Breeding techniques of Boer Goat

Boer goat male and female lambs have their first estrus at the age of proestrus, which is usually called sexual maturation, and can produce mature germ cells (sperm or eggs). It has the ability to reproduce, but is not suitable for immediate breeding. The first estrus of Boer goat female lambs is usually from 6 months to 8 months old, and the body weight is 40% to 60% of that of adult sheep. Rams have sex at the age of 4 months, such as climbing and ejaculation. However, because the reproductive organs of rams and ewes are not fully mature when they have just reached sexual maturity, early mating is disadvantageous to the growth and development of sheep and their offspring. Therefore, the first mating age of Boer goats is generally more than 10 months old, and the first mating age of rams is more than 12 months old.

Estrus

The proestrus of Boer goats is generally from 6 months to 8 months old, and the estrus season is obvious. In the season when the temperature is suitable in spring and autumn and the forage is sufficient, estrus is relatively concentrated and seldom in summer. The estrous cycle ranged from 19 days to 24 days, with an average of 21 days, the duration of estrus was 24 hours to 48 hours, and ovulation was 30 hours to 40 hours. Lactating ewes can be in estrus 7 ~ 10 days after weaning. Ewes are mainly characterized by excitement, singing, constantly wagging their tails, frequent urination, crawling across other ewes, loss of appetite, swelling and swelling of the vulva, flabby and secretion of mucus, and sometimes mucus outflow from the vulva. Abnormal estrus is caused by malnutrition, improper feeding management or sudden change of environmental conditions. There are the following common ones.

① quiet estrus: due to insufficient secretion of estrogen, lack of obvious estrus performance during estrus, but the follicles on the ovary mature and ovulate.

② short estrus: estrus is very short, if you don't pay attention to it, you will miss the mating period.

③ intermittent estrus: ewe has a long period of estrus, and estrus is intermittent, which often occurs in malnourished ewes in early spring.

Estrus identification

Estrus identification is a very important link in the breeding of Boer goats. The purpose of identification is to find ewes in time and correctly grasp the time of mating or artificial insemination so as to prevent mismatch and mismatch and reduce the conception rate and lambing rate. There are three main methods for estrus identification of Boer goats.

① external observation: mainly observe the external performance and mental state of ewes. Boer goats showed obvious excitement during estrus, loss of appetite, cessation of rumination, loud singing, tail shaking, vulvar congestion, swelling, relaxation, and excretion of a small amount of mucus.

② examination: estrus was judged by examining the changes of mucous membrane, secretion and cervical orifice. During the inspection, first keep the ewe well, wash the vulva, then clean and disinfect the opener, apply lubricant, the inspector holds the opener horizontally in his left hand, close the front end, slowly insert it from the vulva door, gently open the front end, and check the internal changes with a flashlight. When it is found that the mucous membrane is congested, red, the surface is bright and moist, there is transparent mucus exudation and cervical congestion, relaxation, opening, and mucus outflow, it can be defined as estrus. After the inspection, close the opener and pull it out gently.

③ trial method: once a day or once in the morning and evening, put the test ram into the ewe flock at regular intervals. The location of the trial should be flat, so that it is easy to observe and drive the ewes. When the trial ram is put into the ewe flock, the staff should not shout, but can drive the ewe herd properly so that the ewe is not crowded together. When it is found that the ewe sniff the ewe with its nose or tease the ewe with its hoof, or even climb onto the ewe's back, while the ewe stands still or takes the initiative to approach the ram, such an ewe is an ewe. At this point, ewes in estrus should be separated immediately for breeding. The suitable time for trial is about 1 hour.

Determination of ovulation time and timely mating

Boer goats ovulate mostly in late estrus, 90% of young ewes ovulate about 30 hours after the beginning of estrus, and 75% or 85% of pregnant ewes ovulate about 40 hours after the beginning of estrus. According to the relevant data, the general suitable time for mating can begin 5 ~ 8 hours before the end of estrus, that is, 30 ~ 35 hours after the beginning of estrus, young sheep slightly earlier, and menstrual sheep slightly delayed. In addition, according to the needs of sheep estrus, sheep with a long duration of estrus can be rematched once at intervals of 5 to 10 hours.