Functional Characterization of Mammary Gland of Holstein Cows under Humid Tropical Summer Climates

  • Lu, C.H. (Division of Reproduction and Endocrinology, Department of Medical Research) ;
  • Chang, C.J. (Department of Animal Science, National Chung Hsing University) ;
  • Lee, P.N. (Department of Animal Science, National Chung Hsing University) ;
  • Wu, C.P. (Department of Animal Science, National Chia Yi University) ;
  • Chen, M.T. (Institute of Agricultural Biotechnology, Da-Yeh University) ;
  • Zhao, X. (Department of Animal Science, McGill University)
  • Received : 2002.09.26
  • Accepted : 2003.04.04
  • Published : 2003.07.01


Physiological parameters were measured on six primiparous, non-pregnant Holstein cows prior to peak lactation over a 3-month summer season in southwestern Taiwan. The objectives were to characterize heat stress-induced change in functionality of mammary gland under natural climates of tropical summer and to establish physiological indices applicable to this environment in referring to this change. Environmental and physiological readings, milk and blood samples were taken at 15:00 h biweekly for totally five time points during the study. Climate readings showed that the afternoon humidex value reached the highest (53.5) around mid summer. Rectal temperature of cows taken simultaneously varied between $38.26^{\circ}C$ and $40.02^{\circ}C$ in parallel to humidex. Milk production declined drastically from 29.2 to 22.2 kg/d the first month entering summer but leveled up at end of the summer season suggesting effects exerted by heat stress rather than stages of lactation. Lactose content decreased linearly (p<0.05) with times in summer, from 4.69 to 4.38%. On the other hand, activity of N-acetylglucosaminidase (NAGase) in milk increased linearly to over two folds (p<0.05) during the same intervals. Elevations of fractional constituent of BSA in whey protein and serum cortisol level were also noticed in the course. Measurement of arteriovenous concentration (A-V) difference across the mammary gland demonstrated net uptake of glucose and net release of urea throughout the study period. The amount of urea released from mammary gland increased (p<0.05) progressively from 1.54 to 7.76 mg/dl during summer. It is concluded that gradual regression of mammary gland occurred along the humid tropical summer season. This regression is likely initiated through elevation of body temperature, which is irreversible above certain point. The increased release of urea from mammary gland during heat stress suggests its potential role as an early indicator of suboptimal mammary function.


  1. Armstrong, D. V. 1994. Heat stress interaction with shade and cooling. J. Dairy Sci. 77:2044-2050.
  2. Cant, J. P., E. J. Depeters and R. L. Baldwin. 1993a. Mammary amino acid utilization in dairy cows fed fat and its relationship to milk protein depression. J. Dairy Sci. 76:762-774.
  3. Cant, J. P., E. J. Depeters and R. L. Baldwin. 1993b. Mammary uptake of energy metabolites in dairy cows fed fat and its relationship to milk protein depression. J. Dairy Sci. 76:2254-2265.
  4. Mepham, T. B. 1983. Biochemistry of Lactation. Elsevier Science Publ. B.V., Amsterdam.
  5. Nardone, A., N. Lacetera, U. Bernabucci and B. Ronchi. 1997. Composition of colostrums from dairy heifers exposed to high air temperatures during late pregnancy and the early postpartum period. J. Dairy Sci. 80:838-844.
  6. Sano, H., K. Ambo and T. Tsuda. 1985. Blood glucose kinetics in whole body and mammary gland of lactating goats exposed to heat. J. Dairy Sci. 68: 2557-2564,
  7. Roseler, D. K., J. D. Ferguson, C. J. Sniffen and J. Herrema. 1993. Dietary protein degradability effects on plasma and milk urea nitrogen and milk nonprotein nitrogen in holstein cows. J. Dairy Sci. 76:525-534.
  8. Prosser, C. G., S. Turner, R. D. McLaren, B. Langley, P. J. L'hullier, P. Molan and M. J. Auldist. 2000. Milk whey protein concentration and mRNA associated with $\beta$-lactoglobulin phenotype. J. Dairy Res. 67:287-293.
  9. SAS Institute Inc. 1988. SAS/STAT User's Guide, release 6.03. SAS Institute Inc., Cary, North Carolina.
  10. West, J. W., B. G. Mullinix, J. C. Johnson, Jr., K. A. Ash and V. N. Taylor. 1990. Effects of bovine somatotropin on dry matter intake, milk yield, and body temperature in Holstein and Jersey cows during heat stress. J. Dairy Sci. 73:2896-2906.
  11. West, J. W. 1994. Interactions of energy and bovine somatotropin with heat stress. J. Dairy Sci. 77:2091-2102.
  12. Chang, C. J., C. F. Chen and C. P. Wu. 1996. Changes in apparent mammary uptake of blood metabolites during involution in dairy goats. Small Rumin. Res. 24:49-54.
  13. Elvinger, F., P. N. Roger and J. H. Peter. 1992. Interactions of heat stress and bovine somatotropin affecting physiology and immunology of lactating cows. J. Dairy Sci. 75:449-462.
  14. Bequette, B. J., F. R. C. Backwell and L. A. Cromptont. 1998. Current concepts of amino acid and protein metabolism in the mammary gland of the lactating ruminant. J. Dairy Sci. 81: 2540-2559.
  15. Gonda, H. L. and J. E. Lindberg. 1994. Evaluation of dietary nitrogen utilization in dairy cows based on urea concentrations in blood, urine and milk, and on urinary concentration of purine derivatives. Acta Agric. Scand. Sect. A. Anim. Sci. 44: 236-245.
  16. Shuster, D. E., R. J. Harmon, J. A. Jackson and R. W. Hemken. 1991. Suppression of milk production during endotoxininduced mastitis. J. Dairy Sci. 74:3763-3774.
  17. Dantzer, R. and P. Mormede. 1983. Stress in farm animals: A need for reevaluation. J. Anim. Sci. 57:6-18.
  18. Stelwagen, K. and S. J. Lacy-Hulbert. 1996. Effect of milking frequency on milk somatic cell count characteristics and mammary secretory cell damage in cows. Am. J. Vet. Res. 57:902-905.
  19. Collier, R. J., R. M. Eley, A. K. Sharma, R. M. Pereira and D. E. Buffington. 1981. Shade management in subtropical environment for milk yield and composition in Holstein and Jersey cows. J. Dairy Sci. 64:844-849.
  20. Kitchen, B. J., G. Middleton and M. Salmon. 1978. Bovine milk N-acetyl-$\beta$-D-glucosaminidase and its significance in the detection of abnormal udder secretions. J. Dairy Res. 45:15-20.
  21. Mepham, T. B. and J. L. Linzell. 1967. Urea formation by the lactating goat mammary gland. Nature 29: 507.
  22. Miller, P. S., B. L. Reis, E. J. Calvert and R. L. Baldwin. 1991. Patterns of Nutrient uptake by the mammary glands of lactating dairy cows. J. Dairy Sci. 74:3791-3799.
  23. West, J. W., B. G. Mullinix and T. G. Sandifer. 1991. Effects of bovine somatotropin on physiologic responses of lactating Holstein and Jersey cows during hot, humid weather. J. Dairy Sci. 74:840-851.
  24. Muroya, S., F. Terada and S. Shioya. 1997. Influence of heat stress on distribution of nitrogen in milk. Anim. Sci. Technol. 68(3): 297-300.
  25. Staples, C. R., H. H. Head and D. E. Darden. 1988. Short-term administration of bovine somatotropin to lactation dairy cows in a subtropical environment. J. Dairy Sci. 71: 3274-3282.
  26. Noma, A., H. Okabe and M. Kita. 1973. A new colorimetric microdetermination of free fatty acids in serum. Clin. Chim. Acta 43: 317-320.
  27. Guinard, J., H. Rulquin and R. Verite. 1994. Effect of graded levels of duodenal infusions of casein on mammary uptake in lactating cows. J. Dairy Sci. 77:2221-2231.
  28. Clark, J. H., C. L. Derrig and H. R. Spires. 1975. Metabolism of arginine and ornithine in the cow and rabbit mammary tissue. J. Dairy Sci. 58:1808-1813.
  29. Linzell, J. L. 1974. Mammary blood flow and methods of identifying and measuring precursors of milk. In: Lactation, a Comprehensive Treatise. vol. 1. (Ed. B. L. Larson and V. R. Smith). Academic Press, New York, New York. pp.143.
  30. Mepham, T. B. 1982. Amino acid utilization by lactating mammary gland. J. Dairy Sci. 65:287-298.
  31. Trottier, N. L., C. F. Shipley and R. A. Easter. 1997. Plasma amino acid uptake by the mammary gland of the lactating sow. J. Anim. Sci. 75:1266-1278.
  32. Griinari, J. M., M. A. Mcguire, D. A. Dwyer, D. E. Bauman, D. M. Barbano and W. A. House. 1997. The role of insulin in the regulation of milk protein synthesis in dairy cows. J. Dairy Sci. 80: 2361-2371.

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