1, Niu
Cattle (Latin name: cattle) belong to Bovine, belonging to Bovine subfamily. Bison with chromosome number 56, cattle with chromosome number 60 and cattle with chromosome number 58 have fertile offspring, which are mammals, prone to robertsonian translocation (filament fusion) to change the chromosome number and reduce the reproductive rate. They are herbivores, and some species are domestic animals (including domestic cattle, cattle, buffalo and yak). The body is stout, and some bull heads have diagonal lines. Cattle can help human beings in agricultural production.
2. Growth and reproduction
The rate of singleton and twin in cattle generally only accounts for 1 ~ 2.3% of the total pregnancy. Except that yaks in alpine regions are in seasonal estrus due to perennial grazing and climate influence, cows kept in houses are generally in estrus for many times all the year round. The estrous cycle is basically similar, with an average of about 2 1 day and a gestation period of about 280 days. Four cattle breeds of the genus Bos can cross each other, and some of them (such as tumor cattle × common cattle) have reproductive ability. Some cattle breeds (such as yak × common cattle, bison × common cattle) can breed, but bulls can't have children. Buffalo species of the genus Buffalo can also cross with each other to produce offspring, but they cannot cross with any cattle species of the genus Bovine to get pregnant. According to these characteristics, creating new varieties or using them through interspecific hybridization has been widely valued by breeders. In the United States, Brahman beef cattle crossed with European beef cattle to cultivate beef cattle breeds suitable for tropical and subtropical climate conditions, such as Boluo, Borgos, St. Gertrudis, Beef King and so on. Australia bred heat-resistant and tick-resistant Australian cows by crossing red with Shahihua cattle. The United States also used American bison (3/8) and hereford cattle (1/4) and (3/8) to cross three breeds. After thousands of crossbreeding experiments, the obstacle of sterility of crossbred bulls was finally overcome, and a new beef breed "Bifaro" was bred, which has the advantages of fast weight gain, roughage tolerance, more meat production, good meat quality and low feeding cost. Canadian bison (1/2) and brahmin cattle (1/2), Charolais cattle (1/4), (116), Hereford cattle (1//. In China and Russian, ordinary cattle and yaks cross, and their interspecific hybrid, the first generation yak, not only has a larger body size and stronger labor force, but also greatly improves its milk production performance.
3. How to raise cattle
Adding additive "scientific cattle raising, technology requires meat" is an important way to develop beef cattle industry and improve the efficiency of cattle raising. At present, the technology of planting weighting agent is widely used, which increases the yield of beef cattle and improves the feed reward. Fattening bulls at home can be planted at any time, and the effect of castration is the best, and the cows are not buried with medicine. For cattle with long feeding cycle, it can be repeatedly planted every 100 days/time, and the fattening effect is better.
Intensive Feeding and Fine Management During the transition period of feeding ammoniated forage, 30 mg albendazole per kg body weight can still strengthen the stomach after taking it. Grazing in the grass season for 1-2 months in the fattening stage, no less than 1 month in the later stage, and fattening time with high-concentrate diet is 60-90 days. When mixing materials, it is required to wet the materials 1 hour, and then mix them evenly with grass. In addition, water must be fed twice a day. Cowshed should be dehumidified and padded frequently to keep it dry and clean.
Hybrid cattle bred by hybrid cattle combine the excellent characters of different breeds, have obvious heterosis, and can produce a large number of high-quality beef in a short time. If there is no crossbred cattle, you can choose local castrated cattle of 3-8 years old, weighing 250 kg, medium fat, healthy and disease-free for short-term fattening.
Feeding ammoniated grass Feeding cattle with ammoniated grass can improve nutrient conversion rate, enhance palatability and reduce production cost. Ammoniated grass can be made according to the ratio of 100 kg grass, 3 kg urea and 40 kg water, and sealed in an ammoniated room. The ammoniated straw should be transferred to the open field on sunny days, and the stack should be continuously turned over to release ammonia gas, and then piled indoors for later use after it has no ammonia smell. Feeding ammoniated grass requires a transition period of 7- 10 days, and the normal intake of cattle generally accounts for 2% of body weight. Feed it three times a day on the principle of eating well and not wasting. Grazing during the day in the grass season and mixing silage in winter and spring.
The reference formula of supplementary feed mixture is: corn 60%, vegetable cake or cotton cake 37%, starch 2%, salt 1%, and soybean meal can be used when there is no cake to reduce the feeding cost. Feed is fed regularly according to 1% of body weight and supplemented twice a day. ? Besides keeping cold and cleaning, three measures should be taken. First, when the weather is fine, go to the grassland or hillside or forest to graze, so that cattle and sheep can choose to eat some excellent grass leaves. In particular, Sophora japonica leaves contain more lysine, which is very beneficial to the health of cattle and sheep. Second, when the weather is cold and the snow on the ground is thick, we should feed cattle and sheep, and choose some excellent hay, silage is better. In addition, you should often feed some tuber juicy feed, such as carrots and pumpkins. The third is to change single concentrate into compound feed. In the cold season, farmers and professional households often use corn or bran as concentrate to supplement cattle and sheep, and the feeding effect is poor. Supplementing some compound feed often doubles the effect. Its formula is: corn 10%, wax gourd 10%, sorghum 8%, oil cake (bean cake, cottonseed cake, peanut cake, etc. ) 10%, bran 60%, bone meal 1.5%, salt 0.5%. The preparation method: pulverizing the above feed, adding water, stirring to make it adhere, and then drying in the sun to form irregular and weak granular compound feed. This kind of feed is crisp and palatable, especially popular with cattle and sheep.
reference data
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