Feed Additives in Dairy Diets
Many different types of feed additives are marketed to the dairy producer. Some are beneficial and some are not. It is difficult to make a decision based solely on information provided by advertisements and sales reps. An impartial evaluation of scientific data is necessary. Dr. Mike Hutjens, dairy nutritionist with the University of Illinois has written many papers evaluating the use of various additives.
The following information has been condensed and adapted from an article he wrote for the September 25, 1999 issue of Hoard’s Dairyman. In this table, function describes how the additive may impact your cattle. Level is the recommended amount that should be fed to obtain the desired result. Cost will be somewhat variable depending on location and product. Unless otherwise stated, cost is listed on a cents/head/day basis. Benefit-to-cost ratio is the value of the additional daily milk or growth compared to the daily additive cost. Feed strategies are situations when the additive may provide a profitable response. Status is classified in the following ways:
- Recommended: use as needed for a specific problem or situation
- Experimental: additional research is needed but looks favourable
- Evaluative: caution, research results vary
- Not Recommended: lacks economic responses based on current research
Note: This table is not meant to list all feed additives currently available to dairy producers. It is a list of products about which I receive more frequent questions. Inclusion on this list does not imply a specific product endorsement nor is any slight intended against the numerous products which were not included. Additional information on these and other products is available.
| Additive | Function | Level | Cost | Benefit Cost Ratio | Strategy | Status |
| Anhydrous ammonia | Provides NPN, reduces mold growth, improves silage stability and fibre digestibility of low quality forage | 1-3% of forage dry matter. | Variable, about $15/T DM | Favourable | Apply to corn silage before ensiling; do not apply to alfalfa-grass silage; very dangerous to handle and apply | Recommended if needed |
| Anionic salts | Causes ration to be more acidic raising blood Ca levels by improving bone mobilization of Ca and absorption from small intestine | Reduce cation:anion balance to –5 and –10 meq/100 g dry matter | 40-75 cents | 10:1 | Feed to dry cows 2-3 weeks before calving | Recommended |
| Aspergillus oryzae | Stimulate fibre digesting bacteria, stabilize rumen pH and reduce heat stress | 3 grams/day | 3 cents | 6:1 | Use with high grain diets, acidic rumen conditions, heat stress, calves receiving liquid diet | Not Recommended |
| Biotin | Reduces heel warts, claw lesions, cracks and sole ulcers | 10-20 mg/cow/ day for 6 months to a year | 6-8 cents | 4:1 | Herds with chronic foot problems may need 6 months of supplementation before evaluation | Experimental |
| Calcium propionate | Increases blood glucose and Ca levels | 120-225g | 20-40 cents | Not available | Feed 7 days prepartum to 7 days postpartum or until appetite improves (unpalatable) | Recommended for transistion problem |
| Monensin (Rumensin) | 1. Ionophore for calves and heifers to improve feed efficiency and control scours | Up to 200 mg/head/day depending on body weight | 1-2 cents | 8:1 | Feed to calves (coccidiosis control) and heifers to improve growth | Recommended |
| 2. Aid for prevention of subclinical ketosis | One controlled release capsule | Variable, about $13/cow | Not available | Dose cows 3 weeks before calving | Recommended for control of ketosis | |
| Niacin | Improves energy balance in early lactation cows; helps control ketosis | 6 g/cow (prepartum) 12 g/cow (postpartum) | 6-12 cents | 6:1 (6g level) | Begin feeding 2 weeks prepartum and continue to maximum dry matter intake is reached | Recommended for control of ketosis |
| Probiotics (direct fed microbials) | Produce compounds that destroy undesirable organisms, provide enzymes to improve nutrient availability | Not clearly defined | 5-15 cents | Not available | Feed to cows at calving and during stress, milk-fed calves | Evaluative for cows; Recommended for calves |
| Yeast culture | Stimulates fibre digesting bacteria, stabilizes rumen environment, utilizes lactic acid | 10-120g depending on yeast culture concentration | 4-6cents | 4:1 | Feed 2 weeks prepartum to 10 weeks postpartum, during stress and off-feed conditions | Recommended to ensure rumen health |