Optimizing Medication Dosage for Efficient Poultry Production: A Business Perspective

Medication costs in the poultry industry (excluding vaccination costs) can account for up to 1% of the total production cost. This amount may not seem significant, however, when we talk about cash flow and investment from a business perspective, we can measure that it represents thousands of dollars, whose profitability often falls on the production unit manager and the person responsible for managing medications. In a layer hen business unit, for every 1 million layer hens, up to $500,000 can be invested annually, solely on medication. This is why the correct administration of pharmaceuticals used in the poultry industry is crucial for the profitability of companies, and knowledge of dosage calculation is an important tool for achieving this goal. This study compiles key methods for accurate dosage calculation in commercial poultry production, aiming to promote best practices in medication administration as a means to enhance profitability. By doing so, it seeks to prevent empirical or arbitrary medication practices that can lead to unnecessary losses for companies.

All medication in flocks should be calculated based on a unit measure (measurable variable) that represents a parameter or indicator of the flock, such as:

These data should be compiled in production units to ensure easy access when medication needs to be administered. When calculating dosages for any product, it's essential to know the product's concentration. This information indicates the amount of active ingredient in the commercial product, which is the component that will exert the desired pharmacological effect.

For example, iodine products marketed for sanitizing drinking water often have a concentration of 1.75%. This means that for every 100 units of the commercial product, less than 2 units are pharmacologically active iodine, while the remaining 98.25 units are merely the diluent and inert compounds (a liquid with no medicinal action). In contrast, some tiamulin fumarate and chlortetracycline products have concentrations of up to 40% and even 80%. The recommended dosages in veterinary pharmacology literature, such as books, encyclopedias, and scientific articles, are based on controlled pharmacokinetic studies under research protocols. Similarly, due to regulatory requirements, all technical data sheets and safety sheets for medications marketed in North America recommend dosages supported by scientific trials and years of research. In this context, overdosing or underdosing will lead to unnecessary expenses, increased production costs, and, in the worst-case scenario, intoxication of the treated animals.

Avilamycin is indicated for the treatment of necrotic enteritis and infections caused by Gram-positive bacteria in broiler chickens at doses of 15 to 40 parts per million (ppm). To implement dosing in parts per million, it's essential to understand this concept. One part per million can be understood as one-millionth of any compound. In pharmacology, one part per million expressed as a percentage is equal to 0.0001%, which represents the ratio of 1 to 1 million. To calculate the equivalent dose in parts per million, we can multiply the dose by 0.0001% and then by the quantity of volume where it will be diluted (in this case, feed). For example, avilamycin is dosed in feed. Assuming:

1 US ton = 2,000 pounds

to dose 15 ppm of avilamycin:

15 (0.0001%) (2,000) = 0.03 pounds of avilamycin

It's crucial to simplify any percentage by dividing by 100 (in this case, 0.0001/100) for accurate calculation. We need 0.03 pounds of avilamycin per US ton or short ton (approximately 1,000 kg). However, this calculation assumes avilamycin is 100% concentrated or undiluted, which is rare. Avilamycin is typically marketed at a 10% concentration. To simplify any concentration, we need to know how many times the concentration fits into 100 and multiply the result by the amount of medication needed. In this case:

0.03 (10) = 0.3 pounds

The final result is: 0.3 pounds of avilamycin are needed per ton of feed.

Iodine is indicated for sanitizing the water system in poultry farms at a dose of 12.5 parts per million (ppm). In this case, water needs to be medicated, not feed. The house being treated consumes 9,000 gallons of water per day. Using the previous example, the calculation is:

12.5 (0.0001%) (9,000) = 0.1125

As mentioned earlier, the concentration of iodine is 1.75%. To account for the concentration, we calculate:

(100 / 1.75) = 57.1428

Then:

0.1125 (57.1428) = 6 gallons per day of iodine

To be precise, the dose is in gallons because we are medicating gallons of water, and it's the volume for which we want to know the concentration in parts per million.

Another example to consider is treatments that require dosing based on a concentration (percentage) in water or feed. This concept differs from parts per million, although a calculation can be made to determine its equivalence. An example is amprolium, used for treatment and prevention of coccidiosis in young and adult birds. The recommended dose for amprolium is 0.024%. This means the treated drinking water should have a concentration of 0.024% pharmacologically active amprolium. A common formulation of amprolium is 9.6%. For this type of treatment, a stock solution is prepared with the daily dose of medication, and this stock solution is connected to the house's water system. Dosifiers or injectors are used for this purpose, and their use is common in North America. These injectors have injection ratios, which determine the amount of medication applied to the water. Knowing the volume needed for the stock solution is critical for this type of treatment

Analyzing the previous table, it can be concluded that the lower the ratio, the higher the requested concentration, and therefore, the greater the amount of stock solution injected into the same volume of water. Let's consider a house with a daily water consumption of 5,500 gallons. To calculate the volume of the stock solution, the formula is:

Volume = Water consumption x Ratio / 100

In this example, an injector adjusted to a ratio of 1:128 or 0.78% is used. Then:

Volume = 5,500 (0.78) / 100 Volume = 43 gal

The volume of the stock solution should be 43 gallons to ensure the medication is injected at a proportion of 0.78% into 5,500 gallons of water per day.

The following table shows the amount of stock solution needed for the same 5,500 gallons of water based on the injection ratio. At lower ratios, more stock solution needs to be injected to meet the required stock solution/total water ratio

Once the amount of water for the stock solution is determined, the next step is to calculate the amount of amprolium needed to add to those 43 gallons of stock solution. To do this, the dose is calculated based on the amount of stock solution. Remember that any percentage needs to be converted by dividing by 100.

0.024% (43) = 0.010 gal

The required dose of pharmacologically active amprolium is 0.010 gallons or 1.32 ounces. Again, since amprolium comes in a 9.6% concentration, the concentration needs to be accounted for:

100 / 9.6 = 10.4

Then:

1.32 (10.4) = 14 ounces

In conclusion, to administer the medication correctly, 14 ounces of 9.6% amprolium should be added daily to 43 gallons of stock solution.

The modern poultry industry is a complex market. To succeed, businesses must prioritize key factors such as animal health, biosecurity, and access to highly skilled labor. With thin profit margins, poultry producers cannot afford economic losses or unmanaged risks. Effective dosage and medication administration are essential tools in achieving this goal.