BREEDING MANAGEMENT PRACTICES IN CATS
Female Heat Cycle
The female cat’s heat cycle is the first step in the breeding process. This is the time when she is most fertile and receptive to a male cat’s advances. Cycles usually begin when a female reaches 6 months old, and only last two days on average, but are repeated approximately every two weeks thereafter unless mating takes place. Once a cat has mated and becomes pregnant, her heat cycles will end.
The queen
Female cats go through puberty, defined by onset of their first estrus, at an average age of 8-9 months, with a range from 4-18 months. Long-haired breeds enter puberty earlier in life than short-haired breeds. Puberty onset is also dependent on season; cats reaching an appropriate age during the seasonal anestrus will not go through their first estrus until the breeding season begins.
Cats are seasonally polyestrous, cycling for an average of about 6 days every 2-3 weeks from January through mid-October. The seasonal anestrus from mid-October through December is defined by day length; cats maintained under artificial lights for 12 continuous hours daily will cycle year-round and may exhibit increased fertility. Length of estrus may or may not be affected by breeding. Some studies suggested a shortening of estrus in bred cats while others showed no effect of breeding. Bred cats that are induced to ovulate but do not conceive will undergo a prolonged luteal phase, lasting 45-60 days. Induction of ovulation in estrous queens may be used to decrease cyclic activity between desired breedings.
Proestrus is not routinely discernible in cats. Shille et al documented proestrus in only 27/168 (16.1%) of cycles followed. Estrus behaviors in the cat include monotonous vocalization, increased affection, lordosis (elevation of the hindquarters with lateral deviation of the tail) and rolling. A positive correlation has been shown between estrous behavior and cornified vaginal cytology. Cornified vaginal cytology specimens may be useful in defining estrus in queens which exhibit no overt estrous behavior. Cats may rarely have clear vulvar discharge associated with estrus.
Cats are induced (reflex) ovulators, as are rabbits, ferrets, mink, skunks, 13-lined ground squirrels, camels, llamas, short-tailed shrews and giant fruit bats. In these species an external trigger, usually coitus, stimulates release of gonadotropin releasing hormone (GnRH) from the hypothalamus. This stimulates release of luteinizing hormone (LH) from the pituitary within 2-4 hours, which will then cause ovulation in 1-3 days. The amount of LH released in dependent on the number of copulations and the time during the estrous cycle when copulation occurs. Queens bred only once exhibit great variability in serum LH concentrations and fewer than 50% will ovulate. Concannon et al demonstrated that greater than 4 copulations were required to insure LH release adequate for ovulation.
In the colony at the University of Minnesota, 14 cats were bred at 23 cycles. They were bred an average of 5.6 times per cycle, with a range of 4-8 times per cycle. The pregnancy rate was 73.9%, and those queens that did not become pregnant had prolonged interestrous intervals, averaging 61.5 ± 14.5 days in length. This suggests that breeding an average of 5.6 times/cycle was sufficient for reliable induction of ovulation.
There is some evidence that cats may occasionally spontaneously ovulate. Wildt et al failed to demonstrate spontaneous ovulation in 17 queens by laparoscopy. However, cats housed at Ralston Purina were noted to have high incidence of uterine disease, an unexpected finding in cats which were not induced to ovulate. Serial blood samples were drawn from 20 queens that were housed individually and who had no perineal contact with other cats or from their handlers. Thirty-five percent of these cats had serum progesterone concentrations suggestive of ovulation at one or more samplings. This suggests that queens may occasionally spontaneously ovulate, may ovulate secondary to a trigger other than coitus, or may undergo luteinization of follicles instead of atresia after a non-ovulatory cycle.
The tom
Tom cats go through puberty, defined by first appearance of sperm in the ejaculate, at 8-12 months of age. The penis of male cats is encircled at the level of the corpus cavernosum glandis by 100-200 cornified papillae, commonly called penile spines. These are androgen-dependent; they appear at 6-7 months of age and disappear after castration. Mature tom cats are capable of mating repeatedly over a 4-5 day period without a decrease in sperm numbers. Males maintained under 12 hours continuous light daily showed no seasonal change in breeding behavior or semen quality.
What is Breeding Timing?
Estrus, or “heat” as it is commonly known, usually occurs for the first time in female cats at anywhere from four to six months of age. It is a period where their ovaries are capable of producing eggs, and if bred by a male cat during this time, it is likely that the mating will result in pregnancy.
Breeding timing in cats can refer to the period of time during which a female cat, or queen, is most fertile, and the chances of a breeding resulting in pregnancy are at their highest. You may notice that the queen has become very vocal, yowling and meowing loudly and frequently. She may roll on the ground, make kneading motions with her back feet, and rub against you or your belongings. By showing these behaviors, she is showing any potential suitors that she is ready to mate and produce a litter of kittens.
Signs Your Cat is Ready for Breeding
Since cats don’t leave traces of blood behind during heat, many breeders rely on their female cat’s behavior to let them know when she is coming into breeding condition. By observing your cat on a regular basis, you will be able to notice even subtle differences in her behavior. These differences include:
- Flirting:Females become more affectionate than normal. Some become affectionate to the point that it is overwhelming, whereas others will become just slightly more friendly.
- Rump raising:Females in heat will tend to raise their rumps when you stroke them along their backs.
- Tail flagging:Rump raising may be accompanied by a quick back and forth twitching of the tail. This is the way the female advertises her readiness.
- Calling:Females in heat can be extremely vocal, calling constantly in search of male partners. Any capable male within earshot will do their best to answer that call.
Symptoms of Breeding Timing in Cats
It is fairly easy to determine if a female cat is ready to breed, as symptoms of estrus are usually observable through behavior changes. Some cats may develop physical symptoms, but this is much less apparent than other household pets such as dogs, and the major symptoms typically last for about a week. You may be able to observe some of the following behaviors or changes in a female cat that is ready to breed:
- Vocalizations, such as meowing, chirping, or yowling, that are much more frequent and louder than normal.
- Rolling or rubbing on objects, people, or other animals.
- Kneading the ground or objects with either front or back paws.
- Raising the hindquarters and tail while lying on the ground, particularly if petting is near the rump.
- Slight swelling or puffiness of the external vulva or vaginal area
- Receptive to mating behaviors displayed by a male cat, or “tom”, such as biting of the neck, mounting, or even allowing the tom to complete the full act of mating.
Causes of Breeding Timing in Cats
Sexual maturity in cats brings on hormonal changes, which can indicate that the cat is physically able to breed.
- Between 4-6 months of age, the ovaries begin producing the hormones progesterone and estrogen.
- The cycle of estrus can be brought on by longer daylight hours, usually during early to mid-spring.
- During the pre-estrus period, or “proestrus”, the female cat’s body begins secreting hormones, such as progesterone and estrogen, that will bring on the fertile time in her cycle.
Diagnosis of Breeding Timing in Cats
Your veterinarian will be able to diagnose breeding timing in your cat by performing a physical examination, including taking her temperature, observing any common estrus-related behaviors she may be displaying, or in some cases by collecting secretions from the cat’s vaginal opening with a sterile swab, which is then tested for the hormone progesterone. In some cases, breeding timing can also be detected by use of an ultrasound, which is used to see if the queen’s ovaries are creating follicles in readiness to release ovum, or eggs.
Pet owners can diagnose breeding timing by observing the clinical symptoms, most often behavior changes that differ strongly from the cat’s usual behavior. Owners can begin tracking periods of estrus using a standard calendar, which can give a good indication of when the next hormonal period will occur and, if desired, breeding with a male cat can take place.
A veterinarian will ask how old your cat is, how long she has been experiencing estrus for, and about any existing health issues when determining her readiness to breed. They may also review the cat’s recent vaccination and worming schedules to ensure that she is protected against common diseases, and that she is not carrying worms that could impact her health or draw important nutrients away from any potential fetuses. In certain breeds of cat, genetic testing may be recommended to ensure that the queen does not carry genetics that may predispose her offspring to congenital defects known to exist in a particular breed.
Treatment of Breeding Timing in Cats
Pregnancy
Should you desire to breed your queen and have a litter of kittens, estrus will cease once she has mated with a male cat and become pregnant. Pregnancy typically lasts between 65-69 days in cats, but pregnancy and birth do come with risks of complications to both the mother and offspring. Once the queen has given birth and weaned her litter, she will once again enter her normal estrus cycle.
Ovariohysterectomy
If you do not desire your queen to go into estrus or breed, you may elect to have her undergo an ovariohysterectomy, more commonly known as spaying. This is a very common surgical procedure, performed under general anesthesia, whereby the veterinarian removes all internal reproductive organs. This includes the ovaries, uterus, uterine horns, and oviducts. Surgery typically lasts for less than twenty minutes. Full recovery is generally under a week to ten days. The queen will no longer experience the signs or symptoms of estrus, and she cannot breed or carry a litter after the surgery has been completed. Spaying may improve her behavior around the home, as well as prevent common cancers of the uterus or mammary glands.
Chemical Suppressant Treatments
Several chemical suppressant options exist that will prevent the queen from entering estrus.
- Medroxyprogesterone acetate – Given as a single injection, or in tablet form. Oral medication is administered until the queen is no longer in estrus.
- Suprelorin – A long-acting chemical suppressant, this is administered through a subcutaneous implant that lasts between 8-12 months. It is considered generally safe and effective for queens, but can also be administered to toms as well.
- Melatonin – Administered orally or via injection, melatonin may suppress estrus by mimicking hormone levels present in the queen’s body during times of limited sunlight.
Compiled & Shared by- Team, LITD (Livestock Institute of Training & Development)
Image-Courtesy-Google
Reference-On Request.
