In spite of achieving the highest milk production, the performance of Indian cattle has been extremely poor and average milk yield is far below the yield in other countries. Poor performance of indigenous cattle is due to more populations of non-descript animals and inadequate exploitation of their productivity because of poor nutritional and managemental factors. In spite of more number of non-descript animals, certain breeds of Indian cattle (Bos indicus) yields good amount of milk and also well adopted for harsh Indian climate. Various selection methods based on different measures of persistency have been applied in the past. The molecular genetic markers in breeding programs could make selection more precise and efficient. Some of these markers are called candidate genes like GH genes, which are usually selected because of their biological significance on the quantitative traits of interest. The book entitled “Lactation Persistency and its Association with Bovine Growth Hormone Gene authored by “Shweta Sachan and I D Gupta” has been designed to meet the needs of the research scholars, teachers, and scientists associated with Animal Genetics and Breeding. The work described in this book is the research work of M.V.Sc. dissertation entitled “Genetic analysis of lactation persistency and its association with genetic variants of bovine growth hormone gene in Sahiwal cattle”. The content in the book represents an attempt to summarize and consolidate a considerable amount of information relative to the lactation persistency and its association with bovine growth hormone gene. Each section of the book provides a structured approach to learning by covering the topics in a uniform and systematic format.