Detailed Explanation of Key Technical Points and Management Methods for Meat Sheep Raising

Meat sheep have physiological characteristics such as early sexual maturity, estrus in all four seasons, high lambing frequency, and giving birth to more than two lambs per litter. Therefore, meat sheep have a short raising period and fast turnover, and can fully utilize seasonal forage resources, achieving lambing in the same year, fattening in the same year, slaughtering in the same year, and benefiting in the same year. Moreover, meat sheep production requires low investment in pens and housing, has low feeding costs, and good economic returns, making them suitable herbivorous livestock for the vast number of farmers to raise.
　　
I. Main Breeds of Meat Sheep
The Boer goat originated in the subtropical regions of South Africa and was introduced to China in 1995. This goat has the characteristics of large body size, early maturity, fast growth, high reproductive rate, high meat yield, and strong disease resistance. Adult rams weigh 95-105 kg, and ewes weigh 65-75 kg. At 9 months of age, body weight is 50-75 kg; at 3 and 5 months of age, body weight is 19-36.5 kg; dressing percentage is 52.4%, and carcass quality is good. Estrus is obvious in spring and autumn, lambing rate is 150%-190%, with an average of more than 2.25 lambs per litter, and the reproductive survival rate is 123%-184%.
The Nanjiang Yellow goat is produced in Nanjiang County, Sichuan Province. It has the characteristics of large build, fast growth and development, estrus in all four seasons, strong reproductive capacity, good lactation ability, strong disease resistance, good feed intake, tolerance to roughage, strong adaptability, high productivity, and good hide quality. Adult rams weigh 57.3-58.5 kg, and ewes weigh 38.25-45.1 kg. The average body weight at 10 months of age is 27.53 kg, which is the optimal time for slaughter. Sexual maturity is early, with first estrus at 3 months of age. Rams are mated at 12-18 months of age, and ewes at 6-8 months of age. The average lambing rate is 194.62%, and the lambing rate of multiparous ewes is 205.2%.
The Hu sheep is mainly produced in the Taihu Lake basin region. It has the characteristics of strong reproductive capacity, early sexual maturity, estrus in all four seasons, and rapid early development. Adult rams weigh 52 kg, and ewes weigh 39 kg. The average number of lambs per litter is more than 2, and the lambing rate is above 245%.
The White goat is produced in the Jiangsu, Zhejiang, and Shanghai regions. It has a medium to small build and is entirely white. Adult rams weigh 28.6 kg, and ewes weigh 18.4 kg. Most ewes produce 3 litters in two years, with 2-3 lambs per litter for the second litter and beyond, sometimes 4-5, and the lambing rate is 228.37%.
　　
II. Feeding and Management of Meat Sheep
(I) Feeding and management of rams. The general requirement is to ensure that rams are in upper-middle body condition, robust and lively year-round, energetic, and have strong libido. The pen should be well-ventilated, dry, and facing the sun. Feed should have high nutritional value, with sufficient high-quality protein, vitamins A and D, and minerals. From 1-1.5 months before mating, increase concentrate feed, supplying 60%-70% of the daily amount for the mating period, and gradually increase to the full daily amount for the mating period. That is, 1 kg concentrate, 2 kg high-quality hay, 0.5 kg carrots, 15-20 g salt, and 5-10 g bone meal. Feed in 2-3 portions per day. Breeding rams with large body weight, good semen quality, and heavy mating tasks should be additionally fed milk and eggs. During the non-mating period, provide 500 g concentrate, 3 kg hay, 0.5 kg carrots, and 5-10 g salt per day. To ensure semen quality and sperm vitality of rams, in addition to ensuring nutritional supply, exercise for rams should also be strengthened.
(II) Feeding and management of ewes
The amount of feed required for non-pregnant ewes and ewes in late lactation is 2.4%-2.6% of body weight. Work on restoring body condition and strive for mating at full body condition. The gestation period of ewes is 150 days. During the first 3 months of gestation, fetal development is relatively slow, and nutrition is the same as during the non-pregnant period, with appropriate supplemental concentrate and forage in the evening. During the last two months of gestation, fetal development is rapid, heat energy metabolism increases by 15%-20%, phosphorus and calcium should be increased by 40%-50%, with a calcium-to-phosphorus ratio of 2:1. Graze nearby 7-8 days before lambing to prevent squeezing and eating spoiled forage or feed.
The lactation period of ewes is 120 days. During the first 2 months, lamb nutrition depends on breast milk. To ensure lamb growth and development, sufficient forage and feed must be supplied to lactating ewes. For every 100 g of lamb weight gain, 500 g of breast milk is needed, requiring 0.3 kg of air-dried feed, namely 33 g protein, 1.2 g phosphorus, and 1.8 g calcium. Ewes with twin lambs should be supplemented daily with 0.4-5 kg concentrate, 1 kg high-quality hay, and 1.5 kg succulent feed; ewes with single lambs should be given 0.3-0.5 kg concentrate, 0.5 kg high-quality hay, and 1.5 kg succulent feed.
In late lactation, ewe milk production decreases, and lambs are already able to consume mixed concentrate and green grass, so supplemental feeding can be gradually reduced until stopped.
(III) Feeding and management of lambs during the suckling and fattening periods
1. Newborn lambs should receive colostrum promptly. Within one month, they mainly rely on breast milk, with feeding as a supplement. Start feeding early, train them to eat grass and feed, promote stomach development, and increase nutrient sources. After two months of age, transition to mainly eating feed, with suckling as a supplement. Provide appropriate exercise, separate ewes and lambs into groups, improve body condition, and deworm.
After weaning, lambs gaining more than 150 g per day should be supplied with 0.7-1 kg of air-dried feed. In winter when green grass is scarce, more supplementary feed such as hay and silage should be added to ensure nutritional needs for growth and development.
2. Meat sheep fattening includes fattening of culled sheep and lambs. After weaning, separate male and female lambs into groups by size and strength. Select excellent female lambs as replacement ewes, and the rest are grouped as fattening sheep. Fully utilize the characteristics of fast growth and high feed conversion efficiency of lambs from 3-6 months after weaning, carry out confined feeding, and supply sufficient and comprehensive nutrients to achieve good fattening results. That is, the body weight of meat sheep at 3 days of age can reach 50% of that of yearling sheep, and at 6 months of age can reach 75%. Feed conversion efficiency decreases with increasing age. The feed required by lambs at 1, 2, and 3 months of age is 1.8 kg, 4 kg, and 5 kg respectively, and digestible protein is 225 g, 450 g, and 600 g respectively. In addition, supply sufficient high-quality forage. Fattening of culled sheep has slow weight gain and usually requires 75-100 days; too long or too short a period results in poor fattening results. The total diet requirement for fattening sheep is 60%-70% roughage (dry) and 30%-40% concentrate. To improve fattening results, compound feed additives are commonly used. These include trace elements (iron, copper, manganese, zinc, selenium), rumen metabolism regulators, growth promoters, and harmful microorganism inhibitors. They can increase weight gain rate and feed conversion rate by 23.1% and 18.7% respectively. That is, feed each sheep 2.5-3.3 g of additives mixed evenly with concentrate daily. Monensin sodium (also called rumensin) can also be used, which can increase daily weight gain by 35% and feed conversion rate by 27%. The method is to add 25-30 mg per kg of daily ration, mix evenly and feed; the initial amount can be less and gradually increased later.
　　
III. Reproduction of Meat Sheep
(I) Sexual maturity and initial mating age of sheep
Under normal feeding conditions, about 70% of meat-type rams reach sexual maturity, and the initial mating age is around 12 months. The timing of lambing is arranged according to production needs.
(II) Estrus of meat sheep. When lambs grow and develop to a certain age, ewes exhibit a series of sexual behaviors, namely estrus, and ovulate at a certain time. From the beginning of one estrus to the beginning of the next estrus is one estrous cycle, which is 18-23 days for meat sheep, averaging 20 days. From the beginning to the end of estrus in ewes, goats last 24-48 hours.
(III) Estrus detection is carried out by combining teasing and external observation. For teasing, 1 teaser ram (with a marking harness) can test 40 breeding ewes, conducted once in the morning and once in the evening in the sheep pen. Ewes in estrus appear excited and restless, continuously bleat, strongly wag their tails, have reddened and swollen vulva, may mount other ewes, and accept mounting by rams. In production, if there are many breeding ewes, hormone treatment can be used to synchronize estrus, mating, lambing, and lamb rearing, achieving centralized management and improved efficiency. There are 3 methods. One of them is when 5% of the ewe flock shows estrus, inject 1 mL of "triple hormone" (ITC) into the head and neck of non-estrous ewes; estrus begins within 24 hours and lasts until the 5th day. The most ewes are in estrus on the second and third days.
(IV) There are two methods of mating ewes: one is natural mating. The other is artificial insemination. Under normal circumstances, we all use artificial insemination. This is an advanced and scientific breeding method with five advantages: first, it improves the utilization rate of excellent breeding rams. Second, it reduces the number of breeding rams kept, saves grass and feed, and lowers feeding costs. Third, it improves the conception rate of ewes. Fourth, it prevents infectious diseases. Fifth, it extends and expands the useful life and supply range of semen from excellent breeding rams. In meat sheep production, economic crossbreeding (crossing two or more breeds) is commonly used to produce meat sheep with more lambs, fast growth, high meat yield, good meat quality, high feed conversion efficiency, and good economic returns. When selecting breeding stock, emphasis should be placed on selecting breeds with more lambs, strong vitality, fast growth, large body size, and high feed conversion efficiency as breeding sheep. It is very important to master the timing of estrus and ovulation in ewes for timely mating. Under normal conditions, ewes ovulate 24-36 hours after estrus, and most estrous ewes ovulate between 12-24 hours after estrus. In production, for ewes in estrus in the morning, the first insemination is performed at 4-5 PM, and the second supplementary mating is performed the next morning. For ewes in estrus in the afternoon, the first mating is performed at 8-9 AM the next day, and the second mating is performed in the afternoon.
(V) Pregnancy. The fertilized egg formed by the union of ram sperm and ewe egg develops in the ewe's reproductive tract for 146-161 days, averaging 152 days, before being delivered. There are four methods to confirm pregnancy in ewes: first, external examination. Mainly observe that the ewe stops cyclic estrus, has increased appetite, glossy and shiny coat, and gentle temperament. After 3 months of pregnancy, the right side of the abdomen protrudes more than the left, and the udder enlarges. Second, rectal examination. Third, vaginal examination. After 3 weeks of pregnancy, when a vaginal speculum opens the vagina, the mucosa is white and turns pink after a few seconds. Fourth, progesterone content determination. At 20-25 days after mating, pregnancy can be confirmed when the progesterone content in pregnant ewe milk is greater than or equal to 8.3 ng/mL or plasma progesterone is greater than or equal to 3 ng/mL.
(VI) Parturition, lamb delivery, and postpartum care of ewes and lambs
At about 150 days of pregnancy, the ewe's udder swells and enlarges, teats become firm, and a small amount of yellow milk can be squeezed out by hand; vaginal mucus flows out and changes from thick to thin; the ewe stands restlessly and frequently bleats. At this time, leave the ewe in a lambing pen spread with dry straw. After 5-6 hours, multiparous ewes will smoothly deliver the lamb, and after another 0.5-2 hours the placenta will be expelled. First-time ewes and those with overly large fetuses require manual assistance during lambing. After the lamb is born, wipe off the mucus from the mouth and nose, and let the ewe lick the lamb dry. Cut the umbilical cord, squeeze out the blood in the umbilical cord, and disinfect with iodine. If false death occurs, hold the lamb's front and hind limbs separately with both hands, slowly move the chest, or perform artificial blowing. After lambing, feed the ewe warm salt water mixed with wheat bran. The placenta is expelled after 2-3 hours and should be removed to prevent the ewe from eating it. Train the ewe to nurse the lamb. From 1-3 days after lambing, provide supplemental feeding to the ewe, 0.25-0.5 g per day per sheep; of which corn is 35%, wheat grain 47%, soybean cake 15%, salt 0.5%, and mineral premix 2.5%. Gradually increase concentrate and succulent feed over time. Within 1 hour after birth, the lamb must receive colostrum from the ewe; lambs unable to suckle should be assisted manually, which is an important measure to ensure lamb survival. After 10 days, train lambs to eat, first feeding tender green grass; after 30 days of age, supplement 50-100 g/day of concentrate per lamb; after 60 days, each lamb should consume 100-150 g/day of concentrate. Within 30 days after birth, castrate male lambs. Wean at 42-84 days of age and raise in separate groups.
　　
IV. Construction of Sheep Housing
Sheep housing should be built on higher terrain, well-ventilated and facing the sun, not too close to roads, and in a place convenient for water use and management. Sheep housing should be designed to prevent heat and lower temperature in summer, and prevent cold and keep warm in winter. Pens mostly adopt a "straight-line" shape, which has good lighting, small temperature differences, and is economical and practical. Single-slope or small-span sheep housing has good natural lighting and is suitable for small sheep farms or farming households. Sheep housing area: 1-2 sq m per lambing ewe, 2-2.5 sq m per breeding ram, 0.7-1 sq m per young ram, 0.7-0.8 sq m per young ewe, 0.2-0.3 sq m per weaned lamb, and 0.6-0.8 sq m per fattening lamb. The area of the exercise yard for sheep housing is calculated at 25% of that for lambing ewes. The floor should have a slope of 1%-1.5%, not accumulate water, facilitate drainage, be easy to clean, and convenient for disinfection. Simple sheep housing can be built according to local conditions. The main facilities of a sheep farm include: forage racks, feed troughs, neck racks, movable ewe-and-lamb pens, movable lamb supplemental feeding pens, grouping pens, medicated bath pools, sheep cages, and scales.
V. Disease Prevention and Control of Meat Sheep
1. The main measure for preventing epidemic diseases is to strengthen feeding management and enhance the disease resistance of sheep. Establish and improve veterinary health and epidemic prevention systems. Do a good job in sanitation management of the environment, sheep housing, exercise yards, feed, drinking water, and utensils. Strictly implement the quarantine system, earnestly implement immunization plans, regularly carry out epidemic prevention injections, and do well in deworming and spring and autumn medicated baths.
2. For the prevention and control of infectious diseases, the main approach is timely detection, diagnosis of Class I, II, and III sheep infectious diseases stipulated by the state, and reporting to higher authorities as soon as possible, rapidly blocking and isolating, disinfecting contaminated items, using vaccines (bacteria) and antisera for emergency vaccination, and providing timely and reasonable treatment for sick sheep; dead or culled sheep are handled according to regulations.
3. For the prevention and control of parasites, the main approach is to control and eliminate sources of infection, cut off transmission routes, and protect susceptible sheep.