Is Linear Assessment linked to production and/or longevity?

[Rob R]

Food for thought; She Ain’t Pretty – She Just Milks That Way!

[Duncan MacIntyre]

No not directly - difficult to see how this could be done other than retrospectively, which in the case of teenage cows would take a long time to set up.

But --- surely the criteria selected, feet, udders, general good body shape, will indirectly select for good long productive life.

Duncan

[Rob R]

But --- surely the criteria selected, feet, udders, general good body shape, will indirectly select for good long productive life.

Duncan

Instinctively, yes, but scientifically I don't know if they are correlated or conincidence. It would be interesting to hear if anyone has any data that links productivity with [a range of] LAs. If a cow with a good LA score costs more money to buy, she has already has to work x-times harder to earn her keep...

[Duncan MacIntyre]

Ah, there we have it, Rob just wants to buy cheap cows from Robin!

Duncan

[Duncan MacIntyre]

Seriously though, those with good scores will tend to be more productive for a whole raft of reasons. good conformation will make more meat in relation to bone, good pelvic conformation will mean better calvings, good legs and feet will mean less lameness and arthritis. Good udders will generally produce more milk, have less mastitis, be easier for newborn calves to find teats, etc etc. You would need to do an extensive 20 year study to prove it, I may not be keeping dexters in another 20 years time.

Duncan

ps but I hope I will!

[Rob R]

Ah, there we have it, Rob just wants to buy cheap cows from Robin!

Duncan

Bah, rumbled.

I just wonder how accurate our aesthetic analysis is when it comes to relating that to the production figures. In theory these parameters should contribute to longevity and production, but only if they're accurate indications. In the Holstein, at least, it doesn't seem to have been tested, merely assumed, and in a breed where production stats are routinely collected this is relatively easy to assess, over that 20 year period of data, when compared to the Dexter, which is less widely recorded. That's not to say the cows with good scores aren't of higher merit but equally some cows with poorer scores could, potentially, be more productive than the very best, but if noone is counting it could very easily be missed.

[Duncan MacIntyre]

Yes if you are saying that linear assessment is not perfect, of course I agree, but it is a lot lot better than any system we have tried before in Dexters. All bulls used to be inspected, but there was no grading system and some of what passed was terrible. We had several goes at getting a better system for bull inspections in the 1990's, culminating in the elite bull scheme. Some of what passed was terrrible. Some of what I myself passed was terrible, and I came to the conclusion that it looked at just a few bits in isolation and when you had scored each separately the animal containing all the bits that had passed just looked like a gather up of bits and pieces - the system though well intentioned just did not seem to work. I think linear assessment is doing a better job, and it is in the hads of highly trained and skilled assessors. They are not just assessing Dexters as though they were Holsteins, the system has been adapted and they know what they are looking for. I intend to have my herd, at least as many as possible, done this summer - would have done it last year but due to fertility failure by poor old Shilton Pontius too many cows were empty.

Duncan

[Rob R]

They are not just assessing Dexters as though they were Holsteins, the system has been adapted and they know what they are looking for.

Duncan

I'm not worried that they are, I'm just wondering what is the 'best' cow, statistically. Looking at the 2 year old GP-83 cow 'Smurf' in the article, who took until her 10th lactation to score EX, and how the majority of bull mothers are not the highest scoring. I'm sure LA will be a useful tool, but I'd need a bit more convincing that the higher classifications are necessarily the 'best' cows. I hope other people are considering this too and recording other data to go against their LA scores to give it context. It would make an interesting research project for someone in the future to compare the outcomes of high scoring crosses, high/low and low/low, providing there isn't a trend towards only using high scoring bulls, of course.

[Duncan MacIntyre]

I see it developing as a breeding tool. For example I have some which tend to have long low feet. If I were able to look not just at overal scores but the component parts, I would look for a bull who himself has high feet scores, and whose parents also have, and I think it would be reasonable to use such a bull because I need heifers with better feet. Someone else might be looking for better udders, it is not only the overal score which will be of value.

Duncan

[Saffy]

This is a very interesting subject. My father strived to have a dairy herd that wore well as replacing is very expensive! To this end when choosing a bull we looked carefully at the Linear assessment figures that his daughters had thrown up and chose a bull that way. Legs and feet first....they have to walk before they can do anything else!!! Then top line and good udder - before thinking of temperament and production.

It worked well we had a long lived herd, averaging several lactations more than most, I milked a cow that was nearly 20 until she gorged on apples one day and when the herd was sold an 18 year old cow went through the ring - not for sale - with her new born calf, just to show the longevity of the herd, legs, feet, top line, udder, still in good order, she was more than 50% holstien.

Of the few dexters I have had assessed the top 2 were looked at - at the ages of 15 and nearly 17 years, they achieved Ex 91 and VG 88.

However my opinion is...you cannot linear assess for longevity, you have to breed for it - but having your herd assessed may well help you work out which ones to breed from/keep and thereby help achieve better longevity....

Stephanie

[Tim Watson]

This is a great thread. Making me think!

I have no previous experience of LA, being new to cattle but have every intention of getting ours done as and when possible.
I think, if I understand this correctly, it will give us the following in the first instance:-
1) a snapshot of the condition/quality of a particular cow at the time of assessment (for surely it can only be that as condition may change?).
2) an education as to the quality of the parts.
3) an indication of which cow may produce better calves (note 'indication' and 'may').
4) an indication of which cows may be more valuable - it's still based on what people are prepared to pay, ie the 'street price'.
5) in this high TB area, some ammunition for compensation should the worst happen.

However without the bull being similarly assessed in some way it seems to me to be only qualitative until that particular cow has had a number of heifers/cows that have also been LA'd.

Once that has happened it would seem that it really becomes a useful and can be used as a quantitative tool by having the historical scores and seeing if you are trending up in all areas, have missed something somewhere or perhaps something has appeared having jumped a generation?

Looking forward to the answers!

[Rob R]

I see it developing as a breeding tool. For example I have some which tend to have long low feet. If I were able to look not just at overal scores but the component parts, I would look for a bull who himself has high feet scores, and whose parents also have, and I think it would be reasonable to use such a bull because I need heifers with better feet. Someone else might be looking for better udders, it is not only the overal score which will be of value.

Duncan

As an aside, do the assessors have composite pictures of 'ideal' and 'undesirable' cows, as per the article? And if so, would it be possible to see an example of these? It would certainly be a lot less subjective than the breed standard, but hopefully it'll be adopted as a breeding tool, rather than relying upon it too much , given that most breeders don't record any other information than, perhaps, age and calves reared.

[Mark Bowles]

Great debate...
Alot of the points for linear have been made above. 1st calving heifers can only score VG 89 if they are "perfect" only when a cow has had 5 or more calves can she attain a score out of 97. The system is therefore weighted towards production ie producing calves and longevity. If you look at the high scoring animals they usualy will have produced at least 5 calves. Lets face it, if you see a cow thats say 12 years old that has produced 10 calves and still looks in good order with good confirmation......i suggest they are the cows you want, so many dexters seem to have their udders shot to pieces before they have produced 5 or 6 calves.
As for bulls, i think this is the most important thing for LA, i would like to see it compulsary that bulls get LA, not sure how many years before this will get passed but i think it is so important.
My herd is totally LA, nothing held back so now i have several generations of LA cows that are showing in my bull lines. I have also had bulls and cows that have since died but there stats live on for all to see, how many times have you heard one person say a certain bull from 30 years ago was brilliant then another person to say it was rubbish, all you could see was a dodgey black and white photo,... now we have a record!
I am sure there is still plenty to bedate.

[Rob R]

As for bulls, i think this is the most important thing for LA, i would like to see it compulsary that bulls get LA, not sure how many years before this will get passed but i think it is so important.

I agree - I don't think it has that much value for the breed as a whole if all bulls aren't classified.

My herd is totally LA, nothing held back so now i have several generations of LA cows that are showing in my bull lines. I have also had bulls and cows that have since died but there stats live on for all to see, how many times have you heard one person say a certain bull from 30 years ago was brilliant then another person to say it was rubbish, all you could see was a dodgey black and white photo,... now we have a record!
I am sure there is still plenty to bedate.

This is the bit where I remain to be convinced - I'm not sure the scoring proves it as we all run different systems, on different land, so there is always going to be some bias as to what works better in a certain scenario. I can see the value in cross referencing LA scores with other production data, as they do in the dairy breeds, but without that extra level of data to correlate the production to the scores, we may never know if an EX cow really is the best, or whether a VG works hardest.

[Mark Bowles]

Rob,i think you would be a little further convinced if you actually saw the EX and high end VG cows in the flesh, i think that would help the cause. We are very pleased how Holsein UK are applying our standard, you dont need cows that have hit the big time in the showring to get good scores, thats the beauty of it...as they say, a good cow is a good cow and any stockman can see that across all breeds.
I would suggest you plan a visit which would only cost you £60 + vat to do 10 cows ( they have to be in milk) then you would see for yourself, you can refuse a score for an animal if you dont want it recorded, its not a problem. You could invite others to come and watch, something some breeders have done so far to spread the word around.