The core tips: The quality of boars directly affects the quality of the entire herd. One boar can be allocated 20 or more sows. The genetic influence of boars on offspring is significant. Play the genetic potential of excellent boars. First, the choice of varieties and appearance characteristics 1. Variety characteristics Different breeds have different breed characteristics. The selection of breeder boars must first have typical breed characteristics such as coat color, head shape, ear shape, appearance, etc., and must meet the species requirements of this species, especially pure breed males. Pig selection. 2, body structure The boar's overall structure should be well-balanced, and the head and neck, front torso, middle and hindquarters combine naturally and well, and the eyes have a very solid feeling. The head is large and wide, the neck is short and thick, the eyes are divine, the chest is wide and deep, the back is straight, the body is long, the abdomen is of medium size, the buttocks are wide and big, the tail is thick, the tip of the tail is curled, swing freely without sagging, limbs Strong, well-posted, stout, symmetrical, no hoof. 3, sexual characteristics The boars require good testis development, symmetry, clear outline, no single testicles, cryptorchidism, and Hernia, and the foreskin urine accumulation is not obvious. Sexual function is strong, sexual behavior is normal, and semen quality is good. The ventral line is well-distributed, milk is well-arranged and well developed, and there are no inverted nipples and deputy nipples, and there are 6 to 7 pairs of them. Second, the choice of production performance and record results 1, production performance Some boar production performance, such as growth rate, feed conversion rate and backfat thickness. All have medium to high heritability. Therefore, the selected boars should determine their performance in this regard, selecting the boar with the highest performance index as a boar. 2. Genealogical data The use of pedigree data for selection is mainly based on the performance of the selected boars measured by the production performance of the parents, siblings, and descendants. Individuals with excellent performance can demonstrate good genetic quality in offspring. The pedigree selection must have a complete record file. According to the records, the trend of each trait transmission from generation to generation is selected, and the individual with the best comprehensive evaluation index is selected as the boar. 3, individual growth and development The individual growth and development choice is based on the body weight and body development of the boar. The weight and body size of the boar at different stages are determined. Individuals selected under the same conditions have higher scores on body weight and body measurements. The boar's grade is high. For young boar selection, growth and development is one of the important choices. Anesthesia Mask,Air Cushion Mask,Disposable Anesthesia Masks,Medical Disposable Air Cushion Mask Shaoxing Jenston Medical Products Co., Ltd. , https://www.sxjcmed.com