1. 1. Culbertson, M. S., Mabry, J. W., Bertrand, J. K. and Nelson, A. H. 1997. Breed-specific adjustment factors for reproductive traits in Duroc, Hampshire, Landrace and Yorkshire swine. J. Anim. Sci. 75: 2362–2367.
2. 2. Cutler, R. S., Fahy, V. A., Cronin, G. M. and Spicer, E. M. 2006. Preweaning mortality. pp. 993–1009. In: Diseases of Swine, 9th ed. (Straw, B. E., Zimmerman, J. J., D’Allaire S. and Taylor, D. J. eds.), Blackwell Publishing, Ames.
3. 3. DeRouchey, J. M., Dritz, S. S., Goodband, R. D., Nelssen, J. L. and Tokach, M. D. 2007. pp. 2–5. Breeding Herd Recommendations for Swine. Kansas State University Press, Ames.
4. 4. Dourmad, J. Y., Etienne, M., Prunier, A. and Noblet, J. 1994. The effect of energy and protein intake of sows on their longevity: A review. Livest. Prod. Sci. 40: 87–97.
5. 5. Edwards, S. A., English, P. R. and Fraser, D. 2006. Animal welfare. pp. 1065–1073. In: Diseases of Swine, 9th ed. (Straw, B. E., Zimmerman, J. J., D’Allaire S. and Taylor, D. J. eds.), Blackwell Publishing, Ames.