摘要:

The almost complete eradication of tuberculosis and brucellosis in cattle is of great credit to both the staff of the Ministry of Agriculture and Fisheries (MAF) and the veterinary practitioners in this country. As we now move into new fields of disease control, it is vital that our expertise and resources are used for maximum effect in promoting agricultural production.

ISSN:0048-0169    

DOI:10.1080/00480169.1981.34834

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Induction of premature calving contributes to subsequent failure of some dairy cows to become pregnant and calve. Of a sample of 276 cows 16.7% failed to calve the following year despite the occurrence of oestrus relatively early after calving, and several matings. The cows which did conceive had a normal first-mating calving rate of 53.9%, requiring 1.7 matings per pregnancy. Two of the 18 survey herds under consideration suffered lengthy calving-to-first-mating oestrus intervals, presumably because the induced cows were in poor condition at the time of calving.

ISSN:0048-0169    

DOI:10.1080/00480169.1981.34835

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

The avermectins are macrocyclic lactones with exceptional potency and spectrum of activity against nematode and arthropod parasites. They are produced by a new species of actinomycete,Streptomyces avermitilis. They are active when given orally or parenterally, at dosages of a fraction of a milligram per kilogram, against many immature and mature nematode and arthropod parasites of sheep, cattle, dogs, horses and swine. The avermectins appear to paralyze nematodes and arthropods by potentiating the presynaptic release of gamma-aminobutyric acid, thereby blocking post-synaptic transmission of nerve impulses. A chemically modified derivative, 22,23-dihydroavermectin B1, known generically as ivermectin, has been selected for development.

ISSN:0048-0169    

DOI:10.1080/00480169.1981.34836

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Aujeszkyś disease is predominantly a nervous disease of piglets, weaners, and fatteners in which the mortality may vary from 540%. Respiratory disease is also a feature of infection with certain strains of the virus. Infection of pregnant sows may cause abortion, stillbirths, and mummification, and infertility may result in both boars and sows. Traditionally the serum neutralisation test has been used as an indicator of past infection with Aujeszky s's disease virus (ADV). However, cell-mediated immunity has recently been shown to play an important role in recovery and protection from infection with ADV and antibody-dependent cell-mediated cytotoxicity can be used as an alternative diagnostic test for detection of antibody. A number of inactivated, and live, avirulent vaccines are now available for control of the disease but their use is contraindicated in countries such as New Zealand which have a low prevalence of infection. Where possible early eradication is the best policy to follow.

ISSN:0048-0169    

DOI:10.1080/00480169.1981.34837

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

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).

ISSN:0048-0169    

DOI:10.1080/00480169.1981.34839

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Sit., — We have recently been called upon to investigate an outbreak of respiratory disease amongst the occupants of a boarding cattery, which involved a number of apparently vaccinated cats.

ISSN:0048-0169    

DOI:10.1080/00480169.1981.34840

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Sir. — During the past 10 years pour-on insecticides for cattle louse control have largely superseded spray-on insecticides in New Zealand. Most pour-on formulations tested have proved highly effective. although within-trial eradication has not been reported(1)(2)(3).

ISSN:0048-0169    

DOI:10.1080/00480169.1981.34841

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Sir, — Cat owners, cat breeders and veterinarians are now well aware that feline leukaemia virus (Felv) is a cause of serious disease in cats and also that Felv is involved in the pathogenesis of many diseases other than lymphosarcoma(8). Epidemiological studies using a variety of techniques to detect virus and antibodies have defined populations of cats that are at risk from the effects of the virus and methods of control have been suggested(2)(3)(4). All methods of control are based on separation cf Felv-infected cats from susceptible animals. To do this, viraemic cats need to be identified either by the demonstration of Felv-specific antigen in the cytoplasm of circulating leucocytes or platelets (by immunofluorescence on blood smears), demonstration of viral antigen in serum or plasma, or by isolation of virus from the plasma in feline cell cultures.

ISSN:0048-0169    

DOI:10.1080/00480169.1981.34842

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor

摘要:

Sir, — We wish to report the isolation of two potent neurotoxins from herbage collected from pastures on which the disease of livestock known as ldryegrass staggers rd(8)(11)occurred. These neurotoxins have been partially characterised by their mass spectral properties (see below) and appear to be new compounds not previously reported. We propose the general name lolitrems for the neurotoxins, based on their association with ryegrass (Lolium perenneL.) and on their ability to produce tremors in animals, and name the isolated compounds lolitrem A and lolitrem B.

ISSN:0048-0169    

DOI:10.1080/00480169.1981.34843

出版商:Taylor & Francis Group    

年代:1981

数据来源: Taylor