Final answer:
Cows and sows are both polyestrous, having multiple estrous cycles throughout the year, which allows them to mate and potentially conceive multiple times annually.
Step-by-step explanation:
The cow (typically a breed of cattle like the Holstein) and the sow (a female pig) both exhibit a type of estrous cycle known as polyestrous. This means they have multiple estrous cycles throughout the year. The polyestrous cycle is characterized by having a series of recurring periods of sexual receptivity ('heat') during which the animals can conceive. This is in contrast to animals that are monestrous (having one estrous cycle per year), diestrous (having two estrous cycles per year), or seasonally polyestrous (having multiple estrous cycles only during certain seasons of the year). Cattle and pigs do not restrict their reproductive behavior to one period of the year, unlike species that follow a seasonal estrus cycle, such as the pronghorn antelope which mates only during certain seasons.