Modelling the transmission dynamics of Echinococcus granulosus in sheep and cattle in Kazakhstan     

Torgerson PR  Burtisurnov KK  Shaikenov BS  Rysmukhambetova AT  Abdybekova AM  Ussenbayev AE 《Veterinary parasitology》2003,114(2):143-153

Cystic echinococcosis, caused by Echinococcus granulosus, is an emerging disease in many parts of the world and, in particular, in eastern Europe and the former Soviet Union. This paper examines the abundance and prevalence of infection of E. granulosus in cattle and sheep in Kazakhstan. Observed data are fitted to a mathematical model in order to determine if the parasite population is partly regulated by intermediate host immunity and to define parameters in the model. Such data would be useful to develop simulation models for the control of this disease. Maximum likelihood techniques were used to define the parameters and their confidence limits in the model and the negative binomial distribution was used to define the error variance in the observed data. The results indicated that there are significant variations in the infection pressure to sheep depending on their location. In particular sheep from Almaty Oblast and from central and northern Kazakhstan appeared to have a greater exposure than sheep from Jambyl or South Kazakhstan Oblasts. The infection pressure to cattle was somewhat lower in comparison. In common with other similar studies, there was no evidence of parasite-induced immunity in sheep or cattle in Kazakhstan due to natural infection. The highest abundance and prevalence were seen in the oldest age classes of animals.  相似文献   

A survey of beef cattle farmers in New Zealand,examining management practices of primiparous breeding heifers     

RE Hickson  WJ Anderson  PR Kenyon  N Lopez-Villalobos  ST Morris 《New Zealand veterinary journal》2013,61(4):176-183

AIM: To obtain an estimate of the incidence of assistance at calving in primiparous (first-calving) beef heifers and the prevalence of breeding heifers at 15 months of age in New Zealand in 2006,and to identify factors contributing to farmers' decisions regarding breeding strategies for heifers, using a survey of beef cattle farmers.

METHODS: A questionnaire was sent to farmers listed in a Massey University database and to members of selected breed societies, as well as published in an industry newspaper; 331 valid responses were received. Information was gathered on the age and number of primiparous heifers, number of heifers assisted, and the importance of various reasons for and against breeding heifers at 15 months of age. Respondents were also required to outline the criteria used for selecting bulls to join with heifers, and the strategies used to manage dystocia in primiparous heifers.

RESULTS: Sixty-five (95% CI=58–71)% of respondents had only 2-year-old primiparous heifers in 2006, whilst a further 11 (95% CI=8–16)% had both 2- and 3-year-old primiparous heifers. The mean reported incidence of assisted calving was 7.0 (95% CI=6.4–7.5)% for 2-year-old primiparous heifers and 1.7 (95% CI=1.2–2.2)% for 3-year-old primiparous heifers. The reported incidence of assistance at calving within individual herdsranged from 0 to 100% for 2-year-old heifers. Respondents with bull-breeding herds most commonly observed their primiparous 2-year-old heifers twice daily, whilst respondents with commercial herds most commonly observed them once daily during calving. The most important reason for breeding heifers at 15 months of age was “increased profit”, whereas the most important reason for not breeding them at that age was “concern about rebreeding performance of 2-year-old heifers”. Estimated breeding value (EBV) for birth weight was the factor considered most frequently when selecting bulls to join with maiden heifers; age of bull and body shape of bull were the next most frequently considered factors. Selection of an appropriate bull was the most common strategy used to manage dystocia in 2-year-old beef heifers.

CONCLUSIONS: The majority of respondents calved their heifers at 2 years of age, and “increased profit” was the primary motivator. Concern about the rebreeding performance of 2-year-old heifers was the most important reason among the remainder of respondents for not breeding heifers at 15 months of age. Dystocia in 2-year-old heifers was “not a problem” or “a minorproblem” in most herds, but there was much variation amongst herds.  相似文献   

Prevalence and clonal diversity of Campylobacter jejuni from dairy farms and urban sources     

B Adhikari  JH Connolly  P Madie  PR Davies 《New Zealand veterinary journal》2013,61(6):378-383

AIM: To investigate the role of free-living animals such as spar- rows, rodents and flies as potential reservoirs of Campylobacter spp on a dairy farm, and to assess the genetic diversity among Campylobacter isolates from the farm and an urban source.

METHODS: A total of 290 samples (bovine, passerine and ro- dent faeces, and whole flies) were collected from a large com- mercial dairy farm in the Manawatu district in New Zealand, and from faeces from urban sparrows in a nearby city. Other samples collected from the dairy farm included five from silage, two from aprons worn by workers during milking, two from workers' boots and two from water in troughs in a paddock. Isolates of thermophilic Campylobacter spp were identified mor- phologically and phenotypically and further characterised mo- lecularly using pulsed-field gel electrophoresis (PFGE) and the restriction enzyme SmaI.

RESULTS: Campylobacter jejuni was the only Campylobacter species isolated from all samples. The highest prevalence was found in faeces from dairy cows (54%), followed by faeces from sparrows from the urban area (40%) and the farm (38%), and from rodents (11%) and whole flies (9%). Other samples from the farm environment such as silage, trough water, and work- ers' aprons and boots were also positive for C. jejuni. Of the 22 restriction patterns obtained, seven were common to more than one source.

CONCLUSIONS: Cattle, sparrows, rodents and flies are po- tential reservoirs of C. jejuni on dairy farms. Identical clones of C. jejuni carried by cattle, sparrows, flies and rodents prob- ably indicate a common source of infection. The high level of asymptomatic carriage of C. jejuni by healthy dairy cows could be sufficient to maintain infections within the dairy farm sur- roundings via environmental contamination.  相似文献   

The effect of individual liveweight and use of teaser rams prior to mating on the reproductive performance of ewe hoggets     

PR Kenyon  PCH Morel  ST Morris  DM West 《New Zealand veterinary journal》2013,61(5):340-343

AIM: To determine the effects of liveweight (LW) and use of teaser rams prior to mating on both the mating performance and pregnancy rate of ewe hoggets.

METHODS: Romney hoggets (n=841) were weighed and randomly assigned to one of two treatment groups; either exposed to seven harnessed, vasectomised (teaser) rams for 17 days prior to the breeding period (n=283); or not exposed to teaser rams (unteased, n=558). Harnessed Perendale rams were then introduced for two oestrous cycles. Using crayon marks, hoggets were identified as having been mated during the first 17 days only, during the second 17 days only, during both periods, or not mated. All mated hoggets were then scanned for pregnancy using ultrasound, 48 days after the end of the breeding period, and identified as being either non-pregnant, or as single-, twinor triplet-bearing.

RESULTS: Hoggets mated in either the first 17 days only or in both the first and second 17-day periods were heavier than those mated in the second period only (p<0.001). Those mated in the first or second 17-day period only, and those mated in both periods were all heavier prior to mating than those not mated at all (p<0.001). Twin-bearing hoggets were heavier than both their single-bearing and non-pregnant counterparts (p<0.001). A greater proportion of the teased hoggets were mated in the first 17 days only compared with unteased hoggets (62.6 vs 32.1%; p<0.001). In contrast, more of the unteased hoggets were marked in the second 17-day period only (p<0.001). A greater proportion of mated, unteased hoggets were found to be non-pregnant in comparison to their teased counterparts (17.8 vs 11.2%; p=0.02).

CONCLUSIONS: Heavier hoggets at breeding were more likely to be mated in the first 17 days of the breeding period and more likely to be twin-bearing. Use of teaser rams for 17 days prior to the breeding period increased the proportion of hoggets mated in the first 17 days, increased conception rates, and thus increased the proportion of pregnant hoggets. These results indicate that farmers should utilise teasers for 17 days prior to commencement of the breeding period and avoid mating hoggets that weigh below 36 kg.  相似文献   

Some histological lesions seen in macroscopically normal mesenteric lymph nodes of deer     

RG Clark  JC Glossop  PR Wilson  C Heuer 《New Zealand veterinary journal》2013,61(1)

  相似文献   

The effect of the maturity and prior breeding activity of rams and body condition score of ewe hoggets on the reproductive performance of ewe hoggets     

PR Kenyon  SL Smith  PCH Morel  ST Morris  DM West 《New Zealand veterinary journal》2013,61(5):290-294

Abstract

AIM: To determine the effect of age and prior use of mature rams at a given ram-to-ewe ratio, and the effect of body condition on breeding performance and pregnancy rate of ewe hoggets.

METHODS: Ewe hoggets (n=733) aged 7–8 months were weighed and their body condition scored, then randomly assigned to one of three treatment groups (Day 0) and joined with either four two-tooth rams (20 months of age) not used previously (n=244; Two-tooth), four mixed-aged mature rams that had not been used earlier in the season (n=244; Mature-fresh), or four mixed-aged mature rams that had been used with mature ewes immediately prior to joining with hoggets (n=245; Mature-used). The breeding period was 34 days. Ewe hoggets were identified as having been marked during the first 17 days only, during both 17-day periods, during the second 17 days only, or not marked. Hoggets were re-weighed on Day 34, and pregnancy status determined using ultrasound on Day 92. The breeding soundness of the rams was assessed on Days ?34 and ?1.

RESULTS: Semen samples obtained from the rams did not differ significantly in any of the parameters measured (p>0.05). Ewe hoggets joined with Mature-fresh rams were less likely (p<0.05) to be marked in the second 17 days of breeding only than those joined with either Two-tooth or Mature-used rams. No other breeding parameters were affected by breeding group (p>0.05). Hoggets marked in the first 17 days only were heavier (p<0.05) at Day 0 than those marked in the second 17 days only or not marked. Hoggets diagnosed as twin-bearing were heavier (p<0.05) than non-pregnant or single-bearing hoggets. Those hoggets marked in the first 17 days only had a greater (p<0.05) body condition score (BCS) than those marked in the second 17 days only or not marked at all. These differences were no longer apparent after correction for liveweight (LW).Correction for LW at Day 0 or change in LW during the breeding period did not affect the results for breeding performance.

CONCLUSIONS: Under the conditions of this study, two-tooth rams and mature rams that had been used previously were just as suitable as mature rams that had not been used previously for breeding with ewe hoggets. Further studies are warranted to verify this result. The re-use of rams without reducing breeding performance would reduce breeding costs and may make breeding hoggets a more viable option for farmers. The BCS of ewe hoggets affected breeding performance, and can thus be used to identify those animals most suitable for breeding.  相似文献   

Comparison of concentrations of copper in plasma and serum from farmed red deer (Cervus elaphus)     

RA Laven  PR Wilson 《New Zealand veterinary journal》2013,61(3):166-169

AIM: To determine the relationship between the concentrations of Cu in plasma and serum in red deer, and to compare this relationship with those previously reported in cattle and sheep.

METHODS: Paired serum and heparinised plasma samples from 114 red deer from 10 herds (n=6-20 per herd) were analysed for concentrations of Cu. Samples were collected either at slaughter (n=84; eight herds) or by jugular venepuncture (n=30; two herds). Thirty-nine of the samples taken at slaughter were from adult hinds from four herds, while other samples were taken from 10–14-month-old males, except for one herd (10 samples) where an equal number of 8–9-month-old males and females were sampled. The effect of age, gender and herd on the relationship between concentrations of Cu in plasma and serum was assessed using univariate ANOVA. The individual results for concentrations of Cu in serum were compared with those in plasma, using limits-of-agreement plotting.

RESULTS: The mean concentration of Cu in plasma was not significantly different from that of serum (0.048; 95% CI=-0.14 to 0.24 µmol/L). There was no effect of age, sex or herd on this relationship.

CONCLUSIONS: In deer, there was no significant difference between concentrations of Cu in plasma and serum regardless of age, sex or herd of origin.

CLINICAL RELEVANCE: In contrast to the situation in cattle and sheep, the concentration of Cu in serum can be used interchangeably with that in plasma for the estimation of concentration of Cu in blood of red deer.  相似文献   

Factors affecting rectal temperature measurement using commonly available digital thermometers     

Naylor JM  Streeter RM  Torgerson P 《Research in veterinary science》2012,92(1):121-123

Rectal temperature measurement is an essential part of physical examination of cattle and some physiological experiments. Modern digital thermometers are often used to measure rectal temperatures by students; this study describes their reliability and appropriate use. Students measured rectal temperature on 53 occasions using their personal digital thermometer and techniques gained from previous instruction, rectal temperature was also measured by an experienced person using a Cornell mercury thermometer completely inserted in the rectum. Cornell mercury thermometers values were 38.95±0.05°C (mean±1 SE, n=53). Student rectal temperature measurements using their initial technique were nearly 0.5°C lower, 38.46±0.07°C. After receiving instruction to insert the digital thermometer to the window, student obtained values were 38.77±0.06°C; these are significantly higher than with the student's initial technique and closer to those obtained with a Cornell thermometer. In a series of 53 water bath tests, student owned thermometers recorded similar mean values to those of a traceable (reference) digital thermometer, Cornell mercury thermometer readings were 0.2°C higher. 10 individual digital thermometers were repeatedly tested against a traceable thermometer in a water bath, one was inaccurate. In a separate experiment a trained clinician tested the effect of angle of insertion of a digital thermometer on temperature readings and the affect was <0.1°C. We conclude that accurate temperature measurements using digital thermometers are only likely if the thermometer is inserted to the beginning of the window and the thermometer's accuracy is checked periodically.  相似文献   

Effects of supplementation of medium with different antioxidants during in vitro maturation of bovine oocytes on subsequent embryo production          下载免费PDF全文

TC Sovernigo  PR Adona  PS Monzani  S Guemra  FDA Barros  FG Lopes  CLV Leal 《Reproduction in domestic animals》2017,52(4):561-569

The aim of this study was to assess the effects of different antioxidants on the levels of reactive oxygen species (ROS) and glutathione (GSH) in oocytes during in vitro maturation (IVM), as well as on the production of embryos. Oocyte of slaughterhouse‐derived cattle ovaries were placed in IVM with different antioxidants: quercetin (2 μM), cysteamine (100 μM), carnitine (0.5 mg/ml), vitamin C (50 μg/ml) or resveratrol (2 μM). Oocytes matured without any antioxidant supplementation were used as control. The oocytes were assessed for maturation rates and for ROS and GSH levels by fluorescence staining in 2′,7′‐dichlorodihydrofluorescein diacetate and Cell Tracker Blue, respectively. Embryo production was assessed in terms of cleavage, blastocysts and hatching rates and embryo cell numbers. The results expressed in arbitrary fluorescence units showed ROS reduction (p < .05) in the groups with quercetin (27.5 ± 3.4), vitamin C (27.1 ± 3.0) or resveratrol (28.1 ± 4.7), in comparison with those with cysteamine (34.9 ± 4.5), carnitine (34.6 ± 3.8) or to the control group (36.5 ± 5.2). GSH levels increased (p < .05) in cysteamine (63.5 ± 5.5) or carnitine (60.8 ± 4.4) groups in comparison with quercetin (52.7 ± 5.1), vitamin C (53.0 ± 3.8), resveratrol (53.1 ± 4.4) or to the control (49.6 ± 4.5). Nuclear maturation cleavage and hatched blastocysts rates did not differ (p > .05) between groups. However, blastocyst rates after in vitro fertilization in quercetin (53.5 ± 3.9%), vitamin C (52.1 ± 3.1%) resveratrol (54.2 ± 4.0%), cysteamine (52.4 ± 2.7%) or carnitine (54.2 ± 3.1%) groups were higher (p < .05) than in the control (47.2 ± 2.7%). Total cell numbers in embryos from the vitamin C, resveratrol, cysteamine or carnitine groups were higher than in quercetin and control groups, which were similar to each other. The results suggest that using antioxidants during IVM may reduce oxidative stress either by decreasing ROS levels directly or by increasing GSH levels in oocytes, depending on the type of antioxidant used. Overall, oxidative stress control during IVM with the antioxidants examined here improved blastocyst development with similar efficacy.  相似文献   

Consequences of Nitric Oxide Synthase Inhibition During Bovine Oocyte Maturation on Meiosis and Embryo Development     

KRL Schwarz  PRL Pires  THC de Bem  PR Adona  CLV Leal 《Reproduction in domestic animals》2010,45(1):75-80

The importance of nitric oxide synthase (NOS) in bovine oocyte maturation was investigated. Oocytes were in vitro matured with the NOS inhibitor N^w- l -nitro-arginine methyl-ester (10⁻⁷, 10⁻⁵ and 10⁻³  m l -NAME) and metaphase II (MII) rates and embryo development and quality were assessed. The effect of l -NAME (10⁻⁷  m ) during pre-maturation and/or maturation on embryo development and quality was also assessed. l -NAME decreased MII rates (78–82%, p < 0.05) when compared with controls without l -NAME (96%). Cleavage (77–88%, p > 0.05), Day 7 blastocyst rates (34–42%, p > 0.05) and total cell numbers in blastocysts were similar for all groups (146–171 cells, p > 0.05). Day 8 blastocyst TUNEL positive cells (3–4 cells) increased with l -NAME treatment (p < 0.05). For oocytes cultured with l -NAME during pre-maturation and/or maturation, Day 8 blastocyst development (26–34%) and Day 9 hatching rates (15–22%) were similar (p > 0.05) to controls pre-matured and matured without NOS inhibition (33 and 18%, respectively), while total cell numbers (Day 9 hatched blastocysts) increased (264–324 cells, p < 0.05) when compared with the controls (191 cells). TUNEL positive cells increased when NOS was inhibited only during the maturation period (8 cells, p < 0.05) when compared with the other groups (3–4 cells). NO may be involved in meiosis progression to MII and its deficiency during maturation increases apoptosis in embryos produced in vitro . Nitric oxide synthase inhibition during pre-maturation and/or maturation affects embryo quality.  相似文献