Production and physical characteristics of composted poultry carcases

1. Experiments were designed to determine whether composting could be a safe and effective method for the disposal of poultry carcases in the UK climate. Laying hen carcases (125) were composted in a wooden compost bin over autumn and winter months, using the United States Department of Agriculture method. 2. The process took 8 weeks and effectively decomposed the carcases to leave only leg and breast bones. The compost was turned once, which ensured that all the material reached the high temperatures (60 degrees to 70 degrees C) required to control pathogens. Salmonella was fully heat-inactivated, indicating that many poultry-associated bacterial pathogens would also have been inactivated. 3. It is concluded that this method is suitable for use in the UK and provides a sanitised fertiliser supplement.     

The presence of precipitating antibodies in the sera of horses with chronic obstructive pulmonary disease (COPD).

The sera of horses affected and not affected with chronic obstructive pulmonary disease (COPD) were examined for precipitins to Micropolyspora faeni and Aspergillus fumigatus. Precipitins to both antigens were not restricted to COPD cases but occurred more frequently in animals affected with COPD. Many animals without detectable precipitins responded clinically to inhalation challenge with these antigens.     

Experimental infection of neonatal pigs with Campylobacter sputorum subspecies mucosalis with special reference to the oral cavity

After oral exposure Campylobacter sputorum subsp. mucosalis became established in the mouth of piglets for up to eight weeks. C. sputorum subsp. mucosalis was not isolated from the same pigs each week, although some pigs were positive for a number of consecutive weeks. Spread also took place from orally dosed piglets to an undosed litter mate maintained with them. Other catalase negative, serologically distinct Campylobacters were also demonstrated in the oral cavity.     

Descriptive spatial analysis of the epidemic of bovine spongiform encephalopathy in Great Britain to June 1997

This was a spatial analysis of the epidemic of bovine spongiform encephalopathy (BSE) in Great Britain, based on agricultural census data collected between 1986 and 1996 and BSE case data collected up to June 1997. Kernel smoothing techniques were used to plot the distribution of BSE-positive cattle holdings per 100 holdings per square kilometre and the distribution of confirmed BSE cases per 100 head of cattle per square kilometre. In the early stages of the epidemic reported BSE cases were scattered widely throughout Great Britain, with no clearly identifiable focus. By June 1997, a statistically significant cluster of BSE-positive holdings was identifiable in the eastern part of the South west region of England. During the epidemic the highest densities of confirmed BSE cases per 100 cattle per square kilometre occurred in the greater part of the South west region of England and within Dyfed in the south west of Wales. In Wales, a small number of holdings experienced large numbers of confirmed BSE cases. In the South west region of England a large number of holdings experienced small numbers of confirmed cases. By June 1997, the distribution of BSE-positive holdings across Great Britain was largely determined by factors that influenced the amount of recycled infectious material they were exposed to.     

Ground cover during fallow from wheat, sorghum and sunflower stubble under three tillage practices in Central Queensland

As part of a large scale study into the effect of soil-surface conditions and crop residues on runoff and soil loss, techniques to estimate cover were developed. The vertical projection of cover was measured from photographs of 9 treatments (3 crop species × 3 tillage practices), while stubble weight was estimated using a calibrated visual-rating technique. The techniques were then used to quantify the stubble resulting from different crops, grain yields, tillages and over time.

Projected cover post-harvest is a function of crop species and seasonal effects as expressed in grain yield, and was in the order wheat (90.3), sorghum (58.5) and sunflower (43.1). Projected cover was linearly related to grain yield. During the fallow, tillage had a large effect on decreasing projected cover, with change in projected cover during the fallow being in the order: zero tillage

Projected cover and stubble weight were related in the form: Projected Cover=m[1−e^{−stubble weight}], with the asymptote value, m, varying for each crop and ranging from 98.1 for wheat and 64.7 for sorghum to 49.3 for sunflowers. From the relationships of projected cover to grain yield or stubble weight and a knowledge of how it changes over time or owing to cultivation, a predictive equation was developed to determine projected cover at any stage in the fallow.     

The water balance of irrigated forages in northern Victoria, Australia

Knowledge of the components of the water balance - evaporation, transpiration and deep drainage - would be beneficial for targeting productivity improvements for irrigated forages in northern Victoria. We aimed to estimate these components using a simple water balance and the dual crop coefficients provided in FAO-56. Soil water deficits from a field experiment, comparing the water use of six border-check and one spray irrigated forage system, agreed well with the modelled values, except for alfalfa where irrigation intake was restricted. About 85% of the water applied to perennial forages (perennial ryegrass/white clover, tall fescue/white clover and alfalfa) was used for transpiration, 10% for evaporation and 5% was lost as drainage below the root zone. Evaporation was highest from the double-cropped (oats/millet) system (30%) and was 5-25% of the water used by winter-growing annual pastures (Persian clover/Italian ryegrass and both border-check and spray irrigated subterranean clover/Italian ryegrass). The high proportion of water used as transpiration by the perennial forages was due to their high ground cover maintained throughout the year. When compared over similar seasonal conditions, actively growing forages used similar amounts of water, indicating that any increases in water productivity will be mainly due to higher production and/or to matching the growing season of the forage to periods of lower potential evapotranspiration.     

Pore Fluid Constraints on the Temperature and Oxygen Isotopic Composition of the Glacial Ocean

Pore fluids from the upper 60 meters of sediment 3000 meters below the surface of the tropical Atlantic indicate that the oxygen isotopic composition (delta18O) of seawater at this site during the last glacial maximum was 0.8 ± 0.1 per mil higher than it is today. Combined with the delta18O change in benthic foraminifera from this region, the elevated ratio indicates that the temperature of deep water in the tropical Atlantic Ocean was 4°C colder during the last glacial maximum. Extrapolation from this site to a global average suggests that the ice volume contribution to the change in delta18O of foraminifera is 1.0 per mil, which partially reconciles the foraminiferal oxygen isotope record of tropical sea surface temperatures with estimates from Barbados corals and terrestrial climate proxies.