Recently, I was looking over a bull sale and noticed the cooperators had gone out and determined how they would base quality rather than using the mainstream tried and proven way to do so. Here are their quality parameters in blue.
Quotes from Powerline Genetics Bull Sale catalog 2/13/2016
When using EPDs it is best to compare the values of potential herd candidates. The difference between two candidates for some trait indicates the potential increase or decrease in that trait. However, profit is rarely based on a single trait and will be based on a combination of performance measures associated with growth, feed efficiency, and carcass value.
Instead of using the tried and proven method already outlined in American Simmental Association using all the traits of economic importance like CE, BW, WW, YW, ADG, MCE, Milk, MWW, DOC, CW, YG, Marb, BF, REA and Shear; Indexes API and TI and based on sound science; this group decided that only WW, Feed Conversion, CW and Carcass Quality are needed to assist you in your buying decisions and preferences.
They go on to explain their Index called the Power Bull Index (PBI):
A powerful tool that simplifies the selection process is the Power Bull Index (PBI), combining the genetic and profit potential for a bull based on his genetic merit for growth, efficiency and carcass. The index value is measured in dollars per calf marketed.
They reiterate their quality parameters associated with their Index.
The relative emphasis put on traits includes weaning weight (25%), feed conversion (20%), carcass weight (30%), and carcass quality (25 %)
They give you how each quality parameter is weighted in the computation of their Index PBI. On to an example below:
As an example in using the PBI, in Table 2 we present three potential herd bull candidates. Last year Buyer A purchased a bull with a 115 PBI and was very pleased with the calves overall performance but would like to see a slight increase in weaning.
He is interested in either Bull A or B. In order to see the increase in WW desired, Bull B would potentially bring higher calf weaning weights for this buyer.
Alternatively, Buyer B retains ownership on his calves through finishing and markets his feeders on the grid. He is looking to maintain a high percentage of calves grading choice with Yield Grades of 1 or 2. With the highest PBI value of the three bulls and superior REA and MARB and with above average WW performance Bull C is likely the best herd sire candidate for Buyer B.
Bull PBI WW REA Marb
A 115 30 0.30 0.25
B 115 35 0.32 0.20
C 120 30 0.35 0.30
This looks a lot like a common core math problem to me. Now on to their new definitions:
• BIRTH WEIGHT (BW) – in pounds, predicts the weight at birth of the bull’s progeny compared to progeny of other bulls. A bull with a BW EPD of -1 is expected to have progeny which average 3 lb lighter than progeny of a bull with an EPD of +2.
• WEANING WEIGHT (WW) – in pounds is a measure of the weaning growth of a bull’s progeny minus maternal milk production.
This has been altered to fit their needs with the addition of minus Maternal Milk production. You will see later in some of their choices in Sire, with very low MM.
• YEARLING WEIGHT (YW) – evaluates adjusted weight performance to 365 days.
Yearling weight is highly correlated to carcass weight and mature size.
This has been altered, as well, with more rhetoric trying to substantiate their Index
• CARCASS WEIGHT (CW) – predictor of an animal’s finish weight in pounds.
This statement is reaching as well —
• RIBEYE AREA (REA) – measured in square inches between the 12th and 13th rib and adjusted to 365 days.
This is a good predictor of the total amount of muscle in the carcass and is highly related to carcass weight.
That, I striked through is an addition to what REA actually stands for, just more rhetoric trying to prove their Index.
• MARBLING (MARB) –
This is a 365-day adjusted marbling score measured in USDA marbling degrees. This is the primary factor in USDA quality grades.
More included rhetoric here with adjusted and degrees
• DRY MATTER INTAKE (DMI) – reported in pounds of feed consumed per day with a lower numeric value being associated with less feed consumed on a dry matter basis. When comparing two bulls a lower number indicates lesser feed intake for comparable gains.
• POWER BEEF INDEX (PBI) – provides a balanced indicator of a bull’s profitability based on a combination of weaning performance, carcass weight, carcass quality and feed intake.
Adapted from EPD Basics and Definitions, Matt Spangler, Univ. of Nebraska, http://www.ebeef.org.
Again a reiteration of what is included in the PBI Index —
For real definitions of the EPD’s and Indexes associated with Simangus™ you can find those here.
Now scrape your boots off as we enter the sale tent — a look at the bulls. I find it quite interesting that all the bulls associated with this sale are not registered with the American Simmental Association (ASA).
Registration numbers would have been really helpful when making bull buying decisions because looking at EPD’s and Indexes based on Sound Science have a higher degree of reliability than a set of made up quality parameters that only further the agendas of a few co-operating chuckleheads.
Also, interesting, the Dam’s side of the genetics aren’t published, so there is no way of finding the genetics of the Maternal Grand Sire (MGS). Bulls are made genetically by their Sire and MGS. More smoke and mirrors.
Lastly, we as potential bull buyers are left with the Reference Sires as we try to determine the worth of the bulls in question. A person would have to travel the world over to find this many low quality, low grade reference sires, sons — assembled under one tent.
Here are the Reference Sires:
My advice to bull buyers is to purchase your Simangus™ bulls based on the quality parameters within American Simmental Association.