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1.
Stief B Kiesow C Ellenberger C 《Tierarztliche Praxis. Ausgabe K, Kleintiere/Heimtiere》2012,40(1):64-69
Two cases of disseminated fatal toxoplasmosis of a pet mouse and a red panda are described. The pet mouse had a private owner; the red panda lived in a zoological garden in Saxony. At necropsy, both animals suffered from a systemic toxoplasmosis. A severe necrotizing hepatitis was the main histological feature in both animals. Parasitic cysts could be abundantly found in the liver, moderately in the brain and in a low number in other organs. With the PAS-reaction, cysts showed a weak staining in the mouse and a strong staining in the red panda. Diagnosis was confirmed by PCR and immunohistochemistry. 相似文献
2.
J Jansen 《The Veterinary quarterly》1987,9(2):97-102
The trichostrongylid and strongylid egg output in a group of ewes lambing in March, the middle of the usual lambing time in the Netherlands, was compared with counts in groups of older ewes and yearling ewes lambing in May-June and with counts in a group of barren ewes. The groups lambing in March showed only a rise related to parturition date as normally seen in the Netherlands. A few of the late lambing ewes showed a slight rise in spring, but all of them showed a peri-parturient rise related to parturition date. In the late lambing ewes and in the barren ewes egg counts due to reinfection were seen in summer. It is concluded that under the present circumstances a true spring rise, the calendar phenomenon, occurs very irregularly, while a peri-parturient rise related to the parturition date is a common phenomenon. The occurence of high egg counts in summer, excluding consideration on the barren ewes, in the late lambing ewes only, suggests that changing the traditional husbandry system may influence the epidemiological pattern of the trichostrongylid infections. 相似文献
3.
为研究西藏"一江两河"流域高山草甸和灌丛草场的时空变化特征,在牧草发青季(2017年7月份)、丰草季(2017年9月份)和枯草季(2018年3月份),对不同海拔梯度林周河谷南山阴坡和北山阳坡草地进行调查分析。结果表明:(1)林周河谷南山阴坡低海拔处以白草为优势种,海拔升高100 m左右时出现灌丛植被类型;山坡中段为草甸草场,主要以高山嵩草和苔草为主。总盖度最高月份为7—9月,随海拔升高,盖度相应增加,不同季节同一海拔高度总盖度间均差异不显著(P>0.05),而不同海拔高度、同一季节中总盖度差异极显著(P<0.01)。(2)季节显著影响牧草含水率(P<0.01),可饲用牧草含水率7—9月份最高,10月份后随牧草枯萎而下降,进入冬季降至0%;同一季节不同海拔梯度中,低海拔和中段海拔可饲用牧草中含水率较高。(3)不同季节可饲用牧草的产草量间差异极显著(P<0.01),单位面积总可饲用牧草产草量10月末最高,夏秋季最低;随海拔高度升高,可饲用牧草的产草量显著增高(P<0.05)。(4)经三维响应曲线拟合,总盖度y、海拔梯度x_1、月份x_2之间的关系为:y=a_1+a_2×x_2~2+a_3×x_1+a_4×x_2(a_1,a_2,a_3,a_4分别为-657.137 4、-0.882 8、0.167 1、12.507 0);含水率y、海拔梯度x1、月份x2的关系为:y=a_1+a_2×x_2~2+a_3×x_1+a_4×x_2(a_1,a_2,a_3,a_4分别为-146.147 1、-3.883 9、-0.010 0、62.100 6);产草量y、海拔梯度x1、月份x2的关系为:y=a_1+a_2×x_2~2+a_3×x_1+a_4×x_2(a_1,a_2,a_3,a_4分别为-131.065 5、2.977 2、0.069 0、-36.511 1)。结论:通过研究,建立了林周河谷南山阴坡主要高山草甸放牧草场的总盖度、含水率与产草量的立体时空变化特征;北山阳坡主要为高山灌丛,非天然放牧场所,作为饲用牧场,研究意义不大。 相似文献
4.
Epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor that stimulates cell proliferation and survival and becomes dysregulated in a range of solid tumours in man. It is recognized as a key oncogenic driver and has become a favoured therapeutic target and a prognostic and predictive marker of cancer in man. In animals, EGFR dysregulation is emerging as a potential factor in the development of a number of naturally occurring tumours including mammary, lung, glial and epithelial cancers. Comparative analyses suggest that these diseases share many features with equivalent diseases in man and EGFR may have value as a prognostic or a biological marker of animal disease. There is still little direct evidence that EGFR is a critical oncogenic driver in naturally occurring animal disease and there are no veterinary trials of EGFR-targeted therapy. These will be critical steps in establishing a role for EGFR in veterinary oncology. 相似文献
5.
J Perrin J Nicolet 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1992,39(9):662-667
A sterile plastic tube, a boric acid-glycerol-sodium formate tube and a dip-slide tube were compared for transport of dog urine for bacteriological examination under practice conditions, at ambient temperature. In a first part, 50 dog urine samples were cultured on agar plates and on a dip-slide kit within 2 h after collection and after storage at 20 degrees C in a sterile tube and in a boric acid tube for 24 h and 48 h. Culture of the samples stored in the boric acid tube and culture on the dip-slide yielded results which correlated very well with those of the culture of fresh urine. However, culture of the samples stored in the sterile tube yielded up to 65% false positive results. In a second part, a comparison was drawn with culture results of 100 dog urine specimens collected by different practitioners and simultaneously mailed to our laboratory in a sterile tube, in a boric acid tube and in a dip-slide kit. Samples sent in the boric acid and in the dip-slide tube showed comparable culture results. Culture of the samples sent in the plastic tube yielded 53% false positive results in comparison with those of the samples preserved in boric acid. 相似文献
6.
We describe the case of a 14-year-old Domestic Short Hair male cat that presented with a single mammary tumour one centimetre in diameter, classified as invasive micropapillary carcinoma. Histology and immunohistochemistry revealed a high mitotic index, a KI-67 index of 10%, a lack of reactivity to myoepithelial markers, and a dense infiltration with T and B lymphocytes at the periphery of the tumour. Micrometastases were detected in the regional lymph node at the time of surgery. Overall survival time was 10 months with a disease-free interval of 7.5 months. Distant metastases in the sublumbar lymph nodes confirmed the aggressiveness of this tumour, which has recently been subtyped in female cats. This is the first case reported in male cats with a complete follow-up, highlighting the importance of prompt and aggressive treatment in the presence of mammary tumours in male cats. 相似文献
7.
The first method is applied when adding corrosive preparations to epoxid resin. The corrosive preparation is soaked in a mixture of epoxid resin and hardener in a ratio, experimentally determined. The induration proceed at room temperature for 12 h. The second method has two options and is applied for the conservation of biological objects and anatomical preparations in polymethylmethacrilate by a successive immersing of the object in a system of dehydrating mixtures: 50%, 70%, 90% and 96% water solution of methanol and ethanol and in a mixture of acetone and ethanol (1:1) and in acetone or in methylenechloride. The object, thus prepared, is impregnated in vacuum with forpolymer of methylmethacrylate, benzoil peroxide and stearine acid or in a composition containing: methylmethacrylate, benzoilperoxide, dibutilphtalat and tertiary aromatic amin, in optimum correlations of the components, experimentally determined. The induration proceed by heating in a water bath (37 + 3°C) for 3 h and at 30°C temperature in the course of 6-8 h in the first option or at room temperature for about 3 days in the second option. The advantages of the proposed methods are: the use of cheap and available materials for the production of a simplified technological scheme of strongly transparent packages, preserved over a long period; preserving the sizes, the form and natural colour of the objects and preparations as well as a possibility for selective tinting of the separate tissues and systems in the preserved biological objects and anatomical preparations; a possibility for stereomicroscopic observation of the objects and preparations preserved. 相似文献
8.
Erysipelothrix rhusiopathiae is a facultative, non-spore-forming, non-acid-fast, small, Gram-positive bacillus. The organism was first established as a human pathogen late in the nineteenth century. Three forms of human disease have been recognised since then. These include a localised cutaneous lesion form, erysipeloid, a generalised cutaneous form and a septicaemic form often associated with endocarditis. The organism is ubiquitous and able to persist for a long period of time in the environment, including marine locations. It is a pathogen or a commensal in a wide variety of wild and domestic animals, birds and fish. Swine erysipelas caused by E. rhusiopathiae is the disease of greatest prevalence and economic importance. Diseases in other animals include erysipelas of farmed turkeys, chickens, ducks and emus, and polyarthritis in sheep and lambs. Infection due to E. rhusiopathiae in humans is occupationally related, principally occurring as a result of contact with contaminated animals, their products or wastes, or soil. Erysipeloid is the most common form of infections in humans. While it has been suggested that the incidence of human infection could be declining due to technological advances in animal industries, infection still occurs in specific environments. Additionally, infection by the organism is possibly under-diagnosed due to the resemblance it bears to other infections, and problems encountered in isolation and identification. Various virulence factors have been suggested as being involved in the pathogenicity of E. rhusiopathiae. The presence of a hyaluronidase and neuraminidase has been recognised, and it was shown that neuraminidase plays a significant role in bacterial attachment and subsequent invasion into host cells. The role of hyaluronidase in the disease process is controversial. The presence of a heat labile capsule has been reported as important in virulence. Control of animal disease by sound husbandry, herd management, good sanitation and immunization procedures is recommended. 相似文献
9.
F Ponce J P Magnol T Marchal L Chabanne D Ledieu C Bonnefont P Felman C Fournel-Fleury 《Journal of veterinary diagnostic investigation》2003,15(4):330-337
The aim of this study is to determine the clinical, morphological, and immunophenotypical presentation of 9 cases of a particular type of canine T-cell lymphoma/leukemia. The morphological presentation was a diffuse infiltration of small, medium-sized, or large blast cells with eccentric nuclei, hyperbasophilic cytoplasm, and a juxtanuclear, pale cytoplasmic area, giving a plasmacytoid appearance and suggesting a B-cell morphology. Surprisingly, all 9 cases were of T-cell phenotype (CD3+). Among the 7 immunophenotyped cases, 4 were CD4-/CD8+, 2 CD8+/CD4+, and 1 CD4+/CD8-. The median Ki-67 index was 65.7%, which placed this lymphoma in the high-grade group. This type of lymphoma/leukemia was found in dogs between 1 and 11 years of age, with a median age of 5.8. The male-female ratio was 0.8 for a reference population of 1.04. The most significant clinical findings were lymphadenopathy either generalized or localized in all cases, a mediastinal mass in 4 cases, bone marrow involvement in 7 cases, hypercalcemia in 4 cases, along with an aggressive clinical course and a poor response to chemotherapy in all cases, with a median disease-free survival time of 3 months. 相似文献
10.
Paul Y Barthez DVM René Léveillé DVM Peter V Scrivani DVM 《Veterinary radiology & ultrasound》1997,38(5):387-393
Side lobes and grating lobes are both unwanted parts of the ultrasound beam emitted off axis that produce image artifacts due to error in positioning the returning echo. The purpose of this study was to reproduce artifacts associated with side lobes and grating lobes in vitro using different transducer types and recognize these artifacts in vivo. A phantom, composed of a water bath, a metallic wire, and a wooden tongue depressor, was imaged using a linear array, a curved linear array, a vector array, and a sector mechanical transducer. When imaging the metallic wire in a transverse plane, an echogenic artifact was constantly seen on each side of the wire, with a shape and intensity variable with the transducer type. The artifact was curvilinear and concave (linear and curved linear arrays), or curvilinear and convex (vector array and the mechanical transducer). When the tongue depressor was imaged in a longitudinal plane, the artifact was a straight line (linear array), a curved convex line(curved array), a series of convex curvilinear echo (vector array) or a small convex curvilinear echo (mechanical transducer). In vivo situations similar to the phantom experiment were investigated using clinical patients. Artifacts produced in vitro were recognized in vivo when a highly reflective object (urinary bladder wall) was imaged adjacent to an anechoic region (urine). These artifacts corresponded to the principle of secondary ultrasound lobes, and were therefore interpreted as such. 相似文献
11.
Coffman JR 《Journal of veterinary medical education》2002,29(2):66-70
Veterinary medical education is undergoing rapid change in terms of pedagogy, the demographics of the student body, and, in turn, the membership of the profession. Central to the value of the traditional curriculum and the total student experience is the small-group environment, both in client service and in clinical rounds. It is one of the few Socratic learning experiences in higher education today. Similarly, experience in private practice is of inestimable value in terms of developing people skills and a lasting sense of service and accountabilty. In a generation, the student body has transformed from vanishingly small numbers of women to a predominance of female students. However, the profession still is very white, in a world becoming more and more diverse. With a predominantly white faculty and student body today, this circumstance shows little promise of rapid enough change to maintain relevance to a workforce that, a generation from now, likely will be dominated numerically by people of color. The incorporation of various world views and the impact of stereotyping on performance are central to issues of success and failure of minorities and, in somewhat different ways, women in the veterinary medical profession. These issues must become better understood and addressed. And to accomplish this, and to address a host of other culturally important issues, a greater diversity of world views must be engaged in the work and planning of veterinary medical education and the profession at large. Addressing these issues in an environment in which the values of faculty and administrators are intensely focused on the science of veterinary medicine, and in which the participants hold dear a system that places value only on teaching, research, and clinical service, is a formidable undertaking and will require substantial reconsideration of faculty role and reward systems. 相似文献
12.
This study compared the effectiveness of a number of procedures designed to label and eliminate plasmids that may play a role in virulence in Salmonella. Twenty strains of Salmonella of 9 serovars were subjected to 3 methods for labelling plasmids with transposons. Strains containing labelled and unlabelled plasmids were exposed to physical and chemical curing agents. Plasmids in 9 of 20 strains of Salmonella were tagged by conjugation with a donor Escherichia coli containing a temperature-sensitive RP4 plasmid that carried the Tn1 transposon. Plasmids in 2 of 5 strains of Salmonella were labelled by conjugation with a donor E. coli that contained a F' tslac::Tn5 plasmid. Transduction of Salmonella with a P22 bacteriophage that carried a temperature-sensitive Tn10 transposon resulted in chromosomal insertion of Tn10 in 2 of 10 strains. Use of chemical curing agents resulted in curing of plasmids in only 6 of 17 strains. Two strains were cured by ethidium bromide, two by a combination of ethidium bromide and novobiocin, two by a combination of imipramine and methylene blue, and none by acridine orange, novobiocin, sodium dodecyl sulfate or rifampicin. In contrast, plasmids in 14 of 17 Salmonella strains were eliminated by incubation at 45.5 degrees C. 相似文献
13.
C. Nakajima T. Sakogawa A. Okayama A. Nakamura & T. Hayama 《Journal of veterinary pharmacology and therapeutics》1998,21(4):269-273
Disposition of mirosamicin, a macrolide antibiotic, to honeybee adults, larvae, honey and royal jelly in the beehive after in-feed administration to adult bees was studied. Treatment was initiated at the end of July when the availability of natural pollen and nectar was poor. The drug was mixed with pollen-substitute paste and administered to honeybee colonies continuously for a week at a dossage of 200 mg/hive/week. High distributions in adult bees, jelly, larvae and a relatively low distribution in honey, of mirosamicin were observed. One day dosing of microsamin in sucrose syrup, a nectar substitute, resulted in a very high and long lasting residue in honey. Both royal and worker jelly, secreted from the jelly glands of adult bees, are acidic, so that a high distribution of a basic drug, such as mirosamicin, in jelly can be expected. This mechanism was considered to be responsible for a high concentration of mirosamicin in honeybee larvae, the host of Paenibacillus-larvae infection (American foulbrood), as primary larval food is jelly. 相似文献
14.
As part of a high-throughput mutagenesis and phenotyping process designed to discover novel drug targets, we generated and characterized mice with a targeted mutation in Slc24a5, a gene encoding a putative cation exchanger. Upon macroscopic examination, Slc24a5-/- mice were viable, fertile, and indistinguishable by coat color from their heterozygous and wild-type litter mates. Ophthalmoscopic examination revealed diffuse retinal hypopigmentation, and a histologic examination of the eye confirmed the presence of moderate-to-marked hypopigmentation of the retinal pigmented epithelium (RPE), ciliary body, and iris pigment epithelium (IPE). Hypopigmentation was most severe in the anterior layer cells of the IPE, where melanosomes were smaller, paler, and more indistinct than those of the anterior stroma and posterior IPE. The pigment granules of the posterior IPE appeared to be nearly as dark as those in stromal melanocytes; however, both cell layers were thinner and paler than corresponding layers in wild-type mice. Ultrastructural analysis of the RPE, IPE, and ciliary body pigmented cells confirmed that mutation of Slc24a5 results in marked hypopigmentation of melanosomes in optic cup-derived pigmented neuroepithelium in the eyes. Milder reductions in melanosome size and pigmentation were noted in neural crest-derived melanocytes. The severe hypopigmentation of neuroepithelium-derived cells in the eyes resulted in a novel form of ocular albinism in Slc24a5-/- mice. Our findings suggest that SLC24A5 may be a candidate gene for some forms of ocular albinism and for the BEY1/EYCL2 locus previously associated with central brown eye color in humans. 相似文献
15.
In the bitch, progression from early to late anoestrus is characterized by a higher amplitude and a larger number of gonadotrophin-releasing hormone (GnRH) pulses generated by the hypothalamus, an increase in the sensitivity of the pituitary to GnRH, and an increase in ovarian responsiveness to gonadotrophins. An increase in basal plasma follicle-stimulating hormone (FSH) concentration is a critical event required for initiation of folliculogenesis. A period of increased luteinizing hormone pulsatility has been reported shortly before the onset of pro-oestrus. Apart from these changes in the hypothalamic-pituitary-ovarian axis, there is also involvement of dopaminergic influences in the initiation of a new follicular phase in the bitch. Administration of the dopamine-agonists bromocriptine and cabergoline shortens the anoestrus and is associated with a decrease in the plasma prolactin concentration, suggesting that the shortened anoestrus is the result of suppression of prolactin secretion. Yet, the anoestrus is not shortened in bitches treated with metergoline, a drug, which in a low dosage lowers the plasma prolactin concentration via a serotonin-antagonistic pathway. In addition, under physiological conditions low plasma prolactin concentrations are found during the entire anoestrus. Furthermore, a low dosage of bromocriptine, insufficient to cause a decrease in the plasma prolactin concentration, prematurely induces folliculogenesis. These observations indicate that not the decrease in the plasma prolactin concentration, but another dopamine-agonistic influence plays a critical role in the transition to a new follicular phase. The dopamine-agonist induced shortening of the anoestrus is associated with a rapid rise in the basal plasma FSH concentration, similar to what is observed during the physiological late anoestrus. This observation underlines the importance of an increase in the circulating plasma FSH concentration in the initiation of folliculogenesis in the bitch. 相似文献
16.
《Veterinary immunology and immunopathology》2015,163(1-2):16-22
Diagnosis of chronic progressive lymphoedema (CPL) in draught horses, including the Belgian Draught Horse, is mainly based on clinical evaluation of typical lower limb lesions. A deficient perilymphatic elastic support, caused by a pathological elastin degradation in skin and subcutis, has been suggested as a contributing factor for CPL. Elastin degradation products induce the generation of anti-elastin Ab (AEAb), detectable in horse serum by ELISA. For a clinically healthy group of draught horses, a significantly lower average AEAb-level than 3 clinically affected groups (mild, moderate and severe symptoms) was demonstrated previously. To improve CPL-diagnosis, we evaluated the AEAb-ELISA as an in vitro diagnostic aid in individual horses. Test reproducibility was assessed, performing assays independently in 2 laboratories on a total of 345 horses. Possible factors associated with AEAb-levels (age, gender, pregnancy, test lab and date of blood collection) were analyzed using a mixed statistical model. Results were reproducible in both laboratories. AEAb-levels in moderately and severely affected horses were significantly higher than in healthy horses. Nevertheless, this was only demonstrated in barren mares, and, there was a very large overlap between the clinical groups. Consequently, even when a high AEAb cut-off was handled to obtain a reasonable specificity of 90%, a very low sensitivity (21%) of AEAb for CPL-diagnosis was obtained. Results on the present sample demonstrate that the described ELISA procedure is of no use as a diagnostic test for CPL in individual horses. 相似文献
17.
Pérez R Bianchi P Calleros L Francia L Hernández M Maya L Panzera Y Sosa K Zoller S 《Veterinary microbiology》2012,155(2-4):214-219
Canine parvovirus type 2 (CPV-2), which causes acute hemorrhagic enteritis in dogs, is comprised of three antigenic variants (2a, 2b, and 2c) that are distributed worldwide with different frequencies. Variant prevalence was analyzed in 150 CPV-2-positive samples collected from the Uruguayan dog population in 2007-2010. Samples were analyzed with polymerase chain reaction, restriction fragment length polymorphism, and sequencing of the coding region for the largest and most variable loop of the VP2 capsid protein. CPV-2c was the only strain detected from 2007 to 2009. Uruguayan CPV-2c showed high homogeneity in both nucleotide and amino acid sequences, indicating a low level of genetic variability. In 2010, an unexpected epidemiological change occurred in Uruguay as a consequence of the appearance of a novel CPV-2a strain. This variant rapidly spread through the Uruguayan dog population and was detected in 20 of the 52 cases (38%) analyzed in 2010. CPV-2a sequences were identical in all field viruses analyzed, and in addition to the characteristic 426Asn residue, the sequences showed amino acid substitutions (267Tyr, 324Ile, and 440Ala) not observed in the Uruguayan CPV-2c. These data and the first detection in April 2010 suggest that the CPV-2a variant recently emerged in Uruguay and underwent clonal expansion. This observation is the first case in which a CPV-2a variant increased its frequency in a dog population where CPV-2c was prevalent. Our results emphasize the dynamic changes in CPV variants and highlight the importance of ongoing surveillance programs to provide a better understanding of virus epidemiology. 相似文献
18.
Incidence of antibodies to Borrelia burgdorferi in dogs in small animal practice in North Bavaria] 总被引：2，自引：0，他引：2
With help of indirect immunofluorescent assay antibodies were detected to Borrelia burgdorferi, agent of Lyme borreliosis in 46 (35.5%) serum samples of 130 randomly selected dogs of a small animal practice in Northern Bavaria. A positive reaction of the indirect immunofluorescent assay was demonstrated in 15 cases in a serum dilution of 1:64, in 9 cases in a serum dilution of 1:128, in 5 cases in a serum dilution of 1:256, in 2 cases in a serum dilution of 1:512, in 3 cases in a serum dilution of 1:1024, in 2 cases in a serum dilution of 1:2048 and in 10 cases in a serum dilution of 1:4096 and higher. There was significant correlation between the symptoms pain of segments or muscles in dorsal region, between painful arthritis, between paralysis of hind legs or between chronic erythema ("hot spot") and the positive reaction of the immunofluorescent assay in the serum dilution of 1:256 ("borderline titre") and higher. 相似文献
19.
Ortiz GG García JJ Feria-Velasco A Rosales-Corral SA Reiter RJ 《Anatomia, histologia, embryologia》2004,33(3):158-160
The presence of a cortex and medulla in the superficial pineal gland has been a controversial point in the morphology of this structure in mammals. The published reports indicate contradictory data especially in rodents. In this study the pineal gland of 15-day-old male rats (Rattus norvegicus) were studied, using scanning electron microscopy, in an attempt to determine whether or not a cortex and medulla are apparent in the pineal gland of young rats. The superficial pineal gland of the 15-day-old rat exhibited both a cortex and a medulla; these areas exhibited different structural organizations. The cortex had a thickness of 40-80 microm and the cells did not show a particular arrangement. The center of the gland was composed of a medulla, which had a width of 1000-1200 microm, and consisted of cells arranged in cords; its morphology was distinctly different from that of the cortex. 相似文献
20.
D E Bauman 《Domestic animal endocrinology》1999,17(2-3):101-116
Bovine somatotropin (bST) results in increased milk yield and an unprecedented improvement in efficiency. Beginning in the 1930s to present day, investigations have examined animal-related factors such as nutrition, bioenergetics, metabolism, health and well being and consumer-related factors such as milk quality, manufacturing characteristics, and product safety. Overall, bST is a homeorhetic control involved in orchestrating many physiological processes. Direct effects involve adaptations in many tissues and the metabolism of all nutrient classes--carbohydrates, lipids, protein, and minerals. Mechanisms include alterations in key enzymes, intracellular signal transduction systems, and tissue response to homeostatic signals. Indirect effects involve the mammary gland and are thought to be mediated by the insulin-like growth factor (IGF) system. Specific changes include increased cellular rates of milk synthesis and enhanced maintenance of secretory cells. Indirect effects are modulated by environment and management factors, especially nutritional status. This modulation is a central component in allowing ST to play a key role in regulating nutrient utilization across a range of physiological situations. U.S. commercial use began in 1994, and adoption has been extensive. From a consumer perspective, bST was unique, and special interest groups loudly predicted dire consequences. However, introduction of bST had no impact on milk consumption, and milk labeled as recombinant bST-free occupies a minor niche market. From a producer perspective, commercial use verified scientific studies and enhanced net farm income. Overall, ST is a key homeorhetic control regulating nutrient partitioning, and the ST/IGF system plays a key role in animal performance and well being across a range of physiological situations. 相似文献