For veterinary drugs, usually a dose calibration study is employed, to determine the effective dose range, typically in mg of active ingredient per kg of bodyweight per day, also to determine the best timing and duration of treatment. Once this is done the inclusion rate in feed can be calculated, taking into consideration the required daily dose (mg/Kg bodyweight/day) and the expected daily feed consumption (kg per head).

Hope this helps, if not please ask further questions.............Kevin.

Kevin has outlined perfectly how things should be done.

Two things to remember:

1. Sick animals usually eat less than healthy ones

2. To evenly distribute a drug in animal feed , a (specialised) feed mill is essential.

Therefore many people choose water as the carrier, as sick animals usually do drink

1-As I understand from the title you dnt wont administerin the frug by intrgastric gavage which can introduce exact amount of drug, you aim at giving the drug mixed with anima diet. To do this:1-calculate the average drug consumptin; b-mix the drug with diet by preparing especial food form; c-Be aware of the drug lost with the food escape. You do this by preparin special cage with special food case so that the food waste from animal chewing can bt weighed. d-wath the general condition of the animals because any condition interferrin with appetite will influence food consumption. 2- Calculate  amount of drug  consumed and convert it (as mg, microg etc.) per kg, or 100 g(rat) or 10 g (mice) etc.

You can use the following formula: (a x b) / (c x 100) where (a) is the dose needed in g per 100 kg live weight, (b) is average weight of the animals to be treated and (c) is the average daily feed consumption at time of treatment.

I forgot to add: the result of the formula is kg premix to add per ton of feed

Dear Cedric R Müntener

We have a formulation of Levofloxacin 10 %. The dose of levofloxacin is 8 mg/kg/b.w . Please let me know the exact dose of formulation added in the per ton of the feed of poultry having average weight of 1 kg and average daily feed consumption 120 gm.

Dear Cedric R Müntener

Please let me know is their any corelation of dosage calculation with the size of animal and their basic metabolic rate.

Hi Neeraj,

Hope I got it right (I am not doing it on a daily basis!):

1. Levofloxacin 10% -> 100 g/kg or 100 mg Levo per g premix

2. Determine how many g premix contain the required daily dose (8 mg/kg/day): 0.08 g premix contain 8 mg Levo -> chicken need to eat 0.08 g premix in the feed per day

3. (A x B) / (C x 100), where A = 0.08 x 100 = 8 (need to express per 100 kg live weight), B = 1 kg (live weight of animals) and C = 0.12 (feed consumption expressed in kg)

4. Result is 666 g premix per ton or 666 mg premix per kg feed

Assuming:

1. premix is 10% active ingredient

2. bird weight is 1 Kg

3. daily dose is 8mg active ingredient/kg BW/day

4. daily feed consumption is 0.12kg/bird/day

then my calculation matches yours (666g premix per tonne feed)..

Dear Kevin Healey

Please let me know whether you adopted formula of Cedric or you have other way to calculate the same.

How you perform this calculation, please let me know in detailed so that i will able to perform similar type of excercise for other premix.

Here's how I do it, working from first principles:

Step 1: Calculate the quantity of the premix (mg) required per bird per day.

Formula is: dose required (mg active /Kg Bodyweight/day) x Bodyweight (Kg) X 100 / purity of premix (%).

In this case its 8mg active/kg bodyweight; bodyweight = 1 kg;  purity = 10%

So: 8 x 1 x100/10 = 80mg premix per head per day.

Step 2: Find out how much feed is consumed per animal per day (please note the comment in a previous posting that sick animals will probably be eating less than normal). In this case its 0.12kg. So we need 80mg premix per 0.12 kg feed.

Step 3: Convert to a "per tonne feed" basis

80 mg premix per 0.12 kg feed = 80mg premix / 0.12 per kg feed = 667mg premix per kg feed

This is equivalent to 667g premix per tonne.

I think you'll find that Cedric's formula will give the same answer, but whichever method you use you need to be very rigorous and consistent in your use of units of measure (mg, g, etc.) or you can easily make an error of 1000x! Also, the formula expresses the purity of the premix as %, if the purity is given as mg/kg then you'll need to convert this to % before you start. Always get someone to check your calculation.

This will be helpful for you for dose calculation.

Briefly here are steps.

1. calculate how much your animals take feed.

2. mix amount of your drug into the feed which should provide you your required dose/kg of body weight.

3. make feed with that weight of drug which is usually in ppm.

Thanks and hope this works.

Please see the attached publication.

Best,

Touqeer

Article Pharmacological effects of Ibuprofen on learning and memory,...

For dietary suppliments, you should have mash/ powdered feed not the pelleted feed. Best result comes when animals are kept and fed individually, not in group.

• Record daily feed intake of each animal
• Record the body weight of each animal
• Multiply the dose rate of the drug (in mg/kg body weight/day) to the body weight of the animals
• Add the amount of drug to the daily intake amount of feed and mix well.

Thanks to all for providing me such a elaborative explanation for the question.

Dear Kevin Healey

Whether same formula is applicable for liquid feed ?

Yes, except that in Step 2 the consumption will be in litres (L) and in step 3 the amount will be "per kilolitre (KL)".

Hope this helps................Kevin.

Thanks Kevin Healey.

is there any publication, book or reference or official guideline so that these approaches are valid as per regulatory requirements

I agree with Kevin Healey .

Here's how I do it, working from first principles:

Step 1: Calculate the quantity of the premix (mg) required per bird per day.

Formula is: dose required (mg active /Kg Bodyweight/day) x Bodyweight (Kg) X 100 / purity of premix (%).

In this case its 8mg active/kg bodyweight; bodyweight = 1 kg;  purity = 10%

So: 8 x 1 x100/10 = 80mg premix per head per day.

Step 2: Find out how much feed is consumed per animal per day (please note the comment in a previous posting that sick animals will probably be eating less than normal). In this case its 0.12kg. So we need 80mg premix per 0.12 kg feed.

Step 3: Convert to a "per tonne feed" basis

80 mg premix per 0.12 kg feed = 80mg premix / 0.12 per kg feed = 667mg premix per kg feed

This is equivalent to 667g premix per tonne.

I think you'll find that Cedric's formula will give the same answer, but whichever method you use you need to be very rigorous and consistent in your use of units of measure (mg, g, etc.) or you can easily make an error of 1000x! Also, the formula expresses the purity of the premix as %, if the purity is given as mg/kg then you'll need to convert this to % before you start. Always get someone to check your calculation.

For albino Rats:

The suitable rat dose was calculated by referring to the table of Paget and Barnes.

Human adult dose x Body surface area ratio convertible factor

If human adult dose is 125 mg then

= 125 x 0.018

= 2.25 mg / 200 g body weight of rat.

= 2.25 x 5 (converting to mg / kg by multiplying with suitable factor 5)

= 11.25 mg / kg body weight of rat.

Suitable mouse dose was calculated by referring to the Paget and Barnes table.

Human adult dose x Body surface area ratio convertible factor

= 125 x 0.0026

= 0.325 / 20 g body weight of mouse

= 0.325 x 50 (Converting to mg/kg by multiplying with suitable factor 50)

= 16.25 mg/kg body weight of mouse