Epidemiology of Bovine Venereal Campylobacteriosis: Geographic Distribution and Recent Advances in Molecular Diagnostic Techniques

Bovine venereal campylobacteriosis (BVC) is a major cause of economic loss to the cattle industries in different parts of the world. Camplylobacter fetus subsp. venerealis (Cfv), the main causative agent of BVC, is highly adapted to the genital tract of cattle and is transmitted by carrier bulls. However, infertility and abortions can also be caused by the intestinal pathogens C. fetus subsp. fetus (Cff), and C. jenuni, which are not venereally transmitted. Bovine venereal campylobacteriosis, caused by Cfv associated with lowered fertility, embryo mortality and abortion, repeated returns to service, reduced pregnancy rates and extended calving intervals, has the highest prevalence in developing countries where natural breeding in cattle is widely practised. The epidemiology, pathogenesis and diagnosis of the disease have been the subject of previous reviews. The main focus of this review is to highlight the epidemiology of this disease with particular reference to geographical distribution and recent advances in molecular diagnostic techniques. It is hoped that further research interest of scientists will be stimulated with a view to finding lasting solutions to the reproductive problems associated with the disease for better livestock productivity, particularly in developing endemic countries.     

The Effects of Different Manurial Treatments on The Yield and Mineral Composition of Red Beet

Red beet was grown in factorial manurial experiments at two sites: at Wellesbourne annually from 1954 to 1964 in a rotation of vegetable crops and at Efford in 1959 only.

At Wellesbourne applications of FYM (20 tons per acre per crop), together with NPK fertilizers, consistently gave much higher yields than mineral fertilizers alone, but the relative effect of FYM did not increase as the experiment proceeded.

In the presence of FYM, yields of red beet increased with increasing rates of application of Nitrochalk (up to 124 lb. N per acre), but applications of phosphate and potash fertilizers did not affect yields.

In the absence of FYM, phosphate fertilizers did not increase yields significantly after 1959; there was an important interaction between the effects of the applications of Nitrochalk and SUlphate of potash. Each fertilizer applied alone produced small increases in yield, but when they were applied together at the highest rates used (186 lb. Nand 192 lb. K₂O per acre) large increases in yield were obtained and there was some indication that an even higher rate of application would have given a further increase in yield. At Efford, nitrogenous fertilizers increased yields significantly.

Applications of FYM increased the potassium and decreased the calcium and magnesium contents of red beet leaves and had only small effects on the nitrogen and phosphorus contents; in the roots, only the potassium content was altered (increased) by the FYM applications.

In general, in the absenc~ of FYM only potash fertilizer applications had large, consistent and significant effects on the mineral composition of the leaves and roots. At both sites, applications of sulphate of potash increased the potassium content of the leaves and had a much smaller depressing effect on the calcium and magnesium contents of the leaves but not, in general, of the roots.

The effects of the nitrogenous fertilizers on the total nitrogen content of the roots were relatively small, but could be important in relation to the processing quality of the beet.

The marked differences between the responses of red beet and early potatoes to the manurial treatments are discussed in relation to the nutrient contents of the plants.     

A conservation framework for the golden eagle in Scotland: Refining condition targets and assessment of constraint influences

Conservation strategies have three elements: species protection, site protection and, the most challenging component, conservation in the wider environment. Watson and Whitfield [Watson, J., Whitfield, P., 2002. A conservation framework for the golden eagle Aquila chrysaetos in Scotland. Journal of Raptor Research 36(1 Suppl.), 41-49.] proposed a conservation framework for the golden eagle in Scotland whose main innovation, taking a lead from EU conservation Directives, was to incorporate the concept of favourable condition and its maintenance by implementing conservation policies that are regionally targeted at known constraints in the wider environment. Three criteria were suggested to judge favourable condition: a national abundance target of breeding pairs, national and regional targets for breeding productivity, and regional targets for the extent of suitable habitat which is occupied by breeding pairs. Here we refine these criteria, first to take the national abundance target and use it to set regional targets. Distribution targets were implicitly incorporated by this process because abundance targets were set regionally, with regard to the proportion of known territories which should be occupied. This allowed us to dispense with the distribution criterion as originally proposed. Our next refinement was to base regional demographic targets not only on breeding productivity, but also on indirect measures of survival (which are likely to have more influence on population dynamics). Despite apparent overall population stability over the last 20 years, the national golden eagle population failed to meet the abundance target and only 3 of 16 regions where eagles have occupied territories since 1982 were considered to be in favourable condition. The key constraint preventing favourable condition being met was persecution, predominantly in some areas managed for grouse shooting. The advantages of a conservation framework over similar approaches, such as species action plans, are highlighted.     

Vitamin B12 responses to cobalt pellets in beef cows

Objective To assess the effectiveness of cobalt pellets in maintaining adequate vitamin B₁₂ in beef cows on pasture of low cobalt content.
Design A field experiment in a herd grazing cobalt deficient pasture.
Animals Mature Murray Grey cows.
Procedure Cows were given a single oral dose of 0, 1, 2 or 4 cobalt pellets (30 g pellets containing 30% by weight cobaltic oxide) with a selenium pellet and a grub screw. Samples of blood, liver, faeces and milk for chemical analyses were collected at intervals over a period of 2 years after treatment.
Results A single cobalt pellet raised liver vitamin B₁₂ concentration of cows above that of untreated cows for at least 28 weeks, and 2 or 4 pellets for 57 weeks. Plasma vitamin B₁₂ concentration was an unreliable indicator of the effectiveness of cobalt pellet therapy. Milk vitamin B₁₂ and faecal cobalt concentrations increased in response to cobalt pellet therapy.
Conclusion These studies show that one cobalt pellet will prevent vitamin B₁₂ inadequacy in beef cows for between 28 and 57 weeks; two or four pellets will prevent inadequacy for 57 to 75 weeks. Milk vitamin B₁₂ concentration may be a useful indicator of the effectiveness of cobalt pellets in increasing the vitamin B₁₂ supply in lactating cows.