Levels of mortality in hens by end of lay on farm and in transit to slaughter in Great Britain     

Weeks CA  Brown SN  Richards GJ  Wilkins LJ  Knowles TG 《The Veterinary record》2012,170(25):647

The average mortality for end of lay hens dead on arrival (DOA) was 0.27 per cent (median 0.15 per cent) in a survey of 13.3 million hens transported during 2009. A statistical model of the data indicated main risk factors for DOA to be slaughter plant, distance travelled and external air temperature, with longer journeys and low external air temperatures increasing the risk. Other highly significant risk factors (P<0.001) related to the condition of the birds on farm, where an increased risk of DOA was positively associated with poor feather cover, lower body weight, cumulative mortality of the flock and poor health (indicated by a high proportion of the load rejected at the plant for traumatic injury and disease state). However, the data indicate that by taking risk factors into consideration it is possible to transport hens up to 960 km with low losses in temperate conditions. Mean levels of on-farm mortality, during the laying period, for a total of 1486 flocks were significantly lower in cages (5.39 per cent) than in barn (8.55 per cent), free-range (9.52 per cent) or organic flocks (8.68 per cent) according to producer records a median of seven days before depopulation, with considerable variation between flocks in all systems.  相似文献   

Factors affecting the mortality of weaned piglets during commercial transport between farms     

Averós X  Knowles TG  Brown SN  Warriss PD  Gosálvez LF 《The Veterinary record》2010,167(21):815-819

Factors affecting the number of weaned piglets found dead after commercial transport between farms were studied by means of multilevel Poisson regression. Information relating to 58,682 piglets during 109 journeys in different EU countries was collected at the end of each journey by means of questionnaires. Overall, 0.07 per cent of all the transported piglets were found dead on arrival, and deaths of piglets were recorded in 13.8 per cent of journeys. The final regression model, which was calculated using the complete records from 105 journeys, included the total duration of the journey, the mean outside temperature during the journey, whether the piglets were fasted before transport, whether drinking water was provided, the type of ventilation in the vehicle and the interaction between journey duration and the mean outside temperature. The duration of the journey and the mean outside temperature showed a significant interaction effect, with a gradual increase in the predicted number of dead piglets with increasing journey duration as the outside temperature increased. Providing the piglets with drinking water and having mechanically assisted ventilation (fans) in the vehicle during the journey significantly reduced the number of deaths, as did fasting the piglets before transport.  相似文献   

Mountain Gem Russet: a Potato Variety with High Early and Full Season Yield Potential and Excellent Fresh Market and Early Processing Characteristics     

J. C. Stark  R. G. Novy  J. L. Whitworth  N. R. Knowles  M. J. Pavek  M. Thornton  R. Spear  C. R. Brown  B. A. Charlton  V. Sathuvalli  S. Yilma  N. Olsen  T. L. Brandt 《American Journal of Potato Research》2016,93(2):158-171

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Effects of lairage time on body temperature and glycogen reserves of broiler chickens held in transport modules.     

P D Warriss  T G Knowles  S N Brown  J E Edwards  P J Kettlewell  M A Mitchell  C A Baxter 《The Veterinary record》1999,145(8):218-222

Commercial broiler chickens killed in two processing plants, one in the south of England, the other in Scotland, in two seasons (winter and summer) and on two occasions in each season, were used to investigate the effects of killing the birds immediately on arrival or holding them in lairage for one, two, three or four hours. The two most important consequences of holding the birds in lairage were that their body temperature increased and their liver glycogen was depleted. The body temperature increased with the time they were held in lairage, although most of the increase occurred in the first hour and the increase was greater in summer when ambient temperatures were higher. Liver glycogen depletion became apparent after about one to two hours in lairage. No evidence was obtained that the birds were significantly dehydrated or physically stressed by being kept longer in lairage.  相似文献   

Factors associated with insulin responses to oral sugars in a mixed-breed cohort of ponies     

Edward J. Knowles  Patricia A. Harris  Jonathan Elliott  Yu-Mei Chang  Nicola J. Menzies-Gow 《Equine veterinary journal》2024,56(2):253-263

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Potato Tuber Length-Width Ratio Assessment Using Image Analysis     

Yongsheng Si  Sindhuja Sankaran  N. Richard Knowles  Mark J. Pavek 《American Journal of Potato Research》2017,94(1):88-93

Potato tuber length to width (L/W) ratio is a critical crop trait evaluated during the development and selection of new cultivars to assess the effects of environment and management on tuber size and shape. The major challenges in manual measurement of L/W ratio are that it is labor-intensive, time consuming, and sometimes inconsistent. A high-throughput, digital image-based method for estimation of L/W ratio was developed in this study. Tests were conducted using tubers from a local retail market (red, white and russet) and from a field experiment with Payette Russet cultivar specifically designed to alter tuber size and shape. An image processing algorithm was developed to process the potato tuber images and the L/W ratio data from the images were compared to manual caliper measurements. A high accuracy in tuber L/W ratio estimation was consistently observed using image-based analysis. Among the different potato cultivars, red cultivars had a lower average accuracy in L/W ratio estimation of 94%, while other cultivars exhibited 96% and higher average accuracies.  相似文献   

Genetic Fingerprinting of Potato Varieties from the Northwest Potato Variety Development Program     

Sapinder Bali  Vidyasagar Sathuvalli  Chuck Brown  Rich Novy  Lorie Ewing  Jeanne Debons  David Douches  Joseph Coombs  Duroy Navarre  Jonathan Whitworth  Brian Charlton  Solomon Yilma  Clinton Shock  Jeff Stark  Mark Pavek  N. Richard Knowles 《American Journal of Potato Research》2017,94(1):54-63

The Northwest Potato Variety Development (NWPVD) Program has released 45 improved potato varieties since 1985. Thirty-four potato varieties, four breeding clones and two advanced selections from NWPVD Program, and six commonly-grown potato varieties were fingerprinted using 32 simple sequence repeat (SSR) markers and 12,808 single nucleotide polymorphism (SNP) markers. Of 32 SSR markers, 29 exhibited significant polymorphism across all the 46 potato clones studied. A total of 143 alleles were observed with an average of 4.6 alleles per SSR marker. These markers span all 12 chromosomes of potato, with a maximum of five markers from chromosome VIII and minimum of one marker from chromosome VI. The polymorphic information content (PIC) and expected heterozygosity (H_e) of the SSR markers ranges between 0.18 to 0.75 and 0.20 to 0.78, respectively. Based on PIC, H_e, and ease of scoring, we recommend a set of eight SSR markers: STG0016, STI0004, STI0012, STI0023, STI0030, STI0033, STM1016 and STM1104 for fingerprinting NWPVD varieties. Out of 12,808 SNPs, 88.8% resulted in reliable three cluster diploid calling of which 87.8% were polymorphic. Tetraploid calling resulted in 44.2% of SNPs of which 94.5% were polymorphic. Our study provided fingerprinting resources for the NWPVD varieties and can be used in issues related to intellectual property rights, ownership, trademark and diversity analysis.  相似文献   

High-Resolution Aerial Imaging Based Estimation of Crop Emergence in Potatoes     

Sindhuja Sankaran  Juan José Quirós  N. Richard Knowles  Lisa O. Knowles 《American Journal of Potato Research》2017,94(6):658-663

Plant emergence and stand establishment are key indicators of early crop development that are routinely assessed in potato agronomy and crop improvement research. The standard method for evaluating emergence is through manual plant counts at regular intervals. In this proof-of-concept study, unmanned aerial vehicles integrated with multispectral imaging were used for high-throughput evaluation of crop emergence under field conditions. High-resolution aerial imaging was performed at 15 m above ground level to capture data from potato plots of two varieties (‘Alturas’ and ‘Payette Russet’) in which the seed had been treated with different concentrations of growth regulators (including non-treated controls). The treatments resulted in differences in plant emergence and establishment. The images were collected at 32, 37, and 43 days after planting (DAP). Image-based features such as plant count, SUM-NDVI, and SUM-BINARY were computed from normalized difference vegetation index (NDVI) images for each treatment plot using ArcGIS^®. The Pearson’s correlation coefficients (r) were significant (p < 0.05) between image-based plant counts (r = 0.82) and SUM-NDVI (r = 0.62-0.73) with that of manual plant counts for both varieties, especially at early growth stages (32 DAP) when differences in emergence among treatments were more pronounced. The treatment effects on plant emergence and establishment were effectively resolved in the aerial multispectral images. Selection of the pertinent polygon threshold area to eliminate noise in delineating individual plants during image processing was important for resolution of treatment effects. The data shows that the technique can be applied in potato establishment evaluation.  相似文献   

Determination of strontium-90 in water: collaborative study     

E J Baratta  F E Knowles 《Journal of the Association of Official Analytical Chemists》1973,56(1):208-212

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Gamma spectroscopic determination of cesium-137 in milk, using simultaneous equations: collaborative study     

E J Baratta  F E Knowles 《Journal of the Association of Official Analytical Chemists》1973,56(1):204-207

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