Detailed Explanation of Key Techniques for Gestation and Parturition in Velvet Deer

1. Gestation When sperm enters the egg and combines to form a zygote, this is called fertilization; when the zygote implants in the uterus, it is gestation (pregnancy). After a doe becomes pregnant, estrus stops, metabolism becomes more active, appetite increases, digestive capacity improves, body weight increases, coat color becomes glossy, temperament becomes docile, and behavior becomes cautious, calm and steady. By March to April of the following year, when the doe is fasted, except for a few that are too obese, it can be observed that the left flank is not sunken or not obviously sunken, and more than 90% are pregnant.

2. Parturition The series of physiological changes through which the doe delivers the mature fetus from the uterus to the outside of the body is called parturition.

(1) Parturition season (fawning period) The normal fawning date is generally from May to early July, and the peak fawning period is from May 15 to June 15, during which at least more than 80% of pregnant does give birth. Red deer (Cervus elaphus) come into estrus and are mated 10-15 days earlier than sika deer (Cervus nippon), and their gestation period happens to be 10-15 days longer than that of sika deer, so their fawning dates are similar. For does to give birth, it is most advantageous for them to basically finish fawning in a concentrated manner in late May and early June. If the fawning period is delayed to July to early August, this is precisely the midsummer rainy season; once sanitation conditions are poor, because newborn fawns have weak resistance, the incidence of disease is high, affecting growth and development.

(2) Formula for estimating the expected birth date This is mainly calculated based on the mating date and the number of gestation days. For sika deer, subtract 4 from the month and subtract 13 from the day; for red deer, subtract 4 from the month and add 1 to the day (Northeast red deer), or add 2 to the day (Tianshan red deer). Using these simple formulas, the accuracy of estimating the expected birth date can reach about 90%.

(3) Signs of parturition in does The udder enlarges; the enlargement period for sika deer and red deer is generally 26 +/- 6 days, with some at around 15 days or 40 days. From 2-7 days before parturition, they like to eat concentrate residues and are reluctant to leave the feed trough, and from 2-1 days before parturition they eat little or fast. They like to stay around the pen, and a few does call while pacing. The flanks and rump sink. They frequently lick the rump, back and nipples, urinate frequently, and a clear egg-white-like mucus flows from the vulvar opening. They seek a birth site, repeatedly stand up and lie down, expel a pale yellow amniotic fluid sac, and

4 calmly tear it open; a few first-time does and does with vice habits become extremely frightened when the amniotic fluid sac is delivered, with hair standing erect, tear pits opening, eyes glaring, and urgently turning in circles to throw it off.

(4) Normal birth position and stages of labor Most does give birth normally in the head position, with the fetus's two forelimbs entering the birth canal first and appearing outside the vulvar opening, and the head resting on the carpal joints of the two forelimbs as it is delivered; some tail-position births are also normal. The normal stages of labor for does are 0.5-2.0 hours for does that have given birth before, 3-4 hours for first-time does, and 6-8 hours for normal tail-position birth.

(5) Monitoring of does during parturition Preparatory work before parturition: thoroughly clean and disinfect the fawning pen; set up a fawn protection railing on one side of the deer shed, and spread dry, clean bedding straw, etc., to create a quiet and comfortable habitat and living environment for the fawns; prepare cow milk, goat milk, or cow or goat colostrum (preferably colostrum); prepare various relevant equipment, drugs, instruments and items for assisting difficult births in deer and preventing and treating fawn diseases; prepare fawning record forms, etc.

Work during the fawning period: pay attention to watching over the does and fawns in the fawning pen, promptly ear-tag and weigh newborn fawns, and carefully fill in the fawning records (including the fawning serial number, fawning date, number of the doe that has given birth before, number of fawns born, fawn sex and ear tag number, birth weight, etc.). On rainy days or when fawning at night, or when dealing with does with vice habits, using the small-pen fawning method can increase the fawn survival rate; when there are insufficient fawning pens during the concentrated fawning period, if the weather is clear, docile does that have given birth before can be allowed to freely choose a location in the pen to give birth; when the fawning herd is very large, deer farms with the conditions can, according to the dates before and after parturition and the size of udder development, raise them in groups and have them give birth in batches, so that the fawns are roughly the same age and situations in which older fawns snatch milk do not occur, which is beneficial for synchronous development of the fawns. Does with difficult births should be assisted promptly; does with the vice habit of pawing and biting newborn fawns should be promptly removed, isolated for raising, or culled; when encountering abandoned fawns and weak, small fawns, a foster doe should be found to raise them, or artificial nursing should be carried out.

3. Gestation period is the period from the fertilized egg to the normal delivery of the fetus. The gestation period of sika deer is 229 +/- 6 days (pregnancy with a male fawn is on average 3 days longer than with a female fawn, and pregnancy with twins is about 5 days shorter than with a single fetus); the gestation period of Northeast red deer is 243 +/- 6 days; the gestation period of Tianshan red deer is 224 +/- 7 days. The gestation period of reindeer is 215-238 days, and the gestation period of sambar deer is about 250 days. Whether sika deer or red deer, the gestation period of artificially inseminated deer is shorter than that of naturally mated deer.