Page 164 - Calculating Agriculture Cover 20191124 STUDENT - A

14-14 Feeds and Feeding CH 14]

Example B: Grain Mixtures for dry cows and freshening cows, Calculate the DP% and TDN % of this ration.
Look up Perform
TDM: Total Dry Matter % Data from Table 14-1 Calculations
Feed TDM Pounds DP% TDN% DP# TDN#
Ground Corn, Dent #2 ...................... 85.0 760 lbs 6.7 80.1 50.92 608.76
Ground oats, usual commercial ......... 89.8 600 lbs 9.0 68.5 54.00 411.00 Look up values from Table 14.1
Wheat Bran, hard wheat .................... 90.5 500 lbs 14.1 67.5 70.50 337.50 and multiply by weights
Linseed meal ..................................... 92.4 100 lbs 31.5 75.6 31.50 75.60
Bone meal, cooked ............................ 93.6 20 lbs 17.9 17.9 3.58 3.58
Salt .................................................... — 20 lbs — — — —
—————————————————————————
Total ................................................ 2,000 lbs — — 210.50 1436.44 Sum to Totals

Digestible Protein % = [ ΣDP# ÷ Total Weight ] x 100% = Avg DP %
Digestible Protein % = [ 210.50# ÷ 2000# ] x 100% = 10.5%

Total Digestible Nutrient % = [ ΣTDN# ÷ Total Weight ] x 100% = Avg TDN%
Total Digestible Nutrient % = [ 1436.44# ÷ 2000# ] x 100% = 71.8%

Solution algorithm:

1) Look up the feedstuffs in Table 14-1 Average composition and digestible nutrients for each. The
description and %TDM (Percent Total Dry Matter) will identify the correct feed. Record the
Digestible Protein Percent (DP%) and Total Digestible Nutrients Percent (TDN%) to the right of
the feedstuff of each.
Using Ground oats with a TDM of 89.8 and a DP% of 9.0%, expressed as a decimal of 0.09
and a TDN% of 68.5% which expressed as a decimal is 0.685.

DP% TDN%
Ground oats .......................... 89.8 600 lbs 9.0 68.5

2) Calculate the pounds of DP and TDN by multiplying the pounds of each feedstuff by their recorded
DP% and TDN% as decimals; place those answers under their DP# and TDN# column.

DP# = 600 # x 0.09 = 54.00 #
TDN# = 600 # x 0.685 = 411.00 #

3) Sum up for a Total DP# and TDN#: In this problem the Total Pounds of DP is 210.50 and the Total
TDN pounds is 1436.44.

4) Calculate the DP % and the TDN % for the ration. Divide each, ΣDP# and ΣTDN# by the total
weight of the feed ration as stated.

Digestible Protein % = [ Σ DP# ÷ Total Weight ] x 100% = Avg DP %
Digestible Protein % = [ 210.50# ÷ 2000# ] x 100% = 10.5%

Total Digestible Nutrient % = [ Σ TDN# ÷ Total Weight ] x 100% = Avg TDN%
Total Digestible Nutrient % = [ 1436.44# ÷ 2000# ] x 100% = 71.8%

Beef Cattle
The ration example for beef cattle are for fattening cattle with feed available at the pounds
listed in each Example. This ration example is for wintering mature beef yearlings to gain 0.75
to 1.00 lbs per head daily. If a gain of more than 1.00 pound per head daily is desired, it will
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