Supplements for Beef Cows Example forage analysis Nutrient% DM88.0 Crude protein8.5 NDF65.0 ADF36.0

Supplements for Beef Cows Estimate DM intake DMI, %BW = (120/%NDF) DMI, %BW = (120/65) = 1.85% BW 1,200 lb cow x = 22.2 lb DMI

Supplements for Beef Cows Estimate CP intake 22.2 lb DMI x = 1.89 lb CP

Supplements for Beef Cows Estimate TDN intake TDN, % = 88.9 – (0.779 x %ADF) TDN, % = 88.9 – (0.779 x 36) TDN, % = 60.9% 22.2 lb DMI x = 13.5 lb TDN intake

Supplements for Beef Cows Are requirements being met? Late gestation requirements CP TDN Late gestation2.0 lb12.6 lb Estimated intake1.89 lb13.5 lb Difference-0.11 lb0.9 lb

Supplements for Beef Cows Are requirements being met? Lactation – superior requirements CP TDN Lactation – superior2.9 lb15.7 lb Estimated intake1.89 lb13.5 lb Difference-1.01 lb-2.2 lb

Supplements for Beef Cows Do I need a protein or energy supplement? Both contain CP and energy Difference is relative concentration of CP

Supplements for Beef Cows Protein supplements usually have 25% CP or higher Energy supplements usually have less than 15% CP Calculate first limiting nutrient

Late Gestation CP supplied/CP required 1.89 lb/2.0 lb = 0.95 or 95% TDN supplied/TDN required 13.5 lb/12.6 lb = 1.07 or 107% First limiting nutrient is CP

Late Gestation CP needed = 0.11 lb Corn gluten feed – 22% CP, 80% TDN 0.11 lb/0.22 = 0.5 lb corn gluten feed

Lactation – Superior CP supplied/CP required 1.89 lb/2.9 lb = 0.65 or 65% TDN supplied/TDN required 13.5 lb/15.7 lb = 0.86 or 86% First limiting nutrient is CP

Lactation – Superior CP needed = 1.01 lb Corn gluten feed – 22% CP, 80% TDN 1.01 lb/0.22 = 4.6 lb corn gluten feed 4.6 lb x 0.80 = 3.7 lb TDN added