Welfare assessment of broiler breeders that are food restricted after peak rate of lay     

Hocking PM  Maxwell MH  Robertson GW  Mitchell MA 《British poultry science》2002,43(1):5-15

1. Broiler breeder females were reared on one of three growth curves (ad libitum, conventional or modified restriction) and given rations containing a high or low concentration of crude protein. After the peak rate of lay they were fed ad libitum or a decreasing quantity of food in response to declining egg production. The welfare of the birds was assessed by determining the changes in indices of welfare at 36, 48 and 60 weeks of age. 2. Body weight increased rapidly in restricted birds fed ad libitum post-peak and water intake declined. 3. Post-peak food restriction was associated with a decrease in resting and increased drinking and spot-pecking activities. Birds that were food restricted during rearing spent more time foraging and spot-pecking at 36 and 48 but not 60 weeks of age. 4. Immune function increased with age but was not affected by the experimental treatments. The heterophil-lymphocyte ratio in birds fed ad libitum during rearing was numerically lower at 36 and higher at 48 and 60 weeks of age compared with restricted birds. 5. There was no effect of treatment on plasma corticosterone concentration. Creatine kinase activity was high at 60 weeks in treatments that were characterised by poor reproductive status and the activities of other enzymes reflected differences in reproductive status and mortality. 6. There was no long-term welfare or production advantage from feeding low protein rations or more generous feeding during the rearing period compared with conventional food restriction programmes.  相似文献   

Tomato leaf curl Karnataka virus from Bangalore, India, Appears to be a Recombinant Begomovirus     

Chatchawankanphanich O  Maxwell DP 《Phytopathology》2002,92(6):637-645

ABSTRACT The genome of Tomato leaf curl virus (ToLCV) from Bangalore, India, a whitefly-transmitted geminivirus, was cloned (pIND9) and sequenced. The circular DNA of 2,759 nucleotides (U38239) is organized similarly to that of other begomoviruses with monopartite genomes. Comparison of the nucleotide sequence of pIND9 with other tomato-associated begomoviruses from India (Tomato leaf curl Bangalore virus [ToLCBV, Z48182]) and Tomato leaf curl New Delhi virus-Severe (ToLCNdV-Svr, U15015) showed moderate DNA sequence identities (82 to 87%) between capsid protein (CP) genes but low identities (66 to 67%) for the intergenic regions and the replication-associated protein (Rep) genes (75 to 81% identity). Phylogenetic trees generated with nucleotide sequences of the Rep and CP genes of 26 begomoviruses indicated that this ToLCV is distinct from other begomoviruses and that it may be a recombinant virus derived from at least three different viral lineages. Tomatoes (Lycopersicon esculentum) inoculated with the cloned DNA monomer of ToLCV (pIND9) via particle bombardment developed leaf curling and yellowing symptoms. The virus was transmitted by Bemisia tabaci biotype B from tomatoes infected via particle bombardment to healthy tomatoes and by sap inoculation from infected tomatoes to tomato, Nicotiana benthamiana and N. tabacum. This ToLCV is a distinct member of the genus Begomovirus from India that differs from the previously characterized Tomato leaf curl Sadasivanagar virus isolate Bangalore 1 (L12739), ToLCBV (Z48182), ToLCBV isolate Bangalore 4 (AF165098), and the bipartite ToLCNdV (U15015, U15016). Thus, this ToLCV is named Tomato leaf curl Karnataka virus (ToLCKV).  相似文献   

Effect of bovine leukaemia virus on embryonic development and association with in vitro fertilised embryos     

Bielanski A  Maxwell P  Simard C 《The Veterinary record》2000,146(9):255-256

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Reduced serum insulin-like growth factor (IGF) and IGF-binding protein-3 concentrations in two deerhounds with congenital portosystemic shunts     

Maxwell A  Hurley K  Burton C  Batt R  Camacho-Hübner C 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2000,14(5):542-545

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First report of a begomovirus associated with the common weed Jatropha gossypifolia in Jamaica     

M. E. Roye  A. M. Collins  D. P. Maxwell 《Plant pathology》2006,55(2):286-286

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Simulation study of the competitive ability of erect, semi-erect and prostrate cowpea (Vigna unguiculata) genotypes   总被引：1，自引：1，他引：1  

G WANG  ME MCGIFFEN JR  JL LINDQUIST†  JD EHLERS  & I SARTORATO‡ 《Weed Research》2007,47(2):129-139

Ecophysiological simulation models provide a quantitative method to predict the effects of management practices, plant characteristics and environmental factors on crop and weed growth and competition. The INTERCOM interplant competition model was parameterised, calibrated by monoculture data for three cowpea (Vigna unguiculata) genotypes that differed in growth habit, common sunflower (Helianthus annuus) and common purslane (Portulaca oleracea), and used to simulate competition of cowpea cover crops with sunflower or purslane. The simulation results were compared with observations from field competition experiments in 2003 and 2004. INTERCOM more accurately simulated actual field data for the competition of cowpea genotypes and sunflower than companion field experiments for the competition of cowpea and purslane. The validated simulation model of cowpea and sunflower at two densities was used to study the effects of cowpea growth habit on final biomass production of cowpea and sunflower. The model suggested that erect growth habit was more competitive than semi‐erect and prostrate growth habit, when cowpea genotypes were grown with sunflower. Cowpea leaf area distribution was important to higher cowpea biomass production, while cowpea height growth was important to reduce sunflower biomass. Our simulation approach is suggested as a method for crop breeders to gauge the likely success of selection for competitive crops before undertaking expensive long‐term breeding experiments.  相似文献   

Electron microscopy of the juxtaglomerular apparatus in young fowl fed a salt deficient diet     

M H Maxwell  L Martindale 《Research in veterinary science》1985,39(3):340-352

Kidneys from young fowl fed a salt deficient diet for up to five weeks were examined under the electron microscope. The presence of maculae densae (MD) were confirmed and the concentrations of nuclei in the MD and the remainder of the distal convoluted tubules were compared. In the proximal convoluted tubules, salt deprivation caused mitochondrial changes, an increase in intranuclear and cytoplasmic lipid and the deposition of urates. Regional thickening of the glomerular basement membrane was observed in many kidneys. In the normal kidney, there is an age dependent increase in the juxtaglomerular granules in the cortical glomeruli (P less than 0.02), but not in the juxtamedullary glomeruli. In salt deprived birds, juxtaglomerular granules were increased in the juxtamedullary glomeruli (P less than 0.01) but not in the cortical glomeruli. Salt deprivation also caused a significant reduction in bodyweight after five weeks (P less than 0.002) and increases in heterophil (P less than 0.02) and monocyte (P less than 0.05) counts in the blood.  相似文献   

Failure of passive transfer in foals: incidence and outcome on four studs in New South Wales     

CM TYLER-McGOWAN  JL HODGSON  DR HODGSON 《Australian veterinary journal》1997,75(1):56-59

Objective To determine the regional incidence and effectiveness of treatment of failure of passive transfer (FPT) in foals. Design A study of disease incidence. Animals Eighty-eight foals and 57 mares from four studs in the practice area of the Rural Veterinary Centre were tested. Procedure Foals were tested for their serum IgG and total serum protein (TSP) concentration within the first 72 hours of life. Colostrum was collected from mares and specific gravity determined. FPT and partial failure of passive transfer (PFPT) of immunoglobulins was diagnosed when serum IgG concentrations were < 4 g/L and 4 to 8 g/L respectively. Owners of foals diagnosed with FPT were offered treatment with 1 to 2 L plasma (TSP > 70 g/L); 9 (64%) of the affected foals were treated. Results Fourteen foals (16%) had FPT whereas 15 (17%) had PFPT. There were significant differences between the mean TSP concentration in foals with FPT (42.6 ± 4.2 g/L), PFPT (48.1 ± 3.9 g/L) and those acquiring adequate passive immunity (58.9 ± 5.5 g/L) (P < 0.01). Sixteen (29%) mares had pre-suck colostral specific gravity < 1.060 and 12 (71%) foals raised by these mares had FPT or PFPT. The incidence of severe disease (categorised by a sepsis score > 11, positive culture of bacteria from blood or disease requiring hospitalisation) in all foals in the first 2 months of life was 10%. However, none of the nine foals with FPT that received plasma experienced severe disease. In contrast, foals with PFPT had an increased susceptibility to severe disease (P < 0.001) when compared with normal foals. Conclusion Treatment of foals with FPT may reduce the subsequent incidence of severe disease. Pre-suck colostral specific gravity and foal TSP may be used to predict the likelihood of FPT and PFPT. Even though the number of foals studied is small the results highlight the importance of optimal management practices in reducing the incidence of FPT and disease associated with this process.  相似文献   

Immunohistochemical Expression of Growth Factors in the Follicular Wall of Normal and Cystic Ovaries of Sows          下载免费PDF全文

FJF Sant'Ana  JL Reis Junior  GR Blume  EJ Gimeno  F Rey  HH Ortega 《Reproduction in domestic animals》2015,50(2):327-332

The expression of growth factors was evaluated immunohistochemically in normal and cystic ovaries of sows. The immunohistochemically stained area (IHCSA) was quantified by image analysis to analyse the expression of these proteins in the follicular wall of secondary, tertiary and cystic follicles. IGF‐I immunoreactivity was strong in the granulosa cell layer (GC), moderate in the theca interna (TI) and mild in the theca externa (TE) of the normal follicles. There was severe reduction of the labelling to IGF‐I in the GC of the follicular and luteinized cysts. In the normal follicles, the reactivity for IGF‐II was very similar to pattern noted in IGF‐I. There was reduction of the IHCSAs in the GC of the follicular and luteinized cysts, but the decrease was not significant. The staining of the IGF‐II in the TI and TE of the cysts was increased, in comparison with normal follicles. The IHCSAs for VEGF were higher in the GC and TE of the normal follicles in contrast to TI, but this difference was noted only in the tertiary follicle. The VEGF reactivity increased in the GC of the cysts, in relation to normal follicles. The results of the current study show that the formation of ovarian cysts in sows is associated with alterations in the immunohistochemical expression of some growth factors.  相似文献   

Effect of body weight on the pharmacokinetics of flunixin meglumine in miniature horses and quarter horses     

C. D. Lee  L. K. Maxwell 《Journal of veterinary pharmacology and therapeutics》2014,37(1):35-42

In most species, large variations in body size necessitate dose adjustments based on an allometric function of body weight. Despite the substantial disparity in body size between miniature horses and light‐breed horses, there are no studies investigating appropriate dosing of any veterinary drug in miniature horses. The purpose of this study was to determine whether miniature horses should receive a different dosage of flunixin meglumine than that used typically in light‐breed horses. A standard dose of flunixin meglumine was administered intravenously to eight horses of each breed, and three‐compartmental analysis was used to compare pharmacokinetic parameters between breed groups. The total body clearance of flunixin was 0.97 ± 0.30 mL/min/kg in miniature horses and 1.04 ± 0.27 mL/min/kg in quarter horses. There were no significant differences between miniature horses and quarter horses in total body clearance, the terminal elimination rate, area under the plasma concentration versus time curve, apparent volume of distribution at steady‐state or the volume of the central compartment for flunixin (P > 0.05). Therefore, flunixin meglumine may be administered to miniature horses at the same dosage as is used in light‐breed horses.  相似文献