Animal systems

Although stockless systems can be practised on arable farms, by the use of green manures to maintain soil nutrient status, the need for the addition of animals as a source of recycled excreta, and as graziers, has long been recognised. At the time of the golden hoof, field owners paid shepherds for the use of their sheep, if only to have them penned up on a particular field overnight. 

By housing cattle overwinter and composting the farmyard manure, the organic farmer has ready access to a balanced fertiliser that can be spread where most required. The grazing animal does not actually import fertility onto the farm but it does recycle nutrients where it grazes and provides a source of manure when housed. This is as true of sheep, pigs and poultry as of cattle. The only problem with outdoor pigs is that they tend to rip up pastures. 

The control of internal parasites in sheep is acknowledged to be one of the harder problems in the management of both organic and conventional enterprises. The organic farmer is allowed to dose any animal that is seen to be suffering from parasitic infection, but only those animals that are suffering, not the whole flock. The animals that 

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An effective therapeutic agent must also have the abiUty to reach its target sequence m vivo. BioavailabiUty requires that the antisense oligonucleotide be able to pass through the cell membrane, and that it have a low affinity for nontarget cellular compartments and, in animal systems, nontarget organs. 

Cormier, M. J. (1978). Comparative biochemistry of animal systems. In Herring, P. J. (ed.), Bioluminescence in Action, pp. 75-108. Academic Press, London. 

Pharmacokinetic Model—A set of equations that can be used to describe the time course of a parent chemical or metabolite in an animal system. There are two types of pharmacokinetic models data-based and physiologically-based. A data-based model divides the animal system into a series of compartments which, in general, do not represent real, identifiable anatomic regions of the body whereby the physiologically-based model compartments represent real anatomic regions of the body. 

The use of mierobial systems as in vitro models for dmg metabohsm in humans has been proposed sinee there are many similarities between certain microbial enzyme systems and mammalian liver enzyme systems. The major advantages of using miero-organisms is their ability to produce significant quantities of metabohtes that would otherwise be diffieult to obtain from animal systems or by chemical synthesis, and the considerable reduetion in operating costs compared with animal studies. 

Effects of Allelochemlcals on ATPases. Several flavonoid compounds inhibit ATPase activity that is associated with mineral absorption. Phloretin and quercetin (100 pM) inhibited the plasma membrane ATPase Isolated from oat roots (33). The naphthoquinone juglone was inhibitory also. However, neither ferulic acid nor salicylic acid inhibited the ATPase. Additional research has shown that even at 10 mM salicylic acid inhibits ATPase activity only 10-15% (49). This lack of activity by salicylic acid was substantiated with the plasma membrane ATPase Isolated from Neurospora crassa (50) however, the flavonols fisetln, morin, myricetin, quercetin, and rutin were inhibitory to the Neurospora ATPase. Flavonoids inhibited the transport ATPases of several animal systems also (51-53). Thus, it appears that flavonoids but not phenolic acids might affect mineral transport by inhibiting ATPase enzymes. 

Human prion disease models have also been developed in mice [154,155]. Crossing the species barrier into an experimentally accessible animal system, the prions responsible for Creutzfeldt Jakob disease, new variant CJD, Gerstmann-Straussler-Scheinker disease, and fatal familial insomnia produce a reproducible time-dependent neuronal degeneration leading to death. 

O Shaughnessy, W. B. On the preparations of the Indian Hemp, or Gunjah (cannabis indica) their effects on the animal system in health, and their utility in the treatment of tetanus and other convulsive diseases. Provincial Medical Journal and Retrospect on the Medical Sciences, London, 1843 5 343-398. 

Beckwith R.S., Tiller K.G., Suwadji E. The effects of flooding on the availability of trace metals to rice in soils of differing organic matter status In Trace Elements in Soil-Plant-Animal Systems, Nicholas DJD, Egan AR. eds. New York, NY Academic Press, Inc., 1975. 

McKenzie R.M. The mineralogy and chemistry of soil cobalt. In Trace Element in Soil-Plant-Animal Systems, Nicholas, D.J.D., Egan, A.R., eds. New York Academic Press Inc., 1975. 

In recent years, plants have emerged as a promising new system for the production of recombinant proteins. Plants are widely described as green factories because they provide possible solutions to several of the safety and economic concerns raised by animal systems. The advantages of plants include economical large-scale... 

Drummond, R.O. 1968. Further evaluation of animal systemic insecticides, 1967. Jour. Econ. Entomol. 61 1261-1264. 

The third criterion that animal systems should demonstrate with respect to the psychedelic trip in man is the observed tolerance to both the mental effects and mydriasis. This appears to be complete after several daily doses and to be lost after 4 days without LSD. With respect to biologic mechanisms, occurrence of acute tolerance in both man and animals (20) poses a problem. Whether tachyphylactic or other processes are entailed remains to be defined. 

Although many published volumes exist regarding the cytochemical/ histochemical localizations of cellular and tissue chemicals for animal systems (1-10), there are only a few relatively recent monographs concerning plant cell/tissue cytochemistry and histochemistry (11-15). 

Most of the research on the influence of zinc on calcium bioavailability has been in connection with zinc toxicity or the effects of high levels of dietary zinc on various animal systems. Such studies and/or investigations have been conducted on a variety of animal species and humans, but those studies which have revealed a possible effect of zinc on calcium bioavailability have generally involved the lamb, pig, and rat. This paper will be primarily a discussion of the effects of high levels of dietary zinc on calcium status in the rat. The effect of zinc on phosphorus status, however, has been included because there is the possibility that the effect of zinc on calcium bioavailability may be dependent upon the phosphorus status of the system. 

If animal systems are chosen, preparations derived from fish (see, e.g., Kada, 1981) and birds (Parry et al., 1985) have been used. However, by far the most widely used and validated are those derived from rodents, in particular, the rat. Hamsters may be preferred as a source of metabolizing enzymes when particular chemical classes are being screened, for example, aromatic amines, heterocyclic amines, N-nitrosamines and azo dyes (Prival and Mitchell, 1982 Haworth et al., 1983). 

In vivo effects of a chemical are due to an alteration in the higher-order integration of an intact animal system, which cannot be reflected in a less complex system. 

McMillan DE. 1982. Effects of chronic administration of pesticides on schedule controlled responding by rats and pigeons. In Chambers JE, Yarbrough JD, eds. Effects of chronic exposures to pesticides on animal systems. New York, NY Raven Press, 211-226. 

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