Birth weight and postnatal growth of purebred kittens including Norwegian Forest Cats
In general, the birthweight of the larger cat breeds such as the Maine Coon and Norwegian Forest Cat (NFC) is higher than the birthweight of kittens of cats of smaller cat breeds such as the Persian, Siamese and Birman. This is to be expected. However, the weight of newborn NFC kittens relative to the ultimate adult weight of females of that breed is lower than for the smaller cat breeds. The same applies to Maine Coons (MC). The MC adult is larger than the NFC but not by a lot.
The other words there is a bigger difference in weight between the newborn kitten and the adult cat in respect of the larger cat breeds such as the NFC and MC.
And what happens is that the kittens grow faster in the bigger cat breeds such as the NFC. And the scientists say that the, "Absolute growth was faster in larger breeds than in smaller breeds. They also state, to use their words, "Relative birthweight was lower than that described in the literature for colony cats".
This means, on my understanding, that the newborn kittens a purebred cats had a weight relative to adult cats of that breed which was smaller than for colony cats. In other words, in colony cats, by which I presume they mean feral cat colonies, the kittens have less growing to do before they become adult compared to purebred cats. Is this to do with enhancing the chances of survival of newborn kittens?
The relative birthweight of the breeds studied are as below. As a reminder, "relative birthweight" means the difference of the weight of a kitten when born compared to the weight of a mature female in percentage terms.
- MC newborn kittens, in the study, weighed 115 g which is 2.3% of the mature female weight of this cat breed;
- NFC newborn kittens weighed 106 g which is 2.7% of the weight of a mature female;
- Birman newborn kittens weighed 97 g representing 2.8% of female adult weight;
- Siamese newborn kittens weighed 92 g representing 2.8% of female adult weight and;
- Persian newborn kittens weighed 82 g which represented 3.2% of the adult weight of a female cat of this breed.
My reading of this study is that the bigger cat breeds such as the NFC have newborn kittens which are larger than those of other breeds because the NFC is one of the biggest cat breeds. However, in relation to the size of the adult cats of this breed the newborn kittens are relatively smaller than normal. Which leads to the next conclusion namely that they grow up faster than for other breeds which has to be the conclusion otherwise they would not end up at the size that they are when adult!I hope some people find this useful. The information comes from breeders. And the study is called: Birth weight and postnatal growth of pure-bred kittens. It was published on 12 October 2011.