Principles of selection for milk production in dairy goats

Selection for increased milk production in dairy goats is discussed. Breeding programmes with artificial insemination and without artificial insemination are included. Selection based on progeny testing of bucks is quite essential to obtain maximum genetic progress in a trait like milk production. Evaluation of breeding values of does is also a valuable tool in order to obtain an effective selection scheme. How to organize the progeny testing, size of progeny groups, use of part lactations and how to use selected proven bucks are also discussed. It is possible to obtain a considerable genetic progress in programmes based on natural matings if the goat farmers are able to cooperate well enough. With artificial insemination the organizing of the breeding programme may be more simple, and the genetic gain may be increased by 20 - 60 percent. Artificial insemination also allows larger progeny groups per buck, and hence it is possible to take into account traits with smaller heritabilities, for instance traits related to reproduction. The expected genetic gain is found to be 1.5 - 3 percent per year depending on the design of the breeding programme and the population size. If the realized genetic gain is about 80 percent of the theoretical estimate, it will be about 1 - 2.5 percent per year. Based on parameters from the Norwegian goat production with average lactation yield of 600 kg, the annual genetic gain is likely to be 10 - 15 kg per year