抗菌肽是生物体内诱导表达具有广谱抗菌活性的小分子多肽。这些多肽是生物体非专一性的免疫应答产物，是生物体内免疫系统的重要成分。目前国内关于猪源抗菌肽的研究，主要针对于猪的小肠中的抗菌肽，而猪血中抗菌肽的提取及抗菌活性研究在国外虽已有少量报道，在国内却未见报道。由于猪血液中白细胞是免疫系统中起主要作用的免疫细胞，而其中性粒细胞约占白细胞总量的70%，从猪血液中性粒细胞中分离提取抗菌肽也就比较合理。因此本实验采用从猪血液中性粒细胞中分离提取小分子多肽，根据小分子多肽抗菌活性特点进而分离鉴定出抗菌多肽。同时，通过优化提取工艺，提高抗菌肽的得率和含量。

The antibacterial peptide has the broad spectrum antibacterial activity which in the organism to induce and express the micromolecule peptides. These peptides are the organism non-specific immunological response products, and they are the important ingredient in the immunity system of organism.At present the research of swine antibacterial peptides mainly to aim directly at swine intestine and blood in domestic. In domestic they also mainly have progressed the reseach about swine intestine, Although the study on the abstraction and antibacterial activity of swine blood has been few reported, in domestic has not actually seen the report about it.because of among the swine blood the white blood cell excute archfunction in the immunity system,at the same time the neutrophile granulocyte have approximately composes 70% of the quantity in white blood cell, and it is reasonable that abstract swine antibacterial peptide from blood. So the experiment abstract micromolecule peptides in neutrophil of fresh swine blood, according the active characteristic of micromolecule peptides to abstracte and identificate the antibacterial peptides. Meanwhile through grading-up extraction artwork, elevating yield and content of antibacterial peptides.