Estudo de componentes da curva de lactação de caprinos leiteiros das raças saanen e alpinas no interior paraibano.

Abstract

Knowledge of milk production during the productive life of a goat is one of the most important characteristics for the efficiency of milk production systems. The detailed description of the lactation curve of a herd is of great use for the introduction of management practices and genetic improvement in dairy goats in the different production systems. The objective of this work was to study the lactation curve of dairy goats from the goat and sheep breeding laboratory of the Center for Human, Social and Agrarian Sciences of the Federal University of Paraíba. Controls were used for the lactations of goats of the Saanen and Alpina breeds. The animals are kept in an intensive regime. Artificial feeding is used and weaning is done at sixty days of age. The controlled mountaineering system is used, with two mountaineering stations during the year. Sanitary control is systematic. The milk control was performed every seven days, in two daily milks, with approximate interval of 10 hours between milking. Milk production was recorded in individual records containing data on the reproductive life of each animal. From the production and reproduction sheets a file containing the goat number, mother number, father's number, date of birth, date of delivery, daily milk production and date of milk control were edited. Animals with less than four controls and those with contemporary groups with less than two animals were eliminated from the file. After the data collection, we evaluated the influence of non-genetic factors on milk production. The environmental factors used to compose the sources of variation were: birth season (water and drought), order of delivery (1, ..., 5). The environmental factors used to compose the sources of variation were: labor season and labor order. Higher milk yields are observed in animals born in the dry season, both for Alpine goats and for Saanen goats. Fourth-order delivery animals are more productive. Selection and management strategies should be implemented considering the breeding season and the reproductive age of the animals.