首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
OBJECTIVE: To determine reference limits for urinary fractional excretion of electrolytes in Greyhound dogs. METHODS: Urinary fractional excretion was calculated using a spot clearance method preceded by a 16 to 20 hour fast in 48 Greyhound dogs. Raw data analysed using the bootstrap estimate was used to calculate the reference limits. RESULTS: The observed range for urinary fractional excretion in Greyhound dogs was 0.0 to 0.77% for sodium, 0.9 to 14.7% for potassium, 0 to 0.66% for chloride, 0.03 to 0.22% for calcium and 0.4 to 20.1% for phosphate. Expressed as percentages, the suggested reference limits for fractional excretion in Greyhound dogs are as follows: sodium < or = 0.72, potassium < or = 12.2, chloride < or = 0.55, calcium < or = 0.13 and phosphate < or = 16.5. CLINICAL SIGNIFICANCE: Veterinary practitioners may use these reference limits for urinary electrolyte fractional excretion when investigating renal tubular disease in Greyhound dogs.  相似文献   

2.
Blood and urine chemical values at parturition in clinically normal Holstein cows (n = 12) were compared with the same values in Holstein cows developing udder edema (n = 12). There was no statistically significant mean difference between the 2 groups for the serum and urine chemical data. Furosemide (500 mg) given IV caused a significant increase in serum calcium and sodium, urine chloride, potassium, and sodium, and fractional excretional ratio of chloride, potassium, and sodium. There was a significant mean decrease in the serum potassium, urine creatinine, osmolality, pH, and specific gravity. Hydrochlorothiazide (250 mg) given IV caused a significant mean increase in serum chloride, urine chloride, potassium, and sodium, and fractional excretion ratio of chloride, potassium, and sodium. There was a significant mean decrease in serum potassium and sodium, urine osmolality, pH, and specific gravity. Acetazolamide (500 mg) given IV caused a significant mean increase in blood urea nitrogen, serum chloride and glucose, urine sodium, and fractional excretion ratio of sodium, while causing a significant mean decrease in serum potassium, sodium, and phosphorus, and urine creatinine. Dextrose (500 g) given IV as a 50% solution caused a statistical mean increase in serum glucose, urine chloride, potassium, and sodium, and fractional excretion ratio of chloride and potassium. A statistical mean decrease occurred in the packed cell volume, blood urea nitrogen, serum calcium, potassium, sodium, and phosphorus, urine creatinine, osmolality, and pH.  相似文献   

3.
OBJECTIVE: To determine the prevalence of hypomagnesemia and hypocalcemia in horses with surgical colic. ANIMALS: 35 horses with surgically managed colic. PROCEDURE: Serum concentrations of total magnesium (tMg2+) and calcium (tCa2+), as well as ionized magnesium (iMg2+) and calcium (iCa2+) were analyzed before surgery and 1, 3, 5, and 7 days following surgery. A lead-II ECG and pertinent clinical data were also obtained at each time. RESULTS: Preoperative serum tMg2+ and iMg2+ concentrations were below the reference range in 6 (17%) and 19 (54%) horses, respectively. Serum concentrations of tCa2+ and iCa2+ were less than the reference range in 20 (57%) and 30 (86%) horses before surgery. Horses with strangulating lesions of the gastrointestinal tract had significantly lower preoperative serum concentrations of iMg2+ and iCa2+, as well as a higher heart rate than horses with nonstrangulating lesions. Horses that developed postoperative ileus had significantly lower serum concentrations of iMg2+ after surgery. Serum concentrations of magnesium and calcium (total and ionized) correlated significantly with the PR, QRS, QT, and corrected QT (QTc) intervals. Horses that were euthanatized at the time of surgery (n = 7) had significantly lower preoperative serum concentrations of iMg2+, compared with horses that survived. Neither serum magnesium nor calcium concentrations were predictors of hospitalization time or survival. CONCLUSIONS AND CLINICAL RELEVANCE: Hypomagnesemia and hypocalcemia were common during the perioperative period, particularly in horses with strangulating intestinal lesions and ileus. Serum concentrations of tMg2+ and tCa2+ were less sensitive than iMg2+ and iCa2+ in detecting horses with hypomagnesemia and hypocalcemia.  相似文献   

4.
OBJECTIVE: To establish reference values for protein-bound, ionized, and weak-acid complexed fractions of calcium and magnesium in equine serum and determine stability of ionized calcium (iCa) and ionized magnesium (iMg) in serum samples kept under various storage conditions. ANIMALS: 28 clinically normal horses. PROCEDURE: Total calcium (tCa) and magnesium (tMg) in equine serum were fractionated by use of a micropartition system that allows separation of protein-bound calcium (pCa) and magnesium (pMg) and ultrafiltrable calcium (microCa) and magnesium (microMg) fractions. Serum concentrations of iCa and iMg were measured in the ultrafiltrate by use of selective electrodes. Serum concentration of complexed calcium (cCa) or magnesium (cMg) was calculated by subtracting iCa or iMg from microCa or microMg, respectively. RESULTS: Mean +/-SE serum tCa concentration was 3.26 +/- 0.06 mmol/L. Calcium fractions were as follows: pCa, 1.55 +/- 0.03 mmol/L (47.4 +/- 0.9%); iCa, 1.58 +/- 0.03 mmol/L (48.5 +/- 0.7%); and cCa, 0.13 +/- 0.02 mmol/L (4.1 +/- 0.9%). Serum tMg concentration was 0.99 +/- 0.04 mmol/L. Magnesium fractions were as follows: pMg, 0.33 +/- 0.04 mmol/L (33.3 +/- 4.2%); iMg, 0.57 +/- 0.02 mmol/L (57.6 +/- 1.7%); and cMg, 0.09 +/- 0.02 mmol/L (9.1 +/- 1.9%). Refrigeration (4 degrees C) did not affect iCa values, whereas iMg declined by 8% after 120 hours. Neither iCa nor iMg was affected by freezing (-20 degrees C). CONCLUSIONS AND CLINICAL RELEVANCE: In equine serum, iMg is less stable than iCa; thus, when serum samples are not going to be analyzed promptly, freezing may be preferable to refrigeration for storage.  相似文献   

5.
The effect of ethacrynic acid, bumetanide, frusemide, spironolactone and antidiuretic hormone (ADH) on the urinary and faecal excretion of water and electrolytes by ponies was studied. Ethacrynic acid, bumetanide, and frusemide given intravenously, increased urinary sodium excretion, and, excepting frusemide, decreased faecal sodium excretion. Given by stomach tube ethacrynic acid reduced urinary and faecal sodium. Bumetanide, given intravenously, spironolactone, frusemide and ADH increased urinary sodium and all except frusemide intravenously decreased faecal sodium regardless of route of administration. Ethacrynic acid and bumetanide, given by stomach tube or intravenously decreased urinary and faecal potassium excretion, as did spironolactone and frusemide given orally. Ethacrynic acid and bumetanide given orally or intravenously, frusemide given orally and ADH intranasally reduced urinary chloride excretion; these same drugs by the same routes also reduced faecal chloride excretion. Excepting frusemide given intravenously, and ethacrynic acid orally, the effect of the drugs studied was not the same on urinary sodium excretion as on faecal sodium excretion. This suggested that different mechanisms were involved in the control of sodium excretion by the kidney and in the gut. There were similarities in the treatment of potassium and chloride by these organs.  相似文献   

6.
Two Holstein heifers and a steer fitted with ruminal and duodenal cannulas were used to determine acid-base and electrolyte changes associated with metabolic alkalosis induced by duodenal obstruction. Obstruction was induced distally to the pylorus, but proximally to the common bile duct entrance. Ruminal fluid, blood, and urine samples were obtained before and after obstruction was induced. Duodenal obstruction resulted in increased blood pH, bicarbonate concentration, and base-excess values. Severe hypochloremia and hypokalemia were evident in 48 hours. Serum sodium concentration decreased only slightly. Packed cell volume and serum concentrations of urea nitrogen, creatinine, glucose, and inorganic phosphate increased, whereas calcium concentration showed no change. Renal chloride excretion reached near zero in 24 hours, whereas sodium and potassium excretions decreased in the steer, but were unchanged in the heifers. Urine creatinine concentration increased markedly in the heifers and steers. Acid urine was not evident up to 96 hours. Ruminal fluid pH decreased and chloride concentration increased in the steer, but remained unaffected in the heifers. Duodenal obstruction had no effect on rumen sodium, calcium, and magnesium concentrations, but the potassium concentration increased in the heifers. The degrees of alkalosis and electrolyte changes were greater in the steer than in the heifers.  相似文献   

7.
本实验在山羊饲喂棉饼日粮时，分别添加２％、４％、６％棉饼量的ＮａＣｌ，以探讨添加ＮａＣｌ对饲喂棉饼所致的磷酸钾镁尿沉渣生成作用的影响。结果表明，添加ＮａＣｌ后，磷酸钾镁尿沉渣生成量明显减少。其机理为：１．添加ＮａＣｌ后，能使饮水量、尿量增加，尿液ｐＨ值降低，从而减少尿液中磷酸钾镁的析出。２．添加ＮａＣｌ后能降低血清醛固酮含量，导致尿钾浓度降低，从而降低了磷酸钾镁生成的速率。本实验还对比了三种ＮａＣ  相似文献   

8.
OBJECTIVE: To determine blood ionized calcium (iCa) and serum total calcium (tCa) concentrations in dogs with blastomycosis and to evaluate whether serum tCa concentration, albumin-adjusted serum calcium concentration (AdjCa-Alb), and total protein-adjusted serum calcium concentration (AdjCa-TP) accurately predict iCa status. DESIGN: Retrospective case series. ANIMALS: 38 client-owned dogs with a cytologic diagnosis of blastomycosis. PROCEDURES: Dogs were classified as hypocalcemic, normocalcemic, or hypercalcemic on the basis of blood iCa concentration, serum tCa concentration, AdjCa-Alb, and AdjCa-TP; classification on the basis of serum tCa concentration, AdjCa-Alb, and AdjCa-TP was compared with blood iCa concentration. RESULTS: Except for 2 hypercalcemic dogs, all dogs had blood iCa concentrations within the reference interval. Use of serum tCa concentration overestimated hypocalcemia in 57.9% (22/38) of dogs and underestimated hypercalcemia in 1 dog. Use of AdjCa-Alb correctly reclassified all dogs as normocalcemic that were classified as hypocalcemic on the basis of serum tCa concentration, but failed to predict hypercalcemia in 1 dog. Use of AdjCa-TP correctly reclassified all but 2 dogs as normocalcemic that were classified as hypocalcemic on the basis of serum tCa concentration, and failed to predict hypercalcemia in 1 dog. No correlation was found between blood iCa concentration and serum concentrations of tCa, total protein, and albumin; AdjCa-Alb; or AdjCa-TP. CONCLUSIONS AND CLINICAL RELEVANCE: High blood iCa concentration was uncommon in dogs with blastomycosis. Hypoalbuminemia contributed to a low serum tCa concentration despite a blood iCa concentration within reference limits. The use of serum tCa concentration, AdjCa-Alb, and AdjCa-TP may fail to identify a small number of dogs with high blood iCa concentrations.  相似文献   

9.
Background: Serum hypercalcemia in dogs has been reported in association with a variety of diseases. Serum-ionized calcium (iCa) concentration is a more accurate measure of hypercalcemia than total serum calcium or corrected serum calcium concentrations. The severity of hypercalcemia has been utilized to suggest the most likely differential diagnosis for the hypercalcemia.
Hypothesis: Diseases causing ionized hypercalcemia may be different than those that cause increases in total or corrected serum calcium concentrations. The severity of ionized hypercalcemia in specific diseases cannot be used to determine the most likely differential diagnosis for ionized hypercalcemia.
Animals: One-hundred and nine client-owned dogs with a definitive cause for their ionized hypercalcemia evaluated between 1998 and 2003 were included in this study.
Methods: Retrospective, medical records review.
Results: Neoplasia, specifically lymphosarcoma, followed by renal failure, hyperparathyroidism, and hypoadrenocorticism were the most common causes of ionized hypercalcemia. Dogs with lymphoma and anal sac adenocarcinoma have higher serum iCa concentrations than those with renal failure, hypoadrenocorticism, and other types of neoplasia. The magnitude of serum-ionized hypercalcemia did not predict specific disease states.
Conclusions and Clinical Importance: Serum-ionized hypercalcemia was most commonly associated with neoplasia, specifically lymphosarcoma. Although dogs with lymphosarcoma and anal sac adenocarcinoma had higher serum iCa concentrations than dogs with other diseases, the magnitude of the serum iCa concentration could not be used to predict the cause of hypercalcemia. Total serum calcium and corrected calcium concentrations did not accurately reflect the calcium status of the dogs in this study.  相似文献   

10.
The influence of induced chronic renal failure on 24-hour urinary excretion and fractional excretion of sodium and potassium was studied in cats. Induction of chronic renal failure significantly increased fractional excretion of potassium (P less than 0.0001) and sodium (P less than 0.05); however, 24-hour urinary excretion of sodium and potassium decreased slightly following induction of chronic renal failure. Fractional excretion and 24-hour urinary excretion of sodium and potassium were compared by linear regression in clinically normal cats, cats with chronic renal failure, and clinically normal and affected cats combined. In clinically normal cats, linear regression revealed only moderate correlation between fractional excretion and 24-hour urinary excretion for sodium and potassium. Linear regression of these same relationships in cats with chronic renal failure, and in clinically normal cats and cats with chronic renal failure combined, indicated low correlation. Fractional excretions of sodium and potassium were not reliable indicators of 24-hour urinary excretion of these electrolytes in cats with chronic renal failure or unknown glomerular filtration rate. Fractional excretion of potassium and sodium correlated only moderately with 24-hour urinary excretion in clinically normal cats.  相似文献   

11.
The changes in serum and urinary levels of calcium and phosphorus and serum parathyroid hormone (PTH) were studied during controlled, chemically induced, acute renal disease in 4 ponies. There was an initial rise in daily urinary calcium and hydroxyproline excretion in 2 ponies which may have indicated increased bone resorption. Mild hypercalcemia, hypophosphatemia and elevated C-terminal PTH levels were associated with oliguria. Total daily urinary excretion of calcium and phosphorus decreased as oliguria developed. The levels of C-terminal PTH were increased in all four animals. This appears to have been related to their diminished renal function in that C-terminal fragments of intact PTH (which require functioning kidneys in order to be cleared) were probably being accumulated. Although there was no evidence with regard to an actual increase in PTH secretion, prolongation of intact PTH half-life due to renal tubular damage may have contributed to the development of hypercalcemia.  相似文献   

12.
Raekallio M., M. Hackzell and L. Eriksson: Influence of medetomidine on acid-base balance and urine excretion in goats. Acta vet. scand. 1994,35,283-288.– Seven goats were given medetomidine 5 μg/kg as an iv bolus injection. Venous blood samples were taken repeatedly and urine was collected continuously via a catheter up to 7h after the injection.Medetomidine caused deep clinical sedation. Base excess, pH and PCO2 in venous blood rose after medetomidine administration. There were no significant changes in plasma concentrations of sodium, calcium, magnesium, creatinine or osmolality, whereas potassium and bicarbonate concentrations increased, and phosphate and chloride decreased. Medetomidine increased plasma glucose concentration, and in 4 of 7 goats glucose could also be detected in urine. Medetomidine did not influence urine flow rate, free water clearance, bicarbonate and phosphate excretion or pH, but renal chloride, sodium, potassium, calcium, magnesium and creatinine excretion were reduced.The results suggest that the metabolic alkalosis recorded after medetomidine administration is not caused by increased renal acid excretion.  相似文献   

13.
An investigation was made to determine the effects of water deprivation induced dehydration on changes in urine specific gravity (Usg) and urine osmolality (Uosm) in 6 horses with normal renal function. In addition, the effects of dehydration on serum and urine urea nitrogen, creatinine and various electrolytes as well as the effects of dehydration on acid-base status were studied.Following water deprivation sufficient to produce 12–15% decrease in body weight, 95% of the normal horses should have a Usg of at least 1.042, a Uosm of 1310 mOsmg/kg and a urine osmolality/serum osmolality ratio of 4.14.After 72 hours of water deprivation, the mean weight loss was 13.5% of previous body weight. Serum and urine urea nitrogen concentrations increased by 68% and 130%, respectively, while plasma sodium and chloride concentrations increased by 10% and 14%, respectively. In contrast, urine chloride and calcium concentrations decreased by 90.8% and 52.5%, respectively. There was little change in plasma potassium, phosphorus or calcium concentrations. Urine sodium and potassium concentrations increased initially but were near normal after 72 hours of water deprivation. Azotemia developed and was considered to be of extrarenal origin on the basis of normal routine urinalysis and renal clearance ratio of sodium.  相似文献   

14.
Alterations of acid-base status, and fluid and electrolyte balance subsequent to exercise in Thoroughbred racehorses in North America have not been well-characterized. Des-cribed here are the results of an observational study conducted to characterize changes in fluid and electrolytes following strenuous exercise of 16 Thoroughbreds under routine training conditions. Changes following strenuous exercise were determined for the following variables: serum concentrations of sodium (Na), potassium (K), chloride (Cl) and protein; pH of blood; osmolality of plasma and urine; body weight; and, fractional urinary excretion (FE) of Na, K and Cl. The following changes occurred during exercise: increased concentration of Na in blood; increased FE of Na; decreased concentration of Cl in blood; decreased FE of Cl; increased urinary and plasmal osmolality; weight-loss; decreased pH of blood; and, increased concentration of lactic acid. The concurrent decreased concentration of chloride in plasma and acidemia in these horses differed from the hypochloremic, metabolic alkalosis previously described among endurance horses. Acidemia was attributed to production of lactic acid by anaerobic glycolysis.  相似文献   

15.
Twenty goats which served as the experimental group were administered ascorbic acid (AA) per os at a dosage rate of 100 mg/kg body mass, while 20 others served as controls and were given 10 ml each of sterile water. Forty minutes after the administration and loading, the goats were transported for 12 h. Handling and loading of the experimental and control groups of goats decreased (P < 0.05) the potassium and sodium serum concentrations. The concentration of serum chloride, sodium and calcium increased significantly (P < 0.05) immediately post-transportation, while potassium and magnesium decreased (P < 0.05) in the control goats. In AA-treated goats sodium and magnesium concentrations decreased abruptly (P < 0.05), while calcium increased significantly (P < 0.05) after transportation. Handling, loading and transportation adversely affected the electrolyte balance of the goats which suggested respiratory alkalosis, dehydration and muscular damage in the transported goats, and the administration of AA alleviated the adverse effects of road transportation stress on serum electrolytes.  相似文献   

16.
The ultrastructure of parathyroid chief cells was examined from four groups of nude mice (NIH:Swiss) with different serum calcium concentrations. The groups consisted of eight male mice with hypercalcemia induced by transplantable canine adenocarcinoma (CAC-8), eight female mice with hypercalcemia induced by infusion of parathyroid hormone-related protein, ten male control mice, and six male mice fed a low calcium (0.01%) diet. Hypercalcemia induced by malignancy or parathyroid hormone-related protein infusion was associated with low serum phosphorus concentration, a decrease in the number of secretory and prosecretory granules in the parathyroid chief cells, and an increase in the cytoplasmic area of chief cells. Prominent myelinlike membranous whorls were present in the cytoplasm of chief cells of tumor-bearing and parathyroid hormone-related protein-infused hypercalcemic mice. Mice fed a low calcium diet had decreases in the number of secretory granules and cell area but increases in the number of prosecretory granules compared with control mice. The number of mitochondria and the nuclear area of chief cells were similar in all four groups. The prominent membranous whorls and increased cytoplasmic area of chief cells from these hypercalcemic mice mark these cells as distinctly different from the parathyroid chief cells of other species with hypercalcemia.  相似文献   

17.

Background

Hypocalcemia is a documented electrolyte disturbance in people and animals with sepsis, but its mechanism is poorly understood.

Objective

To investigate mechanisms of hypocalcemia in dogs with experimentally induced endotoxemia.

Animals

Six healthy mixed breed dogs were included in this nonrandomized, placebo‐controlled, crossover study.

Methods

Dogs initially were injected with placebo (0.9% NaCl; 1 mL, IV) and then lipopolysaccharide (LPS; 2 μg/kg, IV) after a 5‐day washout period. Blood and urine samples were collected for measurement of serum total calcium (tCa), ionized calcium (iCa), total magnesium (tMg), ionized magnesium (iMg), parathyroid hormone (PTH), 25‐hydroxyvitamin D (vitamin D), venous blood gases, and fractional excretion (FE) of calcium.

Results

After LPS administration, body temperature increased and blood pressure decreased. Both iCa and tCa decreased (P < .01), but iMg was not significantly different between control and LPS treatments. PTH concentrations increased (P < .01) and vitamin D concentrations decreased (P < .01). Venous pH, bicarbonate, base excess, and blood glucose also decreased (P < .01). Urine tCa concentration was below the limit of detection for all dogs after LPS administration.

Conclusions

Hypocalcemia occurs during endotoxemia in dogs and is associated with hypovitaminosis D. Hypomagnesemia, hypoparathyroidism, alkalosis, and increased calciuresis are not associated with hypocalcemia in endotoxemic dogs.  相似文献   

18.
OBJECTIVE: To determine the effects of a 24-hour infusion of an isotonic electrolyte replacement fluid (IERF) on weight, serum and urine electrolyte concentrations, and other clinicopathologic variables in healthy neonatal foals. ANIMALS: 4 healthy 4-day-old foals. DESIGN: Prospective study. PROCEDURE: An IERF was administered to each foal at an estimated rate of 80 mL/kg/d (36.4 mL/lb/d) for 24 hours. Body weight was measured before and after the infusion period. Urine was collected via catheter during 4-hour periods; blood samples were collected at 4-hour intervals. Variables including urine production; urine and serum osmolalities; sodium, potassium, and chloride concentrations in urine and serum; urine and serum creatinine concentrations; urine osmolality-to-serum osmolality ratio (OsmR); transtubular potassium gradient (TTKG); and percentage creatinine clearance (Cr(cl)) of electrolytes were recorded at 0, 4, 8, 12, 16, 20, and 24 hours during the infusion period. Immediately after the study period, net fluid and whole-body electrolyte changes from baseline values were calculated. RESULTS: Compared with baseline values, urine and serum sodium and chloride serum concentrations, urine and serum osmolalities, OsmR, and percentage Cr(cl) of sodium and chloride were significantly increased at various time points during the infusion; urine production did not change significantly. After 24 hours, weight, TTKG, serum creatinine concentration, and whole-body potassium had significantly decreased from baseline values. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of an IERF containing a physiologic concentration of sodium may not be appropriate for use in neonatal foals that require maintenance fluid therapy.  相似文献   

19.
OBJECTIVE: To provide reference values for serum biochemical variables that are used for evaluation of mineral metabolism in donkeys and compare values with those in horses. ANIMALS: 18 donkeys and 18 horses. PROCEDURES: Total calcium (tCa), total magnesium (tMg), and inorganic phosphorus (P) concentrations were measured in serum samples via spectrophotometry. Ionized calcium (iCa) and magnesium (iMg) concentrations were quantified with selective electrodes. By use of a micropartition system, tCa and tMg were fractionated to separate protein-bound (pCa, pMg) and ultrafiltrable fractions. Complexed calcium (cCa) and magnesium (cMg) concentrations were calculated by substracting ionized fractions from ultrafiltrable fractions. Parathyroid hormone (PTH) and calcitriol (CTR) concentrations were measured via radioimmunoassay. RESULTS: Serum tCa concentration in donkeys (3.37 +/- 0.21 mmol/L) was composed of pCa (1.59 +/- 0.21 mmol/L [47.0 +/- 4.2%]), iCa (1.69 +/- 0.04 mmol/L [50.4 +/- 3.0%]), and cCa (0.09 +/- 0.08 mmol/L [2.6 +/- 2.9%]). Serum tMg concentration (1.00 +/- 0.08 mmol/L) was fractioned in pMg (0.23 +/- 0.08 mmol/L [23.4 +/- 8.1%]), iMg (0.59 +/- 0.04 mmol/L [58.8 +/- 5.1%]), and cMg (0.18 +/- 0.08 mmol/L [17.8 +/- 7.2%]). Serum concentrations of P (1.14 +/- 0.30 mmol/L), PTH (20.4 +/- 21.2 pg/mL), and CTR (13.4 +/- 5.9 pg/mL) were determined. CONCLUSIONS AND CLINICAL RELEVANCE: Serum variables of mineral metabolism in donkeys were within reference ranges for horses. However, when compared with horses, donkeys had higher iCa, cMg, and CTR and lower pMg and PTH concentrations.  相似文献   

20.
The absorption and urinary and faecal excretion of calcium, phosphorus, magnesium, sodium, potassium and chloride were studied in four colostomised laying hens during 24 hr periods. The urinary excretion of ammonia was also determined. Data for 10 laying and 5 non‐laying days were obtained. On laying days (a) net absorption of all minerals, expressed either as actual weights or as a percentage of intake was greater, (b) urinary excretion of phosphorus, potassium and ammonia was greater and of calcium, magnesium and chloride less and (c) retention of all minerals was greater, than on non‐laying days.

The urinary findings can be largely explained in terms of the requirements of the shell gland for calcium and bicarbonate ions and the need to excrete the phosphate liberated from the skeleton during egg shell formation.  相似文献   


设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号