Pharmacokinetics of carprofen and firocoxib for medication control in racing greyhounds

Animals used in sport should be treated as required to ensure animal welfare but any such use of medication should also be controlled to ensure integrity. Pharmacokinetic studies on groups of six greyhounds were performed to measure plasma and urine levels of carprofen and firocoxib to inform medication control advice. Using the standard methodology for medication control the Irrelevant Plasma Concentration was determined as 20 and 2 ng/mL for carprofen and firocoxib, respectively. The Irrelevant Urine Concentration was also determined as 0.3 and 2 ng/mL for carprofen and firocoxib, respectively. These Irrelevant Plasma and Urine Concentrations will allow laboratory Screening Limits, Detection Times and Withdrawal Time advice to be determined and publicised by regulators of greyhound racing. The Screening Limits will also inform Recommended Limits of Detection if meat-containing residues of these medications are fed to greyhounds.     

Relationship between nutrition and reproduction in beef cattle

The primary nutrient consideration for optimum reproductive performance in beef cattle is energy. Low energy intake delays the onset of puberty in heifers and bulls. Heifers should reach approximately 66 per cent of mature body weight by 14 to 15 months of age and be bred 30 days prior to breeding the main cow herd. Body conditioning scores (BCS) (1 = emaciated, 9 = obese) should be used to evaluate pregnant cows entering their third trimester. Cows should calve with body conditioning score 5 to 7. Forage quality and environmental factors influence maximum dry matter intake and nutrient requirements and must be considered in the clinical setting. Crude protein dietary content should be 11 to 12 per cent for lactating beef cattle. Mineral (calcium, phosphorus, magnesium, potassium, sulfur, sodium, chloride) nutrition is not a major cause of decreased reproductive performance in beef cattle. Trace mineral deficiencies (particularly selenium, copper, and zinc) can cause decreased reproductive performance. Diagnosis of these trace mineral deficiencies can be confirmed by elemental analysis of blood or tissues.     

Residues of endosulfan in the tissues of lactating goats

SUMMARY: The sites of tissue accumulation in lactating goats of the organochlorine insecticide endosulfan were studied. Twelve lactating goats were dosed orally with endosulfan (1 mg/kg body weight per day) for 28 days. Groups of 3 animals were killed on days 1, 8, 15, and 21 after endosulfan treatment ended and their tissues examined for the presence of endosulfan. Total residues of α and β endosulfan and endosulfan sulphate (mg/kg) were detected in kidney (0.29), gastro-intestinal tract (0.20), liver (0.12), brain (0.06), muscle and spleen (0.04), lung and heart (0.01) and milk (0.02) on the flrst sampllng day but within 15 days, concentrations had fallen to < 0.01 mg/kg in all tissues except kidney (0.20). Endosulfan could not be detected in animals 21 days after dosing had ceased. The residue in milk could only be detected on day 1 of sampling. This study indicates that kidney rather than fatty tissue should be used to monitor the presence of endosulfan in animals intended for human consumption.     

Minimizing salt in drain water by irrigation management — Arizona field studies with citrus

A field experiment was conducted for 5 years in the Wellton-Mohawk Irrigation and Drainage District of southwest Arizona to investigate the potential for reducing the salt load in irrigation return flow by decreased leaching in citrus. Leaching treatments of 5, 10, and 20%, replicated nine times, were established on mature Valencia orange trees (Citrus sinensis L.) and compared with conventional flood irrigation management.The annual evapotranspiration was found to be about 1470 mm. The leaching fractions, determined indirectly by several techniques, were close to those intended. The leaching fraction for the flood check was 0.47. During the first 4 years, the leaching treatments had no observable influence on fruit yield or quality or on tree growth. During the last year of the study, however, the yield of the 5% leaching treatment was significantly lower than the other treatments. Thus, with some uncertainty, the leaching requirement for Valencia orange irrigated with Colorado River water exceeds 5% but is less than 20%.Results verify that water applications could be reduced substantially below typical commercial practice without loss of crop yield. At the conclusion of the experiment reducing the leaching fraction to 0.20 for the 3000 ha of citrus in the District would reduce the salt load in the irrigation return flow by 127000 Mg annually. After steady state conditions are reached at 20% leaching the annual reduction would be 42500 Mg.     

The current status and outlook for insecticide,acaricide and anthelmintic resistances across the Australian ruminant livestock industries: assessing the threat these resistances pose to the livestock sector

The Australian ruminant livestock industries are faced with the need to control parasitic infectious diseases that can seriously impact the health of animals. However, increasing levels of resistance to insecticides, anthelmintics and acaricides are substantially reducing the ability to control some of these parasites. Here we review the current situation with regard to chemical resistances in parasites across the various sectors of the Australian ruminant livestock industries and assess the level of threat that these resistances pose to the sustainability of these sectors in the short to long terms. We also look at the extent to which testing for resistance occurs across the various industry sectors, and hence how well-informed these sectors are of the extent of chemical resistance. We examine on-farm management practices, breeding of parasite-resistant animals, and non-chemical therapeutics that may act as short to long term means to reduce the current reliance on chemicals for parasite control. Finally, we look at the balance between the prevalence and magnitude of current resistances and the availability and adoption rates of management, breeding and therapeutic alternatives in order to assess the parasite control outlook for the various industry sectors.