The application of a selenium fertiliser for the ... - Semantic Scholar

Article — Artikel

The application of a selenium fertiliser for the correction of marginal deficiencies in grazing sheep a

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S W P Cloete , F E van Niekerk , M Young , G D van der Merwe and J Clark

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MATERIALS AND METHODS ABSTRACT A commercial fertiliser, consisting of a poorly soluble barium selenate core with a coating of highly soluble sodium selenite, was evaluated in 2 trials for the provision of selenium (Se) to grazing sheep. The fertiliser was administered at a level of 1 kg per hectare to 3 of 6 kikuyu paddocks during 1995 and 1996 in Trial 1, while the other paddocks were left untreated. The Se status of SA mutton merino ram lambs, as reflected by whole blood, liver and kidney Se concentrations, was elevated (P < 0.01) for at least 5 months after application of the fertiliser. Whole blood and liver Se concentrations of animals grazing unfertilised control paddocks were indicative of a subclinical Se deficiency at times (0.90 of the available variation. Whole blood Se

concentrations of ewes and lambs were increased (P < 0.01) on the Se-fertilised paddocks relative to the control paddocks during 1995 and 1997 (Table 2). During 1997, the responses in both ewes and lambs were greater than in 1995. This resulted in an interaction (P 12 months) of the pastures was not adequately assessed in this study. Viewed against the results of Whelan et al.26 and Whelan and Barrow25, it is clear that products of a similar nature are able to provide sufficient Se to eliminate deficiencies for up to 4 years following application. Those studies, as well as that of Whelan24, suggest that fertilisation with BaSeO4 as a slow-release product provides a practical and safe way of Se supplementation to grazing ruminants for periods of up to 3 years after application. REFERENCES 1. Cloete S W P, Van Niekerk, F E, Kritzinger N M, Van der Merwe G D, Heine E W P, Scholtz A J 1994 Production responses of sheep supplemented with copper, cobalt and selenium on kikuyu ryegrass pastures. Journal of the South African Veterinary Association 65: 52–58 2. Donald G E, Langlands J P, Bowles J E, Smith A J 1993 Subclinical selenium insufficiency 4. Effects of selenium, iodine, and thiocyanate supplementation of grazing ewes on their selenium and iodine status, and on the status and growth of their

lambs. Australian Journal of Experimental Agriculture 33: 411–416 3. Donald G E, Langlands J P, Bowles J E, Smith A J 1994 Subclinical selenium insufficiency 6. Thermoregulatory ability of perinatal lambs born to ewes supplemented with selenium and iodine. Australian Journal of Experimental Agriculture 34: 19–24 4. Farquharson B C 1984 The prevention and treatment of trace element deficiencies in sheep and cattle. Proceedings of the New Zealand Society of Animal Production 44: 147–149. 5. Hartley W J 1963 Selenium and ewe fertility. Proceedings of the New Zealand Society of Animal Production 23: 20–27 6. Harvey W R 1990 User’s guide for LSMLMW and MIXMDL. PC-2 version, Mimeograph, 4255 Mumford Drive, Columbus, Ohio. 7. Heine E W P, Dekker F A J J, Hudson N 1989 Methods in biochemistry, haematology and toxicology. Veterinary Services, Directorate of Animal Health, Stellenbosch. 8. Hupkens van der Elst F C C, Watkinson J H 1977 Effect of topdressing pasture with selenium prills on selenium concentration in blood of stock. New Zealand Journal of Experimental Agriculture 5: 79–83 9. Langlands J P, Donald G E, Bowles J E, Smith A J 1991 Subclinical selenium insufficiency 1. Selenium status and the response in liveweight and wool production of grazing ewes supplemented with selenium. Australian Journal of Experimental Agriculture 31: 25–31 10. Langlands J P, Donald G E, Bowles J E, Smith A J 1991 Subclinical selenium insufficiency 2. The response in reproductive performance of grazing ewes supplemented with selenium. Australian Journal of Experimental Agriculture 31: 33–35 11. Langlands J P, Donald G E, Bowles J E, Smith A J 1991 Subclinical selenium insufficiency 3. The selenium status and productivity of lambs born to ewes supplemented with selenium. Australian Journal of Experimental Agriculture 31: 37–43 12. Langlands J P, Donald G E, Bowles J E, Smith A J 1994 Selenium concentration in the blood of ruminants grazing in northern New South Wales IV. Relationship with tissue concentrations and wool production of merino sheep. Australian Journal of Agricultural Research 45: 1701–1714 13. Koh T S, Benson T H 1983 Critical reappraisal of fluorometric method for determination of selenium in biological samples. Journal of the Association of Official Analytical Chemists 66: 918 14. Kott R W, Ruttle J L, Southward G M 1983 Effects of Vitamin E and selenium injections on reproduction and preweaning lamb survival in ewes consuming diets marginally deficient in selenium. Journal of Animal Science 57: 553–558 15. Masters D G, Peter D W 1990 Marginal deficiencies of cobalt and selenium in weaner sheep: responses to supplementation. Australian Journal of Experimental Agriculture 30: 337–341 16. Mudd A J, Mackie I L 1973 The influence of vitamin E and selenium on ewe prolificacy. Veterinary Record 93: 197–199 17. Segerson E C, Gunsett F C, Getz W R 1986 Selenium-vitamin E supplementation and production efficiency in ewes marginally deficient in selenium. Livestock Production Science 14: 149–159 18. Snedecor G W, Cochran W G 1967 Statistical

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methods (6th edition). Iowa State University Press, Ames 19. Spears J W, Harvey R W, Segerson E C 1986 Effects of marginal selenium deficiency and winter protein supplementation on growth, reproduction and selenium status of beef cattle. Journal of Animal Science 63: 586–594 20. Van Niekerk F E, Cloete S W P, Van der Merwe G D, Heine E W P, Scholtz A J 1995 Parenteral copper and selenium supplementation of sheep on legume-grass pastures: biochemical and production responses in lambs to maternal treatment. Journal of the South African Veterinary Association 66: 11–17 21. Van Ryssen J B J, Bradfield G D, Van Malsen S, De Villiers J F 1992 Response to selenium supplementation of sheep grazing cultivated pastures in the Natal Midlands.

Journal of the South African Veterinary Association 63: 148–155 22. Watkinson J H 1983 Prevention of selenium deficiency in grazing animals by annual topdressing of pasture with sodium selenate. New Zealand Veterinary Journal 31: 78–85 23. Whelan B R 1989 Uptake of selenium fertiliser by subterranean clover pasture in Western Australia. Australian Journal of Experimental Agriculture 29: 517–522 24. Whelan B R 1993 Effect of barium selenate fertiliser on the concentration of barium in pasture and sheep tissues. Journal of Agricultural and Food Chemistry 41: 768–770 25. Whelan B R, Barrow N J 1994 Slow-release selenium fertilisers to correct selenium deficiency in grazing sheep in Western Australia. Fertilizer Research 38: 183–188 26. Whelan B R, Peter D W, Barrow N J 1994 Selenium fertilisers for pastures grazed by

sheep I. Selenium concentrations in whole blood and plasma. Australian Journal of Experimental Agriculture 45: 863–875 27. Whelan B R, Peter D W, Barrow N J 1994 Selenium fertilisers for pastures grazed by sheep II. Wool and live weight responses to selenium. Australian Journal of Experimental Agriculture 45: 877–887 28. Wichtel J J, Thompson K G, Graigie A L, Williamson N B 1996 Effects of selenium and iodine supplementation on the growth rate, mohair production, and thyroid status of Angora goat kids. New Zealand Journal of Agricultural Research 39: 111–115 29. Wilkins J F, Kilgour R J 1982 Production responses in selenium supplemented sheep in northern New South Wales. 1. Infertility of ewes and associated production. Australian Journal of Experimental Agriculture and Animal Husbandry 22: 24–29

Book review — Boekresensie

A quantitative biology of the pig Edited by I Kyriazakis 1999. CABI Publishing, Wallingford, UK, 398 pp., 62 figures, 52 tables. Price £60.00. ISBN 0 85 199 273 0.

The measurability of pigs is not a new concept, but this book adds depth and brings much of new investigative techniques to the questions of pig biology. The overall intention is to improve simulation modelling as an eventual production tool. The editor states, in the final chapter, that there are problems involved in converting models into practice and difficulties in including stochastic elements when trying to predict population performance from quantitative measurements in individual animals. This does not detract from the wealth of usable information in this excellent book. The editor has enlisted some 30 contributors from outstanding scientific teams worldwide. In the course of the 16 chapters, most aspects of the pig, its composition, reaction to environment, social interaction, breeding patterns, pre- and post-natal growth, sow lactation, lean and fat development, hormone controls and other factors are examined, quantified and presented in readable form, aided by numerous tables, graphs and diagrams. The major area of investigation is, understandably, nutrition. Nearly half of the book is devoted

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to detailed examination of this subject, from constituents of feeds and their absorbability and metabolism to the requirements of pigs at all ages and in various circumstances. The contributors take a new and critical look at many conventional wisdoms – are we really able to analyse amino acids, is sow milk the best food for piglets, why do we use 6.25 to convert N to CP, why do we have problems balancing the energy flow equation, should we not be more concerned with physical and physiological attributes of feeds than chemical analysis ...? Although this book is written largely for nutritionists, animal scientists and statisticians, every chapter has a final discussion or conclusion paragraph that summarises the content, and the references are numerous and recent. Any veterinarian who is concerned with modern pig production will find a great deal of up-to-date, authentic and useful information in its pages. J T R Robinson Department of Herd Health Faculty of Veterinary Science Medunsa

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