I’m no historian, but rumour has it that the origins of St. Valentine’s day are quite unromantic. Valentine was a Roman guy who helped Christian couples to get married. This was frowned upon in Rome at the time so the Emperor, Claudius Gothicus, had Valentine stoned and beheaded.

Anyway, I thought I’d continue this soft, gooey theme and offer you some nuggets of information about the romantic lives of domestic animals.

Brace yourselves…..




For dairy farmers, it is crucial that a cow produces milk for as much of the year as possible. In order to get milk from a cow, there has to be a pregnancy. Cows are pregnant for just over nine months. Farmers aim to produce one calf every year from each of their cows and to meet this target it is important to ‘catch’ the cow when she comes back into season so that pregnancy is immediate (‘dry’ time, when she is not making milk, doesn’t bring in any money). Historically, farmers kept a bull on site for this task, but nowadays most dairy cows get pregnant by artificial insemination.



The racing year starts on 1st January in the Northern hemisphere and all foals born in the same year can be expected to race against one another. So a foal born in January might race against one born in September, putting the September foal at a distinct disadvantage.

Every racehorse owner in Britain therefore wants their foal to be born as soon after midnight as possible in the new year, so ideally a mare would have become pregnant on around the 7th of the previous February.

It takes a mare a little time to feel ‘in the mood’ for mating. Manipulating day-length using lights will help. In order to avoid ‘wearing out’ an expensive stallion, a ‘teaser’, stallion may be used to make sure the mare is aroused. A quick switch can then be made as the two become ready to couple.




They call it ‘tupping’ where I come from. The ‘tups’ (males) are put in with the ewes in October for lambing in Spring. One tup might cover about thirty ewes but this number varies dramatically. Suffice to say that rams work very hard at this time of year!

In order to ensure that as many females are mated as possible, farmers sometimes fix a crayon to a tup’s belly known as a ‘raddle crayon.’ This leaves a brightly coloured mark on the ewe when she’s been covered. If the colour of the crayon is changed part-way through tupping, the farmer also has an idea when each ewe’s lambs are due, or whether the first mating didn’t work.



It is considered the norm in Britain to have pets neutered if breeding is not required. Spays and castrations are amongst the most common operations in small animal practice.


Bitches (females) who are not spayed come into season typically once or twice a year and are only receptive to males at this time.

There is a gland on the male’s penis which swells inside the bitch during mating. This can result in the male being unable to withdraw for a while afterwards, leaving them ‘locked’ together – called a “mating tie”. A mating that produces a tie is more likely to result in pregnancy.



Dogs and humans are social animals. Females produce an egg which will be wasted if it not fertilised, but then naturally there would be lots of potential partners around when she is ready to mate. Female cats (queens) on the other hand, are more solitary. Their bodies don’t go to the trouble of ovulating (releasing eggs) unless they are actually mating with a partner. Repeated mating induces ovulation (possibly triggered by the little barbs on a tom’s penis) so cats often mate several times within a short space of time. Queens only come into heat when days are long, and can go in and out of heat all summer. Kittens with different fathers can be born in the same litter.




A mother guinea pig pelvis does an interesting thing; the two halves split apart as a baby guinea pig is born and fuse again later. This is useful because guinea pig babies are relatively big when they are born – and already covered in hair, ready to face the world. Pregnancy lasts up to 73 days, compared with between 20 and 27 days in mice (which are born pink and bald).

Sows can become fertile from only two months old but need to mate while they are young because the pelvis loses it’s ability to split after about 8 months. Females becoming pregnant for the first time after that can face real difficulty.



Did you ever wonder about the origins of that crude term ‘to screw?’ Well, a pig’s penis will rotate, like a corkscrew, as it enters the sow (the same rotation method occurs when sows are fertilised with artificial insemination). The cervix has a complementary shape and it is possible that this minimises the potential for semen dripping out. To test whether a sow is receptive, a stockperson pushes down on female’s back end; she will either move away, or ‘stand.’ Mating is closely supervised to ensure that the boar’s long, thin penis (around 12 inches long) finds it’s target.




I thought I’d put these guys last, because rabbits have a certain reputation when it comes to mating. The Easter bunny may be an ancient symbol of spring and our own sexual culture is loaded with references, from the playboy bunny to phrases like ‘at it like rabbits.’

Indeed, rabbits are rapid breeders, coming into sexual maturity at around 4 months of age. The doe is pregnant for a little over a month and can conceive again as little as a day after giving birth. Does that are continually pregnant tend to decline in condition, however, so commercial breeders will leave a slightly longer gap.

If a doe doesn’t breed and isn’t neutered, she has a high chance (up to a 60%) of contracting uterine cancer. As a result of this, it is highly recommended that non-breeding does are neutered at a young age. In the past, this was associated with a high risk of anaesthetic death, but rabbit anaesthesia has improved dramatically over the years and thankfully does now live much longer.


Wishing you all a warm, fuzzy, romantic Valentine’s day.