The effect of global warming on beef production in developing countries of the southern hemisphere — Oak Academic Publishing
Research ArticleOpen AccessGoogle Scholar indexed
The effect of global warming on beef production in developing countries of the southern hemisphere
ARC-Animal Production Institute, Irene, South Africa&University of the Free State, Bloemfontein, South Africa
,
Insituto Nacional de Ciência e Tecnologia-Informa??oGenético-Sanitária da PecuáriaBrasileira, Brazil&Departamento de Zootecnia, Universidade Federal de Rio Grande do Sul, Porto Alegre, Brazil
,
ARC-Animal Production Institute, Irene, South Africa
,
Centro de Energia Nuclear na Agricultura, Universidade de S?o Paulo, Piracicaba, Brazil
,
Insituto Nacional de Ciência e Tecnologia-Informa??oGenético-Sanitária da PecuáriaBrasileira, Brazil
,
Insituto Nacional de Ciência e Tecnologia-Informa??oGenético-Sanitária da PecuáriaBrasileira, Brazil&Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasilia, Brasilia, Brazil
,
Northern Cape Department of Agricultural, Land Reform and Rural Development, Jan Kempdorp, South Africa
,
University of the Free State, Bloemfontein, South Africa
1 ARC-Animal Production Institute, Irene, South Africa&University of the Free State, Bloemfontein, South Africa
2 Insituto Nacional de Ciência e Tecnologia-Informa??oGenético-Sanitária da PecuáriaBrasileira, Brazil&Departamento de Zootecnia, Universidade Federal de Rio Grande do Sul, Porto Alegre, Brazil
3 ARC-Animal Production Institute, Irene, South Africa
4 Centro de Energia Nuclear na Agricultura, Universidade de S?o Paulo, Piracicaba, Brazil
5 Insituto Nacional de Ciência e Tecnologia-Informa??oGenético-Sanitária da PecuáriaBrasileira, Brazil
6 Insituto Nacional de Ciência e Tecnologia-Informa??oGenético-Sanitária da PecuáriaBrasileira, Brazil&Faculdade de Agronomia e Medicina Veterinária, Universidade de Brasilia, Brasilia, Brazil
7 Northern Cape Department of Agricultural, Land Reform and Rural Development, Jan Kempdorp, South Africa
8 University of the Free State, Bloemfontein, South Africa
Developing countries from the southern hemisphere will be confronted by the same beef production challenges caused by global warming, because these countries are at the same geographical positions in southern latitudes. Global warming is expected to have a more extreme effect on the southern hemisphere than on other continents and will have a negative effect on the beef production environments in these countries. The negative effects will include high ambient temperatures, nutritional stress and altered patterns of animal diseases. Heat stress in beef cattle on veld/savannah is expected to increase as a result of changing weather patterns on a global and regional scale. This may negatively influence food production from beef cattle for the human food chain. Negative effects of increased temperatures and thus heat stress can include lower reproductive rates and weaning weights. The effect of heat stress can be partly addressed by nutritional strategies, such as replacing rapid fermentable carbohydrates with saturated fatty acids and the feeding of more by-pass protein and dietary electrolytes. Global warming will also alter the distribution pattern of animal diseases and the vectors of some of these diseases. This may even include the spread to South American countries. Likewise the nutritional value of natural pastures may be influenced. The effect of global warming on the quality of pastures will depend on whether the global warming is a result of increased carbon dioxide levels or not. An improved understanding of the adaptation of beef cattle to their production environments is important, but adaptation is complex and thus difficult to measure. Fortunately, several proxy-indicators for adaptation such as reproductive, production and health traits are available. The selection of animals and genotypes that are better adapted to the production system, including heat stress, is possible and should be persuade to ensure sustainable beef production in hotter climates.
FAO (2009) Coping with a changing climate: considerations for adaptation and mitigation in agriculture. http://www.fao.org/docrep/012/i1315e/i1315e00.htm
Environment Agency (2009) Climate change, adapting for tomorrow. http://publications.environment-agency.gov.uk/pdf/GEHO0709BQBW-e-e.pdf
Gaughan, J.B., et al. (2009) Response of domestic animals to climate challenges. In: Ebi, K.L., Burton, I. and McGregor, G.R., Eds., Biometeorology of Adaptation to Climate Variability and Change, Springer Science, Heidelberg, 131-170.
Nardone, A., Ronchi, B., Lacetera, N., Ranieri, M.S. and Bernabucci, U. (2010) Effects of climate changes on animal production and sustainability of livestock systems. Livestock Science, 130, 57-69. doi:10.1016/j.livsci.2010.02.011
Thornton, P., et al. (2007) Vulnerability, climate change and livestock—Research opportunities and challenges for poverty alleviation. SAT eJournal, 4, 1-23. www.icrisat.org/journal/SpecialProject/sp7.pdf
McManus, C., et al. (2011) Os desafios da producao animal frente às mudancas climáticas. Revista Veterinária e Zootecnia (Unesp), 18, 142-148. https://uspdigital.usp.br/tycho/producaoacademica/cena/.../P-0.html
McManus, C., et al. (2009) Heat tolerance in Brazilian sheep: Physiological and blood parameters. Tropical Animal Health and Production, 41, 95-101. doi:10.1007/s11250-008-9162-1
Marai, I.F.M. and Haeeb, A.A.M. (2010) Buffalo’s biological functions as affected by heat stress: A review. Livestock Science, 127, 89-109. doi:10.1016/j.livsci.2009.08.001
Gaughan, J.B., Mader, T.L., Holt, S.M. and Lisle, A. (2008) A new heat load index for feedlot cattle. Journal for Animal Science, 86, 226-234. doi:10.2527/jas.2007-0305
Seo, S.N. and Mendelsohn, R. (2008) A structural ricardian analysis of climate change impacts and adaptations in African agriculture. Policy Research Working Paper Series 4603, The World Bank. https://openknowledge.worldbank.org/bitstream/.../WPS4603.txt
Wolfe, M.J., et al. (2008) Developments in breeding cereals for organic agriculture. Euphytica, 163, 323-346. doi:10.1007/s10681-008-9690-9
Yahdjian, M.L. and Sala, O.E. (2008) Climate change impacts on South America Rangelands. Rangelands, 34-39. doi:10.2111/1551-501X(2008)30[34:CCIOSA]2.0.CO;2
Department of Environmental Affairs, Republic of South Africa (2010) National climate change response green paper. http://www.environment.gov.za//Documents/Documents/2010Nov17/climate_change_greenpaper.pdf
Romanini, C.E.B., et al. (2008) Impact of global warming on Brazilian beef production. Proceedings of the Congress on Livestock Environment VIII, Iguassu Falls, 31 August-4 September 2008. http://elibrary.asabe.org/abstract.asp?aid=25597&t=2&redir=&redirType=
Scholtz, M.M., et al. (2010) Environmental-genotype responses in livestock to global warming: A Southern African perspective. South African Journal of Animal Science, 40, 408-413. http://www.sasas.co.za/journals/2010/5
Herrero, M., Hanotte, O., Notenbaert, A. and Thornton, P.K. (2008) Potential of modelling animal genetic resources data in relation to other existing data sets. In: Pilling, D., Rischkowsky, B. and Scherf, B., Eds., Report on the FAO/WAAP Workshop on Production Environment Descriptors for Animal Genetic Resources Report. Caprarola, 6-8 May 2008. www.fao.org/docrep/meeting/022/mb386e.pdf
Smit, B., Mc Nabb, D. and Smihers, J. (1996) Agricultural adaptation to climatic variation. Climatic change, 33, 7-29. doi:10.1007/BF00140511
Hulme, P.H. (2005) Adapting to climate change: Is there scope for ecological management in the face of a global threat. Journal of Applied Ecology, 42, 784-794.
Linington, M.J. (1990) The use of Sanga cattle in beef production. In: Technical Communication No 223, Department of Agriculture, South Africa, 31-37. http://www.cabdirect.org/abstracts/19910191726.html; jsessionid=68526887A6768BEBC40915ECF4C67966
Baccari Jr., F. (2001) Manejo ambiental da vaca leiteira em climas quentes. In: Londrina: Editora da Universidade Estadual de Londrina.
Nardone, A., Ronchi, B., Lacetera, N. and Bernabucci, U. (2006) Climatic effects on productive traits in livestock. Veterinary Research Communications, 30, 75-81. http://dspace.unitus.it/bitstream/2067/139/1/06_Nardone_vet_res_com.pdf
Bonsma, J.C. (1983) Man must measure: Livestock production. Agi Books, Cody.
Silva, R.G. (2000) Introducao a bioclimatalogia animal. Sao Paulo
Salles, M.S.V., Zanetti, M.A., Salles, F.A., Titto, E.A.L. and Conti, R.M.C. (2010) Changes in ruminal fermentation and mineral serum levels in animals kept in high temperature environments. Revista Brasileira de Zootecnia, 39, 883-890. doi:10.1590/S1516-35982010000400025
Bernabucci, U., et al. (2010) Metabolic and hormonal acclimation to heat stress in domesticated ruminants. Animal, 4, 1167-1183. doi:10.1017/S175173111000090X
N??s, I.A. (1989) Princípios de conforto térmico na produ??o animal. ícone, S?o Paulo.
Berman, A., et al. (1985) Upper critical temperatures and forced ventilation effects for high yielding dairy cows in a subtropical climate. Journal of Dairy Science, 68, 1488-1495. doi:10.3168/jds.S0022-0302(85)80987-5
Hahn, G.L. (1999) Dynamic responses of cattle to thermal heat load. Journal of Animal Science, 77, 10-20. www.animal-science.org/content/77/suppl_2/10.full.pdf
West, J.W. (1999) Nutritional strategies for managing the heat stressed dairy cow. Journal of Animal Science, 77, 21-35. http://www.journalofdairyscience.org/article/S0022-0302(10)00717-4/references
Kadzere, C.T., Murphy, M.R., Silanikove, N. and Maltz, E. (2002) Heat stress in lactating dairy cows: A review. Livestock Production Science, 77, 59-91. doi:10.1016/S0301-6226(01)00330-X
Silanikove, N., Shapiro, F. and Shinder, D. (2009) Acute heat stress brings down milk secretion in dairy cows by up-regulating the activity of the milk-borne negative feedback regulatory system. BMC Physiology, 9, 13. http://www.biomedcentral.com/1472-6793/9/13
Morrison, S.R. (1983) Ruminant heat stress: Effect on production and means of alleviation. Journal of Animal Science, 57, 1594-1600. http://europepmc.org/abstract/MED/6370944/reload=0;jsessionid=FPaI4g4WLkzldnQDzLu4.8
Finch, V.A. (1986) Body temperature in beef cattle: Its control and relevance to production in the tropics. Journal of Animal Science, 62, 531-542. http://journalofanimalscience.org/content/62/2/531.full.pdf+html
Du Preez, J.H. (2000) Parameters for the determination and evaluation of heat stress in dairy cattle in South Africa. Journal of Veterinary Research, 67, 263-271. http://www.ncbi.nlm.nih.gov/pubmed/11206394
Thatcher, W.W., Flamenbaum, I., Block, J. and Bilby, T.R. (2010) Interrelationships of heat stress and reproduction in lactating dairy cows. Proceedings of High Plains Dairy Conference 2010, 45-60. www.camposecarrer.com.br/.../2042010-085508-pfizer---novos-enf
Marai, I.F.M., El-Darawany, A.A., Fadiel, A. and Abdel-Hafez, M.A.M. (2007) Physiological traits as affected by heat stress in sheep—A review. Small Ruminant Research, 71, 1-12. doi:10.1016/j.smallrumres.2006.10.003
McDowell, R.E. (1972) Improvement of livestock production in warm climates. W. H. Freeman & Company, San Francisco.
West, J.W. (1994) Interactions of energy and bovine somatotropin with heat stress. Journal of Dairy Science, 77, 2091-2102. doi:10.3168/jds.S0022-0302(94)77152-6
Collier, R.J., Beede, D.K., Thatcher, W.W., Israel, L.A., and Wilcox, C.J. (1982) Influences of environment and its modification on dairy animal health and production. Journal of Dairy Science, 65, 2213-2227. doi:10.3168/jds.S0022-0302(82)82484-3
St-Pierre, N.R., Cobanov, B. and GSchnitkey, G. (2003) Economic losses from heat stress by US livestock industries. Journal of Dairy Science, 86, E52-E77. http://www.sciencedirect.com/science/article/pii/S0022030203740405
Folman, Y., Rosenberg, M., Ascarelli, I., Kaim, M. and Herz, Z. (1983) The effect of dietary and climatic factors on fertility, and on plasma progesterone and oestradiol-17 beta levels in dairy cows. Journal of Steroid Biochemistry, 19, 863-868. doi:10.1016/0022-4731(83)90025-0
Ax, R.L., Gilbert, G.R. and Shook, G.E. (1987) Sperm in poor quality semen from bulls during heat stress have a lower affinity for binding hydrogen-3 heparin. Journal of Dairy Science, 70, 195-200. doi:10.3168/jds.S0022-0302(87)79994-9
Gwazdauskas, F.C. (1985) Effects of climate on reproduction in cattle. Journal of Dairy Science, 68, 1568-1578. doi:10.3168/jds.S0022-0302(85)80995-4
Lucy, M.C. (2002) Reproductive loss in farm animals during heat stress. Proceedings of the 15th American Meteorological Society Biological Systems, 50-53. www.ansci.wisc.edu/jjp1/ansci_repro/.../heatstress/references.html
Ricardo, C., et al. (2004) Factors affecting conception rate after artificial insemination and pregnancy loss in lactating dairy cows. Animal Reproduction Science, 84, 239-255. doi:10.1016/j.anireprosci.2003.12.012
Meyerhoeffer, D.C., Wettemann, R.P., Coleman, S.W. and Wells, M.E. (1985) Reproductive criteria of beef bulls during and after exposure to increased ambient temperature. Journal of Animal Science, 60, 352-357. http://www.journalofanimalscience.org/content/60/2/352.long
Howard, J. (2012) Genetic components of fitness and adaptation: Body temperature regulation. www.bifconference.com/bif2012/...pdf.12
Frisch, J.E. and Vercoe, J.E. (1984) An analysis of growth of different cattle genotypes reared in different environments. Journal of Agricultural Sciences, 103, 137-153. doi:10.1017/S0021859600043409
Koger, M.W., Burns, C., Pahnish, O.F. and Butts, W.T. (1979) Genotype by environment interaction in Hereford cattle: I. Reproductive traits. Journal of Animal Science, 49, 396-402. http://agris.fao.org/openagris/search.do?recordID=US19800540896
Vercoe, J.E. and Frisch, J.E. (1992) Genotype (breed) and environment interaction with particular reference to cattle in the tropics: A review. Asian-Australian Journal of Animal Science, 5, 401-409.
Barlow, R. (1981) Experimental evidence for interaction between heterosis and environment in animals. Animal Breeding Abstracts, 49, 715-737.
Burrow, H.M. (2006) Utilization of diverse breed resources for tropical beef production. Proceedings of the 8th World Congress on Genetics Applied to Livestock Production, Belo Horizonte. www.wcgalp8.org.br/wcgalp8/articles
Burrow, H.M., Griffith, G.R., Barwick, S.A. and Holmes, W.E. (2003) Where to from Brahmans in the Northern Australian herd? Maintaining the economic benefit of earlier infusions of Bos indicus. Proceedings of the Association for the Advancement of Animal Breeding and Genetics, 15, 294-297. www.csiro.au/~/.../RockhamptonBook_CLI_pdf%20Standard.pdf
Prayaga, K.C. (2003) Evaluation of beef cattle genotypes and estimation of direct and maternal genetic effects in a tropical environment. 1. Growth traits. Australian Journal of Agricultural Research, 54, 1013-1025. doi:10.1071/AR03071
Jenkinson, D.M. and Mabon, R.M. (1973) The effects of temperature and humidity on skin surface pH and the ionic composition of skin secretions in Ayrshire cattle. British Veterinary Journal, 129, 282-295. http://www.researchgate.net/publication/18440695_The_effect_of_temperature_and_humidity_on__ skin_surface_pH_and_the_ionic_composition_of_skin_secretions_in_Ayrshire_cattle
Kume, S., Takahashi, S., Kurihara, M. and Aii, T. (1989) Effect of hot environment on Ca and P metabolism in dairy cow. Asian-Australian Journal of Animal Science, 2, 259-260.
Hersom, M.J., Hansen, G.R. and Arthington, J.D. (2010) Effect of dietary cation-anion difference on measures of acid.base physiology and performance in beef cattle. Journal of Animal Science, 88, 374-382. doi:10.2527/jas.2009-1925
Ross, J.G., Spears, J.W. and Garlich, J.D. (1994) Dietary electrolyte balance effects on performance and metabolic characteristics in finishing steers. Journal of Animal Science, 72, 1600-1607. www.journalofanimalscience.org/content/72/6/1600.full.pdf
Escobosa, A., Coppock, C.E., Rowe, L.D., Jenkins, W.L. and Gates, C.E. (1984) Effects of dietary sodium bicarbonate and calcium chloride on physiological responses of lactating dairy cows in hot weather. Journal of Dairy Science, 67, 574-584. doi:10.3168/jds.S0022-0302(84)81341-7
Schneider, P.L., Beede, D.K. and Wilcox, C.J. (1985) Responses of lactating cows to dietary sodium source and quantity and potassium quantity during heat stress. Journal of Dairy Science, 69, 99-110. doi:10.3168/jds.S0022-0302(86)80374-5
Wang, J.P., et al. (2010) Effect of saturated fatty acid supplementation on production and metabolism indices in heat-stressed mid-lactation dairy cows. Journal of Dairy Science, 93, 4121-4127. doi:10.3168/jds.2009-2635
Luna-Nevarez, P., et al. (2010) Growth characteristics, reproductive performance, and evaluation of their associative relationships in Brangus cattle managed in a Chihuahuan Desert production system. Journal of Animal Science, 88, 1891-1904. doi:10.2527/jas.2009-2541
Kattnig, R.M., Winder, J.A., Wallace, J.D. and Bailey, C.C. (1993) Evaluation of biological efficiency of freegrazing beef cows under semi dessert conditions. Journal of Animal Science, 71, 2601-2607. www.animal-science.org/content/71/10/2601.full.pdf
McManus, C., et al. (2009) Heat tolerance in naturalized Brazilian cattle breeds. Livestock Science, 120, 256-264. doi:10.1016/j.livsci.2008.07.014
Tabachnick, W.J. (2010) Challenges in predicting climate and environmental effects on vector-borne disease episystems in a changing world. Journal of Experimental Biology, 213, 946-954. doi:10.1242/jeb.037564
OIE (2008) Report of the Meeting of the OIE Scientific Commission for Animal Diseases. http://www.oie.int/downld/SC/2008/A_SCAD_feb2008.pdf
Calistri, P., et al. (2004) Bluetongue in Italy: Part I. Veterinaria Italaliana, 40, 243-251. http://www.ncbi.nlm.nih.gov/pubmed/20419672
Wilson, W.C., Mecham, J.O., Schmidtmann, E., Jimenezsanchez, C., Herrero M. and Lager, I. (2009) Current status of bluetongue virus in the Americas. http://ddr.nal.usda.gov/dspace/bitstream/10113/23231/1/IND44152599.pdf
Wilson, A. and Mellor, P. (2008) Bluetongue in Europe: Vectors, epidemiology and climate change. Parasitology Research, 103, 69-77. doi:10.1007/s00436-008-1053-x
Purse, B.V., Brown, H.E., Harrup, L., Mertens, P.P. and Rogers, D.J. (2008) Invasion of bluetongue and other orbivirus infections into Europe: The role of biological and climatic processes. Revue Scientifique et Technique, 27, 427-442. http://www.oie.int/doc/ged/D5503.PDF
Mellor, P.S. and Wittmann E.J. (2002) Bluetongue virus in the Mediterranean basin 1998-2001. Veterinary Journal, 164, 20-37. doi:10.1053/tvjl.2002.0713
Gerry, A.C. and Mullens, B.A. (2000) Seasonal abundance and survivorship of Culicoides sonorensis (Diptera: Ceratopogonidae) at a southern California dairy, with reference to potential bluetongue virus transmission and persistence. Journal of Medical Entomology, 37, 675-688. doi:10.1603/0022-2585-37.5.675
Wittmann, E.J., Mellor, P.S. and Baylis, M. (2002) Effect of temperature on the transmission of orbiviruses by the biting midge, Culicoides sonorensis. Medical and Veterinary Entomology, 16, 147-156. doi:10.1046/j.1365-2915.2002.00357.x
Ward, M.P. and Carpenter, T.E. (1996) Simulation modeling of the effect of factors on bluetongue virus infection in cattle herds. II. Model experimentation. Preventative Veterinary Medicine, 27, 13-22. doi:10.1016/0167-5877(95)00567-6
St George, T.D. (1985) Epidemiology of bluetongue in Australia: The vertebrate hosts. In: Barber, T.L. and Jochim, M.M., Eds., Bluetongue and Related Orbiviruses, Alan R. Liss, New York, 519-525.
Gubler, D.J. (2002) The global emergence/resurgence of arboviral diseases as public health problems. Archives of Medical Research, 33, 330-342. http://www.arcmedres.com/article/S0188-4409(02)00378-8/abstract
Anyamba, A., Linthicum, K.J. and Tucker, C.J. (2001) Climate-disease connections: Rift Valley fever in Kenya. Cadernos de Saúde Pública, 17, 133-140. http://www.scielosp.org/pdf/csp/v17s0/3889.pdf
Cêtre-Sossah, C., et al. (2009) Evaluation of a commercial competitive ELISA for the detection of antibodies to Rift Valley fever virus in sera of domestic ruminants in France. Preventative Veterinary Medicine, 90, 146-149. http://www.sciencedirect.com/science/article/pii/S0167587709000774
Anyamba, A., et al. (2009) Prediction of a Rift Valley fever outbreak. Proceedings of the National Academy of Science USA, 106, 955-959. www.pnas.org/content/106/3/955.full
Davies, F.G., Linthicum, K.J. and James, A.D. (1985) Rainfall and epizootic Rift Valley fever. Bulletin of the World Health Organization, 63, 941-943.
Linthicum, K.J., Bailey, C.L., Davies, F.G. and Tucker, C.J. (1987) Detection of Rift Valley fever viral activity in Kenya by satellite remote sensing imagery. Science, 235, 1656-1659. http://www.sciencemag.org/content/235/4796/1656.long
Glantz, M.H. (1991) Introduction. In: Glantz, M.H., Katz, R.W. and Nicholls, N., Eds., Teleconnections Linking World Wide Climate Anomalies: Scientific Basis and Societal Impact, Cambridge University Press, New York, 1-12.
OIE (2009) Rift Valley fever. Technical Disease Cards, 2. www.oie.int/fileadmin/.../RIFT_VALLEY_FEVER_FINAL.pdf
Linthicum, K.J., et al. (1999) Climate and satellite indicators to forecast Rift Valley fever epidemics in Kenya. Science, 285, 397-400. http://www.sciencemag.org/content/285/5426/397.long
Molion, L.C.B. and Toledo, M.R. (1994) Seca de 1992/93 em Alagoas. Proceedings of the VIII Congresso de Meteorologia. www.cbmet.com/.../22-dfa4c3643abd78c04a2fe9
Sajid, S.M., Iqbal, Z., Khan, M.N., Muhammad, G. and Khan, M.K. (2009) Prevalence and associated risk factors for bovine tick infestation in two districts of lower Punjab, Pakistan. Preventative Veterinary Medicine, 92, 386-391. http://www.sciencedirect.com/science/article/pii/S0167587709002554
Jouda, F., Perret, J. and Gern, L. (2004) Ixodes ricinus density, and distribution and prevalence of Borrelia burgdorferi sensu lato infection along an altitudinal gradient. Journal of Medical Entomology, 41, 162-169. http://www.bioone.org/doi/full/10.1603/0022-2585-41.2.162
Cassis, G. (1998) Biodiversity loss: A human health issue. Medical Journal of Australia, 169, 568-569. www.unboundmedicine.com/.../Biodiversity_loss:_a_human_health
Olwoch, J.M., Reyers, B. and van Jaarsveldt, A.S. (2009) Host-parasite distribution patterns under simulated climate: Implications for tick-borne diseases. International Journal of Climatology, 29, 993-1000. http://onlinelibrary.wiley.com/doi/10.1002/joc.1801/pdf
Muraguri, G.R., Kiara, H.K. and McHardy, N. (1999) Treatment of east coast fever: A comparison of parvaquone and buparvaquone. Veterinary Parasitology, 87, 25-37. http://www.sciencedirect.com/science/article/pii/S0304401799001545
Olwoch, J.M., Reyers, B., Engelbrecht, F.A. and Erasmus, B.F.N. (2008) Climate change and the tick-borne disease, Theileriosis (East Coast fever) in sub-Saharan Africa. Journal of Arid Environments, 72, 108-120. http://www.ehrn.co.za/publications/download/33.pdf
Schetters, T.P.M., Arts, G., Niessen, R. and Schaap, D. (2010) Development of a new score to estimate clinical east coast fever in experimentally infected cattle. Veterinary Parasitology, 167, 255-259. http://www.sciencedirect.com/science/article/pii/S0304401709005603
Pegram, R.G., Lemche, J. and Chizyuka, H.G.B. (1989) Effect of tick control on live weight gain of cattle in central Zambia. Medical and Veterinary Entomology, 3, 313-320. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2915.1989.tb00234.x/pdf
Uilenberg, G. (1983) Heartwater (Cowdria ruminantium infection): Current status. Advances in Veterinary Science and Comparative Medicine, 27, 427-480. www.upei.ca/~cavepm/.../O'Callaghan%2520et%2520al%25201998
Uilenberg, G. (1990) Present and future possibilities for the control of cowdriosis and anaplasmosis. Veterinary Quarterly, 12, 39-45. www.researchgate.net/.../20973835_Present_and_future_possibilities
Horner, M.R. (1990) Amblyomma variegatum—Um novo carrapato para a América do Sul? Technical Communication. http://www.cnpgc.embrapa.br/publicacoes/cot/COT36.html
Robinson, J.B., et al. (2009) New approaches to detection and Identification of Rickettsia africae and Ehrlichia ruminantium in Amblyomma variegatum (acari: ixodidae) ticks from the Caribbean. Journal of Medical Entomology, 46, 942-951. doi:10.1603/033.046.0429
Leite, R.C., Faccini, J.L.H. and Granger, S.A. (2001) Occurrence of ticks in cattle in the state of Roraima, northern Brazil. Revista Brasileira de Parasitologia Veterinária, 10, 49-50. http://www.ufrrj.br/rbpv/1012001/c10149_50.pdf
Leng, R.A. (1984) Supplementation of tropical and subtropical pastures for ruminant production. In: Gilchrist, F.M.C. and Macki, R.I., Eds., Herbivore Nutrition in the Tropics and Subtropics, 129-144. http://www.cabdirect.org/abstracts/19861486176.html
Sage, R. and Monson, R. (1999) C4 plant biology. http://books.google.com/?id=H7Wv9ZImW-QC&pg= PA228
Taub, D. (2010) Effects of rising atmospheric concentrations of carbon dioxide on plants. Nature Education Knowledge, 3, 21. http://www.nature.com/scitable/knowledge/library/effects-of-rising-atmospheric-concentrations-of-carbon-13254108
Poorter, H. and Navas, M.L. (2003) Plant growth and competition at elevated CO2: On winners, losers and functional groups. New Phytologist, 157, 175-198. doi:10.1046/j.1469-8137.2003.00680.x
Blackburn, H. and Mezzadra, C. (2006) Policies for the management of animal genetic resources. Proceedings of the 8th World Congress on Genetics Applied to Livestock Production. Belo Horizonte. www.wcgalp8.org.br/wcgalp8/articles
Prayaga, K.C. and Henshall, J.M., (2005) Adaptability in tropical beef cattle: Genetic parameters of growth, adaptive and temperament traits in a crossbred population. Australian Journal of Experimental Agriculture, 45, 971-983. doi:10.1071/EA05045
Barker, J.S.F. (2009) Defining fitness in natural and domesticated population. In adaptation and fitness in animal populations. In: van der Werf, J.H.J., Graser, H.-U., Frankham, R. and Gondoro, C., Eds., Evolutionary and Breeding Perspectives on Genetic Resource Management, Springer, Amsterdam.
Bonsma, J.C. (1980) Livestock production: A global approach. Tafelberg Publishers, Cape Town.
McManus, C., et al. (2009) Heat tolerance in naturalized Brazilian cattle breeds. Livestock Science, 120, 256-264. doi:10.1016/j.livsci.2008.07.014
McManus, C., Louvandini, H. and Paiva S. (2008) Examples of different aspects of adaptive fitness, how they can be measured and possible proxi-indicators. In: Pilling, D., Rischkowsky, B. and Scherf, B., Eds., Report on the FAO/ WAAP workshop on production environment descriptors for animal genetic resources report, Caprarola, 6-8 May 2008.
Spickett, A.M., de Klerk, D., Enslin, C.B. and Scholtz, M.M. (1989) Resistance of nguni, bonsmara and hereford cattle to ticks in a bushveld region of South Africa. Onderstepoort Journal of Veterinary Research, 56, 245-251. www.ncbi.nlm.nih.gov/pubmed/2626263
Scholtz, M.M., Spickett, A.M., Lombard, P.E. and Enslin, C.B. (1991) The effect of tick infestation on the productivity of cows of three breeds of cattle. Onderstepoort Journal of Veterinary Research, 58, 71-74. www.ncbi.nlm.nih.gov/pubmed/1881659
Raberg, l., Sim, D. and Read, A.F. (2007) Disentangling genetic variation for resistance and tolerance to infectious diseases in animals. Science, 318, 812-814. http://lac-repo-live7.is.ed.ac.uk/bitstream/1842/2140/1/Raberg%20text%20figs%20SOM.pdf
McManus, C., Cobuci, J., Braccini Neto, J. and Paiva, S.R. (2011) Decision making in animal breeding programs and their consequences for animal production. Revista Brassileira de Reprodu??o Animal, 35, 69-76. http://www.cbra.org.br/pages/publicacoes/rbra/v35n2/RB358%20McManus%20pag69-76.pdf
McManus, C., et al. (2011) The challenge of sheep farming in the tropics: Aspects related to heat tolerance. Brazilian Journal of Animal Science, 40, 107-120. www.sbz.org.br/revista/artigos/66266.pdf
Verneque, R.S., et al. (2011) Melhoramento genético de gado de leite no Brasil, sociedade Brasileira de melhoramento animal. http://sbmaonline.org.br/anais/viii/palestras/pdfs/7.pdf
Bertipaglia, E.C.A., Silva, R.G., Cardoso, V. and Maia, A.S.C. (2007) Estimativas de parametros genéticos e fenotípicos de características do pelame e de desempenho reprodutivo de vacas holandesas em clima tropical. Revista Brasileira de Zootecnia, 36, 350-359. doi:10.1590/S1516-35982007000200011
Roberto, J.V.B., Souza, B.B., Silva, A.L.N., Justiano, S.V. and Freitas, M.M.S. (2010) Parametros hematológicos de caprinos de corte submetidos a diferentes níveis de suplementa??o no Semi-árido Paraibano. Revista Caatinga, 23, 127-132.
McManus, C. and Miranda, R.M. (1997) Compara??o das ra?as de ovinos santa inês e bergamácia no distrito federal. Revista Brasileira de Zootecnia, 26, 627-636.
Quesada, M., McManus, C., Couto, F.A. and Araújo, D. (2001) Tolerancia ao calor de duas ra?as de ovinos deslanados no Distrito Federal. Revista Brasileira de Zootecnia, 30, 1021-1026.
Madalena, F.E. (2005) Considerations on the management of animal genetic resources in Latin America. EAAP/SLU/FAO/ICAR Workshop on Sustainable Management of Animal Genetic Resources: Linking Perspectives globally, Uppsala, 2 June 2005.
Scholtz, M.M., Nengovhela, N.B., McManus, C., Theunissen, A and Okeyo, A.M. (2012) Political, economical and social challenges for beef production in Southern Africa. In: Developing Countries: Political, Economic and Social Issues, Nova Science Publishers Inc., Hauppauge, New York, (In press).
Timon, V.M. (1993) Strategies for sustainable development of agriculture—An FAO perspective. http://www.fao.org/docrep/004/T0582E/T0582E05.htm
Scholtz, M.M., Bester, J., Mamabolo, J.M. and Ramsay, K.A. (2008) Results of the national survey undertaken in South Africa with emphasis on beef. Applied Animal Husbandry and Rural Development, 1, 1-9. www.sasas.co.za/aahrd/1193
Scholtz, M.M. (2011) Beef breeding in South Africa. 2nd Edition, ARC, Pretoria.
Theunissen, A. (2011) Characterization of breed additive and heterosis effect in beef cattle using experimental results. M.Sc. Thesis, University of the Free State, Bloemfontein.
Scholtz, M.M. and Theunissen, A. (2010) The use of indigenous cattle in terminal crossbreeding to improve beef cattle in Sub-Saharan Africa. Animal Genetic Resources, 46, 33-36.
Prayaga, K.C., Barendse, W. and Burrow, H.M. (2006) Genetics of tropical adaptation. Proceedings of the 8th World Congress on Genettics Applied to Livestock Production. Belo Horizonte. www.wcgalp8.org.br/wcgalp8/articles
IPCC (2011) Climate change: Impacts, adaptation and vulnerability. Summary for policy makers. http://www.ipcc.cg/SPM13ap07.pdf
Jones, P.G. and Thornton, P.K. (2003) The potential impacts of climate change in tropical agriculture: The case of maize in Africa and Latin America in 2055. Global and Environmental Change, 13, 51-59. doi:10.1016/S0959-3780(02)00090-0
Howden, S.M., et al. (2007) Adapting agriculture to climate change. Proceedings of the National Academy of Science, 104, 19691-19696. doi:10.1073/pnas.0701890104