نوع مقاله : مقاله پژوهشی
نویسندگان
1 بخش علوم دامی دانشگاه شهید باهنر کرمان
2 عضو هیئت علمی دانشگاه شهید باهنر کرمان
3 بخش علوم دامی دانشگاه جیرفت
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: The goat population has increased globally despite major changes in agriculture due to industrial mergers, globalization, and technological advances in the developed countries. Goat farming is one of the key elements contributing to the economy of farmers living in the arid and semi-arid regions including most areas of Iran. There are 30 million heads of cashmere goats around the world and 4.5-5 million heads of cashmere goats are bred in Iran. Raini goat is one of the most important Iranian native goats that spread in the southeast of Iran where these animals are kept for both meat and cashmere production. There are almost 3 million heads of this trait in Kerman province. Although many breeding programs were performed, but have not led to much progress in its economic profitability. One of these reasons can be lack of an economic selection index for basic traits. Survival is one of the most important economic traits and effects on income of farmers, because death or early culling of animals decreases income of breeders. Hence, considering this trait in breeding programs can improve it and increase economic performance of animals. Considering the importance of survival, and the fact that survival of Raini goats has never been studied, the aim of this study was to estimate survival distribution function in Raini kids from birth to yearling.
Materials and methods: Data set used in this study were 3055 records of kids (from 201 male goats and 1309 female) related to the breeding station of Raini goat located in the Baft city of Kerman province, collected during the years 1992 to 2007. The frequency distribution for causes of culling and survival distribution function of kids to yearling age was estimated by R software.
Results: The overall kids’ culling up to yearling age was 21.09 percent, which in the first, second, third and fourth triplet months was 11.2%, 5.08%, 2.17%, and 3.64%, respectively. The most causes of removing kids from the flock were extra-fattening kids and mortality due to illness, respectively. The accumulative survival from birth to yearling age of kids was 77.91 percent. The regression coefficient of survival showed that the survival rate decreased by 0.048 percent per day.
Conclusion: Considering the higher mortality rate in the first 3 months of life, it can be recommended to reconsider in the way of management and breeding system, improve genetic capacity and involve survival trait in breeding programs.
کلیدواژهها [English]
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