Balancing Rations

Balancing Rations
A) Formulate a swine diet containing 20% CP using corn and soybean meal. As-fed basis.

1) From packet: Corn = 8.8% CP
SBM = 45.7% CP

2) X = % corn
100 - X = % SBM

3)   .088(X) + .457(100 - X) = 20
    .088(X) + 45.7 - .457(X) = 20
    -.369(X) = 20 - 45.7
X = 69.65

4) Final Diet
69.65% Corn
30.35% SBM

B) Prepare 1 ton of a swine diet containing 16% CP from corn and a mixture of SBM and meat tankage (3 parts SBM to 1 part tankage). As-fed basis.

1) From Packet: Corn = 8.8% CP
SBM = 45.7% CP
Tankage = 47.2% CP

2) Determine CP content of SBM/tankage mix.
3(45.7) + 1(47.2) = 46.075% CP in mix
4

3) X = lbs Corn
2000 - X = lbs Mix

4) .088(X) + .46075(2000 - X) = 320
X = 1613.68

5) Final Diet
1613.68 lbs Corn
289.74 lbs SBM
96.58 lbs meat meal tankage

C) Fixed Ingredients: Formulate 1 ton of a cattle diet that contains 12.5% CP. The diet will contain 17% oats and 3% of a vitamin/mineral premix as fixed ingredients. Remainder of the diet will be corn and cottonseed meal. As-fed basis.

1) Amount of fixed ingredient and CP from each.
2000 X .17 = 340 lbs oats   X .091 = 30.94 lb CP
2000 X .03 = 60 lbs v/m pmx X 0 = 0 lb CP
                                         400 lbs                     30.94 lbs CP

2) Need 250 lbs CP
- 30.94
219.06 lbs CP still needed from corn and CSM

3) X = lbs Corn
1600 - X = lbs CSM

4) .088(X) + .443(1600 - X) = 219.06
-.355X = -489.74
X = 1379.55

5) Final Diet
         1379.55 lbs Corn
           220.45 lbs CSM
340 lbs Oats
   60 lbs Vit/Min Premix

D) Substitution Method: Formulate a balanced ration for a steer with the following requirements:

DM Intake CP TDN Ca P
--------------------------------------lbs/day-----------------------------------------
17.5 2.1 13.74 .091 .046

Use the following Ingredients:

	CP, %	TDN, %	Ca, %	P, %
Corn	8.8	78.0	0.02	0.30
Hay	7.0	51.0	0.73	0.28
Pnut Meal	49.2	74.1	0.18	0.52

(Note: When balancing from a problem the first three steps for formulation are to get 1) Nutrient composition of ingredients to be used; 2) Determine Dry matter intake; 3) Determine nutrient requirements.

4) Air Dry Intake *** DO NOT forget to do this ***
DM Intake = 17.5 = 19.4 lbs/day
.9 .9

5) Balance for energy first:
X = lbs Corn         19.4 - X = lbs hay
.780(X) + .51(19.4 - X) = 13.74
.780(X) + 9.89 - .51(X) = 13.74
.270(X) = 3.846
       X = 14.24
          19.4 - X = 5.16
6 & 7) Determine the nutrients provided and Compare to the requirement:

6)	Feed, lb	CP, lb	TDN, lb	Ca, lb	P, lb
Corn	14.24	1.25	11.11	0.003	0.043
Hay	5.16	0.36	2.63	0.038	0.014
7) TOTAL		1.61	13.74	0.041	0.057
Req.		2.1	13.74	0.091	0.046
Bal. ?		-0.49	0	-0.050	0.011

8) Balance the Protein. Substitute protein source (peanut meal) for the ingredient most like it in energy content (corn).
if add 1 lb peanut meal get .492 lb CP
if take out 1 lb corn lose -.088 lb CP
Net result = .404 lb CP

9) Need .49 lb CP = 1.21 lb of substitution. Add 1.21 lb peanut meal and take out 1.21 lb corn
Net Sub .404 lb CP/lb Sub 14.24 lb corn - 1.21 lb corn = 13.03 lb corn

10 & 11) Determine the nutrients provided and Compare to the requirement:

10)	Feed, lb	CP, lb	TDN, lb	Ca, lb	P, lb
Corn	13.03	1.15	10.16	0.003	0.039
Hay	5.16	0.36	2.63	0.038	0.014
Pnut meal	1.21	0.60	0.90	0.002	0.006
11) TOTAL		2.1	13.69	0.043	0.059
Req.		2.1	13.74	0.091	0.046
Bal. ?		0	-0.05	-0.048	0.013

12) Supplement minerals as needed
NOTE: if Ca is deficient then use limestone
if P is deficient then use phosphoric acid
if both deficient then use dicalcium phosphate

Ca is only mineral deficient so use limestone:
Need .048 lb Ca = .13 lb limestone
Get .37 lb Ca/lb limestone

13) Final Ration
13.03 lbs Corn
5.16 lbs Hay
1.21 lbs peanut meal
0.13 lbs limestone