The quality of a dog is determined by various behavioral traits and can be inherited, and the heritability of different quality traits is different. Therefore, in the process of selecting and breeding dogs for good quality, scientific breeding should be carried out according to the genetic characteristics of each trait, combined with the environmental conditions and training requirements of various places, and breed dogs with a variety of excellent qualities and high comprehensive levels should be selected as much as possible. .

1. body type. The size of the dog is a quantitative trait and generally has a high heritability. Studies have shown that the heritability of dog body size is 0.35~0.65. For example, the heritability of Germanshepherd at 60 days of age is 0.45. Thus, individual phenotypic selection can lead to greater improvements in dog size. In practice, according to the different uses of the dog, the breed dog of the corresponding size should be specially selected.

2. smell. The sense of smell is a very important trait for the dog's work. Generally, dogs have a sense of smell that is several thousand to tens of thousands sharper than humans. There are big differences. This is due to the genetic acuity of a dog's sense of smell. The dog's sense of smell is a quantitative trait, controlled by micro-effect polygenes and influenced by environmental factors. Its heritability is 0.12~0.20. Therefore, the selection of olfactory trait, like other heritability traits, is not suitable for individual selection. Due to the low correlation between smell and training, pedigree selection should be used. Specifically, the average level of littermates (sibs) should be considered when selecting species, and excellent individuals should be selected from dogs with a higher average level of litters.

3. Desire to take. Prey behavior in dogs is an innate instinct. However, due to hereditary reasons, there are also some dogs who have a low desire for uniqueness or a desire to take the title. The study found that the heritability of picking and prey behavior in German Shepherds at 8 weeks of age was 0.415 and 0.35, respectively. The actual selection also proved that the two traits of dog picking and prey have moderate heritability, which can be improved by individual phenotypic selection. Experiments show that male and female dogs have a high desire to take titles, and their offspring (average of three litters) have a pass rate of more than 80%, while male and female dogs have a low desire to take titles, and the pass rate of their offspring is less than 20%. , the ratio of non-title is more than 25%. Therefore, in order to improve the excitability of the entire dog group, the selection of breeding or participation in breeding. In particular, the male dog must have a strong possessiveness towards objects, a high desire to pick up, and a long-lasting hold.

4. courage. Courage is a more general trait that includes many things, such as not being afraid of gunshots, strangers, firelight, and new and unusual environments. The estimation of the heritability of guts results in inconsistent data and large differences, and there is currently no authoritative value. However, practice has proved that courage has a high degree of correlation with training, and it has a moderately low heritability. The measured values of courage at 6 months and 12 months are relatively highly correlated (p < 0.05). Among them, fear of gunshots is a trait. The correlation coefficient was 0.39 (p<0.05). It can be seen that the selection of the trait of guts is relatively accurate after 6 months of age. Therefore, when selecting breeding dogs, individuals with strong adaptability must be selected, and relevant training should be strengthened.

5. aggressive. The dog's aggression is significantly proportional to training. However, it has been proved that the aggression of dogs is hereditary. For example, the heritability of aggression in German Shepherds is about 0.2, and it is related to the phenotype of a higher degree of courage, which can be improved by selection. Therefore, a bold, aggressive dog must be selected as a breeder. Of course, there are breed and gender differences in dog aggression. After long-term selection, some dogs basically lose their aggression, such as Labrador, Peking, etc. Male dogs are more aggressive than female dogs.

6. Excitability and flexibility. The dog's excitability and flexibility can be inherited, and its heritability is moderate. Practice has proved that the excitement and flexibility of breeding dogs are high, and the excitability and flexibility of their offspring are high. In the 6-month-old assessment, 84% of the dogs were excitable and lively, while only 24.5% of the offspring bred by dogs with low excitability and poor flexibility could meet the training requirements. Therefore, dogs who are not excited and flexible should not be kept, especially the male dogs must be highly excited and persistent, and flexible in transformation.

7. other traits. In addition to the above-mentioned main traits, behavioral traits such as obedience, hearing, and ease of training are also related to the use of training. These traits are all heritable. For example, the hearing heritability of American guide dogs is 0.25, the heritability of trainability is 0.12, and the heritability of dog obedience is about 0.20. Therefore, in the selection and breeding work, we must pay attention to the selection and improvement of these characters.

8. The selection and breeding of high-quality dog food must be based on the selection of breeds and completed through matching. In this case, according to the genetic characteristics of various quality traits, with the individual performance of the dog as the basic basis, combined with its pedigree, descendants, compatriots and other data to conduct a comprehensive assessment, comprehensive and systematic polar comparison, proceeding from the actual needs and possibilities, Select excellent breed dogs, and then in accordance with the matching principle, adopt scientific matching methods, and breed a large number of excellent working dogs. For example, homogeneous mating is carried out with dog breeds that are ferocious and tenacious, have a keen sense of smell and good endurance, breed riot-proof, durable, smaller male and female dogs that are not aggressive, and breed dogs that search for drugs and explosives. Another example is to use dogs with good physical appearance and general neurological type to carry out heterogeneous mating with dogs with average physical appearance and good neurological type, and breed working dogs with good physical appearance and neurological type.