Effects of environmental pollutants on the reproduction and welfare of ruminants
S.M. Rhind,
N.P. Evans,
M. Bellingham,
R.M. Sharpe,
C. Cotinot,
B. Mandon-Pepin,
B. Loup,
K.D. Sinclair,
R.G. Lea,
P. Pocar,
B. Fischer,
E. van der Zalm,
K. Hart,
J.-S. Schmidt,
M.R. Amezaga,
P.A. Fowler
Affiliations
S.M. Rhind
Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK
N.P. Evans
Division of Cell Sciences, Institute of Comparative Medicine, University of Glasgow Veterinary School, Glasgow G6 1QH, UK
M. Bellingham
Division of Cell Sciences, Institute of Comparative Medicine, University of Glasgow Veterinary School, Glasgow G6 1QH, UK
R.M. Sharpe
MRC Human Reproductive Sciences Unit, Queen’s Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
C. Cotinot
INRA, UMR 1198, Biologie du Developpement et de la Reproduction 78350, Jouy-en-Josas, France
B. Mandon-Pepin
INRA, UMR 1198, Biologie du Developpement et de la Reproduction 78350, Jouy-en-Josas, France
B. Loup
INRA, UMR 1198, Biologie du Developpement et de la Reproduction 78350, Jouy-en-Josas, France
K.D. Sinclair
Schools of Biosciences, and Veterinary Medicine and Sciences, University of Nottingham, Leicestershire, LE12 5RD, UK
R.G. Lea
Schools of Biosciences, and Veterinary Medicine and Sciences, University of Nottingham, Leicestershire, LE12 5RD, UK
P. Pocar
Department of Animal Science, Division of Veterinary Anatomy and Histology, University of Milan, Via Celoria 10, 20133 Milano, Italy
B. Fischer
Department of Anatomy and Cell Biology, University of Halle, Grosse Steinstrasse 52, 06097 Halle, Germany
E. van der Zalm
Department of Anatomy and Cell Biology, University of Halle, Grosse Steinstrasse 52, 06097 Halle, Germany
K. Hart
Department of Anatomy and Cell Biology, University of Halle, Grosse Steinstrasse 52, 06097 Halle, Germany
J.-S. Schmidt
Department of Anatomy and Cell Biology, University of Halle, Grosse Steinstrasse 52, 06097 Halle, Germany
M.R. Amezaga
Centre for Reproductive Endocrinology & Medicine, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
P.A. Fowler
Centre for Reproductive Endocrinology & Medicine, Division of Applied Medicine, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, UK
Anthropogenic pollutants comprise a wide range of synthetic organic compounds and heavy metals, which are dispersed throughout the environment, usually at low concentrations. Exposure of ruminants, as for all other animals, is unavoidable and while the levels of exposure to most chemicals are usually too low to induce any physiological effects, combinations of pollutants can act additively or synergistically to perturb multiple physiological systems at all ages but particularly in the developing foetus. In sheep, organs affected by pollutant exposure include the ovary, testis, hypothalamus and pituitary gland and bone. Reported effects of exposure include changes in organ weight and gross structure, histology and gene and protein expression but these changes are not reflected in changes in reproductive performance under the conditions tested. These results illustrate the complexity of the effects of endocrine disrupting compounds on the reproductive axis, which make it difficult to extrapolate between, or even within, species. Effects of pollutant exposure on the thyroid gland, immune, cardiovascular and obesogenic systems have not been shown explicitly, in ruminants, but work on other species suggests that these systems can also be perturbed. It is concluded that exposure to a mixture of anthropogenic pollutants has significant effects on a wide variety of physiological systems, including the reproductive system. Although this physiological insult has not yet been shown to lead to a reduction in ruminant gross performance, there are already reports indicating that anthropogenic pollutant exposure can compromise several physiological systems and may pose a significant threat to both reproductive performance and welfare in the longer term. At present, many potential mechanisms of action for individual chemicals have been identified but knowledge of factors affecting the rate of tissue exposure and of the effects of combinations of chemicals on physiological systems is poor. Nevertheless, both are vital for the identification of risks to animal productivity and welfare.
