PEARSON SQUARE Balancing a Ration Feeds and Nutrition

PEARSON SQUARE Balancing a Ration Feeds and Nutrition 3/2/2021 2

Pearson Square n n Useful tool for simplifying and balancing of rations It shows the proportions or percentages of two feeds to be mixed together to give a percentage of the needed nutrient 3/2/2021 3

Pearson Square n n n The Pearson square ration formulation procedure is designed for simple rations. In order for the square to work, follow specific directions for its use. Nutrient contents of ingredients and nutrient requirements must be expressed on the same basis (i. e. , “dry-matter” or "as-fed"). 3/2/2021 4

As-Fed n n n Water (moisture) is contained in both concentrate feedstuffs and forages, including hay and silage Water content of various feeds and forages can vary tremendously Nutrient analyses expressed as “as fed” include this water component As the water content increases in a feedstuff, the amounts of other nutrients present per pound of that feedstuff decrease As fed is what the cattle are offered to eat including the water content of the feed or forage 3/2/2021 5

Dry Matter n n n “Dry matter” represents the percentages of nutrients present excluding water content Important because it reveals the actual amounts of various nutrients available to the animal consuming the feed Dry matter is what the cattle are offered to eat that is not water 3/2/2021 6

Converting as fed and dry matter n As Fed Basis Example #1 n n To convert this nutrient analysis from “as fed” to “dry matter”: n n Moisture 13. 2% Total Digestible Nutrients (TDN) 50. 79% Crude Protein (CP) 7. 2% 1) Figure the dry matter percentage. Subtract the moisture content from 100%. In this example 100% - 13. 2% = 86. 8% dry matter. 2) Convert individual nutrients from “as fed” to “dry matter”. Divide the “as fed” percentage of a particular nutrient by the dry matter percentage calculated in step 1. In this example for TDN, 50. 79% / 86. 8% = 58. 51%. For CP, 7. 2% /86. 8% = 8. 3%. Multiple by 100 to convert the resulting decimal to a percentage. This is the same as moving the decimal two places to the right. The initial 0. 5851 result from the TDN dry matter calculation is equivalent to 58. 51%. Therefore, the dry matter analysis would be as follows: n n n Nutrient Analysis – Dry Matter Basis – Feed Example #1 Moisture 0% Dry Matter 100% Total Digestible Nutrients (TDN) 58. 51% Crude Protein (CP) 8. 3% 3/2/2021 7

Pearson Square-Example 2000# of feed is needed to feed a 100# growing hog. n A feeding standards table shows that an 18% crude protein ration is needed. n Corn and Soybean Meal (SBM) are selected as feeds. 3/2/2021 8

Pearson Square-Example n A feed composition table shows: Corn has 8. 9% crude protein SBM has 44. 4% crude protein 3/2/2021 9

Pearson Square-Example n How much corn and soybean meal need to be mixed together for 2000# of feed? 3/2/2021 10

Pearson Square-Example Step 1 -Draw a 1 - to 2 -inch square. Place diagonal lines across the square. 3/2/2021 11

Pearson Square-Example n Step 2 – Write the percentage of crude protein needed by the animal in the center of the square where the diagonal lines cross 3/2/2021 18. 0 12

Pearson Square-Example n Step 3 –Write the feeds to be used at each corner. Place the percent of crude protein in the feeds after the name of the feed n n 18. 0 n n 3/2/2021 Corn 8. 9% SBM 44. 4% 13

Pearson Square-Example n Step 4 – Subtract the smaller of the numbers from the larger numbers. (This involves crude protein needed by the animal and that provided by the feed. ) Write the difference in the opposite corners 3/2/2021 Corn 8. 9 % 26. 4 parts corn n 18. 0 n n SBM 44. 4% 9. 1 parts SBM 14

Pearson Square-Example n n Step 5 – Add the numbers at the two right corners are parts of the two feed ingredients that are needed. 26. 4 parts corn +9. 1 parts soybean meal (SBM) 35. 5 total parts 3/2/2021 15

Pearson Square-Example n n Corn 8. 9% 26. 4 parts corn 35. 5 total parts 18. 0 n n SBM 44. 4% 9. 1 parts SBM 35. 5 total parts n 3/2/2021 16

Pearson Square-Example n n n Step 6 – The percentage of each feed needed in the ration can be found by dividing the number of parts by the total parts, then multiply by 100. 26. 4/ 35. 5 =. 744 x 100 = 74. 4% corn 9. 1/ 35. 5 =. 256 x 100 = 25. 6% sbm 3/2/2021 17

Pearson Square-Example n n Corn 8. 9% 26. 4 parts corn 35. 5 total parts 74. 4% 18. 0 n n SBM 44. 4% 3/2/2021 9. 1 parts SBM 35. 5 total parts 25. 6% 18

Pearson Square-Example n Step 7 – The amount of each feed ingredient for a large batch of feed is determined by multiplying the percentage of each by the total amount of feed desired 3/2/2021 19

Pearson Square-Example n n n Our batch of feed = 2000 # ( 1 ton) 2000# x. 744 = 1488 # Corn 2000# x. 256 = 512 # SBM 2000# of feed @ 18% Crude Protein 3/2/2021 20

Considerations n n The value in the middle of the square must be intermediate between the two values that are used on the left side of the square. Disregard any negative numbers that are generated on the right side of the square. Be with the numerical differences between the nutrient requirement and the ingredient nutrient values 3/2/2021 21