calves that weigh on average 10 lbs more than a bulls calves with an epd of +20.
I have some simmental cows and honestly don't pay any attention to milk values unless they are uncommonly high or low.  I think that Maternal Calving ease is a much more important factor when evaluating a simmental bull for use as a replacement heifer sire.
Chap
 

CAB

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The milk epds are one of the few traits that you can put faith in if there is a high acc rate for the sire. You don't have to look very far to prove it. Look @ all of the dairy breeds and what they have done over the last 50 years or so as far as lbs of milk/lactation period is concerned. It is different of coarse in the beef business, we sell and measure by lbs. I think it does get confusing for some when the different breed asso. use different formulas for themselves. It is rather hard to keep it all relatively straight in your mind. Brent
 

Chap

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what breed are your low epd cows that milk well? how many lbs below breed average? how is the accuracy of the parents of those cows?  do you turn in performance data to the associaition?  All these questions would go a long way to evalutating your potential "outlier" cows
 

CAB

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 Simtal, if you want to test the milk epds pick a few cows and every time you breed that line on down the road, pick the highest milk epd that you can find with an acc. of @ least .80 and we'll can see what you have let's say 4 generations down the road. If we get started on this project next spring's breeding season, by the spring of 2018 we should have the 5th generation, and I will make a bet with you that you will have very heavy milking cows that are also very hard to keep in good condition. We would have to get heifer calves every year to do this this quickly, could multiply #s by flushing the get larger #s therefore more acc. There are going to be exceptions to the rules, but if you use high acc. bulls, you are going to get what you breed for. Some breeds, such as SM don't have a poor milking issue, therefore you don't have to watch it as closely. In my opinion, you didn't use to have to watch SH so close, but that is not the case today by far. Like Chap said, he doesn't even pay attention to the milk epds for the SM bulls that he uses unless they are extremely high or low and that complete sense for that breed to me. I would say and do the same thing. It would not be the trait that I would be using Sm for in my herd. Brent
 

simtal

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I'm talking generalities here:

Meyer 734, probably one the of the greatest maternal sires around

Milk epd= -0.6
Acc= .93


How many meyer daughters have trouble milking?
 

Chap

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in regards to Meyer 734, None, that i am aware of and this underscores the significance of the aguement in simmentals.  Milk is not a critical issue for the breed and although  being -.06 puts him in the bottom 15% of the breed, it does not make him a poor maternal bull.  he is only 5.2 lbs under the breed average.  Range of -2.4 to +14.5 captures the entire simmental herdbook for milk.  http://herdbook.simmental.org/simmapp/servlet/simmapp/template/evalstats%2Cpurbred.vm
Look at angus as a comparison.  http://www.angussiresearch.com/brekdown.html Range of +10 to +34, top 85% includes +14 milk epd.
Most of your older bulls will be the ones with the lower numbers, but I would say that in many environments a +14 milk epd in an angus cow may be ideal.  Is she gonna milk like a holstein?  no, but she will be adequate and stay in conditition and breed back.  That is the benefit of Meyer 734 as well.  not big hard cows that milk the skin off their back , but rather cows that can fit a wide variety of locals and stay around a long time.
Would a simmental epd of +14 milk when average is +20 make people feel better about the low epd cows in the pasture?  Marketing is important in the beef business and the angus folks do it well.... nobody likes negative numbers.
 

aj

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I myself don't like extreme milking epds. 90 % of shorthorn cattle are terrible hard keepers. Then add on high milk I think I would have a wreck in my semi-arid environment. I know 10 years ago maybe 20...the high indexing cows for weaning(say a 110 ratio for weaning) usually washed ot and came up open their 2,3rd time around. Usually high milk is not free and cost's $ to perpetuate. Then you come down to enviroments again.
 

simtal

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Chap said:
Would a simmental epd of +14 milk when average is +20 make people feel better about the low epd cows in the pasture?  Marketing is important in the beef business and the angus folks do it well.... nobody likes negative numbers.

Well I guess that was what I was getting at.  You will get docked at show (esp the PTP deals) for having low milk numbers, atleast thats been my experience. 
 

Joe Boy

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My best milking cow is a Red Chi/Ang.  She is 14 with an utter about the size of a man's glove, and if you filled it with water that would be the size when she gives birth.  She has a 90 lb calf and it will out gain everything on the place.  She weans a calf 100-150lbs larger than anything born within a week either side of it's birth.  Or it will weigh with those 2 months older than it is.  Yet she is low on the epd's for milk.  She in my book is tops, because she produces and never has an udder problem.  Therefore, I do not pay any attention to this part of the EPD's.
 
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