What age do cats go into heat? Are they only receptive to males during that period of time?
According to Vetstreet, the typical sexual behavior of a domestic cat includes:
Cats are also social animals and will have a certain hierarchy among other cats they are familiar with. During sexual arousal, they will often display submissive behavior.
It is possible to teach the male cat to have multiple sexual partners. But a cat will only mount one partner, at a time, and they need to be able to smell and sense the scent of another cat before mounting.
However, a male cat is not receptive to other males all the time.
The cat is likely to be more receptive to male stimuli on "heat" days (or periods of time where they can get hard erections and feel a need to release sperm) and less receptive to male stimuli on "off heat" days.
Most people get cats when they have families or other pets and are then unable to keep them up to date on sex education.
In addition to what was mentioned, they also have a heat cycle (litter cycle in felids). This will usually start between 2-3 weeks for a new born, then gradually increase to around 6-8 weeks for an adult. The heat cycle can continue for up to 2 months for a new born, but is generally considered a "permanent" condition. It's also important to remember that as cats age, they go through less intense "heat" periods.
The following excerpt is from a great website about the feline cycle:
During the heat cycle, the female feline will begin to experience increased blood flow and changes in her hormone levels. These hormones are called ovarian hormones, and they play a large part in the female cat’s ability to attract and be attracted to males. Females have ovaries that will produce progesterone and estrogens, the most important of these being progesterone. Female feline blood has a slightly greater pH than normal, and it is at this time that female cats will experience the most extreme physical changes. A female cat’s vulva will often have a darker, thicker lining, and will be in a much more receptive mood.
Females also may develop a thickened vaginal tract and a deep, dark scent. Scent glands on the vulva are also enlarged. Female cats who are in heat will also be able to see these physical changes and can often see their “heat” markings on their bodies.
It should be noted that this is from cat behavior and should not be generalized as it is not the same for all felids.
It is important to note that there are many reasons why male felids may not be interested in mating. Not all males will have access to the females that they desire. For male felids, the most common reason is that they are too young to be able to reproduce. This may also explain why your males are not interested in the kittens, but may also be because he has never had kittens before. That may not mean he doesn't like kittens, but it could be because he hasn't been around them.
On the other hand, the same principle applies to the male cats that are interested in the female:
They are too old to produce offspring and there are no female cats around to produce offspring with
They aren't interested in breeding
There are not females around to breed with (a specific reason would need to be specified here)
As for why he isn't interested in the litters that he sees, the reason could range from
He doesn't think there is anything valuable in the kittens
He has just been introduced to them and he just thinks they are uninteresting and could care less
The only way to know for sure is to interact with your male felid and ask him. However, even if you are able to, you should still ask him why he is not interested in breeding. The answers to that may vary, and you should be willing to work with your cat to try to get him to have his own litter, as well as to understand why he doesn't want to have kittens.
As for breeding your felid and raising kittens in a single enclosure with another male, this is a different topic. This is a topic in itself and could require a larger answer.
This post is not intended to answer all of your questions, but will point you in the direction you need to go with your specific question and answer it.
Cats may not be interested in mating if one or both of the opposite sex is absent or not fertile. You might as well keep your cats separated, if the intent is for breeding.
There are various factors that could cause cats to not wish to mate or to not wish to keep their kittens.
Males may not wish to mate if a male is nearby.
This can be true, especially with males that don't like company of any kind. The female will then not want to mate as she isn't likely to want to be near the other male. A male cat may also not wish to mate if the female is with a cat he doesn't find desirable. This is the situation you describe in the question.
In this case, the female may or may not be fertile and want to keep the kittens in the event that she does get pregnant. Males are only fertile when in heat. Heat is a state that the female goes through and can be induced by a male. It is different from a breeding season and can come up very abruptly for a female. Breeding season is when a female is ready to get pregnant, if you are lucky enough to have kittens during this time. A female that wants to keep the kittens during the breeding season is only willing to mate if the male she is mated to is fertile.
If she is not fertile, she will not want to get pregnant and will let the male know. If the male is fertile and is in heat and can get a mating he may still not want to mate. He may wish to mate and be done with it, or he may want to mate and simply go home when he has had his fill. There are numerous other factors that could be in play.
You mention the two cats seem to have been bred in the past. You could have done something like this before.
This could also explain your problem. You could have your cats bred without your knowledge. Your partner could have done this, or another person. It may be that he went away for a long time, the male cat is not mature or fertile enough to keep up the pace, and