Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-10T19:37:13.121Z Has data issue: false hasContentIssue false
  • English
  • Français

Biotechnology — the possibilities

Published online by Cambridge University Press:  25 May 2016

J. J. Robinson  and
T. G. McEvoy
J. J. Robinson
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
T. G. McEvoy
Affiliation:
Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB
Get access

Abstract

A review of recent trends in animal science is used to provide a flavour of how, from a purely technical viewpoint, evolving biotechnology may influence animal production systems in the foreseeable future. The areas considered are: the nutritive value of foods and forages, animal health and welfare, the temporary alteration of production traits to meet an immediate goal, and the permanent alteration of traits to meet an immediate goal, and the permanent alteration of traits by genetic selection or by the production of transgenic animals. In improving the nutritive value of foods, modern biotechnology has produced food grade enzymes and amino acid supplements. Genetically engineered cereals, grasses and legumes, rich in essential amino acids, are on the horizon. In disease prevention, genetically engineered vaccines may be preferable to conventional ones in that they have a defined composition, with a degree of control during manufacture which allows amino acid substitution within the peptide to confer specificity to a particular serotype.

Modern techniques with the potential to promote a transitory alteration in a production trait involve either immunization against an inhibitory biochemical pathway or active promotion of a stimulatory pathway by the administration of recombinant-derived hormones and proteins. Strategies for permanent alteration of traits by gene transfer, initially directed to enhancing growth, are now shifting in emphasis towards the transfer of genes for enhanced nutrient digestion, disease resistance, and improved product quality. The role of recombinant DNA technology in the development of diagnostic probes for use in genetic selection programmes and in the monitoring of disease is also expanding rapidly.

In all areas of animal science, molecular biology is promoting a better understanding of the underlying mechanisms that control production. By so doing it should ensure that science fulfils its primary rôle of providing animal production industries with a range of options from which to choose the most acceptable way forward.

Keywords

biotechnology
Type
Research Article
Information
Animal Production , Volume 57 , Issue 3 , December 1993 , pp. 335 - 352
Copyright
Copyright © British Society of Animal Science 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Agrawala, P. L., Wagner, V. A. and Geldermann, H. 1992. Sex determination and milk protein genotyping of preimplantation stage bovine embryos using multiplex PCR. Theriogenology 38: 969–978.CrossRefGoogle ScholarPubMed
Altenbach, S. B., Pearson, K. W., Meeker, G., Staraci, L. C. and Sun, S. S. M. 1989. Enhancement of the methionine content of seed proteins by the expression of a chimeric gene encoding a methionine-rich protein in transgenic plants. Plant Molecular Biology 13: 513–522.CrossRefGoogle ScholarPubMed
Anderson, G. B. 1987. Identification of embryonic sex by detection of H-Y antigen. Theriogenology 27:81–97.CrossRefGoogle Scholar
Armstrong, D. G. 1986. The potential implications of biotechnology in animal nutrition. In Recent advances in animal nutrition (ed. Haresign, W. and Cole, D. J. A.), pp. 89–103. Butterworths, London.CrossRefGoogle Scholar
Barnes, F., Endebrock, M., Looney, C., Powell, R., Westhusin, M. and Bondioli, K. 1993. Embryo cloning in cattle: the use of in vitro matured oocytes. Journal of Reproduction and Fertility 97: 317–320.CrossRefGoogle ScholarPubMed
Bass, J. J. and Gluckman, P. D. 1990. Regulation of growth by the growth hormone axis. Proceedings of the New Zealand Society of Animal Production 50: 73–79.Google Scholar
Beerman, D. H. and Boyd, R. D. 1992. Recent developments in the use of exogenously administered peptides and polypeptides to influence animal growth. In The control of fat and lean deposition (ed. Buttery, P. J., Boorman, K. N. and Lindsay, D. B.), pp. 249–275. Butterworth Heinemann, Oxford.CrossRefGoogle Scholar
Beers, S. and Jongbloed, A. W. 1992. Effect of supplementary Aspergillus niger phytase in diets for piglets on their performance and apparent digestibility of phosphorus. Animal Production 55:425–430.Google Scholar
Beever, D. E., Dawson, J. M. and Buttery, P. J. 1992. Control of fat and lean deposition in forage fed cattle. In The control of fat and lean deposition (ed. Buttery, P. J., Boorman, K. N. and Lindsay, D. B.), pp. 211–229. Butterworth Heinemann, Oxford.CrossRefGoogle Scholar
Bergen, W. G. and Merkel, R. A. 1991. Body composition of animals treated with partitioning agents: implications for human health. FASEB Journal 5: 2951–2957.CrossRefGoogle ScholarPubMed
Betteridge, K. J., Smith, C., Stubbings, R. B., Xu, K. P. and King, W. A. 1989. Potential genetic improvement of cattle by fertilization of fetal oocytes in vitro. Journal of Reproduction and Fertility, supplement 38, pp. 87–98.Google ScholarPubMed
Biggers, J. D. 1986. The potential use of artificially produced monozygotic twins for comparative experiments. Theriogenology 26:1–25.CrossRefGoogle ScholarPubMed
Blancou, J. 1992. Veterinary biotechnology newsletter, volume 2, pp. 78–93. Office International des Épizooties.Google Scholar
Blecha, F. 1991. Cytokines: application in domestic food animals. Journal of Dairy Science 74: 328–339.CrossRefGoogle ScholarPubMed
Bourne, J. and Bostock, C. 1992. Disease control. In Innovation in agro-biotechnology. Case study on animal production (ed. Thelwall, A. D.), pp. 71–83. Commission of the European Communities.Google Scholar
Brackett, B. G. and Zuelke, K. A. 1993. Analysis of factors involved in the in vitro production of bovine embryos. Theriogenology 39: 43–64.CrossRefGoogle Scholar
Briesacher, S. L., May, T., Grigsby, K. N., Kerley, M. S., Anthony, R. V. and Paterson, J. A. 1992. Use of DNA probes to monitor nutritional effects on ruminal prokaryotes and Fibrobacter succinogenes S85. Journal of Animal Science 70:289–295.CrossRefGoogle ScholarPubMed
Buckrell, B. C., Buschbeck, C., Gartley, C. J., Kroetsch, T., McCutcheon, W., Martin, J., Penner, W. K. and Walton, J. S. 1992. A breeding trial using a transcervical technique for artificial insemination in sheep. Proceedings of the twelfth international congress on animal reproduction, The Hague, vol. 3, pp. 1531–1533.Google Scholar
Bulfield, G. 1992. Animal breeding and genetics. In Innovation in agro-biotechnology. Case study on animal production (ed. Thelwall, A. D.), pp. 84–93. Commission of the European Communities.Google Scholar
Buttery, P. J. 1990. Interactions between diet and the response of ruminants to metabolic modifiers. In Recent advances in animal nutrition (ed. Haresign, W. and Cole, D. J. A.), pp. 201–209. Butterworths, London.CrossRefGoogle Scholar
Buttery, P. J. 1993. Manipulating performance and carcass quality. In Livestock science into practice (ed. Ducker, M. J.), pp. 29–43. Royal Agricultural Society of England and British Society of Animal Production.Google Scholar
Chen, H. Y., Garber, E. A., Rosenblum, C. I., Taylor, J. E., Kopchick, J. J., Smith, R. G., Smith, J. and Mills, E. O. 1989. Expression of bovine growth hormone gene in transgenic chickens. Journal of Cell Biochemistry, suppl. 13B, p. 178.Google Scholar
Chesson, A. 1991. Impact of biotechnology on livestock feeds and feeding. Mededelingen van de Faculteit Landboutwwetenschappen Rijksuniversiteit, Gent. 56: (4a), 1365–1391.Google Scholar
Chesson, A. 1993. Probiotics and other intestinal mediators. In Principles of pig science (ed. Cole, D. J. A., Wiseman, J. and Varley, M. A.). Nottingham University Press In press.Google Scholar
Clark, A. J. 1988. Gene transfer in animal production. In Animal breeding opportunities occasional publication, British Society of Animal Production, no. 12, pp. 1–14.Google Scholar
Clark, A. J., Bessos, H., Bishop, J. O., Brown, P., Harris, S., Lathe, R., McClenaghan, M., Prowse, C., Simons, J. P., Whitelaw, C. B. A. and Wilmut, I. 1989. Expression of human anti-haemophilic factor IX in the milk of transgenic sheep. Bio-technology 7: 487–492.Google Scholar
Clarke, S. D. 1993. Regulation of fatty acid gene expression: an approach for reducing fat accumulation. Journal of Animal Science 71:1957–1965.CrossRefGoogle ScholarPubMed
Close, W. 1992. Enzymes in pig and poultry production. R&H Hall Technical Bulletin No. 3. Dublin.Google Scholar
Crittenden, L. B. and Salter, D. W. 1990. Expression of retroviral genes in transgenic chickens. In Genetic engineering of animals (ed. Hansel, W. and Weir, B. J.), Journal of Reproduction and Fertility, supplement 41, pp. 163–171.Google Scholar
Flint, D. J. 1992. Regulation of fat and lean deposition by the immune system. In The control of fat and lean deposition (ed. Buttery, P. J.Boorman, K. N. and Lindsay, D. B.), pp. 299–313. Butterworth Heinemann, Oxford.CrossRefGoogle Scholar
Flint, H. J. 1993. Molecular probes for studying changes in microbial population in the gut. Agricultural and Food Research Council News, p. 10, July 1993. AFRC Central Office, Swindon.Google Scholar
Flint, H. J., Thomson, A. M. and Bisset, J. 1988. Plasmid-associated transfer of tetracycline resistance in Bacteroides ruminicola. Applied and Environmental Microbiology 54: 555–560.CrossRefGoogle ScholarPubMed
Flint, H. J., Zhang, J-X., Avguštin, G., Daniel, A. and Martin, J. 1993. Applications of molecular genetics to anaerobic rumen bacteria. In Manipulation of rumen microorganisms (ed. El-Shazly, K.) In press.Google Scholar
Foote, R. H. 1982. Cryopreservation of spermatozoa and artificial insemination: past, present, and future. Journal of Andrology 3: 85–100.CrossRefGoogle Scholar
Forsberg, C. W., Cheng, K-J., Krell, P. J. and Phillips, J. P. 1993. Establishment of rumen microbial gene pools and their manipulation to benefit digestion by domestic animals. Proceedings of the seventh world conference on animal production, Edmonton, Alberta, vol. 1, pp. 281–316.Google Scholar
Gandolfi, F., Brevini, T. A. L., Richardson, L., Brown, C. R. and Moor, R. M. 1989. Characterization of proteins secreted by sheep oviduct epithelial cells and their function in embryonic development. Development 106: 303–312.CrossRefGoogle ScholarPubMed
Gannon, F., Powell, R., Barry, T., McEvoy, T. G. and Sreenan, J. M. 1990. Transgenic farm animals. Journal of Biotechnology 16:155–170.CrossRefGoogle ScholarPubMed
Georges, M. and Massey, J. M. 1991. Velogenetics, or the synergistic use of marker assisted selection and germ-line manipulation. Theriogenology 35:151–159.CrossRefGoogle Scholar
Gibson, J. P. and Smith, C. 1989. The incorporation of biotechnologies into animal breeding strategies. In Animal biotechnology. Comprehensive biotechnology, first supplement (ed. Babiuk, L. A.Phillips, J. P. and Moo-Young, M.), pp. 203–231. Pergamon Press, Oxford.Google Scholar
Gilbert, H. J. and Hazlewood, G. P. 1991. Genetic modification of fibre digestion. Proceedings of the Nutrition Society 50:173–186.CrossRefGoogle ScholarPubMed
Gill, M., Beever, D. E., Buttery, P. J., England, P., Gibb, M. J. and Baker, R. D. 1987. The effect of oestradiol-17β implantation on the response in voluntary intake, live-weight gain and body composition, to fish meal supplementation of silage offered to growing calves. Journal of Agricultural Science, Cambridge 108: 9–16.CrossRefGoogle Scholar
Gordon, I. 1990. In vitro maturation (IVM) and fertilization (IVF) of cattle ova. Embryo Transfer Newsletter 8: 6–11.Google Scholar
Gordon, I. and Lu, K. H. 1990. Production of embryos in vitro and its impact on livestock production. Theriogenology 33: 77–87.CrossRefGoogle Scholar
Gray, C. W., Morgan, P. M. and Kane, M. T. 1992. Purification of an embryotrophic factor from commercial bovine serum albumin and its identification as citrate. Journal of Reproduction and Fertility 94: 471–480.CrossRefGoogle ScholarPubMed
Gregg, K., Allen, G., Baucoup, T., Klieve, A. and Lincoln, M. 1993. Practical genetic engineering of rumen bacteria. In Recent advances in animal nutrition in Australia (ed. Farrell, D. J.), pp. 13–21. University of New England, Armidale.Google Scholar
Greve, T. and Madison, V. 1991. In vitro fertilization in cattle: a review. Reproduction Nutrition Développement 31: 147–157.CrossRefGoogle ScholarPubMed
Halbert, G. W., Dobson, H., Walton, J. S., Sharpe, P. and Buckrell, B. C. 1990. Field evaluation of a technique for transcervical intrauterine insemination of ewes. Theriogenology 33:1231–1243.CrossRefGoogle Scholar
Hall, J., Ali, S., Surani, M. A., Hazlewood, G. P., Clark, A. J., Simons, J. P., Hirst, B. H. and Gilbert, H. J. 1993. The generation of non-ruminant transgenic animals with cellulolytic capacity. Animal Production 56:458 (abstr.).Google Scholar
Harlander, S. 1992. Social, moral and ethical issues in food biotechnology. Food Science and Technology Today 6: 66–70.Google Scholar
Hart, I. C. 1988. Altering the efficiency of milk production in dairy cows with somatotrophin. In Nutrition and lactation in the dairy cow (ed. Garnsworthy, P. C.), pp. 232–247. Butterworths, London.CrossRefGoogle Scholar
Hazlewood, G. P., Gilbert, H. J., Rixon, J. E., Sharp, R. S. and O'Donnell, A. G. 1993. The use of genetically engineered Lactobacillus plantarum in the ensilage process. Animal Production 56: 458 (abstr.).Google Scholar
Herr, C. M. and Reed, K. C. 1991. Micromanipulation of bovine embryos for sex determination. Theriogenology 35: 45–54.CrossRefGoogle Scholar
Heyner, S., Shah, N., Smith, R. M., Watson, A. J. and Schultz, G. A. 1993. The role of growth factors in embryo production. Theriogenology 39:151–161.CrossRefGoogle Scholar
Hossepian de Lima, V. F. M., Moreira-Filho, C. A., De Bern, A. R. and Jorge, W. 1993. Sex determination of murine and bovine embryos using cytotoxicity and immunofluorescence assays. Theriogenology 39:1343–1352.CrossRefGoogle Scholar
Johnson, L. A., Flook, J. P. and Hawk, H. W. 1989. Sex preselection in rabbits: live births from X sperm and Y sperm separated by DNA and cell sorting. Biology of Reproduction 41:199–203.CrossRefGoogle ScholarPubMed
Jones, R. J. and Megarrity, R. G. 1986. Successful transfer of DHP degrading bacteria from Hawaiian goats to Australian ruminants to overcome the toxicity of Leucaena. Australian Veterinary Journal 63:259–262.CrossRefGoogle ScholarPubMed
Kang, Y., Jimenez-Flores, R. and Richardson, T. 1986. Casein genes and genetic engineering of the caseins. In Genetic engineering of animals: an agricultural perspective (ed. Evans, J. W. and Hollaender, A.), pp. 95–111. Plenum Press, New York.CrossRefGoogle Scholar
Keane, M. G. and Drennan, M. J. 1987. Lifetime growth and carcass composition of heifers and steers nonimplanted or sequentially implanted with anabolic agents. Animal Production 45: 359–369.Google Scholar
Kelly, D. and King, T. P. 1991. Influence of lactation products on the temporal expression of histo blood-group antigens in the intestines of suckling pigs: lectin histochemical and immuno-histochemical analysis. Histochemical Journal 23: 55–60.CrossRefGoogle Scholar
Ketaren, P. P., Batterham, E. S., Dettmann, E. B. and Farrell, D. J. 1993. Phosphorus studies in pigs. 3. Effect of phytase supplementation on the digestibility and availability of phosphorus in soya-bean meal for grower pigs. British Journal of Nutrition 70: 289–311.CrossRefGoogle ScholarPubMed
Krimpenfort, P., Rademakers, A., Eyestone, W., Schans, A. van der, Broek, S. van den, Kooiman, P., Kootwijk, E., Platenburg, G., Pieper, F., Strijker, R. and Boer, H. de. 1991. Generation of transgenic dairy cattle using in vitro embryo production. Bio-technology 9: 844–847.Google ScholarPubMed
Leibo, S. P. and Loskutoff, N. M. 1993. Cryobiology of in vitro-derived bovine embryos. Theriogenology 39: 81–94.CrossRefGoogle Scholar
Leighton Jones, J. 1991. DNA probes: applications in the food industry. Trends in Food Science and Technology 2: 28–32.CrossRefGoogle Scholar
Lobley, G. E., Connell, A., Morris, B., Anderson, R., Clayton, J., Williams, P. E. V. and Nevison, I. M. 1992. The effect of active immunization against gonadotropin-hormone-releasing-hormone on growth performance and sample joint composition of bulls. Animal Production 55: 193–202.Google Scholar
Lucas-Hahn, A. 1992. Status of cryopreserving micromanipulated bovine embryos. Embryo Transfer Newsletter 10:18–23.Google Scholar
McEvoy, T. G., Gannon, F. and Sreenan, J. M. 1992b. Gene transfer in fish: potential and practice. Animal Biotechnology 3: 221–243.CrossRefGoogle Scholar
McEvoy, T. G., Robinson, J. J. and Sreenan, J. M. 1992a. A role for transgenic animals in food production. Trends in Food Science and Technology 3:294–302.CrossRefGoogle Scholar
McInnes, C. J. 1993. Current research on ovine cytokines. British Veterinary Journal 149: 371–386.CrossRefGoogle ScholarPubMed
McNeilly, A. S., Picton, H. M., Campbell, B. K. and Baird, D. T. 1991. Gonadotrophic control of follicle growth in the ewe. In Reproduction in domestic ruminants II (ed. Lamming, G. E., Flint, A. P. F. and Weir, B. J.), Journal of Reproduction and Fertility, supplement 43, pp. 177–186.Google Scholar
Massip, A., Mermillod, P., Wils, C. and Dessy, F. 1993. Effects of dilution procedure and culture conditions after thawing on survival of frozen bovine blastocysts produced in vitro. Journal of Reproduction and Fertility 97:65–69.CrossRefGoogle ScholarPubMed
Mepham, T. B. 1993. Biotechnology — the ethics. Animal Production 57:353–359.Google Scholar
Mercier, J. C. 1986. Genetic engineering applied to milk producing animals: some expectations. In Exploiting new technologies in animal breeding (ed. Smith, C., King, J. W. B. and McKay, J. C.), pp. 121–131. Oxford University Press, Oxford.Google Scholar
Moore, E., McDonnell, P. and Headon, D. R. 1993. Molecular cloning and expression of rat liver desaturase cDNAs. Journal of Biological Chemistry In press.Google Scholar
Morris, D. G., McDermott, M. G., Diskin, M. G., Morrison, C. A., Swift, P. J. and Sreenan, J. M. 1993. Effect of immunization against synthetic peptide sequences of bovine inhibin α-subunit on ovulation rate and twincalving rate in heifers. Journal of Reproduction and Fertility 97: 255–261.CrossRefGoogle ScholarPubMed
Niemann, H. 1991. Cryopreservation of ova and embryos from livestock: current status and research needs. Theriogenology 35:109–124.CrossRefGoogle Scholar
Palmiter, R. D., Brinster, R. L., Hammer, R. E., Trumbauer, M. E., Rosenfeld, M. G., Birnberg, N. C. and Evans, R. M. 1982. Dramatic growth of mice that develop from eggs microinjected with metallothionein growth hormone fusion genes. Nature, London 300: 611–615.CrossRefGoogle ScholarPubMed
Parks, J. E. and Ruffing, N. A. 1992. Factors affecting low temperature survival of mammalian oocytes. Theriogenology 37: 59–73.CrossRefGoogle Scholar
Pell, J. M. and Bates, P. C. 1990. The nutritional regulation of growth hormone action. Nutrition Research Reviews 3: 163–192.CrossRefGoogle ScholarPubMed
Pell, J. M., Johnsson, I. D., Pullar, R. A., Morrell, D. J., Hart, I. C., Holder, A. T. and Aston, R. 1989. Potentiation of growth hormone activity in sheep using monoclonal antibodies. Journal of Endocrinology 120: R15–R18.CrossRefGoogle ScholarPubMed
Pettersson, D., Graham, H. and Åman, P. 1990. Enzyme supplementation of broiler chicken diets based on cereals with endosperm cell walls rich in arabinoxylans or mixedlinked β-glucans. Animal Production 51:201–207.Google Scholar
Pieterse, M. C., Vos, P. L. A. M., Kruip, Th. A. M., Wurth, Y. A., Beneden, Th. H. van, Willemse, A. H. and Taverne, M. A. M. 1991. Transvaginal ultrasound guided follicular aspiration of bovine oocytes. Theriogenology 35: 857–861.CrossRefGoogle ScholarPubMed
Prather, R. S., Barnes, F. L., Sims, M. M., Robl, J. M., Eyestone, W. H. and First, N. L. 1987. Nuclear transplantation in the bovine embryo: assessment of donor nuclei and recipient oocytes. Biology of Reproduction 37: 859–866.CrossRefGoogle Scholar
Prather, R. S., Sims, M. M. and First, N. L. 1989. Nuclear transplantation in early pig embryos. Biology of Reproduction 41: 414–418.CrossRefGoogle ScholarPubMed
Pursel, V. G. and Rexroad, C. E. Jr. 1993. Status of research with transgenic farm animals. Journal of Animal Science 71: suppl. 3, pp. 10–19.CrossRefGoogle ScholarPubMed
Pursel, V. G., Sutrave, P., Wall, R. J., Kelly, A. M. and Hughes, S. H. 1992. Transfer of cSKI gene into swine to enhance muscle development. Theriogenology 37: 278 (abstr.).CrossRefGoogle Scholar
Pusztai, A., Grant, G., King, T. P. and Clarke, E. M. W. 1990. Chemical probiosis. In Recent advances in animal nutrition (ed. Haresign, W. and Cole, D. J. A.), pp. 47–60. Butterworths, London.CrossRefGoogle Scholar
Reed, M. L., Illera, M. J. and Petters, R. M. 1992. In vitro culture of pig embryos. Theriogenology 37: 95–109.CrossRefGoogle Scholar
Reeds, P. J. 1987. Metabolic control and future opportunities for growth regulation. Animal Production 45: 149–169.Google Scholar
Rees, W. D., Flint, H. J. and Fuller, M. F. 1990. A molecular biological approach to reducing dietary amino acid needs. Bio-technology 8:629–633.Google ScholarPubMed
Rempel, W. E., Lu, M. Y., El Kandelgy, S., Kennedy, C. F. H., Irvin, L. R., Mickelson, J. R. and Louis, C. F. 1993. Relative accuracy of the halothane challenge test and a molecular genetic test in detecting the gene for porcine stress syndrome. Journal of Animal Science 71:1395–1399.CrossRefGoogle Scholar
Rogers, G. E. 1990. Improvement of wool production through genetic engineering. Trends in Biotechnology 8: 6–11.CrossRefGoogle ScholarPubMed
Schalue-Francis, T. K., Farin, P. W., Cross, J. C., Keisler, D. and Roberts, R. M. 1991. Effect of injected bovine interferon-αI,1 on oestrous cycle length and pregnancy success in sheep. Journal of Reproduction and Fertility 91: 347–356.CrossRefGoogle Scholar
Sharp, R., O'Donnell, A. G., Gilbert, H. G. and Hazlewood, G. P. 1992. Growth and survival of genetically manipulated Lactobacillus plantarum in silage. Applied and Environmental Microbiology 58:2517–2522.CrossRefGoogle ScholarPubMed
Sinnett-Smith, P. A., Woolliams, J. A., Warriss, P. D. and Enser, M. 1989. Effects of recombinant DNA-derived bovine somatotropin on growth, carcass characteristics and meat quality in lambs from three breeds. Animal Production 49: 281–289.Google Scholar
Smith, C. 1989. Cloning and genetic improvement of beef cattle. Animal Production 49: 49–62.Google Scholar
Spencer, G. S. G., Garssen, G. J. and Bergstrom, P. L. 1983. A novel approach to growth promotion using autoimmunisation against somatostatin. II. Effects on appetite, carcass composition and food utilization in lambs. Livestock Production Science 10: 469–477.CrossRefGoogle Scholar
Stewart, C. S., Hillman, K. and Maxwell, F. 1993. Effects of probiotics on the gut microbiology of animals. In Recent advances in anaerobic bacteriology (ed. Duerden, B.) In press.Google Scholar
Taylor, St C. S., Moore, A. J., Thiessen, R. B. and Bailey, C. M. 1985. Efficiency of food utilization in traditional and sex controlled systems of beef production. Animal Production 40: 401–440.Google Scholar
Taylor, St C. S., Thiessen, R. B. and Moore, A. J. 1986. Single sex beef cattle systems. In Exploiting new technologies in animal breeding (ed. Smith, C., King, J. W. B. and McKay, J. C.), pp. 183–193. Oxford University Press, Oxford.Google Scholar
Thibodeaux, J. K., Del Vecchio, R. P., Broussard, J. R., Dickey, J. F. and Hansel, W. 1993. Stimulation of development of in vitro-matured and in vitro-fertilized bovine embryos by platelets. Journal of Animal Science 71: 1910–1916.CrossRefGoogle ScholarPubMed
Thomson, A. M. and Flint, H. J. 1989. Electroporation induced transformation of Bacteroides ruminicola and Bacteroides uniformis by plasmid DNA. FEMS Microbiology Letters 61:101–104.CrossRefGoogle Scholar
Travers, A. 1984. Regulation of anti-sense RNA. Nature, London 311: 410.CrossRefGoogle ScholarPubMed
Van Vleck, L. D. 1981. Potential genetic impact of artificial insemination, sex selection, embryo transfer, cloning, and selfing in dairy cattle. In New technologies in animal breeding (ed. Brackett, B. G., Seidel, G. E. Jr and Seidel, S. M.), pp.221–242. Academic Press, New York.Google Scholar
Voelkel, S. A. and Hu, Y. X. 1992. Direct transfer of frozenthawed bovine embryos. Theriogenology 37: 23–37.CrossRefGoogle ScholarPubMed
Walker, S. K., Heard, T. M. and Seamark, R. F. 1992. In vitro culture of sheep embryos without co-culture: successes and perspectives. Theriogenology 37:111–126.CrossRefGoogle Scholar
Wall, R. J. and Seidel, G. E. Jr. 1992. Transgenic farm animals — a critical analysis. Theriogenology 38: 337–357.CrossRefGoogle ScholarPubMed
Wallace, R. J. and Newbold, C. J. 1992. Probiotics for ruminants. In Probiotics—the scientific basis (ed. Fuller, R.), pp. 317–353. Chapman and Hall, London.CrossRefGoogle Scholar
Ward, K. A., Brownlee, A. G., Leish, Z. and Bonsing, J. 1993. Genetic manipulation for disease control. In Proceedings of the seventh world conference on animal production, Edmonton, Alberta, vol. 1, pp. 267–280.Google Scholar
Ward, K. A. and Nancarrow, C. D. 1992. The production of transgenic sheep for improved wool production. In Progress in sheep and goat research (ed. Speedy, A. W.), pp. 257–273. CAB International, Wallingford, U.K.Google Scholar
Watson, J. D. and Crick, F. C. 1953. Molecular structure of nucleic acids. A structure for deoxyribose nucleic acids. Nature, London 171: 737–738.CrossRefGoogle ScholarPubMed
Webb, R., Gong, J. G., Law, A. S. and Rusbridge, S. M. 1992. Control of ovarian function in cattle. In Frontiers in reproductive biology (ed. Brooks, N., Challis, J., McNeilly, A. and Doberska, C.), Journal of Reproduction and Fertility, supplement 45, pp. 141–156.Google Scholar
Webster, A. J. F. 1989. Bioenergetics, bioengineering and growth. Animal Production 48: 249–269.Google Scholar
Westhusin, M. E., Pryor, J. H. and Bondioli, K. R. 1991. Nuclear transfer in the bovine embryo: a comparison of 5-day, 6-day, frozen-thawed, and nuclear transfer donor embryos. Molecular Reproduction and Development 28: 119–123.CrossRefGoogle ScholarPubMed
Whitehead, T. R., Cotta, M. A. and Hespell, R. B. 1991. Introduction of the Bacteroides ruminicola xylanase gene into the Bacteroides thetaiotaomicron chromosome for production of xylanase activity. Applied and Environmental Microbiology 57: 277–282.CrossRefGoogle ScholarPubMed
Willadsen, S. M. 1986. Nuclear transplantation in sheep embryos. Nature, London 320:63–65.CrossRefGoogle ScholarPubMed
Willadsen, S. M. 1989. Cloning of sheep and cow embryos. Genome 31: 956–962.CrossRefGoogle Scholar
Willadsen, S. M., Janzen, R. E., McAlister, R. J., Shea, B. F., Hamilton, G. and McDermand, D. 1991. The viability of late morulae and blastocysts produced by nuclear transplantation in cattle. Theriogenology 35:161–170.CrossRefGoogle Scholar
Wilmut, I., Archibald, A. L., Harris, S., McClenaghan, M., Simons, J. P., Whitelaw, C. B. A. and Clark, A. J. 1990. Modification of milk composition. In Genetic engineering of animals (ed. Hansel, W. and Weir, B. J.), Journal of Reproduction and Fertility, supplement 41, pp. 135–146.Google Scholar
Wilmut, I., Haley, C. S., Simons, J. P. and Webb, R. 1992a. The potential role of molecular genetic manipulation in the improvement of reproductive performance. In Frontiers in reproductive biology (ed. Brooks, N., Challis, J., McNeilly, A. and Doberska, C.), Journal of Reproduction and Fertility, supplement 45, pp. 157–173.Google Scholar
Wilmut, I., Haley, C. S. and Woolliams, J. A. 1992b. Impact of biotechnology on animal breeding. Animal Reproduction Science 28:149–162.CrossRefGoogle Scholar
Woolliams, J. A. 1989. The value of cloning in MOET nucleus breeding schemes for dairy cattle. Animal Production 48:31–35.CrossRefGoogle Scholar
Woolliams, J. A., Angus, K. D. and Wilson, S. B. 1993. Endogenous pulsing and stimulated release of growth hormone in dairy calves of high and low genetic merit. Animal Production 56:1–8.Google Scholar
Woolliams, J. A. and Wilmut, I. 1989. Embryo manipulation in cattle breeding and production. Animal Production 48: 3–30.CrossRefGoogle Scholar
Yang, X. 1991. Embryo cloning by nuclear transfer in cattle and rabbits. Embryo Transfer Newsletter 9:10–22.Google Scholar
Yong, Z., Jianchen, W., Jufen, Q. and Zhiming, H. 1991. Nuclear transplantation in goats. Theriogenology 35: 299 (abstr.).CrossRefGoogle Scholar