Spatial and temporal variations in concentrations of three ions in solutions extracted from a woodland soil

Concentrations of Cl, Mg and K in soil solutions extracted from a gleyic brown earth under mixed oak woodland were measured at weekly intervals over a 1 year period. Spatial variability of ion concentrations was large, with coefficients of variation of 30–90% in a 0.1 ha plot. Seasonal variability in Mg and K was effectively buffered by the soil exchange complex, but Cl displayed a distinct pattern with a maximum concentration in late autumn. Flushing of Cl during soil rewetting is the most probable explanation.     

Quantifying anthropogenic nutrient sources and loadings within a small catchment with conservation interests,eastern Scotland

This paper demonstrates the possibility of quantifying sub-catchment nutrient budgets from routinely monitored hydrological and hydrochemical data. The relative importance of a number of potential anthropogenic nutrient sources was quantified for a small catchment in Scotland. Within the catchment there are two Sites of Special Scientific Interest, including two lochs and a floodplain mire. The study was undertaken to provide information for prescribing strategies to safeguard the conservation interests of these aquatic systems. The principal source of nitrate was found to be groundwater. Phosphate and ammonium loadings were greatest in surface run-off. The evidence indicates that the greatest contributor towards these nutrient sources is agriculture. Even when conservative estimates of losses were applied, current fertilizer and animal inputs could account for present day nutrient loadings. In addition, changes in the area under arable farming and under individual crops during the past 30 years are consistent with trends in nitrate and phosphate loads. Nutrient inputs from sewage works overflows and septic tanks within the catchment were estimated to be small. Leachate from a landfill site within the catchment was also not considered to be a major source of nutrients, but a more intensive water quality monitoring programme would be needed to confirm the absence of leachate plumes. The only long-term solution to reducing nutrient loadings to the aquatic systems is a reduction in agricultural activities within the catchment and avoidance of fertilizer and slurry applications near water sources. Diversion of drainage ditch waters supplying the floodplain mire is also a possibility but the hydrological consequences of such an action could induce more severe degradation than that due to nutrient enrichment.     

Pathological findings in the bulbourethral glands of bulls

The bulbourethral glands of 323 Bos indicus or B. indicus crossbred bulls more than 1 1/2 years old were examined in an abattoir study. Bulbourethral adenitis was diagnosed grossly and confirmed by histological examination in 4 (1.2%). Unilateral chronic interstitial inflammation was seen in 2 cases; one of these was associated with a degenerative-type seminal vesiculitis. In the others adenitis was bilateral; in one case it was associated with a concretion and foreign (plant) material in the principal duct of the left bulbourethral gland; in the other bilateral case, numerous calculi were present and microscopically, a chronic active and diffuse inflammation was observed. Chemical analysis of the calculi showed calcium oxalate and tricalcium phosphate to be the most important components. Corynebacterium spp was isolated from the lesion with multiple calculi but attempts to isolate Chlamydia spp, Mycoplasma spp and Brucella abortus from the 4 adenitis cases were unsuccessful. Congenital abnormalities such as glandular fusion (2.2%) or unilateral aplasia (0.6%) were also observed. Cysts were the most common finding (19.2%), and duct dilation was frequent (7.1%). The significance of these findings in relation to fertility is considered.     

Non-oxidative antibacterial activity of bovine neutrophil granule proteins towards mastitis pathogens

Acid extracts of bovine neutrophil granules displayed potent antibacterial activity towards a number of mastitis pathogens in vitro. Killing of pathogens by acid extractable granule protein was dependent on incubation time, protein concentration, bacterial cell load, pH and ionic strength. Gram-negative and Gram-positive organisms showed variable sensitivity to granule extract. Strains of Staphylococcus aureus were the most resistant of tested organisms to granule extract. Gram-negative organisms were neither consistently more nor less sensitive than Gram-positive organisms. Maximal killing of Gram-positive pathogens, after 30 minutes exposure to granule extract at 37 degrees C, occurred between pH 7.0 and 8.0. The Gram-negative organism Escherichia coli B117 was more sensitive to neutrophil granule extract at pH 5.0.     

In vitro Effect of Zearalenone and α-Zearalenol on Boar Sperm Characteristics and Acrosome Reaction

This study was conducted to determine the in vitro effects of three different concentrations (125, 187.5 and 250 microM in diluted semen) of zearalenone (zen) and alpha-zearalenol (alpha-zen) on boar sperm. Semen parameters such as motility, viability and spontaneous acrosome reaction were evaluated. From the results it was shown that both zen and alpha-zen affected the sperm characteristics significantly (p < 0.05), except for alpha-zen at the low concentration which did not decrease the percentage of live reacted spermatozoa significantly. In conclusion, zen and alpha-zen are directly toxic when they affect boar semen in vitro and consequently decrease the fertilization ability of the sperm. The higher the concentration of mycotoxin tested, the greater the decline of sperm parameters noticed. The influence of mycotoxins was found to be time- and dose-dependent.     

The relationship among current management systems, production, disease and drug usage on Ontario dairy farms

The study involved 110 randomly selected dairy farms located in the Ontario, Canada counties of Bruce, Grey, Huron, Oxford, Perth, Waterloo and Wellington. Herds were classified as "intensive" and "extensive". On extensive farms, data were collected at the herd level only, while on intensive farms, data were recorded at both the individual animal and herd level. Data collection continued for approximately two and one-half years. At each visit, technicians collected production data from the most recent production recording scheme report and from the "daily log" maintained by each producer. As well as the ongoing data collection procedures, a number of supplementary data collections were made. The average 305 day milk production increased gradually during the three calendar years from 6224.6 kg in 1981 to 6443.7 kg in 1983. The average calving interval was stable at 13.2 months for all three years. The majority of cows removed from the herds were culled for beef (0.243 per animal year). The next highest removal rate was for domestic sale, followed by death, export sale and destroyed. The highest disease rate, for those conditions whose rates were based on calving, was for retained placenta (0.09 per calving), while clinical mastitis was highest for those conditions whose rates were based on animal years (0.37 per animal year). The overall crude antimicrobial dosage rate, that is, including any antimicrobial used for either prophylactic or therapeutic purposes, was 3.85 doses per animal year. The rate for therapeutic purposes only was 3.6 doses per animal year. Penicillin/streptomycin was used most often with a rate of 1.45 doses per animal year.