Evaluation of the effects of nematode parasitism on grazing behaviour, herbage intake and growth in young grazing cattle     

Forbes AB  Huckle CA  Gibb MJ  Rook AJ  Nuthall R 《Veterinary parasitology》2000,90(1-2):111-118

Parasitic nematodes, even in the absence of any clinical disease, can cause a reduction in voluntary feed intake in housed ruminants. This trial examined these effects on young cattle grazing pastures. Twenty dairy heifer calves, born in the previous autumn, were blocked according to liveweight and allocated to one of two groups: either untreated or dosed with an IVOMEC((R)) (ivermectin) SR Bolus 10 days prior to turnout on 1 May 1998. The groups grazed separately on two paddocks on predominately ryegrass swards. Liveweights were recorded every 28 days and faecal samples taken for worm egg counts at the same time.In mid-May and mid-July, for two 14-day periods, animals were paired within treatment groups and transferred to one of 10 replicate paddocks of similar sward height and herbage mass. Grazing behaviour and herbage intake were measured during these periods.In mid-May, 2 weeks after turnout, treated and untreated animals showed no difference in grazing behaviour or daily intake of grass. By mid-July, 10 weeks after turnout, the untreated heifers spent on average 105min less per day in grazing time and their daily herbage intake was 0.78kg dry matter (DM) per day lower than that of the treated animals. Residual sward height, mass and composition in the trial paddocks reflected these differences. There were no clinical signs of gastrointestinal parasitism in the untreated group up to this time; in July, the mean worm egg count in this group was 120 eggs per gram (e.p.g.) of faeces. Faecal samples from several untreated animals were positive for lungworm larvae by July, mild clinical signs of bronchitis were observed in two of these animals in mid-July. Over the period from turnout until mid-July, the untreated heifers showed a reduction in mean daily liveweight gain of 150g, compared to the treated animals.  相似文献   

The effects of dietary n-3 vs. n-6 fatty acids on ex-vivo LTB₄ generation by canine neutrophils     

Kevin P. Byrne  Karen L. Campbell  Carol A. Davis  David J. Schaeffer  & Fred H. Troutt 《Veterinary dermatology》2000,11(2):123-131

Dietary n-3 polyunsaturated fatty acids are widely used for amelioration of inflammatory skin disease in dogs. In this study, a diet containing two different sources of n-3 polyunsaturated fatty acid–triglyceride (from menhaden oil) and concentrated ethyl esters–was fed to one group of six purpose-bred dogs, while an isocaloric isonitrogenous diet with corn oil (n-6 polyunsaturated fatty acids) was fed to another group of eight purpose-bred dogs for six weeks. Peripheral blood neutrophils, isolated at week–1 (baseline), week 2 and week 6, were stimulated with calcium ionophore A23187 and the amount of leukotriene B₄ produced was determined via reversed-phase high performance liquid chromatography. Analysis of variance of log-transformed data revealed a significant effect for diet ( P  = 0.005) at six weeks, with dogs fed the high n-3 polyunsaturated fatty acid diet having significantly less mean ex vivo neutrophil leukotriene B₄ production than dogs fed the high n-6 polyunsaturated fatty acid diet. Further studies on the clinical usefulness of n-3 polyunsaturated fatty acid ethyl esters are warranted.  相似文献   

What is your diagnosis? Pituitary mass in a dog          下载免费PDF全文

Melanie S. Spoor  Christina J. Ramirez  Rob J. Daniel  Dan P. Shaw  Fred A. Wininger  Marlyn S. Whitney 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2016,45(2):381-382

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Proximal Digital Annular Ligament Desmotomy in Horses: A Cadaveric Study     

Valeria Albanese  Dewey Wilhite  Fred Caldwell 《Journal of Equine Veterinary Science》2014

Proximal digital annular ligament (PDAL) desmitis occurs in horses for which PDAL desmotomy is the only reported treatment. The presented work aims to develop a technique for safely performing PDAL desmotomy in horses. Twenty hind limbs and 13 forelimbs, harvested from horses dead or euthanized for reasons unrelated to any structure in the pastern region, were used. All horses were free of disease at the level of their PDAL. Proximal digital annular ligament desmotomy was performed using a minimally invasive approach to the digital flexor tendon sheath between the palmar (plantar) annular ligament and the PDAL, using a medial or a lateral access. Limbs were immediately dissected after the procedure to assess the completeness of the PDAL desmotomy and any possible damage to surrounding structures. The PDAL was successfully transected in all limbs except one. Damage to the surrounding tissue included transection of the palmar digital nerve (n = 1), longitudinal tear of the superficial digital flexor tendon (n = 3), and transection of the ligament of the ergot (n = 21). A medial approach was found to be safer than a lateral approach. In conclusion, PDAL desmotomy can be performed in a safe, repeatable, and technically easy way. This is, to our knowledge, the first report of a standardized technique for performing a PDAL desmotomy in the horse.  相似文献   

Local macrophage proliferation, rather than recruitment from the blood, is a signature of TH2 inflammation     

Jenkins SJ  Ruckerl D  Cook PC  Jones LH  Finkelman FD  van Rooijen N  MacDonald AS  Allen JE 《Science (New York, N.Y.)》2011,332(6035):1284-1288

A defining feature of inflammation is the accumulation of innate immune cells in the tissue that are thought to be recruited from the blood. We reveal that a distinct process exists in which tissue macrophages undergo rapid in situ proliferation in order to increase population density. This inflammatory mechanism occurred during T helper 2 (T(H)2)-related pathologies under the control of the archetypal T(H)2 cytokine interleukin-4 (IL-4) and was a fundamental component of T(H)2 inflammation because exogenous IL-4 was sufficient to drive accumulation of tissue macrophages through self-renewal. Thus, expansion of innate cells necessary for pathogen control or wound repair can occur without recruitment of potentially tissue-destructive inflammatory cells.  相似文献   

Stem cells. Setting standards for human embryonic stem cells     

Brivanlou AH  Gage FH  Jaenisch R  Jessell T  Melton D  Rossant J 《Science (New York, N.Y.)》2003,300(5621):913-916

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Effects of two dietary crude protein levels on finishing performance,meat quality,and gene expression of market lambs     

Yongjie Wang  Sarah Shelby  Jason Apple  Ken Coffey  Fred Pohlman  Yan Huang 《Animal Science Journal》2021,92(1):e13641

Seventeen crossbred lambs were assigned randomly to low-protein (LP; 8% crude protein [CP]; n = 9) and high-protein (HP; 13% CP; n = 8) diets for 9 weeks. The final body weight, average daily feed intake (ADFI), and average daily gain (ADG) of the HP lambs were significantly higher (P < 0.05) than the LP lambs; however, gain to feed ratio (G:F) for the LP lambs was significantly higher (P < 0.05) than the HP lambs. Hot carcass weight (HCW), adjusted fat thickness, and drip loss of longissimus dorsi (LD) muscle were significantly higher (P < 0.05) for the HP than LP lambs. In contrast, instrumental color values L*, a*, b*, C*, and hue angle (H) of meat from the LP lambs scored significantly higher (P < 0.05) than the HP lambs. The LD muscle from HP lambs had significantly greater CLA of cis-9 trans-11 isomer (P < 0.05) than the LP lambs. The gene expression of metabolism and meat quality-related genes of LP was significantly higher than HP (P < 0.05). These results suggest that a higher dietary CP level promotes growth performance for finishing lambs, whereas lower dietary CP level is beneficial for meat quality, especially when evaluating color characteristics in the final product.  相似文献   

Determination of five macrolide antibiotic residues in eggs using liquid chromatography/electrospray ionization tandem mass spectrometry   总被引：1，自引：0，他引：1  

Wang J  Leung D  Butterworth F 《Journal of agricultural and food chemistry》2005,53(6):1857-1865

A method using liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) for the determination of trace levels of five macrolide antibiotics (spiramycin, tilmicosin, oleandomycin, erythromycin, and tylosin) in eggs is presented. Data acquisition under MS/MS was achieved by applying multiple reaction monitoring (MRM) of two or three fragment ion transitions to provide a high degree of sensitivity and specificity for both quantification and confirmation. Matrix-matched standard calibration curves were used to achieve the best accuracy of the method. A fully nested experimental design was used to study the measurement uncertainty arising from intermediate precision and trueness or proportional bias. The overall recoveries, that is, those determined by the nested experiments, of spiramycin, tilmicosin, oleandomycin, erythromycin, and tylosin at fortified levels of 60, 100, 200, and 300 microg/kg were 96.8, 98.2, 98.3, 98.8, and 95.4%, respectively. The LC/ESI-MS/MS method detection limits (S/N > or = 3:1) of five macrolides were <1.0 microg/kg.  相似文献   

Hypoxia-inducible factor-1alpha and nitric oxide synthases in bovine follicles close to ovulation and early luteal angiogenesis     

Bajram Berisha  Dieter Schams  Fred Sinowatz  Daniela Rodler  Michael W. Pfaffl 《Reproduction in domestic animals》2020,55(11):1573-1584

The objective of the study was to characterize expression patterns of hypoxia-inducible factor-1alpha (HIF1A), inducible nitric oxide synthase (iNOS) and endothelial (eNOS) isoforms in time-defined follicle classes before and after GnRH application in the cow. Ovaries containing pre-ovulatory follicles or corpora lutea were collected by transvaginal ovariectomy (n = 5 cows/group) as follow: (I) before GnRH administration; (II) 4h after GnRH; (III) 10h after GnRH; (IV) 20h after GnRH; (V) 25h after GnRH; and (VI) 60h after GnRH (early corpus luteum). The mRNA abundance of HIF1A in the follicle group before GnRH was high, followed by a significant down regulation afterwards with a minimum level 25h after GnRH (close to ovulation) and significant increase only after ovulation. The mRNA abundance of iNOS before GnRH was high, decreased significantly during LH surge, with minimum levels afterwards. In contrast, the mRNA of eNOS decreased in the follicle group 20h after GnRH, followed by a rapid and significant upregulation just after ovulation. Immunohistochemically, the granulosa cells of antral follicles and the eosinophils of the theca tissue as well of the early corpus luteum showed a strong staining for HIF1A. The location of the eosinophils could be clearly demonstrated by immunostaining with an eosinophil-specific antibody (EMBP) and transmission electron microscopy. In conclusion, the parallel and acute regulated expression patterns of HIF1A and NOS isoforms, specifically during the interval between the LH surge and ovulation, indicate that these paracrine factors are involved in the local mechanisms, regulating final follicle maturation, ovulation and early luteal angiogenesis.  相似文献   

Image processing and pattern recognition for oyster hinge line detection     

Junming Li  Fred W. Wheaton 《Aquacultural Engineering》1992,11(4):231-250

Image-processing software written in C was developed for the COMPAQ 386 computer to detect the hinge in a trimmed oyster hinge-end image. The error rate was 2·5% and the processing speed was 0·7 s per image. Results will be used in an automated oyster shucking machine.  相似文献