Generally in the animal kingdom, except in higher primates like apes, bamboos, etc., female animals have a particular period they allow a male to mate them. This period is known as ‘heat period’ or ‘oestrus period’. In simple words, heat or oestrus is the period a female animal is ready for ‘service’ (Service in animal husbandry means to mate and the act is called servicing).
This period is very important in animal husbandry and breeding. This is because, it is the period that reproductive physiology and endocrinology (hormone) of the female animal is ready for reproduction. The fact is; “no heat, no pregnancy.” There are many reproductive physiological processes occurring in a female animal’s body. During this period, the graafian follicles are ripe and the ovum (egg) is getting matured before it ruptures (ovulation). The heat period terminates with ovulation. Heat periods don’t last long in animals. Different animals have different oestrous length and different oestrus cycle.
When a female animal is on heat, there are some observable signs the animal will show. These signs are what a good farmer or breeder need to use to determine if it is time to introduce a male to his female animal. There are uncommon occasions where a female animal doesn’t show any sign of heat, but fortunately, the male animal will detect the readiness of the female. So, that is why it is good to have teaser males on your farm. A teaser male is a male that is sexually sensitive but cannot impregnate the female because it cannot release semen* (sperms*).
Signs of Heat in Farm Animals
Restlessness and Isolation: The animal becomes restless and she isolates from other animals.
Excitement: The animal shows sign of sexual excitement.
Reduced or loss of appetite: The reaction of the animal to feed is reduced or totally lost.
Increased body temperature: The animal develops unusual high body temperature.
Vaginal discharge: There would be mucus discharge from the animal vagina/vulva.
Mounting: An animal on heat will always mount or ride other animals as shown on the sketched diagram above.
Other signs include; frequent urination, swollen vulvaa, making of undue noise, and licking of other animals’ body.
A good farmer that meant business will watch out for the above signs. Serious breeders know the repercussion if their animals miss this period, especially when they have already prepared their breeding plan for the season.
There is no need to look out for these signs if the herd is on a free-range system or an extensive system of management, because the male and female animals have access to one another, and there is no restriction of copulation among them.
If a farmer has female animals that don’t show sign of estrus, he/she has to introduce teaser males to them to know when they are ready to be serviced. The above signs are very visible in animal species like cattle, goats, sheep, pigs, horses, camels, and donkeys.