$VALUES ($Weaned Calf and Cow $Energy)
Weaned Calf Value ($W) $Value article $W Questions
Weaned Calf $Value ($W) quantifies four primary economic impact areas:
1.Birth Weight - birth weight influences on calf death losses related to dystocia, weaned calf crop percentage, and resulting revenue per cow.
2.Weaning Weight - direct growth impact on weaning weight revenue (pre-weaning growth and pounds of calf sold) and energy requirements and related costs to necessary to support pre-weaning calf growth.
3.Maternal Milk - revenue from calf pre-weaning growth and pounds of calf sold as influenced by varying cow milk levels, and costs related to lactation energy requirements.
4.Mature Cow Size - expense adjustments are made for maintenance energy as related to differing mature cow size, including mathematical linkages between mature weight and yearling weight.
The impact areas are combined into a bio-economic value expressed in dollars per head assigned to Angus genetics from birth through weaning. Resources used to form the Wean Calf Value ($W) include National Research Council (NRC), US Meat and Animal Research Center (USMARC), Cattle-Fax, SPA and university cow-calf budgets, and the American Angus Association performance database.
$Values only have meaning when used in comparing the relative merit or ranking of two individuals. $W provides the expected dollar-per-head difference in future progeny preweaning performance in a multi-trait fashion, within a typical U.S. beef cowherd. If Bull A has a $W of +25.00 and Bull B has a $W of +15.00, and these sires were randomly mated to a comparable set of females and the calves were exposed to the same environment, and a normal number of replacement females were saved from both sires, on average you could expect Bull A's progeny to have a +10.00 per head advantage in pre-weaning value over Bull B's progeny (25.00 - 15.00 = +10.00 per head). As with any $Value, $W only has meaning when used in comparing the relative merit or ranking of two individuals.
As with other $Values, the Weaned Calf Value includes assumptions, as listed below:
Base Calf Price $115 per cwt
Cow/Heifer Mix 80%/20%
Cow weight 1,300 lb
Feed energy cost $.065 per MCal NEm
Cow Energy Value ($EN)
A Cow Energy Value ($EN) is available to assess differences in cow energy requirements, expressed in dollars per cow per year, as an expected dollar savings difference in future daughters of sires. A larger value is more favorable when comparing two animals (more dollars saved on feed energy expenses). Components for computing the cow $EN savings difference include lactation energy requirements and energy costs associated with differences in mature cow size.
In the above example, the expected difference in cow energy savings per cow per year for future daughters of the two animals is +11.07 (15.75 - 4.68 = +11.07).
The above are the definitions for the two $epd composites from the AAA website. To me these cover the input/ouput issues and should absolutely be available from the AHA also.
