The book tells, the defensins may be used as genetic markers in breeding programs aimed at selecting highly productive dairy farm animals (buffaloes and cows) with increased resistance to udder infections especially mastitis disease. It can be suggested that, the detection and the identification of beta defensin genes at the molecular level in the farm animals and their relation to mastitis disease may be useful for detection mastitis disease early. Also, it is necessary to use and apply genetic engineering techniques for enhancing innate defenses of the mammary gland to improve milk production of animals where, a variety of molecular components of the innate immune system can be expressed in the lactating mammary gland under the control of milk protein gene promoters. May be useful for scientists those use these genes and cloned into cloning vector then, obtain the purified protein where; being used as antigen to produce antibodies to mastitis disease which infect udder's milking farm animals and affect on the economics of these animals.