Cost Effectiveness of Feed Additives

Mike Hutjens

Dept. of Animal Sciences, University of Illinois, 232 A.S.L., 1207 W. Gregory Dr., Urbana, IL 61801 U.S.A

# Take Home Messages

# Introduction

Additives can improve milk production, herd health, and reproduction if positioned properly in the feeding program. Supplementing additives to dairy rations presents several challenges.

# Evaluating Feed Additives

Feed additives are feed ingredients that produce a desired animal response in a non-nutrient role (such as a change in the rumen environment and pH with a buffer). Additives are used to achieve the following effects (1).

Once the additive=s role has been defined, cow response must be monitored on the farm to insure the additive is needed.

# Economics of Additives

Profitability is a key factor when deciding if an additive should be used. If milk improvement is the measured response to monitor, Table 1 can be used to determine the break even point. For example, if an additive costs eight cents a day and milk is priced at 44 cents per liter, every cow must increase milk yield by .19 kg to cover the additive cost. A feed additive should return two dollars or more for every one dollar invested to cover the non-responding cows and variable responses under field conditions.

Table 1. Required increase in milk yield to recover additive feed costs with different milk prices and additive costs (1).

Additive Cost

Milk Price per Liter






Milk response (liters/day)


















# Additive Choices and Strategies

Dairy managers have a number of feed additives to consider when building rations. Table 2 outlines dairy cow additives listing their various functions, recommended level to feed for desired response, cost to add (based on Illinois prices), benefit to cost ratio (based on research and IL costs), feeding strategies, and current recommendation on use. The following classifications were used to group recommendations based on research and on- farm results.

Table 2. Feed additive guidelines for dairy cows (2,3,4).

Anhydrous ammonia

1.Function: Source of non-protein nitrogen, extend fermentation in silage, reduce mold growth, improve bunk life, and increase fiber digestibility

2. Level: Corn silage = 3.6 kg per wet ton Legume/grass hay = 1% dry matter Straw/poor forage = 2-3% dry matter

3. Cost: Depends on level added

4. Benefit to cost ration: Not available

5. Feeding Strategy: Apply to corn silage prior to ensiling, during the baling of wet hay, or under a plastic cover to treat straw

6. Recommendation: Recommended

Anionic Salts

1 Function: Cause metabolic acidosis increasing calcium mobilization and hormonal stimulation

2. Level: 252 gram salts to 1 kg Biochlor

3. Cost: 40 to 76 cents a day

4. Benefit to cost ratio: 10:1

5. Feeding strategy: Feed to close up dry cows three weeks before calving lowering DCAD to -50 to -150 meq/kg of D.M.

6. Recommendation: Recommended

Aspergillus oryzae (AO products)

1. Function: Stimulate fiber digesting bacteria, stabilize rumen pH, and reduce heat stress

2. Level: 3 g per day

3. Cost: 5 cents per day

4. Benefit to Cost Ratio: 6:1

5. Feeding Strategy: High grain diets, low rumen pH conditions, and under heat stress

6. Recommendation: Evaluate


1.Function: Improve reproductive performance, immune response, and mastitis prevention

2. Level: 200 to 300 mg per day

3. Cost: 20 cents per day

4. Benefit to Cost Ratio: Not available

5.Feeding Strategy: In early lactation and during mastitis-prone periods

6. Recommendation: Not recommended

Calcium Propionate

1. Function: Increase blood glucose and calcium levels.

2. Level: 150 grams

3. Cost: $1.65/kg

4. Benefit to Cost Ratio: Favorable

5.Feeding Strategy: Feed 7 days prepartum to 7 days postpartum or until cow aggressively consumes her ration

6. Recommendation: Recommended


1. Function: A methyl donor used to minimize fatty liver formation and to improve fat mobilization

2. Level: 30 g per day

3. Cost: 10 cents (not protected)

4. Benefit to Cost Ratio: 4:1 (when protected)

5. Feeding Strategy: Feed to dry cows two weeks prepartum and cows experiencing ketosis and weight loss

6.Recommendation: Not recommended until rumen protected source is commercially available

Magnesium Oxide

1.Function: Alkalinizer (raises rumen pH) and increases uptake of blood metabolites by the mammary gland raising fat test

2. Level: 45 to 90 g per day

3. Cost: $0.55/kg

4. Benefit to Cost Ratio: Not available

5.Feeding Strategy: Combined with bicarbonate-based buffers (2 to 3 parts bicarb:1 part magnesium oxide)

6. Recommendation: Recommended

Methionine Hydroxy Analog

1. Function: Minimize fatty liver formation, control ketosis, and improve milk fat test

2. Level: 30 g

3. Cost: 3.6/kg

4. Benefit to Cost Ratio: 2:1

5. Feeding Strategy: Feed to cows in early lactation receiving high levels of concentrate which is low in protein

6. Recommendation: Not recommended

Monensin (Rumensin brand name)

1. Function: An ionophore (antibiotic) shifts rumen fermentation increasing feed efficiency, lowers blood ketones, and prevents coccidiosis

2. Level: 22 ppm

3. Cost: 2 to 4 cents

4. Benefit to cost ratio: 8:1

5. Feeding Strategy: To improve feed efficiency and prevent coccidiosis

6. Recommendation: Recommended (Note: only approved claim in Canada is for the control of coccidiosis)

Niacin (B3, nicotinic acid, and nicotinamide)

1. Function: Coenzyme system in biological reactions, improve energy balance in early lactation cows, minimize ketosis, and stimulate rumen protozoa

2. Level: 6 g per cow prepartum and 12 g per cow postpartum

3. Cost: 1 cent per gram (6 to 12 cents)

4. Benefit to Cost Ratio: 6:1 (6 g level)

5. Feeding Strategy: High producing cows in negative energy balance, heavy dry cows, and ketotic-prone cows (begin feeding two weeks prepartum to peak dry matter intake- to 12 weeks postpartum)

6. Recommendation: Recommended

Probiotics (Bacterial direct-fed microbes)

1. Function: Produce metabolic compounds that destroy undesirable organisms, provide enzymes improving nutrient availability, detoxify harmful metabolites, and stimulate dry matter intake (calves and cows off feed)

2. Level: Not clearly defined

3. Cost: 5 to 18 cents per day

4. Benefit to Cost Ratio: Not available

5.Feeding Strategy: To cows at calving and calves on liquid diets and during stress periods

6. Recommendation: Experimental

Propylene Glycol

1. Function: Increases blood glucose reducing blood ketone levels

2. Level: 454 grams

3. Cost: $2 per liter

4. Benefit to Cost Ratio: Favorable

5.Feeding Strategy: Drench seven days prepartum to 7 to 14 days postpartum or until cows aggressively consume ration

6. Recommendation: Recommended

Silage Bacterial Inoculant

1. Function: To stimulate silage fermentation, reduce dry matter loss, decrease ensiling temperature, increase digestibility, and increase VFA production

2. Level: 100,000 CFU (colony forming units) per gram of wet silage including recommended silage fermenting bacteria such as Lactobacillus plantarium, Lactobacillus acidilacti, Pediococcus cereviseae, Pediococcus pentacoccus, and Streptococcus faecium)

3. Cost: $1 to $2 per treated ton of silage

4. Benefit to cost ratio: 4:1

5. Feeding strategy: Apply to wet silage (over 60% moisture), first and last cutting (low natural levels of bacteria), and under poor fermentation conditions

6. Recommendation: Recommended

Sodium Bentonite

1. Function: A clay mineral used as a binder, shifts VFA patterns, slows rate of passage, exchanges mineral, and mycotoxin binding.

2. Level: 45 to 115 g per day

3. Cost: 354/kg

4. Benefit to Cost Ratio: Not available

5. Feeding Strategy: High grain diets, loose stool conditions, low fat test, moldy feed, and when cow consume soil free choice

6. Recommendation: Evaluate

Sodium Bicarbonate/Sodium Sesquicarbonate (Buffer)

1.Function: Increase dry matter intake and stabilize rumen pH

2. Level: 0.75% of ration dry matter intake

3. Cost: 22 cents per pound

4. Benefit to Cost Ratio: 4:1

5. Feeding Strategy: Feed 120 days postpartum with diets high in corn silage (over 50%), wet rations (over 45% moisture), lower fiber ration (<19% ADF), minimal hay (< 2 kg), finely chopped forage, pelleted grain, slug grain feeding (over 3 kg per meal), and under heat stress conditions

6. Recommendation: Recommended

Yeast Culture

1. Function: Stimulate fiber digesting bacteria, stabilize rumen pH and environment, and utilize lactic acid

2. Level: 10 to 120 g per day depending on concentration

3. Cost: 6 cents per day

4. Benefit to Cost Ratio: 4:1

5. Feeding Strategy: Two weeks prepartum to six weeks postpartum and stress conditions

6. Recommendation: Recommended

Zinc Methionine

1. Function: Improve immune response, harden hooves, and lower SCC

2. Level: 9 g per day (Zinpro 40 product)

3. Cost: 4 cents per day

4. Benefit to Cost Ratio: 14:1

5. Feeding Strategy: To cows experiencing foot disorders and with moderate somatic cell counts

6. Recommendation: Recommended


# References

  1. Hutjens, M.F. 1991. Feed additives. Vet. clinic of North America: Food Animal Practice. 7:2:525.
  2. Hutjens, M.F. 1997. Feed additives. AABP Pre-Seminar Proc. Montreal, Canada. p. 175.
  3. Kung, L.,Jr., and R.E. Muck. 1997. Animal responses to silage additives. In Silage: Field to Feedbunk. NRAES-99. p. 187.
  4. Muck, R.E., and L. Kung, Jr. 1997. Effects of silage additives on ensiling. In: Silage: Field to Feedbunk. p. 200.