When you hear the word prescription your thoughts go to a medical practitioner authorizing a medicine for your illness.
Prescription can also apply to eating. Healthy active adults need to consume the correct proportions of vegetables, fruits, protein/meat, dairy and grains each day to maintain a healthy, active body. The proper diet prescription to consume the correct nutrients is the Recommended Daily Allowances or RDA. These RDA are the basis for the nutrients required each day for us to stay healthy.
For dairy cows to stay healthy and perform, the proper prescription of nutrients from grains and forages is critical. The eighth edition of Dairy Cow RDA, published in 2021, contains 481 pages of facts for nutrients for dairy cows. Your farm’s nutritionist must be knowledgeable of the dairy RDA. RDA are published for all livestock species.
In my early nutrition career, I formulated a unique RDA grain for crickets. The Indiana family farm grew acres of caged crickets. The crickets were processed and sold to Chicago pet stores as exotic pet food. You thought rounding up loose dairy cows was difficult; imagine the cage door open to retrieve crickets! My career the last 35 years has been dairy nutrition across the eastern and midwest US for many dairy farms.
Herd production “sweet” spot
Prescription dairy cow nutrition is not new, but it is more complicated now. Modern dairy herds are producing in excess of 7 pounds of daily milk components, and the right prescription of nutrients is critical to sustain high performance and health.
Feed is the largest dairy expense, and your farm nutritionist must have a thorough knowledge and ration software for the ration nutrient prescription to achieve the farm’s best economic return. Each farm has a “sweet spot” of best economic return as high production does not guarantee high profit. Prescribing the right balanced ration is critical for long-term farm success.
Ration nutrients and additives
Dairy cows require nutrients to produce milk and must daily consume the 48 RDA quantities. Many nutrients are best sourced from forages and grains. Modern ration software optimizes these homegrown ingredients to formulate best cost diets.
Ration additives are not required and are optional in the diet and are purchased. Additives have benefits by changing the efficiency of nutrients, rumen function or health of the cow. Commercial additives include buffers, enzymes, probiotics, yeasts and binders. Not all additives will perform in every herd. Steve the dairy farm owner said, “If I used every proposed additive on the market, my cows would be promised to produce 200 pounds of milk per cow per day!”
So which additives work?
Evaluate the conditions under which the proposed additive was research-tested. As an example, a proposed additive is said to have an average 4 milk response. The range of response across herds was a negative of 2 pounds per cow to a gain of 10 pounds per cow. Evaluate the ration and management characteristics of the nonresponsive herds to the responsive herds to determine their economic value for your herd.
Mode of action and return on investment. How a nutrient or additive functions is important in deciding the usage. Know the biology or mode of action, or MOA. If the MOA solves your herd nutrition bottleneck then usage can be considered. A product’s MOA that duplicates a current ration nutrient or additive should not be used as stacked ration products will not provide an economic benefit. A knowledgeable professional nutritionist will understand the MOA of the nutrient or additive. A return on investment must be economically valuable to implement. This can be determined by using partial budget analysis where incremental cost is compared to incremental return.
As an example, methionine is a required nutrient (amino acid) for dairy cows to produce milk protein. A new bypass methionine product (+$0.20/cow/day) is being considered for the current ration. Using ration modeling, if the current diet is deficient in methionine and a potential milk protein response of $0.45 per cow per day can be realized by adding the methionine then it should be considered for use. Handling, mixing and cow health benefits need to be evaluated also.
Another example, a new rumen efficiency additive ($0.16/cow/day) is promoted to improve average milk production by 3 pounds per cow per day. The fine print of the rumen efficiency information indicates that the average result is achieved on herds with poor to moderate quality forage and the range in milk response is minus 1 pound to positive 4 pounds per cow per day. The current ration being fed is high-quality forage and the current ration contains a $0.10/cow/day rumen efficiency yeast product. Based upon this information an economic benefit to using the 16 cent efficiency additive is not beneficial.
Prescription nutrition for dairy cows involves: 1) understanding RDA nutrients are required and additives are optional; 2) knowing the mode of action of nutrients and additives and 3) knowing the return on investment value of nutrients and additives for your dairy using partial budget analysis. A qualified nutritionist who understands cow biology inside and out can use modern ration software to optimize best-cost prescription diets to achieve your farm’s optimal “sweet spot” production for highest economic return.
