Introduction to Breeding Methods and Technical Key Points for Velvet Deer

Physiological Characteristics of Velvet Deer: Sexual Maturity and Suitable Age for First Mating. Sexual maturity is reproductive physiological maturity, at which point deer can produce mature sperm and eggs and exhibit sexual behavior. The sexual maturity of velvet deer is related to factors such as breed, type, sex, genetic status, nutritional conditions and individual development. Sika deer reach it earlier than red deer, and females earlier than males. Within the same breed, deer with good nutritional status and rapid individual development reach sexual maturity earlier. General sexual maturity period: female sika deer at about 16 months of age; well-developed deer reach sexual maturity at 7 months of age; male deer at about 20 months of age; red deer at about 28 months of age, but some deer reach sexual maturity at 16 months of age.

The suitable age for first mating is 16 months for female sika deer and 40 months for male sika deer (third-antler stags); 28 months for female red deer and 40 months for male red deer (third-antler).

Estrus Patterns. Estrus Period: Velvet deer are seasonally estrous animals. In northern China (areas north of 40 degrees north latitude), the estrus season for velvet deer is from September to December, with some individuals continuing until February to March of the following year. The entire estrus and mating period may include 2 to 3 estrous cycles. However, the normal estrus period for sika deer is from September 15 to November 15, with the peak estrus period from September 25 to October 20; while the mating period for red deer can be about 10 days earlier, specifically from September 5 to November 10, with the peak period from September 15 to October 10. About 80% of velvet deer can conceive during the first estrous cycle.

Estrous Cycle: The interval between two consecutive ovulations is called the estrous cycle. For sika deer it is 12 to 16 days, and for red deer 16 to 20 days. The estrous cycle is also related to factors such as age, health status and external environment. Prime-aged, healthy deer have slightly shorter cycles, and vice versa.

Estrus Duration: The duration of each estrus. For sika deer it is generally 24 to 36 hours, with the peak estrus period occurring 11 to 24 hours after the onset of estrus; for red deer it is about 24 hours, with the peak estrus period occurring 6 to 7 hours after the onset of estrus.

Estrus Manifestations: These include three aspects: behavior, reproductive tract changes and ovarian changes. Male deer in estrus exhibit fighting, antler rubbing, lip curling, pawing the ground, thickening of the neck circumference, butting people or objects, long roaring, reduced appetite, and urine dribbling while the penis twitches. Female deer in early estrus exhibit excitement and restlessness, wandering, lip smacking, sometimes calling, willing to approach males but refusing mating; during peak estrus they stand still, raise the tail and arch the back, accept mounting, often show opening of the infraorbital glands, tail swishing and frequent urination, swelling of the vulva, discharge of egg-white-like mucus, low grunting, or rubbing the head against the male, assuming a mating posture to accept copulation; in late estrus, the female becomes calm, refuses mating, and the vulvar mucus changes from egg-white-like to orange-yellow, finally reddish-brown, and dries on the pubic hair.

Whether a deer is in estrus can be judged based on its behavior. In recent years, for red deer, the method of palpating the ovaries as done with cattle and horses has been used to determine estrus status; the teaser method can also be used to determine estrus in female deer, that is, using 1 male deer of the same breed, either surgically altering its penis or fitting it with a teaser cloth, and then placing it into the female deer herd. If a female deer stands still and accepts mounting, it indicates that she is close to ovulation. At this point, remove the teaser male and introduce the breeding male or perform artificial insemination, which can basically ensure conception.

Mating of Velvet Deer. Mating Preparation Work: First, breeding males should be selected based on antler production in previous years, breeding capacity and breeding direction. Males aged 3 to 7 antler cuts, energetic, with strong libido, good semen quality and high antler yield should be used as breeding males. Antler yield requirements: for sika deer, the fresh weight of standard third-branch antlers per unit should be above 3.5 kg; for red deer, above 5.5 kg (third branch) or 7.5 kg (fourth branch). From mid-July onward, feeding of breeding males should be intensified.

Breeding females should be weaned in mid-August and organized into mating groups according to age, body condition and breeding plan (15 to 18 sika deer per group, 10 to 12 red deer per group). Feeding of females should also be intensified. By the mating period they should reach upper-medium body condition, but should not be overly fat. Male and female deer pens should be reasonably arranged, and mating records should be prepared.

Mating Methods: The mating methods for velvet deer include the group-male group-female mating method, the single-male group-female mating method (which is further divided into the mate-throughout and mid-period replacement types), the teaser mating method, the timed pairing mating method and artificial insemination. However, the most commonly used method is the single-male group-female mate-throughout method. The specific method is: for sika deer on September 10, and for red deer around September 5, place 1 breeding male into the female herd. If the male has no special circumstances, it remains until the end of the mating period when it is separated out. However, if superior breeding males are few, the teaser mating method or timed pairing mating method can be used. That is, breeding males and teaser males are kept separately in small pens. At 4:00 to 6:00 every morning and 16:00 to 18:00 every evening, the teaser male or breeding male is placed into the female deer pen at fixed times to seek estrous deer, and then mating is carried out. After each session confirms that there are no estrous females, the male is driven back to the small pen, ending the teaser pairing. This method can maximize the breeding performance of superior males. Each breeding male can mate with about 35 females in one mating period. At the same time, the pedigree of offspring is clear, but the workload is somewhat greater.

Issues to Note in Velvet Deer Mating Work: When selecting mates for male and female deer, avoid inbreeding, and prevent mating between breeding males and females with the same trait defects. Young deer mating for the first time should also not be paired together. Breeding males removed during mid-period replacement should be kept separately; otherwise, because they carry the scent of estrous females, they are easily attacked by other males. At the end of the mating period, choose a clear day and remove the males before 8:00 in the morning, assigning a dedicated person to watch over them to prevent intense fighting among them that could cause losses.

Causes of Female Deer Infertility and Countermeasures. The causes of infertility are relatively complex, but can be broadly attributed to the following:

Congenital infertility. Mainly caused by poor development of the reproductive organs. Such deer should be culled as early as possible.

Nutritional infertility. Due to disease or poor feeding management, the female deer's body condition is too poor, causing embryos or even follicles to fail to develop normally, so conception cannot occur, or the embryonic vesicle disappears after conception. Such deer can be treated for disease and given intensified feeding to reach above-medium nutritional levels, and they are fully capable of reproducing. However, for certain deer with infectious diseases that seriously threaten the herd, they should be culled.

For infertility caused by inbreeding, advanced age of female deer, or an excessively large female herd, targeted measures can be taken to improve the reproductive survival rate of deer.

Pregnancy and Parturition of Velvet Deer. Pregnant female deer: After mating, if a female deer no longer comes into estrus, it can generally be considered that she has conceived. In addition, externally, conceived deer show increased appetite, increasingly better body condition, glossy coat, and become gentle in temperament, cautious and calm in movement. By March to April of the following year, those showing obvious abdominal enlargement before feeding are more than 90% pregnant. The length of gestation in velvet deer is related to factors such as the species of velvet deer, the sex and number of fetuses, feeding methods and nutritional levels. For sika deer, the average is 229±6 days: 231±5 days for male fawns, 228±6 days for female fawns, and 224±6 days for twins, about 5 days shorter than single births. The gestation period is basically the same for various types of red deer, such as 243±6 days for Northeast red deer and 244±7 days for Tianshan red deer, among which 245±4 days for male fawns and 241±5 days for female fawns.

Parturition: The fawning periods of sika deer and red deer are basically the same, generally from early May to early July, with the peak fawning period from May 25 to June 15. However, the fawning period is also related to factors such as the age of the deer, the region and feeding conditions. The formula for predicting the fawning date is mainly calculated based on the mating date and gestation days. Usually for sika deer, subtract 4 from the month and 13 from the day of mating; for red deer, subtract 4 from the month and add 1 to the day to calculate the fawning date.

Manifestations of Parturition: Before parturition, the udder enlarges. The time from the beginning of udder enlargement to parturition is generally 26±6 days. One to 2 days before parturition, the deer reduces food intake or fasts, paces in circles, seeks a birth site, and some deer call while pacing, show sunken flanks and frequent urination. At the time of parturition, egg-white-like mucus flows from the vulvar opening, the deer repeatedly lies down and stands up, then discharges a pale yellow water blister, and finally delivers the fetus. A few first-time mothers or deer with vicious habits, upon seeing the water blister, become extremely frightened and urgently circle or run. Most fawns are born with the head and both forelimbs emerging first; a small number are born with both hindlimbs and the rump emerging first, which is also a normal birth. Positions other than these two are abnormal and require assistance.

Normal duration of labor: 30 minutes to 2 hours for multiparous female deer, 3 to 4 hours for first-time mothers.

Precautions During the Fawning Period: The fawning pen must be clean. Before the fawning period arrives, it should be thoroughly disinfected and spread with clean bedding straw. Throughout the fawning period, the fawning pen should be disinfected once every 10 days.

During the fawning period, keep quiet and decline visitors.

During the fawning period, assign dedicated personnel for watching. If dystocia is found, handle it promptly; if deer with vicious habits are found, take timely measures. Also closely monitor various abnormal conditions of newborn fawns, and treat sick ones promptly.

During the fawning and lactation period, fawn protection rails should be installed in the pen.

Fawning records should be properly filled in.

Technical Measures to Improve the Reproductive Survival Rate of Velvet Deer. On the basis of proper selection of breeding males and females, mate selection work should be done well. Selection and mating are closely related; they are two consecutive links in the unified process of continuously improving the quality of the deer herd and the entire breed. When selecting, comprehensive evaluation must be based on the deer's appearance, constitution, production performance, breed origin and offspring quality; mating is consciously carried out according to people's needs to improve deer quality. Therefore, only by addressing both can the overall quality of the deer be improved.

Breeding females should have an optimal age structure. In the entire female herd, adult females should account for 77.3%, bred yearling females 10.5%, and female fawns 12.2%. Such a structure is favorable for the normal development of the herd; otherwise, age gaps and developmental imbalance will occur.

Breeding females should have a reasonable nutritional level. Overly fat deer are mostly barren due to abnormal follicle development, and thin deer also cannot come into estrus or ovulate normally. Therefore, breeding deer should be fed scientifically and reasonably.

Timely and reasonably cull breeding males, females and reserve bred yearlings. Any deer with very low productivity, not conforming to the breeding direction, or with vicious habits should be culled promptly; otherwise, it will affect the economic benefits and development of the deer industry.

Reasonably arrange the male-to-female ratio in mating groups. If the number of females is too large and exceeds the mating capacity of males, "missed estrus" will occur. This is especially true for red deer, which are large and heavy and cannot bear the burden of continuous mating. Therefore, a large number of females will result in a low conception rate.

For pregnant female deer, feeding management should be intensified, appropriate nutritional levels maintained, and pen changes should not be made lightly. Sudden disturbance, whipping and beating with sticks should be avoided.

All work during the fawning period should be done well to improve the survival rate of fawns.