Group selection "four stages" The selection of gilts should insist on the principle of selecting and selecting carefully. When the group is selected for stay, it can be divided into the following four stages: (1) 2 months of age selection: should be from the offspring of good breeds and excellent individuals, preferably in the litter size, feeding rate, weaning litter weight of 2 to 5 litters of sows in the selection of the remaining generation, select the same Individuals with fast growth, large body size, and no hereditary disorders in the litter of pigs, that is to say, pigs to be selected, can have long service lives. In this case, 200% to 250% of the number of sows to be replaced should be selected. (2) 4 months of age selection: individuals who choose to exceed the average daily weight gain over the same period, all those who have poor growth and growth, slow weight gain, appearance and external genitalia are eliminated. (3) 6 months of age selection: This is a crucial period for the selection of gilts. Strictly choose according to its various properties, such as weighing and measuring body length, body height, chest width, chest depth, hip circumference, etc., to eliminate bad individuals. (4) Selection before initial allocation: At this time, it is the last time to pick out individuals who are not ideal for the development of sexual organs, irregular estrus cycle, unclear estrus phenomenon, and long-term estrus. Individual choice "four notes" When choosing a gilt, the individual must meet the minimum requirements for fur, shape, breast, and genitalia: (1) Fur: Bright hair, soft skin, bright white pork skin, no curls, loose hair, skin dirt. (2) Appearance: Thick mouth, thick nostrils, thick limbs, strong, wide left and right spans, wide and straight back, wide open ribs, full hips, thick tails, well-maintained limbs, and generous hooves. Large, well-proportioned, spaced-apart distribution. (3) Breast: There are enough number of nipples, more than 14 effective nipples (more than 12 lean-type pigs), well-developed, moderate in size, normal in appearance, with thick pores, and more rows of milk ducts. The sides are arranged evenly and prominently, and at least three of them are in front of the umbilicus. There are no secondary nipples or hernias. (4) Reproductive organs: The pus is well developed and drooping, moderate in size, well-placed, with no abnormalities in the vulva, and has a normal estrus cycle before breeding, and the estrus signs are obvious. Avoid the selection of sows with very small vulva or pointed ends of the vulva. It is very difficult to gilt breeding with this type of vulva. Fingerprint recognition is to classify and compare the fingerprint of the identified object. Fingerprint identification technology, as one of the biological characteristics identification technologies, has gradually matured in the new century and entered the field of human production and life. Fingerprint Recognition,Face Fingerprint Recognition,Fingerprint Face Recognition,Biological Fingerprint Reader Recognition ChangChun E-vida Technology Co.,ltd , https://www.evidatech.com
The main advantages of fingerprint identification technology are:
1. Fingerprints are unique features of the human body, and they are complex enough to provide sufficient features for identification;
2. To increase reliability, simply register more fingerprints and identify more fingers, up to ten, each unique;
3, fingerprint scanning speed is very fast, very convenient to use;
4. When reading the fingerprint, the user must contact the finger with the fingerprint collection head, and directly with the fingerprint collection head;
5. Contact is the most reliable method to read human biometrics;