Mark Z. Johnson, Oklahoma State University Extension Beef Cattle Breeding Specialist
Last week we looked at how to evaluate feeds based on cost per unit of crude protein (CP) and energy (TDN) basis rather than just purchasing based on price per ton or bag. The final point of that article was this: determining the most cost-effective ration or supplement should be based on the feeding or supplementation objective. Many factors impact the nutrient requirements of cattle. This week we take a closer look at a specific goal and show the money saved by evaluating purchased feed on a cost of nutrient basis.
The Scenario & Objective
We have 60 mature cows, average weight of 1,300 lbs., due to calve in late January, entering the last trimester of pregnancy, cows are in a Body Condition Score (BCS) of 5.5. We have ample standing forage in the form of native grass which forage analysis indicates is 5% CP and 55% TDN. On grass of this type, cows should consume 1.9 – 2.0% of their body weight resulting in forage dry matter consumption of 25 lbs./day. Knowing that reproductive efficiency is highly correlated to nutrition, our objective is for cows to maintain current weight and BCS until calving.
These cows will need 1.84 lbs. of CP and 13.3 lbs. of TDN per day over the next 100 days.
Whenever possible we would like to maintain cows by utilizing the standing forage. Can this be done?
25 lbs. Forage DM intake x .05 CP = 1.25 lbs./day CP intake.
1.84 lbs. CP required – 1.25 lbs. from the forage equals a daily CP deficiency of .59 lbs./day
25 lbs. Forage DM intake x .55 TDN = 13.75 lbs./day TDN intake. There is no energy deficiency.
We have identified a supplemental need for protein. Research has consistently shown that protein supplementation is extremely effective for cattle grazing protein-deficient forage. In fact, energy supplementation will not be effective if dietary protein is deficient.
Now the questions is: Which of the two protein supplements evaluated last week can most cost effectively meet our goal? The 20% CP range cubes at $312/ton or the 38% range cubes at $425/ton.
It would take 3 lbs./day of the 20% cubes to meet the CP requirement. For example: .59 lb. CP deficiency/.20 CP content = 3 lbs. Last week, we determined the cost per unit of CP in the 20% range cubes to be $.78. Taking the .59 lb. CP deficiency x $.78 = $.47/day cost with 20% cubes to meet CP needs. This daily cost x 100 days of supplementation x 60 cows equals an expense of $2,820
It would take 1.58 lbs./day of the 38% cubes to meet the CP requirement. For example: .59 CP deficiency/.38 CP content = 1.58. Last week, we determined the cost per unit of CP in the 38% range cubes to be $.56. Taking the .59 lb. CP deficiency x $.56 = $.33/day cost to supplement the cows with 38% cubes to meet their CP needs. This daily cost x 100 days of supplementation x 60 cows equals an expense of $1,982.40
Supplementing the 38% range cubes purchased at a cost of $425/ton instead of the 20% cubes at a lower price per ton resulted in a savings of $837.60 to supplement the 60 cows for 100 days.
Un-needed supplementation increases feed cost without real benefit. The goal of supplementation is to feed just enough of the right supplement to improve the overall diet. Determining the most cost-effective means of supplementing cows requires the evaluation of feeds on a cost per unit of protein and energy provided. Can you afford not to?
Computer software, such as OSU Cowculator, can better pinpoint an animal’s nutrient requirement at a specific time and in a specific stage of production. These and other useful tools can be found at beefextension.com.
Beef Cattle Manual. Eight Edition. E-913. Oklahoma Cooperative Extension. Chapters 16 and 17.
The Rancher’s Thursday Lunchtime webinar series is currently about Controlling Winter Feed Costs featuring a current cattle outlook by Dr. Derrell Peel (OSU Extension: Controlling Winter Feed Costs – YouTube), and Efficient Use of Range Cubes by Earl Ward (OSU Extension: Controlling Winter Feed Costs – YouTube).
Go to Rancher’s Thursday Lunchtime Series — Beef Extension (okstate.edu) for links to all the previous Rancher’s Thursday Lunchtime Webinars.