Understanding Genetic Indexes – Keep It Simple Stupid

Go to any purebred dairy cattle sale and listen to the pedigree person. What are they saying? Usually is an exhortation to buy the animal in the ring because it has a gTPI of 2700 or her dam was Grand Champion at prominent show or she comes from eight generation of Excellent dams. In essence what we are being told is that this animal is at the top of the breed and you should buy it. So does dairy cattle breeding work by identifying one number, one show or one family and only using that information to make decisions on. I think we all know the answer to that question … and the answer is…. “NO”! But let’s step back and, regardless of a breeder’s focus, look at how the understanding of all the numbers could be simplified when it comes to genetic information on sires.

The Information We See

Three times a year after each index run, breeders are bombarded with fliers, proof sheets, and fancy sire catalogues with numbers, numbers, numbers and cover girl like photos that make you wonder why the classifier only made the pictured first lactation cow GP 80. Was the classifier blind? Is the photo an accurate depiction of the cow? Maybe The Bullvine is right about photo ethics (Read more: Dairy Cattle Photography: Do You Really Think I am That Stupid?, Dairy Cattle Photography – Over Exposed, Introducing the Dairy Marketing Code of Conduct).

But let’s get back to the numbers, numbers for sires.

So many of them. Often expressed differently. What is good and what is not so good? What’s this thing about a base roll on December 2^nd and what does it mean for dairy cattle breeders? Why oh why can’t the brainy folks who compile the numbers make them so breeders can quickly look at a number for a proven or genomic bull and know if he is a standout, middle of the road, an also ran or an out-and-out loser. Don’t the genetic types know that bottom-line focused milk producers want quick and simple answers on bull rankings as they plant and harvest crops, handle manure, feed and manage cows, coach 4-H or FFA and yes, educate their children.

What is #1? Does it Matter?

However at the same time that milk producers are asking for simplification, many breeders are striving to have Mr #1 Sire. First it was 2500 gTPI and now it is 2700 gTPI. Or first it was 1000 NM$ and now it is 1150 NM$. Can the difference between 2600 and 2700 gTPI be quantified when it comes to mating cows? If a breeder has a cow that needs improvement in protein yield and feet and legs which sire should he use? Is a sire with 39 lbs of protein and 1.81 for Feet & Legs Composite good enough? Bottom line focused breeders need a universally expressed number for all traits so they can say to their genetic advisor whether to include a sire in the mating program. Of course having a breeding plan that includes needs and priorities is needed for a mating program to be successful. (Read more: What’s the plan?)

Percent is Universal

Every student is trained to understand that 100% is the best mark possible, 75% shows good proficiency and 50% is just a passing grade. So why couldn’t the same thing apply to genetic evaluation results? That way breeders would not need to know what is the very best value, how to distinguish if this is on the new or old base or where a sires daughters are inferior.

Breeders Want to Know

Breeders do not want to carry several files on their electronic device on what is top, good, okay or bad for each trait. All they want to know for the sire they are looking at is – what are his strengths and weaknesses relative to his contemporaries?

Breeders expect their nutritional advisors to know the fine details about balancing rations. As well they expect their genetic advisors to know all about how to improve their cows and herd from a genetic perspective. In both cases breeders expect their advisors to use the KISS principle – Keep It Simple Stupid. (Read more: gPs– Genetic Profile Systems – Dairy Cattle Breeding Made Simple)

Does This Fit Breeders Needs?

The following charts are provided so Bullvine readers can consider if breeding the females in their herds would be easier for them if sire indexes were expressed on a percent basis. A percentage of what the very best contemporary’s index is.

Table 1 – Top Ten gTPI Daughter Proven Sires (Aug ’14) Expressed as a Percent*

Segment # Avg. LPI Avg. Sale Price Price/LPI Point

>3000LPI 80 3286 $60,021 $18.26

>2000 LPI <3000 164 2589 $16,384 $6.51

<2000 LPI 56 1637 $8,879 $5.42

R&W 26 2093 $24,600 $11.75

Polled 26 2275 $37,076 $16.30

Show Heifers or All-Canadian Pedigree 52 2005 $17,154 $8.56

Segment	#	Avg. LPI	Avg. Sale Price	Price/LPI Point
>3000LPI	80	3286	$60,021	$18.26
>2000 LPI <3000	164	2589	$16,384	$6.51
<2000 LPI	56	1637	$8,879	$5.42
R&W	26	2093	$24,600	$11.75
Polled	26	2275	$37,076	$16.30
Show Heifers or All-Canadian Pedigree	52	2005	$17,154	$8.56

* Percent of the index for the #1 sire for the trait within the category

A quick review of Table 1 shows:

Facebook achieves the #1 position based on his high production and good type classification conformation
Dorcy, AltaGreatness and Large daughters have the udders
AltaGreatness, AltaFairway and Junior are below average compared to their marketed contemporaries for Feet & Legs
As a group all these sires can be expected to produce daughters that are very high for gTPI
Breeding on gTPI only will miss the fact that sires have strengths and limitations
Using only the top gTPI sires is not likely to produce show winners

Table 2 – Top Ten gTPI Genomic Sires (Aug ’14) Expressed as a Percent*

RANK NAME # OF DAUGHTERS PTAT Udder Comp F&L Comp Body Comp Dairy Comp Stature

1 BRAEDALE GOLDWYN 55 3.03 2.59 2.56 1.93 2.03 3.1

2 REGANCREST ELTON DURHAM-ET 21 2.47 2.31 2.13 1.7 1.98 2.13

3 KHW KITE ADVENT-RED-ET 19 2.53 2.24 1.6 2.04 1.65 2.41

4 REGANCREST DUNDEE-ET 18 2.06 2.18 0.75 1.29 1.55 1.18

5 GEN-MARK STMATIC SANCHEZ 14 3.07 2.17 2.44 3.34 2.83 3.91

6 WILCOXVIEW JASPER-ET 11 2.89 1.94 0.73 2.56 2.52 3.22

7 ERBACRES DAMION 8 3.2 2.22 3.17 2.83 2.72 2.76

7 MAPLE-DOWNS-I G W ATWOOD-ET 8 4.16 3.41 3.46 3.44 2.97 4.31

9 PICSTON SHOTTLE-ET 6 2.66 1.97 1.79 2.42 2.3 2.71

9 ROYLANE JORDAN-ET 6 2.07 1.94 0.32 1.53 2.06 1.93

RANK	NAME	# OF DAUGHTERS	PTAT	Udder Comp	F&L Comp	Body Comp	Dairy Comp	Stature
1	BRAEDALE GOLDWYN	55	3.03	2.59	2.56	1.93	2.03	3.1
2	REGANCREST ELTON DURHAM-ET	21	2.47	2.31	2.13	1.7	1.98	2.13
3	KHW KITE ADVENT-RED-ET	19	2.53	2.24	1.6	2.04	1.65	2.41
4	REGANCREST DUNDEE-ET	18	2.06	2.18	0.75	1.29	1.55	1.18
5	GEN-MARK STMATIC SANCHEZ	14	3.07	2.17	2.44	3.34	2.83	3.91
6	WILCOXVIEW JASPER-ET	11	2.89	1.94	0.73	2.56	2.52	3.22
7	ERBACRES DAMION	8	3.2	2.22	3.17	2.83	2.72	2.76
7	MAPLE-DOWNS-I G W ATWOOD-ET	8	4.16	3.41	3.46	3.44	2.97	4.31
9	PICSTON SHOTTLE-ET	6	2.66	1.97	1.79	2.42	2.3	2.71
9	ROYLANE JORDAN-ET	6	2.07	1.94	0.32	1.53	2.06	1.93

* Percent of the index for the #1 sire for the trait within the category

A quick review of Table 2 shows:

Very little separates #1 and #10 on the list. Remember that genomic bulls are 70% Rel.
Within individual traits there is considerable variation among these sires
The percentages identify that every sire has one or more limiting factors
As is always recommended use several genomic sires instead of one or two
Supershot, Delicious Coin, Delta and Rubicon are high for production
Alta1stClass, Kingboy and Monterey stand out for conformation

Table 3- Top Ten NM$ Daughter Proven Sires (Aug ’14) Expressed as a Percent*

Segment	#	Avg. LPI	Avg. Sale Price	Price/LPI Point
>3000LPI	80	3286	$60,021	$18.26
>2000 LPI <3000	164	2589	$16,384	$6.51
<2000 LPI	56	1637	$8,879	$5.42
R&W	26	2093	$24,600	$11.75
Polled	26	2275	$37,076	$16.30
Show Heifers or All-Canadian Pedigree	52	2005	$17,154	$8.56

* Percent of the index for the #1 sire for the trait within the category

A quick review of Table 3 shows:

The vast majority of these sires will have daughters that produce high volumes of fat and protein
Yano, Erdman, Marian944 and Twist stand out for Productive Life
Robust is in a league all his own for Daughter Calving Ease
Twist claims #3 position on NM$ and has high PL, SCS and DPR.
SCS needs to be interpreted carefully as sires with poor SCS are not returned to active service

Table 4 – Top Ten NM$ Genomic Sire (Aug ’14) Expressed as a Percent*

Segment # Avg. LPI Avg. Sale Price

Picks 74 2789 $28,622

Heifers 203 2528 $24,588

Cows 23 2330 $46,839

Total 300 2476 $27,289

Segment	#	Avg. LPI	Avg. Sale Price
Picks	74	2789	$28,622
Heifers	203	2528	$24,588
Cows	23	2330	$46,839
Total	300	2476	$27,289

* Percent of the index for the #1 sire for the trait within the category

A quick review of Table 4 shows:

Percentages make it quick and easy to identify both strengths and limitations for a sire
Delta, Supershot and Dozer do not have significant limitations
Eight of the sires have over 80% for Productive Life
SCS, DPR and DCE percentages vary quite a bit but that’s to be expected for sires that do not have milking daughters

The Bullvine Bottom Line

Understanding index values is important but having multiple ways of expressing the results of genetic evaluations can result in breeders saying “Too much information. Give it to me in terms I can quickly comprehend”. Being a good dairy farmer requires that managers know a great deal about many disciplines. A good dairy farmer understands that effective breeding requires equal parts art (cow sense) and science (number crunching). Simplifying the expression of genetic evaluation results could be a step forward for all breeders.