Here is a table that might be good to keep in mind and keep track of whether you need to supplement small kittens.
Giving them too little is definitely not good, but giving them too much can be at least as devastating, this table is of course based on kittens that are fed exclusively supplements, kittens who are orphans.
In those cases where you give the kittens supplements, you must remember that they will get a larger or smaller portion of milk from their mother, keep an eye on their weight gain, and do not be in too much of a hurry.
Keep in mind that the figure of 10 grams per day that you often hear is a "guideline" and an average. Sometimes a kitten may gain 15 grams one day and the next day it will stop or gain 4 grams, this is absolutely nothing to worry about, just wait and see, and in the vast majority of cases this kitten will have gained weight again the next day and one of the other kittens may have gained a bit less.
| Age | Weight (gram/ounces) |
20 kcal/100 gr Bodyweight* |
Daily amount of supplement (ml) Concentration 0,74 kcal/ml* |
Stomach Capacity (ml) 4 ml/100 gr bodyweight |
Approx. number of feedings per day** |
| Newborn | 50/1.8 | 10 | 13,5 | 2 | 7 |
| 75/2.6 | 15 | 20 | 3 | 7 | |
| 100/3.5 | 20 | 27 | 4 | 7 | |
| 125/4.4 | 25 | 34 | 5 | 7 | |
| ~1 week | 150/5.3 | 30 | 40 | 6 | 7 |
| 175/6.2 | 35 | 47 | 7 | 7 | |
| 200/7.0 | 40 | 54 | 8 | 7 | |
| 225/8 | 45 | 61 | 9 | 7 | |
| ~2 weeks | 250/8.8 | 50 | 68 | 10 | 7 |
| 275/9.7 | 55 | 74 | 11 | 7 | |
| 300/10.6 | 60 | 81 | 12 | 6-7 | |
| 325/11.5 | 65 | 88 | 13 | 6-7 | |
| ~3 weeks | 350/12.3 | 70 | 95 | 14 | 6-7 |
| 375/13.2 | 75 | 101 | 15 | ~6 | |
| 400/14.1 | 80 | 108 | 16 | ~5 | |
| 425/15 | 85 | 115 | 17 | ~5 | |
| ~4 weeks*** | 450/15.9 | 90 | 122 | 18 | ~5 |
| 475/16.8 | 95 | 128 | 19 | ~4 | |
| 500/17.6 | 100 | 135 | 20 | ~4 | |
| 525/18.5 | 105 | 142 | 21 | ~4 | |
| ~5 weeks*** | 550/19.4 | 110 | 148 | 22 | ~4 |
*Most commercial milk replacers in the US (I do not believe this is a problem we have in Europe at least none I have seen), provide less than 1 kcal/ml (0.74 kcal/ml), acting to increase the volume of milk required to meet calorific needs. This can be problematic in terms of the number and size of feedings given relative to stomach capacity and is more likely to result in gastrointestinal disturbances. This may also account for why bottle-fed kittens grow slower than kittens that nurse off their mother.
I have tried to look up a couple of brands that I use/have used myself but my math skills are not the best, but at least I tried.
5135 kcal/kg 5,135 kcal/gr Royal Canin (1 scoop (10 ml) of powder per 20 ml water)
4700 kcal/kg 4,700 kcal/gr Brit Care (1 scoop of powder for 3 scoops of water); 1 gr = 1175 kcal; 1 scoop = 4 gram/5ml (This one I had and could take a weight to know how much 1 scoop is in grams).
4710 kcal/kg 4,710 kcal/gr Concept for life (1 scoop of powder for 2 scoops of water)
1250 kcal/l 1,250 kcal/ml Beaphar Lactol (31 gr/100 ml)
*** As your kitten adjusts to the milk and feeding volume, you may want to increase feeding to reduce the number of feedings per day. This will exceed the recommended comfortable stomach capacity and may put your kitten at risk of regurgitation, aspiration, and diarrhea.
*** Kittens at this age often eat solid foods, which reduces the amount of formula needed to meet daily calorie needs. This can result in less frequent formula feedings.
