Milk has always been regarded as a necessity for the healthy growth of teenagers, but the latest research in the United States has accused it. In this regard, Chinese and American experts have their own words. Accusation: Drinking milk makes girls precocious. With the rapid rise of milk in the food market, a new study by American health experts claims that milk is indeed the chief culprit of girls' precocity. 1997 or so, a major study found that girls' puberty appeared earlier than before, and many Americans began to doubt the artificial growth hormone widely used in dairy cows. In the natural state, a cow can produce 10 kg of fresh milk at most every day, but now the cows suffering in the pasture produce several times more milk every day than before. In order to improve the milk yield of dairy cows, cows were fed a bovine growth hormone. Are these hormones affecting girls' puberty? Through follow-up investigation, American experts have proved that many 9- 10-year-old girls who have the habit of drinking milk appear earlier, such as breast enhancement, but generally speaking, the adolescent characteristics of girls appear at10-1year. Bovine growth hormone will remain in milk after treatment. Therefore, it will affect the growing little girl and make her puberty advance. Therefore, experts suggest not to blindly drink milk to supplement calcium. Defense: Chinese and foreign milk quality is different. Does our intern reporter report that the milk that China people drink every day also contains hormones? Yesterday, the reporter interviewed Professor Li Shengli, doctoral supervisor of College of Animal Science and Technology of China Agricultural University. Li Shengli reassured reporters that China does not allow cattle breeders to use growth hormone, which is the same as the EU regulations. At present, only the United States and Canada regularly inject bovine growth hormone into cows and beef cattle to promote milk production and beef cattle gain weight. This practice began in the 1960s and 1970s. Domestic milk contains no hormones. Usually, cattle farmers in the United States and Canada use subcutaneous implantation behind their ears to increase the yield of dairy cows and beef cattle. Although they will take out the hormone sustained-release capsules buried under the ears of beef cattle/0/5 days before slaughter, Li Shengli said that after using growth hormone, there will definitely be hormone residues in milk, but the amount is different. If you drink the milk produced by these cows for a long time, it will really affect your health. Li Shengli said that China now mainly improves the milk yield of dairy cows and the weight of beef cattle through "prenatal and postnatal care" and feeding management. For example, select excellent populations for breeding; Feed cattle with high-quality forage such as alfalfa and silage (chopped and fermented with immature corncob and straw) to promote the genetic potential of cattle; Provide a clean and comfortable environment for cattle to grow up in a "happy mood"; Be careful about raising cattle to prevent illness. In this way, healthy cows will produce more milk and beef cattle will have more muscles. So, will farmers give cattle oral growth hormone? Concerned reporter Jing, deputy secretary-general of Beijing Dairy Association, said that cows have four stomachs, but only one is a real stomach, and the other three stomachs have no glands and cannot absorb any substances. If someone feeds auxin to cattle in pursuit of economic benefits, this hormone will be eroded by gastric acid when it reaches the abomasum of cattle and cannot be absorbed by small intestine at all. It is impossible for farmers to increase production by this method. Teenagers should not be "weaned" too early. At present, all countries in the world regard milk as the food that best meets the nutritional needs of human beings. According to a survey conducted by Beijing Municipal Health Bureau, at present, 0/2.3% of primary and middle school students in this city never drink milk, which has great influence on teenagers' bones and growth and development. Nutrition experts clamor that teenagers in the growth and development period should not be "weaned" too early. Generally speaking, infants under 1 year-old are advised to drink 600~800 ml of breast milk or formula milk every day; /kloc-children aged 0 to school age should drink at least 400 ml of milk every day; 1 1 to 17-year-olds should drink 250 ml of milk every day. "Every 100 ml of milk contains 120~ 125 mg of biological calcium which can be absorbed by human body, and the absorption rate reaches 97%~98%. If you eat some vegetables and fruits every day, the calcium needed by the human body will basically be met. " Jing Linbao said. The absorption rate of synthetic organic calcium, that is, various calcium tablets, is only 20%~30%. Li Shengli also said that the calcium in vegetables is definitely not as good as milk, because the proportion of calcium and phosphorus in milk is the closest to human body, and it is protein of animal origin, which is easily absorbed by human body. Jing believes that the precocity of American girls may be related to foreign fast food. Li Shengli said that even if you drink whole milk, the fat content of 20 cups of milk is not as good as that of a fried chicken leg. Therefore, milk will not make people fat, and eating high-calorie food often will lead to the accumulation of fat in the human body.