Nitrate leaching losses and their control in a mixed farm system in the Cotswold Hills, England

Abstract. Nitrate leaching was measured for four years at the Royal Agricultural College 's Coates Farm in the Cotswolds, England. Coates is a typical Cotswold mixed farm with thin, well-drained calcareous soils especially prone to leaching. Over the duration of this study there were dairy, sheep and arable enterprises on the farm. A 'Farm Gate' nitrogen (N) budget was constructed. Small 120 m × 20 m 'farmlets' were sited in ten fields across the farm, covering all parts of the rotation, as the sites for detailed measurements. Each farmlet received the same management as the rest of the field in which they were situated. Using ceramic probes inserted to 60 cm, soil water was sampled every two weeks throughout the winter drainage season. The annual drainage varied from 135 mm under grassland in 1996/7 to 600 mm under cereals in 1998/9. Average N losses by leaching were determined mostly by rainfall and were 65 kg N ha^–1 yr^–1, accounting for 25% of the N inputs. Especially leaky parts of the rotation were the ploughing out of a lucerne ley and the grazing of stubble turnips with sheep, both typical Cotswold farm practices. The research highlights some of the difficulties in developing practicable, profitable management practices to decrease nitrate losses.     

Response of organically managed grassland to available phosphorus and potassium in the soil and supplementary fertilization: field trials using grass–clover leys cut for silage

Abstract. Effective use and recycling of manures together with occasional and judicious use of supplementary fertilizing materials forms the basis for management of phosphorus (P) and potassium (K) within organic farming systems. Replicated field trials were established at three sites across the UK to compare the supply of P and K to grass–clover swards cut for silage from a range of fertilizing materials, and to assess the usefulness of routine soil tests for P and K in organic farming systems. None of the fertilizing materials (farmyard manure, rock phosphate, Kali vinasse, volcanic tuff) significantly increased silage yields, nor was P offtake increased. However, farmyard manure and Kali vinasse proved effective sources of K to grass and clover in the short to medium term. Available P (measured as Olsen-P) showed no clear relationship with crop P offtake in these trials. In contrast, available K (measured by ammonium nitrate extraction) proved a useful measurement to predict K availability to crops and support K management decisions.     

Factors affecting the efficacy of ivermectin against Heligmosomoides polygyrus (Nematospiroides dubius) in mice

The efficacy of ivermectin against Heligmosomoides polygyrus was investigated in 5 mouse strains (CFLP, NIH, C57Bl10, BALB/c and CBA) using a variety of dose levels, and subcutaneous and oral administration. Heligmosomoides polygyrus were not completely eliminated when 5 mg kg-1 of ivermectin was given 6 days after infection, but 10 mg kg-1 was totally effective. Significant mouse-strain variation in drug efficacy was detected, NIH mice requiring treatment with higher doses than CFLP mice in order to bring about a comparable level of larvicidal activity. Ivermectin was more effective when given subcutaneously than when given orally, regardless of the dose administered or the strain of mouse tested. The anthelmintic effect of the treatment was more persistent in CFLP mice given 20 mg kg-1 subcutaneously than in NIH mice or in mice treated orally, and a 20-day interval between administration and infection was insufficient to prevent inhibition of parasite survival. Ivermectin was shown to be totally effective at 20 mg kg-1 given subcutaneously in killing immune arrested larvae of H. polygyrus.     

SOME ECONOMIC ASPECTS OF THE APPLICATION OF PHOSPHATES TO PERMANENT PASTURES IN IRELAND

During the years 1957 to 1959 a number of trials carried out at various centres throughout the country showed that the yield of Irish pastures could be greatly increased through the application of fertilizers. Phosphorus increased both yield and the protein content of herbage. The increase in yield was a linear function of the initial P status of the herbage. For the series as a whole, phosphorus increased the yield by approximately 20%, potassium by 7% and phosphorus and nitrogen by 45%. The national and sociological implications of these results are discussed.     

AAHA dental care guidelines for dogs and cats

The purpose of this document is to provide guidelines for the practice of companion animal dentistry for the veterinary profession. Dental care is necessary to provide optimum health and quality of life. Diseases of the oral cavity, if left untreated, are often painful and can contribute to other local or systemic diseases. This paper includes guidelines for materials and equipment, dental cleaning and evaluation, client communication, and pet home care.     

Successful treatment of acute respiratory distress syndrome in 2 dogs

Acute respiratory distress syndrome (ARDS) was diagnosed in 2 dogs with acute dyspnea. Short-term positive pressure ventilation and intense critical and nursing care were provided. Both dogs improved and were discharged. Few reports describe successful recovery from ARDS. Due to advances in positive pressure ventilation and improvement in the supportive care of critically ill veterinary patients, the prognosis for ARDS may improve.     

Antiproliferative activity of Saponaria vaccaria constituents and related compounds

Total methanolic extracts of Saponaria vaccaria seed derived from several varieties, as well as various purified components obtained through successive chromatographic separations of total extracts were evaluated for their growth inhibitory activity in WiDr (colon), MDA-MB-231 (breast), NCI-417 (lung) and PC-3 (prostate) human cancer cells as well as the non-tumorigenic fibroblast BJ (CRL-2522) cell line using MTT colorimetric assay. Purified bisdesmosidic saponins segetoside H and I were further examined using microscopy and apoptosis assays. Bisdesmosidic saponins exhibited dose-dependent growth inhibitory and selective apoptosis-inducing activity. Growth inhibitory effects were particularly strong in a breast (MDA-MB-231) and a prostate (PC-3) cancer cell line. Total extracts exhibited a different preference being most active against a colon cancer cell line (WiDr). In a comparison of varieties, all of the total seed extracts exhibited similar dose-dependent activities, but with some variation in potency. Monodesmosidic saponins vaccarosides A and B, phenolic vaccarin, and cyclopeptide segetalin A, co-occurring seed substituents, did not exhibit activity. The non-tumorigenic fibroblast cell line BJ (CRL 2522) was growth inhibited but did not undergo apoptosis when treated with bisdesmosidic saponins at low micromolar concentrations. Saponin-rich extracts from Kochia scoparia seed and Chenopodium quinoa were also evaluated alongside Saponaria saponins but did not exhibit activity. Closely related Quillaja saponins exhibited activity but were less potent.     

Surgical management of a subepiglottic thyroglossal duct cyst in a dog

A 2 yr old dog presented for dysphagia and coughing secondary to a 4 cm × 4 cm turgid subepiglottic mass. Cervical radiographs, an esophagram, and computed tomography confirmed the presence of a cystic mass that was not intimately associated with any surrounding structures. An incisional biopsy confirmed the cystic nature of the mass and helped to rule out a malignancy. A marginal surgical excision was performed via a ventral approach. Histopathology of the mass was consistent with a thyroglossal duct cyst. This is the first report of a thyroglossal duct cyst in this location in a dog. There was no recurrence of clinical signs 14 mo after surgery.