A simulation model for predicting the voluntary feed intake of a growing pig

Abstract

The main goal of this simulator is to predict voluntary feed intake based on the effects of temperature and stocking density. The model indicates the limiting factors relative to diet (protein, energy or ash), housing environmental conditions and stocking density. The concepts of compensatory protein growth, correction of lipid growth, the desired feed intake to meet energy, protein and ash requirements, and influences of stocking density, genotype and sex are also introduced in this model. This study draws a flow chart and steps to predict feed intake of a growing pig to make it clear how the model works. The model simulates the outcomes of feed intake, energy and protein requirements for maintenance, the energy cost for cold thermogenesis, and protein and lipid retention on a daily basis until slaughter weight. This model was also validated by comparison with published experiments.     

An apparent nutritional lactational stress infertility in dairy herds

Abstract

Extract

Sir.—I refer to the paper by Day(1 Day, A. M. 1979. Induced termination of the calving season. N.Z. vet. J., 27: 22–29. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) on induction of parturition in a dairy herd. This report was read with a considerable degree of interest as it included results which are significantly different from those which we would have expected from extensive field experience in New Zealand and overseas.     

The effect of large doses of thiamine on the horse

Extract

In conjunction with a trial to determine the effect of nematode infestation upon the liveweight gain and wool production of young sheep (Brunsdon, unpublished), information was sought on the seasonal succession and availability on pasture of infective larvae of the principal trichostrongyle genera parasitic in sheep. Data were collected in the form of nematode populations found at postmortem examination of Romney lambs, previously maintained worm-free, which were exposed to risk of parasitism in the field. A series of these lambs ran with the flock in the above-mentioned trial and served as indicators of the abundance of infective larvae on the pasture.     

The isolation of salmonella oranienburg from an ovine foetus in New Zealand

Extract

In August, 1963, Salmonella oranienburg was cultured in heavy pure growth from the lungs of an autolysed and mummified ovine foetus submitted to the Taieri laboratory from a property in Canterbury experiencing an abortion problem in ewes. Identification of the organism was made by the National Health Institute, Wellington, and confirmed by the Salmonella Reference Laboratory, Colindale, London. This was the first isolation of S. oranienburg from an animal in New Zealand.     

Letters to the editor

Sir;- Outbreaks of ovine abortions caused by Campylobacter fetus fetus (previously C. fetus intestinalis) occur sporadically in mimy areas of New Zealand. The devastating effects on some flocks have stimulated recent studies of the disease,^(1)(3)(7) and have also led to the commercial production of a single strain vaccine (Campylovexin; Wellcome N.Z. Ltd, Auckland). However, it has been shown that single strain C. Fetus vaccines do not protect against serologically distinct strains.⁽²⁾ Since at least two different serotypes of C. fetus fetus are present in New ZealandY) it is not surprising that the commercially available vaccine is only partially effective in some outbreaks.⁽⁷⁾     

The epidemiology of Fasciola hepatica infections in sheep on a Lymnaea columella habitat in the manawatu

Extract

From time to time, interest is shown in the use of licks for providing anthelmintic medication to livestock. This paper presents results from two trials on the use, with sheep, of a solidified molasses block incorporating phenothiazine and thiabendazole.     

Breeding unsoundness in the ram: The incidence of contributing conditions

Extract

Whenever disease is discussed in terms of beef production, in New Zealand it is certain to include infertility (brucellosis, vibriosis), metabolic diseases (bloat, staggers) and possibly exotic diseases and their prevention. On the rare occasion that parasitism is considered it tends somehow to find itself, along with selenium and other deficiency diseases, under a general heading of nutrition or management. This is probably because, while parasitism is still recognized as an infectious disease with clear clinical signs in severe cases, the tendency is to ignore its presence unless nutritional or management changes force a confrontation.     

Evaluation of a screening programme for identification of mannosidosis heterozygotes in angus cattle

Sir, — In recent years, much research effort has been directed towards identifying the cause of Ryegrass staggers (RGS). Many promising leads have been investigated, including studies of fungi in soil, ryegrass leaves, and dead leaf litter that could produce tremorgenic mycotoxins⁽³⁾. Several groups of fungi produce tremorgens⁽⁴⁾ which, when injected into sheep, produce symptoms similar to those in field outbreaks of RGS. However, under field conditions, populations of these fungi have not been shown to differ significantly between toxic and non-toxic pasture⁽⁷⁾ (McKenzie &; Byford, unpublished data).     

Treatment of Taenia hydatigena infections in dogs with-bunamidine hydroxynaphthoate incorporated in food

Abstract

Extract

Theoretically, the life-cycle of the sheep metacestodes with their strobilate phase in dogs permits combinations of at least three methods of control. These are the prevention of dogs gaining access to larval cestodes, the chemical elimination of the strobilate and or the larval stage in the appropiate hosts, and the immunization of either the definitive or intermediate hosts or both. The first approach using arecoline hydrobromide primarilv as a diagnostic agent has reduced the prevalence of Echinococcus granulosus (Gemmell, 1968 Gemmell, M. A. 1968. The Styx field-trial. A study on the application of control measures against hydatid disease caused by Echinococcus granulosus. Bull. Wld Hlth Org., 39: 73–100.  [Google Scholar]). However, it did not markedly reduce the prevalence rate of Taenia hydatigena and may have been indirectly associated with an increase in that of Taenia ovis.     

Malignant hyperthermia in a crossbred landrace-large white pig

Abstract

Extract

Malignant hyperthermia is a rare and usually fatal complication of general anaesthesia. It occurs in man (Britt and Kalow, 1970 Britt, B. A. and Kalow, W. 1970. Malignant hyperthermia: a statistical review. Can. Anaesth. Soc. J., 17: 293–315. [Crossref], [PubMed] , [Google Scholar]) and in certain breeds of pigs, the, Landrace (Hall et al., 1966 Hall, L. W., Woolf, N., Bradley, J. W. P. and Jolly, D. W. 1966. An unusal reaction to suxamethonium chloride. Br. med. J., 3: 594–594.  [Google Scholar]; Berman et at, 1970 Berman, M. C., Harrison, G. G. and Bull, A. B. 1970. Changes underlying halothane-induced malignant hyperpyrexia in Landrace pigs. Nature. Lond., 225: 653–655.  [Google Scholar]; Harrison et al., 1970 Harrison, G. G., Berman, M. C., Heekman, R., Bull, A. B., Terblanche, J. and Kench, J. E. 1970. “Anaesthetic induced malignant hyperpyrexia — Some observations of the syndrome in Landrace pigs”. In Ill Asian Australasian Congress of Anesthesiology, Canberra. Butterworths 158–166.  [Google Scholar]) the Poland China (Jones et al., 1972 Jones, E. W., Nelson, T. E., Anderson, I. L., Kerr, D. D. and Burnap, T. K. 1972. Malignant hyperthermia in swine. Anesthesiology, 36: 42–51.  [Google Scholar]), the Pietrain (Allen et al., 1970 Allen, W. M., Harding, J. D. J. and Paterson, D. S. P. 1970. Experimentally induced acute stress syndrome in Pietrain pigs. Vet. Rec., 87: 64–69.  [Google Scholar]) and the Large White (Mawdesley-Thomas, 1969 Mawdesley-Thomas, L. E. 1969. Cited by Allen, W. M. et al. (1970) [Google Scholar]).