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1.
Summary Longitudinal growth of the appendicular skeleton in the growth plates and the adjacent metaphyseal area includes chondrocyte differentiation, proliferation, maturation, and hypertrophy in the physis and bone (re‐)modelling in the metaphysis. The rate and extent of longitudinal growth are regulated by interactions between biomechanical factors and endogenous growth regulators, i.e., systemic endocrine factors, and local paraor autocrine factors, that act on the growth plate chondrocytes. The most important endogenous regulators of growth and skeletal development are growth hormone (GH) and insulin‐like growth factors (IGFs), and calciotropic hormones, i.e., parathyroid hormone (PTH), vitamin D (vitD), and calcitonin (CT). The biochemistry, synthesis, secretion, target organs, and effects of these endogenous factors are reviewed, and the calcium homeostatic mechanisms, dietary intake, bone turnover, and calcium excretion are discussed. Energy, protein, and calcium are nutritional factors of great importance to (skeletal) growth. The effects of low and high dietary intake of these nutrients are discussed, especially with reference to longitudinal growth and disturbances in endochondral ossification. 相似文献
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从青海海西州茶卡种羊场随机抽取10只青海半细毛羊,采集空腹颈静脉血样分析其血钙、血磷、血清碱性磷酸酶和羟脯氨酸等一系列反映钙磷营养的敏感生化指标,测定系骨组织的稳定化学指标。结果表明,4月、8月、10月绵羊血清钙分别为1.90mmol/L,2.24mmol/L和2.06mmol/L,均低于绵羊血钙正常范围下限;血清无机磷为3.04mmol/L,3.42mmol/L和2.70mmol/L,均在正常范围内;骨中钙/灰分8月和10月测定值低于正常值;骨磷/灰分3次测定值均高于正常值;骨钙/磷夏季(1.71∶1)最高,秋季(0.84∶1)最低,都小于正常参考值2∶1。由此可见:柴达木盆地半荒漠放牧绵羊钙处于不足状态,磷素基本能满足机体需要。 相似文献
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《African Journal of Range and Forage Science》2013,30(4):279-287
In this study, we examined temporal and spatial dynamics of minerals of forage, soil and cattle serum in two savannas (valley and plain) of South Africa. The aims were to explore the relationships between ecosystem components, and plan communal grazing and fodder flow for sustainable livestock production. In each area, grazing sites near, at intermediate distance from (middle) and far from homesteads were selected. In the valley land, site interacted with season to influence local variations (P<0.05) of soil calcium and microelements. In the plain lands, local variations occurred for soil phosphorus and magnesium. At the large scale, most macro-minerals showed differences between the valley and plain lands. In the valley areas, forage calcium differed (P<0.05) locally in the dry season, whereas in the plain areas, potassium and phosphorus showed local variations (P<0.05) in the wet season. Seasonal variations of most forage elements were significant within each local site of both study areas. All forages were deficient in phosphorus and copper. Cattle serum from the valley area had low iron concentrations. The study concluded that biotic and abiotic factors may influence the distribution of soil and forage elements, but their effects may vary between the two areas. Rangeland improvement and supplementation strategies are suggested to sustain animal production. 相似文献
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Lekcharoensuk C Lulich JP Osborne CA Pusoonthornthum R Allen TA Koehler LA Urlich LK Carpenter KA Swanson LL 《Journal of the American Veterinary Medical Association》2000,217(4):515-519
OBJECTIVE: To test the hypothesis that breed, age, sex, body condition, and environment are risk factors for development of calcium oxalate uroliths in dogs. DESIGN: Case-control study. ANIMALS: 1,074 dogs that formed calcium oxalate uroliths and 1,724 control dogs that did not have uroliths. PROCEDURE: A validated multiple-choice questionnaire was designed to collect information from veterinarians and owners within 1 year of the date of urolith detection concerning signalment and environment of the dogs. Univariate and multivariate analyses were performed to calculate odds ratios to assess whether breed, age, sex, body condition, and environment were risk factors for calcium oxalate urolith formation. RESULTS: Middle-aged (8- to 12-year-old) castrated male dogs had increased risk for formation of calcium oxalate uroliths. Urolith formation was also associated with increasing age. Dogs of certain breeds, including Miniature and Standard Schnauzer, Lhasa Apso, Yorkshire Terrier, Bichon Frise, Shih Tzu, and Miniature and Toy Poodle, had increased risk for developing calcium oxalate uroliths. Overweight dogs also had increased risk. CONCLUSIONS AND CLINICAL RELEVANCE: Knowledge of patient and environmental risk factors for development of calcium oxalate uroliths may facilitate development of surveillance strategies that result in earlier detection of this disease. Modification of environmental factors and body weight may minimize calcium oxalate urolith formation and recurrence. 相似文献
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C A Osborne D J Polzin J M Kruger J P Lulich G R Johnston T D O'Brien 《Veterinary Clinics of North America: Small Animal Practice》1989,19(3):561-581
Feline lower urinary tract disease is often associated with uroliths and urethral plugs. Uroliths and urethral plugs are composed of variable quantities of matrix and a variety of minerals (including struvite, calcium oxalate, ammonium urate, calcium phosphate, and cystine). Knowledge of nutritional factors associated with the pathophysiology of uroliths and urethral plugs facilitates the modification of diets for the dissolution of several minerals contained within them. 相似文献
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母猪的生产性能受很多因素的影响，其中日粮矿物质水平是其主要影响因素之一。钙在调控母猪的生产性能方面发挥着重要的作用。机体钙吸收的方式有3种，即主动转运、被动转运和囊泡运输，激素或者其他影响钙吸收的因素大多是通过调控钙吸收方式进而影响日粮钙的利用率。母猪对日粮钙的利用率直接影响其生产性能的发挥，一方面，适当的日粮钙水平可以促进母猪发挥最大的生产潜能，提高养殖效益；另一方面，当日粮钙水平不足或者钙利用率低时，首先，母猪的生产性能潜力不能充分发挥，如产仔数或活仔数低，仔猪的生长速度慢。其次，母猪由于钙利用不足而导致骨骼疾病的发生，尤其是妊娠后期和哺乳期的母猪，最终使其淘汰率居高不下，这一系列的因素最终导致养殖业的生产效益大幅度降低。近年来，国内外学者针对影响母猪对日粮钙利用率的因素进行了大量的研究，并取得了很大的进展，例如，钙的饲喂时间、日粮钙磷比、维生素、激素和消化道pH均影响母猪对日粮钙的吸收利用。因此，研究母猪钙吸收特征及其影响因素对提高母猪生产性能具有重要的实践意义。作者简述了机体钙吸收的作用机制，同时介绍了影响母猪钙吸收的主要因素，旨在为母猪日粮钙的饲喂提供理论依据。 相似文献
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Kogika MM Lustoza MD Notomi MK Wirthl VA Mirandola RM Hagiwara MK 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2006,35(4):441-445
BACKGROUND: Chronic renal failure (CRF) is a common disease in dogs, and many metabolic disorders can be observed, including metabolic acidosis and calcium and phosphorus disturbances. Acidosis may change the ionized calcium (i-Ca) fraction, usually increasing its concentration. OBJECTIVE: In this study we evaluated the influence of acidosis on the serum concentration of i-Ca in dogs with CRF and metabolic acidosis. METHODS: Dogs were studied in 2 groups: group I (control group = 40 clinically normal dogs) and group II (25 dogs with CRF and metabolic acidosis). Serum i-Ca was measured by an ion-selective electrode method; other biochemical analytes were measured using routine methods. RESULTS: The i-Ca concentration was significantly lower in dogs in group II than in group I; 56% of the dogs in group II were hypocalcemic. Hypocalcemia was observed in only 8% of dogs in group II when based on total calcium (t-Ca) concentration. No correlation between pH and i-Ca concentration was observed. A slight but significant correlation was detected between i-Ca and serum phosphorus concentration (r = -.284; P = .022), as well as between serum t-Ca and i-Ca concentration (r = .497; P < .0001). CONCLUSION: The i-Ca concentration in dogs with CRF and metabolic acidosis varied widely from that of t-Ca, showing the importance of determining the biologically active form of calcium. Metabolic acidosis did not influence the increase in i-Ca concentration, so other factors besides acidosis in CRF might alter the i-Ca fraction, such as hyperphosphatemia and other compounds that may form complexes with calcium. 相似文献
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OBJECTIVES: To review the records of 29 dogs diagnosed with primary hyperparathyroidism and see if any factors correlate with renal failure. METHODS: Dogs were selected retrospectively from case files from the QVSH and the QMH. RESULTS: The majority of dogs were middle-aged and four were keeshonds. The primary presenting complaints were polyuria and polydipsia. All dogs had an elevated total and ionised plasma calcium concentration. Plasma phosphate concentrations were variable. Ultrasonography of the parathyroid gland revealed nodular enlargement which was found to correlate well with surgical findings. The majority of dogs underwent surgical parathyroidectomy. Five cases were treated by ultrasound-guided chemical ablation of the parathyroid gland, of which only two cases showed a partial response. Three dogs were euthanased within a week of presentation. Seven other dogs had renal failure diagnosed either at presentation or up to six months after parathyroidectomy. The development of renal failure was correlated with total calcium concentration but did not correlate with any other factor, including the calcium phosphate product. Thirteen treated dogs were known to be alive at the time of writing, which was six months to 3.5 years after parathyroidectomy. CLINICAL SIGNIFICANCE: Primary hyperparathyroidism cases with high total calcium were more likely to develop renal failure in this group of dogs; however, the calcium phosphate product did not seem to be a useful predictor. Ultrasound-guided chemical ablation seemed to have limited advantage over surgery. 相似文献
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M J Lynch R F Slocombe K E Harrigan C J Laing 《Journal of zoo and wildlife medicine》1999,30(4):577-583
Fibrous osteodystrophy of the facial and long bones was diagnosed in four dromedary camels (Camelus dromedarius). None of the animals responded to treatment with antiinflammatory medications or calcium supplements. The lesions were probably caused by multiple factors, including inappropriate diet and gastrointestinal parasitism. A critical factor in lesion formation may have been vitamin D deficiency secondary to gastrointestinal malabsorption and inadequate winter exposure to ultraviolet light. 相似文献
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Udomkusonsri P Kaewmokul S Arthitvong S Phaochoosak N 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(3):301-305
Antibiotic beads have become popular for the treatment of local bacterial infections. The preparation of antibiotic beads from commercial pharmaceutical antibiotics is a convenient method in clinic. The elution characteristics of cefazolin from polymethylmethacrylate (PMMA) (SmartSet HV, Depuy I and Cemfix 3) beads and calcium sulfate beads were studied. Commercial cefazolin formulation was incorporated in PMMA or calcium sulfate at 1 g cefazolin/10 g of matrix substances to form beads. The concentrations of eluted cefazolin during 15 days were greater than MIC for Staphylococcus aureus (ATCC 25923). The eluted cefazolin concentrations were in the range of 3.6 ± 1.2 to 4.6 ± 0.4 mg for PMMA beads and 15.4 ± 1.7 mg for calcium sulfate beads. The accumulated eluted cefazolin from PMMA beads and calcium sulfate beads for 15 days were 34.41 ± 3.93 to 38.67 ± 3.04% and 95.94 ± 3.93%, respectively. The various storage conditions; at room temperature or 4°C, with or without light-protection, for 6 months had little effects on the amounts of eluted cefazolin. The results showed both in-housed cefazolin-PMMA beads and cefazolin-calcium sulfate beads could be the effective tools for the treatment of local bacterial infections. 相似文献
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J S Klausner C A Osborne 《Veterinary Clinics of North America: Small Animal Practice》1986,16(1):171-184
Uroliths composed primarily of calcium phosphate are identified in approximately 3 per cent of canine stone patients. Predisposing factors to the formation of calcium phosphate uroliths include elevated urine pH, hypercalciuria, and the presence of crystallization inhibitors and promoters. Medical therapy of patients forming calcium phosphate uroliths should initially be directed at removing factors contributing to urine supersaturation with calcium phosphate. 相似文献
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Stevenson AE Blackburn JM Markwell PJ Robertson WG 《Veterinary therapeutics : research in applied veterinary medicine》2004,5(3):218-231
Nutrient intake and urine composition were analyzed in calcium oxalate (CaOx)stone-forming and healthy control dogs to identify factors that contribute to CaOx urolithiasis. Stone-forming dogs had significantly lower intake of sodium, calcium, potassium, and phosphorus and significantly higher urinary calcium and oxalate concentrations, calcium excretion, and CaOx relative supersaturation (RSS). Feeding a diet used in the treatment of canine lower urinary tract disease for 1 month was associated with increased intake of moisture, sodium, and fat; reduced intake of potassium and calcium; and decreased urinary calcium and oxalate concentrations, calcium excretion, and CaOx RSS. No clinical signs of disease recurrence were observed in the stone-forming dogs when the diet was fed for an additional 11 months. The results suggest that hypercalciuria and hyperoxaluria contribute to the formation of CaOx uroliths in dogs and show that dietary modifications can alter this process. 相似文献
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P. J. O'Brien 《Veterinary research communications》1987,11(6):527-559
Summary and conclusions Overwhelming clinical, physiological, pharmacological, and biochemical evidence indicates that MH occurs due to a genetic defect of intracellular calcium homeostasis in skeletal muscle. Specifically, the balance of data clearly and plausibly implicates the channel through which calcium is released from the terminal cisternae of sarcoplasmic reticulum as the site of the underlying molecular lesion of MH. This putative channel is commonly believed to be ligand-gated, that is, opened by the binding of specific agonists (Meisner, 1984). Apparently, the gating of the MH channel is abnormally sensitized, that is more tightly coupled than normal, to the binding of agonists such as calcium (and ATP). Consequently, the MH channel requires less trigger calcium or ATP for activation.Caffeine may act as weak agonist of the putative, purinergic (ATP) receptor of the ligand-gated calcium channel of the sarcoplasmic reticulum (Meisner, 1984).Persistent elevations of myoplasmic free calcium in the vicinity of the channel, which would be subliminal for normal muscle, may trigger massive and regenerative calcium-induced calcium-release in MHS muscle. Uncontrollable and sustained activation of the contractile apparatus and metabolic machinery follows. The source of the trigger calcium may be the lumen of the transverse tubules via their voltage-gated calcium-channels (Ikemoto et al., 1984; Curtis & Catteral, 1984; Graf & Schatzmann, 1984), dislodged calcium from binding sites on the inner leaflet of the transverse tubular membrane (Frank, 1979; Curtis & Eisenberg, 1985), or the lumen of the terminal cisternae of sarcoplasmic reticulum via their ligand-gated calcium channels.Such persistent, but normally subliminal, elevations of trigger calcium at the site of the calcium-release channel presumably occurs in MHS muscle with administration of potent volatile anesthetics, especially halothane, and depolarizing muscle relaxants, especially succinylcholine. The gaseous anesthetics apparently act indirectly on the calcium channel by virtue of their being potent but non-specific membrane perturbing agents (Ohnishi et al., 1986) which increase the passive permeability of the sarcoplasmic reticulum, and possibly surface membrane, to calcium.In individuals which are homozygous for the genetic defect the less potent muscle stimuli of anoxia, heat, and exertion may be sufficient to increase the local trigger calcium concentration to a level resulting in uncontrollable calcium-release. Such homozygosity occurs rarely in people but commonly in swine due to inbreeding and the high frequency of the MH gene. Homozygosity for the MH gene may explain the occurrence of porcine (Topel, 1968), human (Wingard, 1974), and canine (O'Brien & Rand, 1985) stress syndromes: a double dosage of the genetic defect may render homozygotes hypersensitive to stimuli less potent than volatile anesthetics.Dantrolene, the MH-preventive and reversing (if administered early enough in the syndrome) drug, apparently acts by a different mechanism than drugs such as ruthenium red and the amide local anesthetics which appear to physically block the pore of the ligand-gated calcium channel (Ohnishi et al., 1986). Dantrolene's effect on the calcium channel is apparently indirect. It blocks the membrane-perturbing effects of halothane (Nelson & Denborough, 1977; Ohnishi et al., 1986) perhaps by stabilizing muscle membranes and therefore their calcium channels (voltage-gated in transverse tubules and ligand-gated in terminal cisternae). However, this muscle relaxant is less effective at inhibiting the calcium-releasing effects of calcium or caffeine probably because these act directly on the calcium channel (Nelson & Denborough, 1977; Nelson, 1984; Britt et al., 1984; Araki et al., 1985; Ohnishi et al., 1986).Modelling the MH defect as a hypersensitive calcium-release channel also provides a plausible explanation for observations of gradations of susceptibility to triggering of MH for individuals and within populations (Gronert, 1980; Ellis & Heffron, 1985). This model predicts gradations due to gene dosage (homozygous versus heterozygous) as well as due to environmental, pharmacologic, and genetic factors which would compromise or challenge calcium homeostatic potential, such as: heat, anoxia, exertion, drugs which stimulate muscle, and other myopathies.Thus, MH is initiated due to a hypersensitive calcium-release mechanism of skeletal muscle sarcoplasmic reticulum. Malignant hyperthermia may be reversed by dantrolene and symptomatic treatment up until a critical irreversible point in the development of the syndrome. This point of irreversibility probably corresponds to the occurrence of significant degenerative structural and functional changes within the muscle fiber. Loss of calcium-sequestration capabilities by sarcoplasmic reticulum is likely the most important factor which contributes to the irreversibility of MH. 相似文献
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Kai Li Lihong Zhao Guangrui Geng Liqin Ma Shishan Dong Tong Xu Jianlin Wang Huiyu Wang Yong Tian Jian Qiao 《Research in veterinary science》2011,90(3):468-473
The decrease of erythrocyte deformability may be one of the predisposing factors for pulmonary hypertension and ascites in broiler chickens. In mammals, the cytoplasmic calcium is a major regulator of erythrocyte deformability. In this study, the erythrocyte deformability was measured, and the precise locations of Ca2+ and Ca2+-ATPase in the erythrocytes were investigated in chickens with ascites syndrome induced by low ambient temperature. The results showed that ascitic broilers had higher filtration index of erythrocyte compared with control groups, indicating a decrease in erythrocyte deformability in ascitic broilers. The more calcium deposits were observed in the erythrocytes of ascitic broilers compared with those of the age-matched control birds. The Ca2+-ATPase reactive grains were significantly decreased on the erythrocyte membranes of ascitic broilers. Our data suggest that accumulation of intracellular calcium and inhibition of Ca2+-ATPase might be important factors for the reduced deformability of the erythrocytes of ascitic broilers. 相似文献
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为了探讨日粮钙水平对泌乳水牛生产性能的影响,本试验选用12头胎次、泌乳时间、泌乳量相近的水牛,随机分成4组,每组3头水牛。采用4×4拉丁方试验方法,4组水牛基础日粮中钙含量分别占基础日粮干物质的0.47%、0.62%、0.78%、0.93%,其他营养成分均相同,其中磷占采食干物质比例为0.50%;共4期试验,每一试验期21 d,其中预饲期7 d,正饲期14 d。试验结果表明:1、不同钙水平日粮对泌乳水牛的产奶性能影响不显著(P>0.05),但0.78%钙水平日粮组水牛的产奶量分别比其他3组提高5.4%、5.5%、3.9%,不同钙水平对水牛奶营养成分影响不显著(P>0.05)。2、不同钙水平日粮对水牛血浆中钙含量影响差异显著(P<0.05);随着日粮钙水平的上升,水牛血液甲状旁腺素和1,25二羟基维生素D呈显著下降趋势(P<0.05)。综合各指标,日粮钙占采食干物质的比例为0.78%能进一步提高泌乳水牛产奶量。 相似文献
19.
Michiko Nakai Junya Ito Ayumi Suyama Atsuko Kageyama Yasuko Tobari Naomi Kashiwazaki 《Animal Science Journal》2020,91(1)
During mammalian fertilization, sperm is fused with the oocyte's membrane, triggering the resumption of meiosis from the metaphase II arrest, the extrusion of the second polar body, and the exocytosis of cortical granules; these events are collectively called 'oocyte activation.' In all species studied to date, the transient rise in the cytosolic level of calcium (in particular, the repeated calcium increases called 'calcium oscillations' in mammals) is required for these events. Researchers have focused on identifying the factor(s) that can induce calcium oscillations during fertilization. Sperm‐specific phospholipase C, i.e., PLC zeta (PLCζ), is a strong candidate of the factor(s), and several research groups using different species obtained evidence that PLCζ is a sperm factor that can induce calcium oscillations during fertilization. However, postacrosomal sheath Tryptophan‐Tryptophan (WW)—domain‐binding protein (PAWP) was recently shown to have a pivotal role in inducing calcium oscillations in some species. In this review, we focus on PLCζ and PAWP as sperm factors, and we discuss this controversy: Which of these two molecules survives as a sperm factor? 相似文献
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R. A. McKenzie R. J. W. Gartner B. J. Blaney R. J. Glanville † 《Australian veterinary journal》1981,57(12):554-557
A supplement system for the control of equine nutritional secondary hyperparathyroidism (NSH) was evaluated on 4 farms in the Arcadia Valley of the Queensland brigalow region. Thirty-three local stock horses (of which 13 had clinical NSH and 7 were recent introductions) were grazed on buffel grass (Cenchrus ciliaris) for the 6 months from September 1979 to February 1980. Each horse was fed 1.0 kg of a mixture of ground limestone plus dicalcium phosphate (1:2) in 1.5 kg molasses each week. The pasture was hazardous during this time (total oxalate content above 0.5% and calcium: oxalate ratio below 0.5), but no new NSH cases occurred and those horses with clinical NSH improved, most becoming normal. After the first 6 months of supplementation, 3 new cases occurred on one farm. Doubling of the supplement dose and substituting rock phosphate in molasses for the previous mixture corrected the problem. The breakdown was thought to be partly because the supplement dose was slightly inadequate and partly because of behavioural factors. 相似文献