Australian Cattle for International Conditions
$ Indices
Hi
We quite like the $ indices as they balance out growth against calving ease and carcase attributes. However have noted that many do not include them in their sale catalogues and also a few expressions of doubt.
Hasn't been much discussion lately so thought I would put this up.
Jo-anne
Views: 38
Replies to This Discussion
-
Permalink Reply by Lachlan James on -
Jo-anne,
Interesting discussion. An index is only as good as the combination and weighting of the traits that are included within the calculation. Personally we find that the current indexes (esp the supermarket index) has a few weightings that do not always create a ranking that fits with the required market. I point to the following.
The Supermarket index has a heavy weighting for calving ease, birthweight and associated traits (eg days to calving). Ie the better the calving ease, bwt and days to calving EBVs the greater the SM index becomes. This sounds fine but the situation in which most breeding herds are run is that they are annual calving (ie cows are not allowed to calve earlier than a 12 mth period because the bulls are not with the cows). Thus cows that have the ability to cycle well within the 12 mth period are given an advantage in SM index but are not able to provide any extra $ to the farmer. This is done at the expense of visual industry inportant traits such as RBY and EMA. These traits are vitally important, esp if selling in the visual (saleyard) market place.
It is similar with Bwt. The lower the Bwt the greater the advantage in the SM index. But once you get below a certain EBV value (lets say +4) there is rarely any actual calving issues related to Bwt, thus again we see cattle geting an advantage in SM index that does not translate to an actual advantage in the production system. Again this comes at the disadvantage of visually important traits at selling time.
It also needs to be noted that those people relying on indexes should make sure that the animals have EBVs for the traits being used to generate the indexes. It has been tightened up in recent years, but previously there were situations where very little data was being used to generate an index, but the index does not carry an accuracy to indicate the quality and amount of data being used to create it.
Cheers
Lachlan James
-
Permalink Reply by Sam Owen on -
All,
I feel the trend and the momentum behind Index Values will continue as it has/is with other breeding programs (dairy, pork, and poultry). It is unfortunate that we do not measure all the parameters that are associated with improving margin and we are currently unable to account for anomalies, such as those raised by LJ. I feel it would be beneficial to use an exponential equation rather than a lineal equation to eliminate the unnecessary emphasis on traits once minimums have been achieved. This needs to be based on validated research and if we don’t have this information we should not attempt to predict the benefit (E.g. Should a bull with a bull with a scrotal of 45cm being penalized against a bull with a scrotal of 55cm?)
Additionally when comparing to other breeds, eg European breeds, we may be comparing to bulls that offer the industry a very similar growth pattern but one offers the industry +$60 per calf but the Murray Grey can offer -$10. Regardless of comparing only within breeds commercial herds using multiple breeds will tend toward the bull with the higher index, even though accuracy is extremely low.
Breed object does offer some additional benefits that I need to read about in more depth. I have been proactive on the above with ABRI and there appears to be some considerations being made at the moment.
What does this mean at a farm level? For the time being we have been forced into pushing Index Values on our selection process albeit to the detriment of providing genetics to our commercial clients that are not adding as much to the bottom line as we are genetically capable of achieving.
Good to see the open discussion, hope it will stimulate progress in improving the calculation process.
Regards,
Sam.
-
Permalink Reply by Rod Hoare & Helena Warren on -
This is an interesting topic with some thoughtful contributions by Lachlan and Sam.
Despite some limitations, we think that $indices are probably the best single figures for promotion to commercial breeders. Commercial buyers are looking for "herd improvers" so they are somewhat influenced by bulls being in top 25% or whatever. Certainly they are more influenced by how the bull looks, moves etc and by structure.
When I am looking at a stud's breeding program I often sort the progeny by Supermarket $index and then scroll down to look at breeding and individual EBVs. This gives a quick overview of the way they think and breed. If I am seriously searching for a bull I will do a wish list (eg born 2009-2010, purebred, male, 600 EBV > 70, BW <4, EMA >1.5, fat >0, IMF% >1 etc) but then usually sort by SM index to put them in some sort of order. The selected bulls will obviously have high indices.
When looking for a bull we look within the top 10% of bulls on SM index for the features we require in our breeding program. If you want to breed animals with high indices there is no point using bulls with average indices.
Lachlan raised issues of which traits are considered in calculating the $indices and the relative weighting applied. Sam queried whether some curvilinear associations would be better than straight line assumptions. I agree with both points.
In our harsh winter environment we sell calves at weaning and the major dollar factor for stud and commercial herds is weight at weaning. We place great importance on it.
How good a predictor is the supermarket $index or any other EBV for weight at weaning?
We have just weaned 20 spring drop calves and I have done a statistical analysis using a corrected 200 day weight. [This is the BW + (average daily weight gain x 200)]. The BWs varied from 49 to 30 kg and 200 day weights varied from 359 to 274 kg. These calves had BW and 200 day weights recorded and EBVs calculated.
The correlation coefficient between 200 day weight and calf 200 day EBV was 0.70 or very good (Coefficient of 1.0 is perfect correlation and 0 is no correlation.) However, if we were selecting cows on assumption that 200 EBVs or supermarket index would indicate their calves performance, on the basis of our cows' figures we would be sadly disappointed. Correlation between calf 200 day weight and dam 200 EBV was -0.09. Correlation between calf 200 day weight and their dam's Supermarket Index was only slightly better at 0.10.
Running a similar analysis on the whole MG population would produce a more accurate figure but unfortunately not a different conclusion. Andrew Byrne said that there is little genetic influence in the 200 day weight figures of MGs. But within our herd we have selected heavily for daily weight gain and the effects are ongoing so we believe there must be a genetic basis for 200 day weight.
Somewhat off the topic, we have long concluded that the major difference between the best and the worst calves is the desire to suck. We see cows that have a couple of average calves and then a stand-out one. The good ones seem to suck the tits off the cows thereby stimulating more milk production. We visited a herd over the weekend where there were about 10 cows with bull calves in a mob. The two stand-out bulls never stopped sucking while we were there. Researchers have tried to identify the genetic or metabolic differences in these high growth calves without success. They concluded that BIG ANIMALS SUCK. Maybe we need a suck index.
-
Permalink Reply by Neil and Jo-anne Southorn on -
Hi
Firstly Rod you should start a new topic on Milk with your paragraph – it is different and interesting in its own right.
Further to the informative and thought provoking contributions on $indices by Lachlan, Sam and Rod – I thought I would throw this bit of data in. We wanted to give a run to a couple of yearling bulls and although E6 had ordinary indices he is by Yamba Bonanza who is by Yamba Waratah both of whom we had seen and admired. We try to practice corrective mating when joining (where possible) and so with a female who was good where he was weak and vice versa. The figures for this calf are of course early days but it is possible to work with them when pedigree is also of importance. G59 actual birth weight was 42kgs. I had to delete a few columns to fit in but if you click on their name you will go to breedplan.
Name/ID
Calv.
Ease
Direct
(%)Birth
Wt.
(kg)400
Day
Wt.
(kg)600
Day
Wt.
(kg)Mat.
Cow
Wt.
(kg)Milk
(kg)Eye
Muscle
Area
(sq.cm)Retail
Beef
Yield
(%)IMF
%Long-
Export
Index
($)SupM
Index
($)
Grass Fed
Index
($)+2.4
+2.4
+21
+38
+30
+4
+1.8
+0.9
+0.1
+$ 45
+$ 41
+$ 48
-6.1
+5.3
+42
+58
+69
+6
+1.0
+0.8
-0.4
+$ 12
+$ 29
+$ 30
-
+5.4
+37
+55
-
-
-
-
-
+$ 33
+$ 41
+$ 45
-1.3
+3.1
+28
+41
+42
+3
+1.1
+0.7
0.0
+$28
+$32
+$36
The other ebv that knocks indices around is Mature Cow weight.
Neil and Jo-anne
-
Permalink Reply by Neil and Jo-anne Southorn on
-
Hi
I checked out the percentage weighting for Supermarket $ see below.
SUPERMARKET INDEX Calving Ease Direct 24% * Calving Ease Maternal 14% * Birth Weight Direct -1% 200 day milk 2% 200 day growth -1% 400 day growth 0% 600 day growth 23% * Carcase IMF 7% Days to calving -5% Scrotal Size 1% Carcase Fat Depth 5% EMA 2% Carc Yield 9% * Mature Cow Weight -6% The asterisks are mine - just the most signigicant. As you can see it is the 600 day ebv rather than 200 that is used - a bit strange. As Lachlan said EMA is virtually ignored which we agree is a shame.
With regard to Rod's comments on milk. Some calves are more vigorous and demanding and so do better. It might be that the calves still sucking are still being rewarded ie their dams have more milk. Our observations in our herd do show that the females with the highest milk do wean the heaviest calves. After that the 600 day ebv is the biggest driver though which is why it is so significant I guess. We like breed average ie +3 for milk. After that you need to be careful that you have the feed otherwise the female puts it all into milk and loses weight and may not go back in calf easily (has happened to us in the worst of the drought with 2nd calvers with big milk).
Neil and Jo-anne
Rod Hoare & Helena Warren said:This is an interesting topic with some thoughtful contributions by Lachlan and Sam.
Despite some limitations, we think that $indices are probably the best single figures for promotion to commercial breeders. Commercial buyers are looking for "herd improvers" so they are somewhat influenced by bulls being in top 25% or whatever. Certainly they are more influenced by how the bull looks, moves etc and by structure.
When I am looking at a stud's breeding program I often sort the progeny by Supermarket $index and then scroll down to look at breeding and individual EBVs. This gives a quick overview of the way they think and breed. If I am seriously searching for a bull I will do a wish list (eg born 2009-2010, purebred, male, 600 EBV > 70, BW <4, EMA >1.5, fat >0, IMF% >1 etc) but then usually sort by SM index to put them in some sort of order. The selected bulls will obviously have high indices.
When looking for a bull we look within the top 10% of bulls on SM index for the features we require in our breeding program. If you want to breed animals with high indices there is no point using bulls with average indices.
Lachlan raised issues of which traits are considered in calculating the $indices and the relative weighting applied. Sam queried whether some curvilinear associations would be better than straight line assumptions. I agree with both points.
In our harsh winter environment we sell calves at weaning and the major dollar factor for stud and commercial herds is weight at weaning. We place great importance on it.
How good a predictor is the supermarket $index or any other EBV for weight at weaning?
We have just weaned 20 spring drop calves and I have done a statistical analysis using a corrected 200 day weight. [This is the BW + (average daily weight gain x 200)]. The BWs varied from 49 to 30 kg and 200 day weights varied from 359 to 274 kg. These calves had BW and 200 day weights recorded and EBVs calculated.
The correlation coefficient between 200 day weight and calf 200 day EBV was 0.70 or very good (Coefficient of 1.0 is perfect correlation and 0 is no correlation.) However, if we were selecting cows on assumption that 200 EBVs or supermarket index would indicate their calves performance, on the basis of our cows' figures we would be sadly disappointed. Correlation between calf 200 day weight and dam 200 EBV was -0.09. Correlation between calf 200 day weight and their dam's Supermarket Index was only slightly better at 0.10.
Running a similar analysis on the whole MG population would produce a more accurate figure but unfortunately not a different conclusion. Andrew Byrne said that there is little genetic influence in the 200 day weight figures of MGs. But within our herd we have selected heavily for daily weight gain and the effects are ongoing so we believe there must be a genetic basis for 200 day weight.
Somewhat off the topic, we have long concluded that the major difference between the best and the worst calves is the desire to suck. We see cows that have a couple of average calves and then a stand-out one. The good ones seem to suck the tits off the cows thereby stimulating more milk production. We visited a herd over the weekend where there were about 10 cows with bull calves in a mob. The two stand-out bulls never stopped sucking while we were there. Researchers have tried to identify the genetic or metabolic differences in these high growth calves without success. They concluded that BIG ANIMALS SUCK. Maybe we need a suck index.
-
Permalink Reply by Neil and Jo-anne Southorn on
-
Hi
Back to this topic and given that the youngest age the $ index kicks in is 15 months I am wondering what people think about lobbying for a Vealer Index. The Red Angus Society have one that can be viewed in more detail on the Breedplan site. But here is a brief description of it.
Vealer Index (VLR)
profitability per cow joined for an example commercial herd targeting vealer production.
Vealers are finished on grass and are marketed at 320 kg live weight (180 kg HSCW and 4
mm P8 fat depth) at 9 months of age. Daughters are retained for breeding. No marbling is
required.
Some commercial breeders are targeting this market so it could be useful.
Jo-anne
© 2012 Created by Steve Dummett.
