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of these fungi have not been shown to differ significantly between toxic and non-toxic pasture⁽⁷⁾ (McKenzie &; Byford, unpublished data).     

Swine dysentery

Extract

Sir, — We have just received a copy of the N.Z. Veterinary Journal for August, 1975 (Vol. 23, No.8) containing a most interesting communication by Pearce and Smith on the epidemiology, diagnosis and treatment of swine dysentery.     

Chemoprophylaxis of fascioliasis with triclabendazole

In a field experiment, moderate to heavy natural concomitant infections with immature and mature Fasciola hepatica were treated with triclabendazole at a dose rate of 10 mg/kg and an efficiency of 99.8% was achieved. Subsequent treatments of all susceptible farm animals at the same dose rate at intervals of eight to eleven weeks were carried out for 14 months; no patent infections could be detected in sheep and cattle during the whole period. Evidence is presented that pasture contamination with liver fluke was reduced to a negligible level for a further 12 months after the final treatment. It is suggested that, if regular treatments with triclabendazole are given within the pre-patent period of Fasciola hepatica infection for the whole season, the infection can be eradicated or reduced to such a low level that control of the disease could be maintained with less frequent strategic drenching for a considerable period.     

Equine herpesviruses causing respiratory disease

Abstract

Extract

Madam:—I read with interest the letter Fu et al.(3 Fu, Z.F., Robinson, A.J., Dickinson, L.G. and Grimmett, J.B. 1986. Equine herpesvirus type 1 (EHV-1) infection and vaccination with an inactivated EHV-1 vaccine. N.Z. vet. J., 34: 14–15. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]in which they state that “Preliminary investigations on this stud have indicated that equine herpesvirus type 1 (EHV1) and type 2 (EHV2) were frequently isolated and might be the initiators of the respiratory disease observed”. Additional evidence that links EHV2 (equine cytomegalovirus or slowly growing equine herpesvirus) to equine respiratory disease will be important. There is some evidence and a very high level of suspicion that recurrent respiratory disease, malaise and poor performance are associated with EHV2 but providing definite evidence has been elusive and tends to be confounded by the fact that EHV2 can be isolated from more than 70% of horses, in some populations at least, but unassociated with recognisable disease.     

A goat mortality study in the southern North Island

A study was undertaken to indicate the importance of different causes of death in goats and to investigate the management factors which influence these problems. Over a 15 month period, 324 dead goats were received from 67 farms in the Horowhenua, Wairarapa, Wanganui and Wellington regions. Although a wide range of diseases was encountered in the study, the major causes of mortality could be divided into 4 groups: problems directly related to management, microbial diseases, nematode parasitism, and trace element related deficiencies and toxicities. The highest proportion of deaths related directly to management problems and included deaths from hypothermia, mismothering, premature birth, ruminal acidosis, pregnancy toxaemia, trauma, and plant and chemical toxicities. In larger flocks, microbial diseases including Pasteurella pneumonia and yersiniosis were major problems. Deaths from nematode parasitism were predominantly observed in goats 12 months of age and older. White muscle disease (selenium/vitamin E deficiency) was the major trace element deficiency causing death in goats.

The influence of factors including age of goat, flock size and management practices on the major causes of death are discussed.     

Anthephora pubescens nees

Grondwaterherverspreiding vind vinnig in die hele grondprofiel van drie subhabitatte nl. Eragrostis pallens, Ochna pulchra en Grewia flavescens van ‘n Burkea‐savanna plaas. Na ‘n reënbui van 50 mm herversprei water binne 12 uur tot op ‘n diepte van 90 cm in ‘n sandgrond wat as die Chesterserie van die Huttonvorm geklassifiseer is. In die E. pallens en O. pulchra subhabitatte vind wateropname hoofsaaklik in die boonste 60 cm van die grondprofiel plaas terwyl vog vrylik beskikbaar is in die ondergrond selfs in die droogste maande nl. Junie, Julie en selfs Augustus. In die G. flavescens subhabitat vind wateropname deur die hele grondprofiel plaas tot op ‘n diepte van 120 cm. Die G. flavescens subhabitat blyk meer onderhewig aan vogstremminge te wees.