Culture results from milk samples submitted to veterinary diagnostic laboratories from August 2003 to December 2006 in New Zealand     

KR Petrovski  NB Williamson  N Lopez-Villalobos  TJ Parkinson  IG Tucker 《New Zealand veterinary journal》2013,61(6):317-322

Abstract

AIMS: To determine the pattern of isolation of major mastitis-causing organisms isolated from milk samples submitted to five veterinary diagnostic laboratories in New Zealand.

METHODS: The culture results of 25,288 milk samples that were collected from dairy cows throughout New Zealand from August 2003 to December 2006 and submitted to a group of veterinary diagnostic laboratories were assembled, reviewed and summarised. Logistic regression was used to analyse the effect of year, region (i.e. North vs South Island), and season on the probability of isolating the two most common organisms.

RESULTS: The most commonly isolated mastitis causing organisms from all samples were: Streptococcus uberis (23.6%), Staphylococcus aureus (23.5%), coagulase-negative staphylococci (CNS; 7.2%), Strep. dysgalactiae (6.2%), Bacillus spp. (4.0%), and coliforms (3.7%). The percentage of samples with isolates of Strep. uberis or Staph. aureus was affected by island, year and season (p<0.001). For most of the year, except in late winter and early spring when Strep. uberis was much more common, the percentage of isolates of Strep. uberis and Staph. aureus were not apparently different despite the former being an environmental pathogen and the other a contagious one.

CONCLUSION: The pattern of isolation of major mastitis-causing organisms, as determined from culture of milk samples submitted to diagnostic laboratories in New Zealand, has changed significantly over the last 40 years, with a substantial increase in the percentage of isolates that are Strep. uberis and a decrease in isolates of Strep. agalactiae. There is a clear seasonal pattern to the isolation of both Strep. uberis and Staph. aureus, particularly the former.

CLINICAL RELEVANCE: Knowledge of the aetiological agents causing bovine mastitis on a farm is of value in determining the choice of treatment. This dataset shows that, although there is seasonal pattern to the isolation of mastitis-causing organisms in New Zealand, both Strep. uberis and Staph. aureus are isolated throughout the year, so bacteriology is of value in determining aetiology even in late winter/early spring.  相似文献   

Canine mast cell tumours (MCTs)     

JS Munday  NL Stedman 《New Zealand veterinary journal》2013,61(1)

  相似文献   

Fungi isolated from bovine udders,and their possible sources     

JH Williamson  ME di Menna 《New Zealand veterinary journal》2013,61(4):188-190

AIM: To identify fungi isolated from infections of the bovine mammary gland, and establish their possible sources.

METHODS: From a herd of 420 cows, milk samples were collected from all quarters at calving and cultured to detect causative organisms. Quarters identified as infected with fungi were further sampled during early lactation. Samples from feedstuffs, the feed pad and ends of teats were also collected and analysed for the presence of fungi.

RESULTS: Eleven of 420 cows were diagnosed with intramammary infections (IMI) caused by yeasts (nine cows, 10 quarters) and moulds (two cows, three quarters). Six of the yeast species had previously been reported as being responsible for mastitis. Elevated somatic cell counts (SCC) were observed in many quarters, but most infections were eliminated spontaneously. Two of the fungi isolated from milk samples were also isolated from feedstuffs and teat swabs, and seven other fungi isolated from milk samples were not isolated from feed, the feed pad or cows' teats.

CONCLUSIONS: Isolation of fungi from the udder is rarely reported in dairy cows in New Zealand. In this herd, contamination of the end of the teat originating from feedstuffs and possibly exacerbated by the use of a feed pad may have led to the establishment of IMI caused by fungi.

CLINICAL RELEVENCE: Fungi are infrequently if ever reported in mastitis trial data or surveys in New Zealand and are probably of little clinical significance.  相似文献   

Forage and breed effects on behavior and temperament of pregnant beef heifers     

Angela R Mays  Michael L Looper  Benjamin C Williamson  Kenneth P Coffey  Wayne K Coblentz  Glen E Aiken  Charles F Rosenkrans  Jr 《畜牧与生物技术杂志(英文版)》2013,4(1):20

Background

Integration of behavioral observations with traditional selection schemes may lead to enhanced animal well-being and more profitable forage-based cattle production systems. Brahman-influenced (BR; n = 64) and Gelbvieh × Angus (GA; n = 64) heifers consumed either toxic endophyte-infected tall fescue (E+) or one of two nontoxic endophyte-infected tall fescue (NT) cultivars during two yr. Heifers were weighed at midpoint and termination of grazing. Grazing behavior (grazing, resting in the shade, lying, or standing without grazing) was recorded (n = 13 visual observations per yr in June and July) for each pasture. During yr 2, exit velocity (EV) and serum prolactin (PRL) were determined.

Results

Grazing behavior was influenced (P < 0.05) by an interaction between fescue cultivar and breed type. Gelbvieh × Angus heifers assigned to E+ pastures had the lowest percentage of animals grazing and the largest percentage of animals resting in the shade. Brahman-influenced heifers had faster EV (P < 0.001) than GA heifers (0.52 vs. 0.74 ± 0.04 s/m, respectively). Body weight (BW) was affected (P < 0.01) by an interaction of tall fescue cultivar and d, and an interaction of tall fescue cultivar and breed type. Heifers grazing NT pastures were heavier (P < 0.01) than heifers grazing E+ pastures at midpoint and termination. Gelbvieh × Angus heifers grazing NT pastures were heavier (P < 0.01) than GA and BR heifers grazing E+ and BR heifers grazing NT pastures. An interaction of forage cultivar and breed type occurred on serum PRL (P < 0.01).

Conclusion

Collectively fescue cultivar, EV, and concentrations of serum PRL were associated with grazing behavior. Heifers grazing NT pastures were observed to be grazing more than heifers assigned to E+ pastures, regardless of breed type, which may have contributed to changes in BW and average daily gain (ADG) in heifers. Integration of behavioral observations along with traditional selection schemes may lead to enhanced animal well-being and more profitable forage-based cattle production systems.  相似文献   

Predictive relationship between polyphenol and nonfat cocoa solids content of chocolate     

Cooper KA  Campos-Giménez E  Jiménez Alvarez D  Rytz A  Nagy K  Williamson G 《Journal of agricultural and food chemistry》2008,56(1):260-265

Chocolate is often labeled with percent cocoa solids content. It is assumed that higher cocoa solids contents are indicative of higher polyphenol concentrations, which have potential health benefits. However, cocoa solids include polyphenol-free cocoa butter and polyphenol-rich nonfat cocoa solids (NFCS). In this study the strength of the relationship between NFCS content (estimated by theobromine as a proxy) and polyphenol content was tested in chocolate samples with labeled cocoa solids contents in the range of 20-100%, grouped as dark (n = 46), milk (n = 8), and those chocolates containing inclusions such as wafers or nuts (n = 15). The relationship was calculated with regard to both total polyphenol content and individual polyphenols. In dark chocolates, NFCS is linearly related to total polyphenols (r2 = 0.73). Total polyphenol content appears to be systematically slightly higher for milk chocolates than estimated by the dark chocolate model, whereas for chocolates containing other ingredients, the estimates fall close to or slightly below the model results. This shows that extra components such as milk, wafers, or nuts might influence the measurements of both theobromine and polyphenol contents. For each of the six main polyphenols (as well as their sum), the relationship with the estimated NFCS was much lower than for total polyphenols (r2 < 0.40), but these relationships were independent of the nature of the chocolate type, indicating that they might still have some predictive capabilities.  相似文献   

Comparison of 2 canine celiotomy closure models for training novice veterinary students     

Julie A. Williamson  Brigitte A. Brisson  Stacy L. Anderson  Robin M. Farrell  Dawn Spangler 《Veterinary surgery : VS》2019,48(6):966-974

  相似文献   

Canine atopic dermatitis: breed risk in Australia and evidence for a susceptible clade          下载免费PDF全文

Hamutal Mazrier  Linda J. Vogelnest  Peter C. Thomson  Rosanne M. Taylor  Peter Williamson 《Veterinary dermatology》2016,27(3):167-e42

  相似文献   

A preliminary investigation of Ehrlichia species in ticks, humans, dogs, and capybaras from Brazil     

Labruna MB  McBride JW  Camargo LM  Aguiar DM  Yabsley MJ  Davidson WR  Stromdahl EY  Williamson PC  Stich RW  Long SW  Camargo EP  Walker DH 《Veterinary parasitology》2007,143(2):189-195

A molecular epidemiologic investigation in two Brazilian states (Rondônia and São Paulo) was undertaken to determine if Ehrlichia species responsible for human and animal ehrlichioses in North America could be found in Brazilian vectors, potential natural mammalian reservoirs and febrile human patients with a tick bite history. Samples, including 376 ticks comprising 9 Amblyomma species, 29 capybara (Hydrochaeris hydrochaeris) spleens, 5 canine blood, and 75 human blood samples from febrile patients with history of tick bites were tested by a real-time PCR assay targeting a fragment of the Ehrlichia dsb gene. Ehrlichia DNA was not detected in any tick, capybara or human samples. In contrast, 4 out of 5 dogs contained Ehrlichia canis DNA in their blood, which were sequenced, representing the first report of E. canis infecting dogs in the Amazon region of Brazil. Further studies are needed to evaluate the presence of other agents of human and animal ehrlichioses in Brazil.  相似文献   

Assortative mating and other observations based upon the relationship between true and apparent breeding values in the Australian thoroughbred     

By S. A. Williamson  R. G. Beilharz 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》1999,116(4):289-304

Studies of heritability in thoroughbred populations are confounded somewhat by the presence of assortative mating. Although assortative mating itself will not make great changes to the magnitude of the assessment of heritability, it can exert a significant impact upon the accuracy of any conclusions made from the study. In order to remove the effects of assortative mating from the data available, use was made of the best linear unbiased predictor (BLUP) method. This procedure was followed using two combinations: sire and dam, and sire and damsire. Due to the size of the datasets it was not possible to directly solve the matrices produced; instead they were solved by approximation over fifty iterations.  相似文献   

Fungicides affect Japanese beetle Popillia japonica (Coleoptera: Scarabaeidae) egg hatch,larval survival and detoxification enzymes          下载免费PDF全文

Glen R Obear  Adekunle W Adesanya  Patrick J Liesch  R Chris Williamson  David W Held 《Pest management science》2016,72(5):966-973

  相似文献