Boer Goat Breeding Techniques Explained: A Practical Guide for Farmers

The age at which male and female Boer goat kids first come into estrus after birth is the puberty stage, commonly called sexual maturity, when they can produce mature reproductive cells (sperm or eggs) and have the ability to reproduce offspring, but they are not suitable for mating immediately. The puberty of female Boer goat kids is generally 6 to 8 months of age, with a body weight of 40% to 60% of that of an adult goat. Males show sexual behavior such as mounting and ejaculation at 4 months of age. However, because the reproductive organs of males and females are not yet fully developed when they first reach sexual maturity, mating too early is detrimental to the growth and development of both the goats themselves and their offspring. Therefore, the initial mating age for female Boer goats is generally over 10 months, and for males over 12 months.

Estrus

The puberty of Boer goats is generally 6 to 8 months of age, with a distinct breeding season. In spring and autumn, when temperatures are suitable and forage and feed are abundant, estrus is relatively concentrated, while estrus rarely occurs in summer. The estrous cycle is 19 to 24 days, averaging 21 days; estrus lasts 24 to 48 hours, and ovulation occurs 30 to 40 hours after the onset of estrus. Lactating does can come into estrus 7 to 10 days after weaning. The main signs of estrus in does include restlessness and agitation, bleating, constant tail wagging, frequent urination, mounting other does, reduced appetite, and the vulva becoming congested, swollen, flushed red, relaxed, and secreting mucus, sometimes with mucus flowing out of the vulva. Abnormal estrus is caused by malnutrition, improper feeding and management, or sudden changes in environmental conditions. The common types are as follows.

① Silent estrus: Due to insufficient estrogen secretion, there are no obvious signs of estrus, but the follicles on the ovaries mature and ovulate.

② Short estrus: The estrus period is very short, and the mating period is easily missed if one is not careful.

③ Interrupted estrus: The doe has a very long estrus period, with estrus occurring on and off, often seen in malnourished does in early spring.

Estrus Detection

In Boer goat breeding work, estrus detection is a very important step. The purpose of detection is to promptly identify does in estrus and correctly determine the time for mating or artificial insemination, so as to prevent missed or improper mating that would reduce the conception rate and kidding rate. There are mainly 3 methods for estrus detection in Boer goats.

① External observation method: This mainly involves observing the external behavior and mental state of the doe. When a Boer goat doe is in estrus, she shows obvious restlessness and agitation, reduced appetite, cessation of rumination, loud bleating, tail wagging, and congestion, swelling, and relaxation of the vulva, with a small amount of mucus discharge.

② Examination method: A vaginal speculum is used to examine the changes in the mucous membrane, secretions, and cervix to determine whether the doe is in estrus. During the examination, first restrain the doe properly and wash the vulva, then clean and disinfect the speculum and apply a lubricant. The examiner holds the speculum horizontally with the left hand, closes the front end, slowly inserts it through the vulvar opening, gently opens the front end, and uses a flashlight to examine the internal changes. When congestion, redness, a bright and moist surface, exudation of transparent mucus, and congestion, relaxation, opening of the cervix with mucus discharge are found, the doe can be confirmed to be in estrus. After the examination, close the speculum and gently withdraw it.

③ Teaser method: A teaser male goat is placed into the doe flock once a day or once each morning and evening at fixed times. The teasing location should be level and flat, making it easy to observe and drive out does in estrus. After the teaser male goat is placed into the doe flock, workers should not shout, and may appropriately drive the doe flock so that the does do not crowd together. When the teaser male goat is seen sniffing does with its nose or nudging them with its hooves, or even mounting on a doe's back, while the doe stands still or actively approaches the male, that doe is in estrus. At this point, the doe in estrus should be separated immediately for mating. The teasing time should preferably be about 1 hour.

Determination of Ovulation Time and Timely Mating

Boer goats mostly ovulate in the late estrus period. 90% of young does ovulate about 30 hours after the onset of estrus, and 75% to 85% of does that have kidded before ovulate about 40 hours after the onset of estrus. According to relevant data, the generally suitable mating time is 5 to 8 hours before the end of estrus, that is, mating can begin on average 30 to 35 hours after the onset of estrus, slightly earlier for young does and slightly later for does that have kidded before. In addition, according to the needs based on the estrus condition of the goat, for does with a long estrus duration, a repeat mating can be carried out at an interval of 5 to 10 hours.