Borg, K. E., D. D. Lunstra and R. K. Christenson. 1993. Semen characteristics, testicular size and reproductive hormone concentrations in mature Duroc, Meishan, Fengjing and Minzhu boras. Biology of Reproduction 49:515-521.
Cameron, D. A. and A. W. Blackshaw. 1980. The effect of elevated ambient temperature on spermatogenesis in the boar. J. Reprod. Fert. 59:173-179.
Cheng, S. P. and S. C. Wung. 1974. A study of seasonal changes in the boar semen characteristics. Annual Research Report of Animal Industry Research Institute, Taiwan Sugar Corporation. pp. 89-103.
Christenson, R. K., H. S. Teague, A. P. Grifo Jr. and W. L. Roller. 1972. The effect of high environmental temperature on the boar. Ohio Swine Research and Information Report. Research Summary 61, Ohio Agricultural Research and Development Center Wooster.
Ciereszko, A., J. S. Ottobre and J. Glogowski. 2000. Effects of season and breed on sperm acrosin activity and semen quality of boars. Anim. Reprod. Sci. 64:89-96
Corteel, J. M., J. P. Sigornet and F. Du Mensil du Buisson. 1964. Variations Saisonnieres de la reproduction de la truie et facteurs favorisant l'anestrus temporaire. Fifth Congr. Intern. Reprod. Anim. Insem. Artif. P. 536.
Enne, G., P. V. Beccaro and C. Tarocco. 1979. A note on the effect of climate on fertility in pigs in the Padana Valley of Italy. Anim. Prod. 28:115-117.
Hsia, L. C. 1990a. The effect of high environmental temperature on animal production. Proceedings of the 5th AAAP Animal Science Congress. Vol. 1:83-218.
Hsia, L. C. 1990b. Effect of high environmental temperature on GF pigs. The Research and Application of Pig Technology. Pig Res. Ins. Taiwan. pp. 75-107.
Hsia, L. C. 2002. How to release heat stress from dairy cattle. International Training on Strategies for Reducing Heat Stress in Dairy Cattle. pp. 128-140. Taiwan Livestock Research Institute, ROC.
Hsia, L. C. and G. H. Lu. 1988. Nutrient requirement of growingfinishing pigs when fed ad libitum under hot and cool seasons. I. The effect of energy level of food on the performance of finishing pigs. J. Agric. Asso. China, New Series 141:62-66.
Hsia, L. C. and G. H. Lu. 1989. Nutrient requirement of growingfinishing pigs when fed ad libitum under hot and cool seasons. II. The effect of protein and amino acid levels of food on the performance of growing-finishing pigs. J. Agric. Asso. China, New Series 145:45-52.
Hsia, L. C. and G. H. Lu. 2004. The effect of high environmental temperature and nutrient density on pig performance, conformation and carcass characteristics under restricted feeding system. Asian-Aust. J. Anim. Sci. 17(2):250-258.
Hurtgen, J. P. and A. D. Leman. 1980. Seasonal influence on the fertility of sows and gilts. J. Am. Vet. Med. Assoc. 177(1):631-635.
Hurtgen, J. P., A. D. Leman and B. Crabo. 1980. Seasonal influence on estrous activity in sows and gilts. J. Am. Vet. Med. Assoc. 176(2):119-123.
Larsson, K and S. Einarsson. 1984. Seminal changes in boars after heat stress. Acta Vet. Scand. Vol. 25:57-66.
Lawrence, J. A., E. J. Turman, T. Rich, A. Sharp and J. C. Hillier. 1970. A study of seasonal changes in boar semen. Mise. Publs. Okla. Agric. Exp. Stn. No. M.P. 84:77-83.
Malmgren, L. and K. Larsson. 1984. Semen quality and fertility after heat stress in boar. Acta Vet. Scand. Vol. 25:425-435.
Mauget, R. and J. Boissin. 1987. Seasonal changes in testis weight and testosterone concentration in the European wild boar (Sus Scrofa L.) Anim. Reprod. Sci. Vol. 13:67-74.
Mazzarri, G., F. Du Mensil du Buisson and R. Ortavant. 1968. Action of temperature on spermatogenesis, sperm production and fertility of the boar. 6th Intern. Congr. Ani. Reprod. A.I. Paris.
McNitt, J. I. and N. L. First. 1970. Effect of 72-hour heat stress on semen quality in boars. Int. J. Biometeor. 14(4):373-380.
McNitt, J. I., C. B. Tanner and N. L. First. 1972. Thermoregulation on the scrotal system of the boar. II. Evaporative heat exchange. J. Anim. Sci. 34(1):117-121.
Mikitas, A. N. 1969. Changes in character of boar semen. Svinovodstvo. Mosk. 23(3):18-19. Anim. Breed. Abst. 37:3905.
Minin, V. I. 1967. Changes in quantitative and qualitative indices of the year. Anim. Breed. Abst. 37:114.
Ninomiya, H., T. Yoshimoto, T. Tanaka, H. Tanida and T. Nakamura. 1988. Effects of high ambient temperature on the physiological responses and spermatogenesis of boars. Proc. 6th Wld. Conf. Anim. Prod. p. 650.
Okauchi, K. and K. Hirakata. 1962. Studies on the characters of boar semen. 1. Effect of environmental temperature. (Bull. Fae. Agric. Univ. Miyazak: 7:117-123 Japan). Anim. Breed. Abst. Vol. 31:2292.
Omtvedt, I. T. 1972. Influence of heat stress on sow reproductive performance. American Pork Congress, March 21-23, pp. 61-69.
Park, C. S. and Y. J. Yi. 2002. Comparison of semen characteristics, sperm freezability and testosterone concentration between Duroc and Yorkshire boars during seasons. Anim. Reprod. Sci. 73:53-61.
Paterson, A. M., J. Baker and D. R. Lindsay. 1977. Summer infertility in pigs: its incidence and characteristics in an Australian commercial piggery. Aust. J. Experi. Agric. Anim. Husb. 18:698-701.
Rasbech, O. 1971. Pathological aspects of pig breeding. Acta Conv. Int. Recond. F.A. Specie Suina, Reggio Emilia.
SAS Institute, Inc. 2000. SAS/STAT User's Guide: Statistics. Version 8. SAS Institute, Inc. Cary, NC.
Steinbach, J. 1968. Effects of ambient temperatures during the processes of follicular development, ovulation and implantation on litter size in swine. A preliminary report. VI Cong. Intern. Reprod. Anim. Insem. Artif. Paris. 1:325-327.
Steinbach, J. 1971. Effect of season and breed on sow performance in the seasonal equatorial climate of southern Nigeria. J. Agric. Sci. Camb. 77:331-336.
Steinbach, J. 1972. The effect of tropical climate on pig fertility. Anim. Res. Develop. Vol. 1:73.
Stone, B. A. 1981. Thermal characteristics of the testis and epididymis of the boar. J. Reprod. Fert. 63:551-557.
Thibault, C., M. Courot, L. Martinet, P. Manleon, F. Dumesnil Du Buisson, R. Ortavant, J. Pelletier and J. P. Signoret. 1966. Regulation of breeding season and estrus cycles by light and external stimuli in some mammals. J. Anim. Sci. (Suppl). 25:119-139.
Trudeau, V. L., D. L. Grinwich and L. M. Sandford. 1988. Seasonal variation in the blood concentration of 16-androstenes in adult Landrace boars. Can. J. Anim. Sci. 68:565-568.
Wallace, H. D. and G. E. Combs. 1962. Sow productivity as influenced by season. Fla. Agric. Exp. Sta. A.H. Mimeo 63-2.
Wettemann, R. P. and C. Desjardins. 1979. Testicular function in boars exposed to elevated ambient temperature. Biology of Reproduction 20:235-241.
Wettemann, R. P., M. E. Wells and R. K. Johnson. 1979. Reproductive characteristics of boars during and after exposure to increased ambient temperature. J. Anim. Sci. 49(6):1501-1505.
Wettemann, R. P., M. E. Wells, I. T. Omtvedt, C. E. Pope and E. J. Turman. 1976. Influence of elevated ambient temperature on reproductive performance of boar. J. Anim. Sci. 42(3):664-669.
Wettemann, R. P., M. E. Wells, I. W. Brock, R. K. Johnson, R. Harp and R. Vencl. 1977. Recovery of normal semen quality after heat stress of boars. Anim. Sci. Res. Rep. 152-156.
Wettemann, R. P., M. E. Wells, R. K. Johnson and R. Vencl. 1978. Influence of cooling methods on boar fertility with summer breeding. Anim. Sci. Res. Rep. 230-232.
Winfield, C. G., P. H. Hemsworth, D. B. Galloway and A. W. Makin. 1981. Sexual behaviour and semen characteristics of boars: effects of high temperature. Aust. J. Exp. Agric. Anim. Husb. 21:39-45.