Animal Reproduction

Breeding livestock is a complicated process, and should be managed as efficiently as possible. This involves knowing the key rates and statistics for a particular herd, including conception rate, pregnancy rate, days open, days to first service, heat detection rate, and more. Using specially-designed reproductive software can help herd managers keep track of all their data and generate reports. Keeping records allows farmers to set expectations for herd performance.

Heat Detection

When female animals mature, the farmer will need to accurately detect when they are in heat (also known as estrus) so that they can be bred. The heat cycle for non-human mammals includes four stages (proestrus, estrus, metestrous, diestrus) and varies depending on the species. For example, the average heat cycle in ewes is 17 days.

There are several methods for heat detection, including record systems, heat detector animals, prostaglandin injections, and mount detection aids. One of the most accurate methods for cows is watching an animal to see when she is standing to be mounted, but it is often impractical for busy farmers. Secondary signs of estrus in cows include mucus discharge, restlessness, trailing of other cows, decreased feed intake, and metestrous bleeding.

Insemination

Once estrus is accurately detected, the herd manager should know the optimal time to inseminate the animal. For cows, there is normally a gap of several hours between the end of standing heat and ovulation. The cow should be inseminated towards the end of standing heat. This is because the fertile life of an egg is shorter than the life of sperm within the female reproductive tract, so conception is more likely if the sperm is awaiting the ovulating egg. A general guideline is to breed animals 10 to 12 hours after heat is detected.

Pregnancy

Animals used for breeding, especially pregnant animals, will have much higher performance on a nutrient-rich diet. Protein and energy levels in the ration need to be finely balanced to keep animals at optimal weight and health during pregnancy. Ensuring the animal also receives essential vitamins and minerals will increase the chances of healthy and viable calves, piglets, lambs, and kids.

Calving and Lambing

A farmer can tell that an animal is entering labor when the water bag begins to be pushed through the birth canal. The animal will usually become restless and try to separate from the herd. After this stage the animal is ready to give birth, which may occur up to a few hours after the expulsion of the water bag. For both cows and ewes, an uncomplicated birth will mean that the calf or lamb is positioned in “normal presentation,” with the head between the front legs. The farmer should carefully observe the birthing process but only interfere if necessary.