Mark Z. Johnson, Oklahoma State University Extension Beef Cattle Breeding Specialist
Oklahoma has finally received much needed moisture and a break from summer heat, finally it feels like fall! Over the next two weeks, we will be discussing the evaluation of feedstuffs on a cost per nutrient basis. From a nutritional standpoint, cattle basically need protein, energy, vitamins, minerals and water. Assuming free choice vitamin/mineral and water is in adequate supply, most nutritional supplementation and feeding focuses primarily on the crude protein (CP) and energy (TDN) needs of cattle. Furthermore, nutritional needs of cattle vary by age, size, stage of production, environmental conditions and weather, gender, breed and other factors. In any nutritional program it is imperative to determine the objective of why we are feeding or supplementing. Are we trying to grow light weight calves in a dry lot until wheat pasture is available? Are we maintaining condition on pregnant cows until calving season or do cows need to gain some condition before calving season? What size are our cows? What is the nutritional content of the standing forage or hay we have on hand? These are just an example of answers needed to determine the goal of our nutritional program. That being said, this week we take a look at evaluating feed based on nutrient content as opposed to just looking at price per ton or bag.
At the time of this writing, 38% CP, 70% TDN range cubes are available at a bulk price of $425/ton, the same commercial feed mill has 20% CP, 70% TDN cubes priced at $312/ton. Protein and TDN contest are on an “As Fed” basis. If we are in a situation requiring protein supplementation of cows grazing warm season grass this fall, either of these protein supplements could meet our needs, but which is the more cost effective alternative? At a glance, $312/ton strikes most of us as a more cost effective feed. So what are we actually getting?
At a cost of $425, one ton of 38% cubes contains 760 lbs. of CP and 1,400 lbs. of TDN:
For example: 2,000 lbs. x .38 = 760 lbs. and 2,000 x .70 = 1,400 lbs.
The cost per unit of CP is $.56/lb., the cost per unit of TDN is $.30/lb.
For example: $425/760 lbs. = $.55921 and $425/1,400 lbs. = $.30357
At a cost of $312, one ton of 20% cubes contains 400 lbs. of CP and 1,400 lbs. of TDN:
For example: 2,000 lbs. x .20 = 400 lbs. and 2,000 x .70 = 1,400 lbs.
The cost per unit of CP is $.78/lb., the cost per unit of TDN is $.22/lb.
For example: $312/400 = $.78 and $312/1400 = $.2228
So, we have determined the more cost effective source of CP is the 38% cubes and the more cost effective source of energy is the 20% cubes.
What is the most cost effective feed? Depends on our objective. What we are we feeding/supplementing and why?
Next week we will take a look at specific feeding/supplementation goals to answer that question and take a closer look at the potential expense of feed purchased strictly based on price per ton or bag.
Beef Cattle Manual. Eight Edition. E-913. Oklahoma Cooperative Extension. Chapter 16