The physiological and physical status of single calves at birth in a dairy herd in New Zealand     

TJ Diesch  KJ Stafford  RN Ward 《New Zealand veterinary journal》2013,61(5):250-255

AIM: To determine the physiological status of calves at birth and the perinatal factors that might predispose newborn calves to debility and death, using criteria previously established for newborn lambs.

METHODS: Friesian mixed-aged cows and heifers on a dairy farm in New Zealand that were close to calving were separated from the main herd and observed 24 h a day until they calved. Cows in which labour did not progress for over 1 h or which were in distress were assisted. About 12–13 min after birth, rectal temperature was measured and a blood sample was taken from each calf. The packed cell volume (PCV) and plasma lactate, glucose and fructose concentrations were determined. The time to stand for each calf and the air temperature and weather conditions at birth were recorded.

RESULTS: The parameters measured were within normal ranges for newborns for the majority of calves. Calves sired by an Angus bull and born to heifers (AngusX) had significantly higher plasma lactate and fructose concentrations than Friesian calves born to cows, but there were no significant differences between the two breeds in any of the other parameters measured. Calves of both breeds born with assistance had significantly higher plasma lactate concentrations than those born without. Friesian calves that were assisted at birth had significantly lower PCvs and took significantly longer to stand than calves born without assistance. Assisted AngusX calves were significantly heavier than their unassisted counterparts. Calves born during windy and wet weather and when air temperatures were below 10°C had lower rectal temperatures, took longer to stand and had higher plasma glucose concentrations than those born in dry weather and when air temperatures were above 10°C.

CONCLUSIONS: Calves with physiological parameters outside the normal range had experienced difficult labour and/or intrapartum hypoxaemia. Placental insufficiency and maternal undernutrition during late pregnancy did not apparently contribute to neonatal problems in the present study.  相似文献   

Cerebral infarction in a steer associated with consumption of Leycesteria formosa (Himalayan honeysuckle)     

FI Hill  TJ Scotland 《New Zealand veterinary journal》2013,61(2)

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The Reinvigoration of Apple Trees by the Inarching of Vigorous Rootstocks     

Joan Hearman  A. Beryl Beakbane  R. G. Hatton  W. A. Roach 《The Journal of Horticultural Science and Biotechnology》2013,88(4):376-390

Summary

The purpose of this research was to determine if established, orchard-grown apple trees that were con®ned in root-restricting membranes received adequate water for growth when irrigated. Previous data had shown positive effects of root restriction on reducing shoot extension growth in apple. Soil matric potential (Ψ_sm), leaf stomatal conductance (g) and leaf water potentials (Ψ_l) were measured over daily cycles during the period of maximum tree water use (July and August). Measurements were also made of the Ψ_sm and fruit size throughout the growing season. Daily and seasonal Ψ_sm showed that the soil within the root restricting membranes (+R) when irrigated (+I) remained closed to field capacity (<100 HPa), which was not the case for unirrigated soil within the membranes (-I +R). Ψ_l measured before dawn, showed that similar levels of drought stress were evident between irrigated and restricted (+I +R) and unrestricted (+I -R and -I -R) trees. The Ψ_sm, and Ψ_l for trees with roots within restricting membranes were significantly more negative, in the absence of irrigation (-I +R). Measurement of g showed that root restricted trees were transpiring at similar rates in the presence of irrigation (+I +R) as unrestricted trees (+I -R) with or without irrigation. Stomatal closure could not explain the increased Ψ_l observed for the restricted irrigated (+I +R) treatment compared with unrestricted (-R) trees. A reduced stomatal aperture was the most likely explanation for the reduction in growth previously observed with the restricted unirrigated trees. Fruit size was also affected by root restriction and the effect became greater as the roots became more restricted with tree age. Similarly, there was also a negative effect, in one year, of root restriction on fruit size at harvest, even in the presence of irrigation. Data show that reductions in soil water availability, Ψ_l and g, for the root-restricted trees (+I +R), were unlikely to be the causes for the previously observed reductions in shoot growth (tree size). These results imply that other factors were in operation, among which root-synthesized chemical regulators of shoot growth are the most likely candidates.  相似文献   

Differential gene expression of CYP3A isoforms in equine liver and intestines     

E. TYDÉN  M. LÖFGREN  S. PEGOLO  F. CAPOLONGO  H. TJÄLVE  P. LARSSON 《Journal of veterinary pharmacology and therapeutics》2012,35(6):588-595

Tydén, E., Löfgren, M., Pegolo, S., Capolongo, F., Tjälve, H., Larsson, P. Differential gene expression of CYP3A isoforms in equine liver and intestines. J. vet. Pharmacol. Therap.  35 , 588–595. Recently, seven CYP3A isoforms – CYP3A89, CYP3A93, CYP3A94, CYP3A95, CYP3A96, CYP3A97 and CYP129 – have been isolated from the horse genome. In this study, we have examined the hepatic and intestinal gene expression of these CYP3A isoforms using TaqMan probes. We have also studied the enzyme activity using luciferin‐isopropyl acetal (LIPA) as a substrate. The results show a differential gene expression of the CYP3A isoforms in the liver and intestines in horses. In the liver, CYP3A89, CYP3A94, CYP3A96 and CYP3A97 were highly expressed, while in the intestine there were only two dominating isoforms, CYP3A93 and CYP3A96. The isoform CYP3A129 was not detected in the liver or the intestine, although this gene consists of a complete set of exons and should therefore code for a functional protein. It is possible that this gene is expressed in tissues other than the liver and intestines. In the intestine, both CYP3A96 and CYP3A93 showed the highest gene expression in the duodenum and the proximal parts of the jejunum. This correlated with a high protein expression in these tissues. Studies of the enzyme activity showed the same K_m for the LIPA substrate in the liver and the intestine, while the maximum velocity (V_max) in the liver was higher than in the intestine. Our finding of a differential gene expression of the CYP3A isoforms in the liver and the intestines contributes to a better understanding of drug metabolism in horses.  相似文献   

The structure of the upper atmosphere of mars: In situ accelerometer measurements from mars global surveyor   总被引：1，自引：0，他引：1  

GM Keating  SW Bougher  RW Zurek  RH Tolson  GJ Cancro  SN Noll  JS Parker  TJ Schellenberg  RW Shane  BL Wilkerson  JR Murphy  JL Hollingsworth  RM Haberle  M Joshi  JC Pearl  BJ Conrath  MD Smith  RT Clancy  RC Blanchard  RG Wilmoth  DF Rault  TZ Martin  DT Lyons  PB Esposito  MD Johnston  al et 《Science (New York, N.Y.)》1998,279(5357):1672-1676

The Mars Global Surveyor (MGS) z-axis accelerometer has obtained over 200 vertical structures of thermospheric density, temperature, and pressure, ranging from 110 to 170 kilometers, compared to only three previous such vertical structures. In November 1997, a regional dust storm in the Southern Hemisphere triggered an unexpectedly large thermospheric response at mid-northern latitudes, increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm. Throughout the MGS mission, thermospheric density bulges have been detected on opposite sides of the planet near 90 degreesE and 90 degreesW, in the vicinity of maximum terrain heights. This wave 2 pattern may be caused by topographically-forced planetary waves propagating up from the lower atmosphere.  相似文献   

Career aspirations of emerging veterinarians     

TJ HEATH  JS WESTERN 《Australian veterinary journal》1991,68(7):246-247

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The effect of artificial Eperythrozoon ovis infection on the growth rate of stressed and non-stressed sheep     

TJ NICHOLLS  PI VEALE  D. OVEREND 《Australian veterinary journal》1989,66(6):184-186

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An overview of Australia''s poultry industry in 1989     

TJ BAGUST 《Australian veterinary journal》1989,66(12):416-418

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Residues from long-acting antimicrobial preparations in injection sites in cattle   总被引：2，自引：0，他引：2  

H MAWHINNEY  SM OAKENFULL  TJ NICHOLLS 《Australian veterinary journal》1996,74(2):140-142

Objective To investigate tissue residues of two longacting oxytetracycline (OTC) preparations in cattle.
Design A randomised drug residue trial.  

Animals

Two hundred and forty beef cattle in 24 groups of ten.
Procedure Two blind-coded 200 mg/mL OTC preparations were used in five treatment regimens of various combinations of injection sites (from one to five) and administrations (one or two). Five cattle from each group were slaughtered at 21, 30 and 60 days after injection and the injection site, urine, kidney and diaphragm muscle analysed for residues.
Results The OTC concentration exceeded the maximum residue limit in kidney in animals slaughtered 21 days after treatment, which is the prescribed withholding period. Concentration at the injection site was much greater than the maximum residue limit 30 days post-treatment, but not 45 days post-treatment. The residue was smaller when OTC had been injected in multiple sites. There was no difference between the two OTC preparations.
Conclusion A review of the maximum injection volume, site of injection and the withholding period is needed for long-acting OTC formulations.  相似文献   

Length of veterinary working life     

TJ HEATH 《Australian veterinary journal》1998,76(7):478-481

Objective To estimate the time veterinary graduates spend in private practice and in veterinary work generally, and to determine what factors influence this.
Methods Questionnaires were completed in the sixth year after graduation by 119 veterinarians who had participated in this longitudinal study since starting the veterinary course, and the data were analysed using the SAS System for Windows.
Results Of those who started the veterinary course, 90% graduated, and 96% of these then entered private practice. Five years later 94% (73% in full-time equivalents) were working as veterinarians, and 64% (50% in full-time equivalents) were still in private practice in Australia. Hours, attitudes of principals and clients, and inadequate rewards were the main reasons for leaving private practice. The likelihood of being still in private practice was greater for those who had had significant responsibility for animals before they entered the course, but it was not related to geographical origin (city vs country), age at entry or gender. Women were, however, more likely than men to be working part time as veterinarians. Predictions of veterinary working life were not affected by geographical origin or by previous experience with animals or on farms, but men expected to work longer than women.
Conclusion The average veterinary career, estimated by veterinarians who graduated 5 years earlier, is 24 years in fulltime equivalents for men, and 16 years for women. Almost all (94%, representing 73% in full-time equivalents) still work as veterinarians after 5 years, most of them (76%, representing 59% in full-time equivalents) in private practice. The likelihood of remaining in private practice is related to previous responsibility for animals.  相似文献