Following is an example of utilizing the information contained in this manual to design a year-round range supplementation program using the NIR feedstuffs analysis.

Step 1: Determine weight and stage of production of the animal.

• 1200 lb

• Production Stage 1 – Weaning to 60 Days Before Calving

• Spring-calving cow

Step 2: Determine nutrient requirements using Table 6

●       Nutrient requirements for spring-calving, 1200 lb cow in Stage 1:

• 1.65 lb/day crude protein

• 11.68 lb/day TDN

• 10.33 Mcal/day NEm

• 19.36 g/day calcium

• 15.27 g/day phosphorus

• 24,000 IU/day Vit. A

Step 3: Determine forage quantity and quality (forage testing)

• Quantity - Adequate forage available (visual appraisal)

• Quality - Lab analysis conducted on grass hay to be fed (see below analysis).

Laboratory Nutrient Analysis of Grass Hay
Nutrient	As-Fed Basis
Moisture, %	6.50
Dry matter, %	93.50
Crude protein, %	6.50
TDN, %	38.50
NEm, Mcal/lb	0.27
Calcium, %	0.32
Phosphorus, %	0.15

 

Step 4: Determine daily forage intake of animal

• Refer to Table 4 to determine % of BW intake for the appropriate forage based on the forage quality. For this example, the dry, bred cow is on low-quality forage and will receive a protein supplement.

• In this example, the cow would consume 1.8% BW intake on a dry basis:
  1200 lb x 1.8% of BW = 21.6 lb DM intake/day.

• Convert DM forage intake to as-fed basis. Divide the daily DM lb by the DM % of the forage: 21.6 ÷ 0.935 (93.5%) = 23.1 lb as-fed.

Step 5: Determine daily nutrient intake from grass hay

• 23.1 lb as-fed intake is the starting point for each calculation ·        

• Multiply percentage of each nutrient (refer to “Laboratory Nutrient Analysis of Grass Hay”) by the as-fed intake of each ingredient. -      

• Crude Protein: 23.1 x 0.065 (6.5%) = 1.5 lb CP from grass hay -     

•  TDN: 23.1 x 0.385 (38.5%) = 8.89 lb TDN -      

• NEm: 23.1 x 0.27 = 6.24 NEm -      

• Calcium: 23.1 x 0.0032 (0.32%) = 0.074 x 454 g/lb = 33.6 g calcium -      

• Phosphorus: 23.1 x 0.0015 (0.15%) = 0.035 x 454 g/lb = 15.73 g phosphorus -      

• To calculate Vit A IU/d, multiply IU/lb in each ingredient by its as-fed intake.  

Step 6: Subtract the nutrient intake provided by grass hay from the nutrient requirements of the animal to determine nutrient deficiencies

	CP (lb/day)	TDN (lb/day)	NEm (Mcal/day)	Calcium (g/day)	Phosphorus (g/day)	Vit. A (IU/day)
1200 lb cow Stage 1 Requirement	1.65	11.68	10.33	19.36	15.27	24,000
Grass Hay	1.50	8.89	6.24	33.60	15.73
Supplementation Needs	(0.15)	(2.79)	(4.09)	14.24	0.46

 

Although calcium and phosphorus needs are provided, the grass hay alone would be deficient in meeting protein, TDN, and NEm needs of the 1200 lb brood cow in Stage 1. Once nutrient needs and forage nutrient content are established, producers can then more accurately determine the best supplementation program to meet the needs of the animal and feeding objectives.

For fine-tuning diets, forage analysis using wet chemistry can be done to determine amounts of micro-ingredients and vitamins. In most situations, supplementation of micro-ingredients and vitamins is taken into account through the supplementation program. Typically, wet chemistry forage analysis is not utilized for range brood cow operations simply because NIR analysis offers a quicker and less expensive means of analyzing forages. The exception is when a nutrient-related problem is suspected.