The Effect of Parity of the Dam on Sexual Maturation,Serum Concentrations of Metabolic Hormones and the Response to Luteinizing Hormone Releasing Hormone in Bull Calves     

ET Bagu  KL Davies  T Epp  A Arteaga  DM Barrett  R Duggavathi  A Barth  NC Rawlings 《Reproduction in domestic animals》2010,45(5):803-810

The objectives of this study were to determine the effect of parity of the dam on age at which a scrotal circumference (SC) ≥ 28 cm was attained and the LH response to Luteinizing Hormone Releasing Hormone (LHRH) in bull calves. We also wanted to confirm, in a large group of bull calves, that the LH response to LHRH could be used to select early maturing bulls. Body weight and SC of the bull calves were measured every other week. At 15, 20 and 25 weeks of age, calves received 4.12 nm /kg body weight of LHRH ischio‐rectally and blood samples were taken every 15 min for 4 h. Calves from primiparous and multiparous dams were separated into two sub‐groups based on age at which an SC ≥ 28 cm was attained (early or late). An SC ≥ 28 cm was attained earlier in calves born to multiparous as compared with primiparous dams (p < 0.05). At 20 and 25 weeks of age, peak serum LH concentrations (LH‐peak) and area under the LH response curve (LH‐AUC) in response to LHRH were higher (p < 0.01) in calves born to multiparous as compared with primiparous dams. In calves born to multiparous dams the LH‐peak at 15 and 25 weeks of age and the LH‐AUC at 15 weeks of age were lower (p < 0.05) in calves that attained an SC ≥ 28 cm early as compared with late. The LHRH‐challenge test sensitivity and specificity ranged from 46% to 86%. We concluded that parity of the dam affected age at which SC ≥ 28 cm was attained and the LH response to LHRH in bull calves. Serum LH responses to LHRH at 15 and 25 weeks of age, in calves born to multiparous dams, show some promise for development into a test to select early maturing bull calves.  相似文献   

Long‐term control of olfactory neuroblastoma in a dog treated with surgery and radiation therapy          下载免费PDF全文

E Gumpel  AS Moore  DJ Simpson  KL Hoffmann  DP Taylor 《Australian veterinary journal》2017,95(7):227-231

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Behavioural responses of lambs to plastic clips as an alternative procedure to mulesing     

PH Hemsworth  GM Cronin  JL Barnett  KL Butler  EC Jongman  GA Karlen  A Coffey  NA Arnold 《Australian veterinary journal》2012,90(10):373-380

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Ecological role of the giant root‐rat (Tachyoryctes macrocephalus) in the Afroalpine ecosystem          下载免费PDF全文

Jan ŠKLÍBA  Tereza VLASATÁ  Matěj LÖVY  Ema HROUZKOVÁ  Yonas MEHERETU  Claudio SILLERO‐ZUBIRI  Radim ŠUMBERA 《Integrative zoology》2017,12(4):333-344

Rodents with prevailing subterranean activity usually play an important role in the ecosystems of which they are a part due to the combined effect of herbivory and soil perturbation. This is the case for the giant root‐rat Tachyoryctes macrocephalus endemic to the Afroalpine ecosystem of the Bale Mountains, Ethiopia. We studied the impact of root‐rats on various ecosystem features within a 3.5‐ha study locality dominated by Alchemilla pasture, which represents an optimal habitat for this species, in 2 periods of a year. The root‐rats altered plant species composition, reducing the dominant forb, Alchemilla abyssinica, while enhancing Salvia merjame and a few other species, and reduced vegetation cover, but not the fresh plant biomass. Where burrows were abandoned by root‐rats, other rodents took them over and A. abyssinica increased again. Root‐rat burrowing created small‐scale heterogeneity in soil compactness due to the backfilling of some unused burrow segments. Less compacted soil tended to be rich in nutrients, including carbon, nitrogen and phosphorus, which likely affected the plant growth on sites where the vegetation has been reduced as a result of root‐rat foraging and burrowing.  相似文献   

Some aspects of tick-borne diseases of British sheep   总被引：6，自引：0，他引：6  

T A Brodie  P H Holmes  G M Urquhart 《The Veterinary record》1986,118(15):415-418

The significance of tick-borne fever (TBF) and other tick-borne diseases of British sheep are reviewed. Experimental and field studies were carried out to clarify the role of TBF as a pathogen per se and as a predisposing factor in other diseases. Experimental TBF infection caused anorexia and depression in two- to three-week-old lambs, which under the stress of a hill environment could alone be a cause of mortality. Nine out of 10 lambs experimentally inoculated with Staphylococcus aureus during the febrile phase of a TBF reaction developed pyaemic lesions compared with four out of 20 lambs inoculated with S aureus alone. Specific pathogen-free lambs inoculated with an aerosol of Pasteurella haemolytica serotype A1 during a TBF reaction showed more severe clinical signs and had more extensive pathological changes at necropsy than control lambs given P haemolytica alone. Dual infection with TBF and louping-ill virus showed that not only were dually infected sheep more susceptible to louping-ill but almost all of them succumbed to a haemorrhagic syndrome involving a systemic mycotic infection with Rhizomucor pucillus. None of eight sheep given louping-ill virus alone developed this syndrome. Field studies indicated that morbidity and mortality in lambs in south-west Scotland could be markedly reduced by dipping and long acting antibiotic prophylaxis. Lamb groups in which both of these were carried out incurred losses of only 0.6 per cent compared with 10.3 per cent in control groups. In addition antibiotic-treated lamb groups demonstrated significantly better weight gains than untreated groups.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

The control of helminthiasis in ruminants     

J Armour  G M Urquhart 《The British veterinary journal》1965,121(9):392-397

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Experimental Ostertagia ostertagi infections in calves: parasitology and pathogenesis of a single infection   总被引：2，自引：0，他引：2  

J D Ritchie  N Anderson  J Armour  W F Jarrett  F W Jennings  G M Urquhart 《American journal of veterinary research》1966,27(118):659-667

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Survey of permanent wound tracts in the carcases of culled wild red deer in Scotland     

Urquhart KA  McKendrick IJ 《The Veterinary record》2003,152(16):497-501

The number and sites of permanent wound tracts in the carcases of 943 wild culled red deer (Cervus elaphus) were recorded. During the peak period of the red deer rut there was a significant increase in the number of these tracts in the carcases, which was associated with a decrease from 89 per cent to 71 per cent in the probability of the first permanent wound tract also being the last (the terminal probability). There were significantly more permanent wound tracts in the carcases of one group (predominantly males) than in a second group (predominantly females and calves). In carcases with a single tract in the trunk, in which the heart and lungs were also examined, 80 per cent had tracts involving the heart and/or lungs, the recommended thoracic target organs. Tracts involving vital structures in the neck were also common, with 15.3 per cent of the carcases with a single permanent tract having damage limited to cervical structures.  相似文献   

Iliac vein blood sampling in wild, culled roe deer (Capreolus capreolus)     

Urquhart KA 《The Veterinary record》1999,144(13):353

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Strategy for lifelong learning     

Urquhart KA 《The Veterinary record》2002,151(3):95

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