As night fell, Xu Ping sat in the study and carefully watched what Tao Liu had written down after he dictated. The pen "Fun" Pavilion www.biquge.info on the other side of the table, and Pan Panban stood on the chair, struggling to hold a brush and lie on the table to practice calligraphy.

The technique of artificial insemination is not particularly difficult, the most important thing is the preservation of semen after extraction from the stallion. In Xu Ping's previous life, the method of freezing was widely used, and low temperature could be stored for a long time. In this era, it is naturally impossible, and the method of room temperature preservation can only be used, and the most reliable is to use a container to directly store it in the animal's body, and the sperm can maintain the vitality for one or two days.

In the past, relying on natural breeding, Xu Ping's Grange tried all kinds of methods, and a stallion could only match eleven or twelve mares to form a small breeding population, and no matter how much, the effect would drop sharply.

Good males and females are very expensive and hard to come by. With the method of natural reproduction, the probability of giving birth to a good breed of offspring is not high, coupled with the death of cubs, it is quite difficult to breed a good horse breed. Nowadays, there is no wild horse herd in the Great Song Dynasty, and excellent stallions can only be imported from Dangxiang and Khitan, which is difficult to breed, coupled with the degradation of breeds, not to mention horses that can be used as military horses, even horses that can be used for service are also very scarce.

The horse ranches of the Han and Tang dynasties were all in the northwest, and the current horse supervisors were mostly in Hebei in the Central Plains. The Central Plains is not unable to raise horses, the climate and aquatic plants can meet the growth and reproduction of horses, and the most lacking is the introduction of excellent stallions. If the breed is not carefully bred in captive breeding, the breed will degrade very quickly, and the import of high-quality stallions in the grassland area is very fatal.

Once artificial insemination is adopted, a stallion can impregnate hundreds or thousands of mares at a time, and the demand for high-quality stallions drops suddenly. Combined with optimal breeding, a high-quality population can be maintained with a small number of good horses, and second-class good stallions are also freed up and can be directly used for riding and service.

This is the only way Xu Ping can come up with to save Ma Zheng in the Central Plains, otherwise, no matter how much manpower and material resources are invested, it will not be able to solve the fundamental problem. The Central Plains can raise horses, but it cannot keep the population from degrading, and only with a high reproduction rate and high elimination rate can it compete with tens of millions of horses on the grassland.

This is science, an objective discipline, and it is not subject to the subjective will of man. If you don't use scientific methods, you will be forcing the officials of the herd department to death, and they will not be able to raise enough good horses.

Pan Pan wrote for a while, felt tired, put down the brush, supported his cheeks with his hand, looked at Xu Ping, who was sitting opposite, and asked in a low voice, "Daddy, what are you looking at?" If you work so hard, you won't come to teach me how to write. ”

Xu Ping raised his head, looked at Panpan a little embarrassed, and said, "This is an adult's business, you children don't have so much heart." It's enough to have a mother teach you to write, how many big things does Daddy have to do! ”

Panpan pretended to sigh: "Mom is going to give birth to Panpan's younger siblings, and she has no time to accompany me!" ”

Lin Suniang was pregnant during the Chinese New Year, and now she has a big belly, she doesn't care about herself, but Zhang Sanniang is watching closely and doesn't let her do anything at all. Even if she is panpan, she can't pester her mother to play, but grandma will talk about her.

Xu Ping is helpless about this kind of thing, there is no man at home to take care of the child these years, and he will not take it, so he had to say to Panpan: "When you have younger brothers and sisters, someone will play with you, are you not happy?" ”

Pan Pan shook his head: "The child is the most annoying, Weng Weng told me that when I didn't remember before, I didn't know how many treasures he broke!" When I have a younger sibling, I'm going to be annoyed by him. ”

This child has been used to talking to the family up and down since he was a child, and Xu Ping had no choice but to say to him: "Don't think like this, when you were a child, you took your younger brothers and sisters, and when they grow up, they will listen to you, what a good thing!" ”

Pan Pan shook his head again and again, with a sad face.

After a while, Panpan suddenly opened his mouth and said, "Daddy, come and take a look, I lost a tooth yesterday and bleed, it's so scary!" Weng Weng said that my teeth will fall out in this mouthful, how can I eat in the future! ”

"If you fall out, it will naturally grow, and the new teeth will be harder, and you can't bite anything! Now a mouthful of milk teeth is useless if it doesn't fall out! ”

Xu Ping said in his mouth, put the paper in his hand on the table, and got up to look at Panpan's mouth. A tooth was missing, and it looked a little ugly.

Pan Pan tilted his head and opened his mouth, asking Xu Ping to look carefully, for fear that he would not understand.

Xu Ping looked at it and asked Panpan: "Does it still hurt now?" Toothache can be very uncomfortable. ”

"It doesn't hurt anymore! In fact, it didn't hurt when I fell off, but it fell down all of a sudden, and it bleed, which scared me! ”

Xu Ping touched his daughter's head: "Children will lose their teeth, and if they fall out, they will grow new ones." When you're done with your teeth, you'll be a big kid. Don't be afraid, this tooth loss is nothing, everyone will come to this once. ”

Pan Pan nodded again and again: "It doesn't hurt, what am I afraid of!" ”

After speaking, he leaned back on the table, looked at Xu Ping and said, "Daddy, did you lose your teeth when you were a child?" ”

"Of course it has been dropped, everyone will change it once, your current baby tooth is called a new one, and it will all fall off and replace it with a new one."

Pan Pan nodded and said to Xu Ping seriously: "Daddy, now that you have grown up, will you still lose your teeth?" ”

"No, it usually won't fall off again. When Daddy's teeth are also removed, he will be seventy or eighty, and he will have to rely on Panpan to raise him. ”

"Daddy, are you going to have new teeth now?"

Hearing this, Xu Ping only felt a little bitter in his mouth, and nodded to Panpan: "Yes, when people grow up, they will grow a few more teeth, and the last one is called the end tooth." Panpan, Daddy is growing this tooth now. ”

"I'll see, I'll see!" When Panpan heard this, she suddenly became excited, got down from the chair opposite, and jumped all the way to Xu Ping's side, stretching her neck to see the way Xu Ping had teeth in his mouth.

Xu Ping took Panpan's hand and said to her: "The teeth that grow up when you grow up, well, they are also called wisdom teeth." Ordinary people grow it out unconsciously, but Daddy doesn't know what's going on, this tooth is a little crooked, and now it hurts when you touch it. ”

"Teething hurts, it's amazing, I've never heard anyone say it!"

Xu Ping looked at his daughter with a curious look, only to feel helpless. People in this era don't call these teeth that grow after adulthood wisdom teeth, and they don't pay attention to them, but they will grow naturally anyway. But I don't know what's going on, Xu Ping's last wisdom tooth is not very straight, and I feel it recently, and I often have a faint pain.

Wisdom teeth were common in his previous life, and I don't know how many people have their wisdom teeth removed every year. But in this era, it is not normal, the human body is actually evolving all the time, and people have not evolved to the extent that wisdom teeth have no place to grow in this year. Xu Ping also asked others, I have never heard of toothache when growing teeth in adulthood, only insect tooth decay will hurt, how can teething hurt?

Xu Ping brushed his teeth in the morning and evening, maintaining the habits of his previous life, and his oral hygiene was better than that of most people this year. Even if you don't usually use a sachet in your mouth, there is no smell, where do you think that you will be tossed by the last tooth.

(I wish readers and friends a happy Mid-Autumn Festival and a family reunion!) (To be continued.) )