Ca Excretion Research Articles

Effect of varying prepartum dietary cation-anion difference and calcium concentration on postpartum mineral and metabolite status and milk production of multiparous cows

Eighty-two multiparous Holstein cows were enrolled 28 d before expected calving and assigned to 1 of 4 dietary treatments in a randomized block design experiment with a 2 × 2 factorial arrangement of treatments to determine the effect of feeding a neutral or acidogenic diet varying in Ca concentration on prepartum and postpartum intake, blood mineral and metabolite concentrations, and postpartum milk production. Prepartum diets were formulated to provide a dietary cation-anion difference (DCAD) of -21 (negative, NEG) or -2 (neutral, NEU) mEq/100 g of dry matter with either 1.3% or 1.8% Ca. After calving, cows remained on trial through 63 d in milk (DIM) and were fed a common lactation diet. Urine pH was lower for NEG compared with NEU and tended to be lower for 1.8% Ca compared with 1.3% Ca. Fractional excretion of Ca and Mg in urine was greater for NEG than for NEU. Prepartum plasma bicarbonate was lower and P was higher for NEG compared with NEU. Prepartum plasma P and blood urea nitrogen to creatinine ratio was higher for 1.3% compared with 1.8% Ca. Postpartum, concentrations of plasma total protein, albumin, blood urea nitrogen, Mg, and ionized Mg (iMg) were higher and Na was lower for NEU compared with NEG. An interaction of DCAD and Ca was observed for plasma creatinine, which was highest for cows fed NEU and 1.3% Ca compared with all other treatments. Interactions of DCAD and DIM were observed for plasma bicarbonate and iMg. Bicarbonate was higher at 3 DIM and lower at 14 DIM for NEU compared with NEG. Concentrations of iMg were higher at 1, 2, and 14 DIM for NEU compared with NEG. Interactions of Ca and DIM were observed for plasma Ca, Cl, and anion gap. Compared with cows fed 1.5% Ca, those fed 1.3% Ca had lower Ca and anion gap and higher Cl at 1 DIM and lower Cl and higher anion gap at 14 DIM. No differences were observed in body weight or body condition score due to DCAD or Ca. Prepartum dry matter intake (DMI) was lower for NEG compared with NEU and lower for 1.8% compared with 1.3% Ca. Postpartum DMI was not different among treatments. An interaction was observed for DCAD and DIM due to higher milk yield after 45 DIM for NEG compared with NEU. No differences were observed in milk component percentage or yield among treatments. There was an interaction of DIM and Ca for milk urea concentrations, which were higher at 5 wk and lower at 6 wk for 1.3% Ca compared with 1.8% Ca. These results suggest that feeding NEG prepartum alters plasma and urine mineral concentrations compared with feeding NEU and supports increased milk yield after 45 DIM. Feeding 1.8% Ca prepartum only improved plasma Ca at 1 DIM. Feeding either NEG or 1.8% Ca reduced DMI prepartum compared with NEU or 1.3% Ca.

Abstract P224: Urinary Excretion of Sodium, Potassium, Calcium and Magnesium and Blood Pressure Among a Population of ≥ 20-Year-Olds: Evidence From Southwest Coastal Bangladesh

We analyzed data from a stepped wedge randomized trial to evaluate how urinary Na, K, Ca and Mg excretion are associated with the change in blood pressure (BP) among the adult population. We followed up a cohort of 1,191 participants (>20 years old) from 540 households in 16 communities of southwest coastal Bangladesh for five visits during December 2016 - April 2017 when they were exposed to high salinity drinking water. In all visits, we measured participants’ BP (N=5,746) and 24-hour urinary Na, K, Ca and Mg. We used multilevel linear regression models to determine the association among change in urinary excretion of Na, K, Ca and Mg with differences in mean systolic blood pressure (SBP) and diastolic blood pressure (DBP). Models included participant-, household-, and community-level random intercepts and were adjusted for age, sex, BMI, physical activity, smoking status, and household wealth. We restricted analysis among participants who had complete 24-hour urine collection based on measured versus expected urinary creatinine ratio of >=0.7 (N=5,103). The median urinary 24 hours Na excretion was 164 mmol, K was 34 mmol, Ca was 126 mg, and Mg was 83 mg in visit 1. The mean population SBP was 115.6 mmHg in visit 1 and 110.2 in visit 5, and the mean DBP was 68.9 mmHg in visit 1 and 65.9 in visit 5. Compared to visit 1, we found 85% higher urinary Ca in visit 3 and 57% higher urinary Mg in visit 5. We found 100 mmol per 24 hours increase in urinary Na was associated with 1.74 (95% CI: 0.85, 2.62) mmHg higher SBP and 0.51 (95% CI: -0.06, 1.08) mmHg higher DBP, and 50 mmol per 24 hours increase in urinary K was associated with 2.39 (95% CI: 0.84, 3.94) mmHg lower SBP and 0.79 (95% CI: -1.76, 0.17) mmHg lower DBP. We found 100 mg per 24 hours increase in urinary Ca was associated with 0.29 (95% CI: 0.02, 0.60) mmHg lower SBP and 0.32 (0.07, 0.57) mmHg lower DBP, and 100 mg per 24 hours increase in urinary Mg was associated with 1.09 (95% CI: 0.55, 1.64) mmHg lower SBP and 0.41 (0.07, 0.76) mmHg lower DBP. We found SBP lowering effect of urinary Mg increased if urinary Ca was lower (p = 0.048). We found urinary K, Ca, and Mg are associated with lower BP in coastal Bangladesh. Our results suggest a high intake of these beneficial minerals alongside Na reduction may successfully lower mean BP of the population.

Abstract P237: Elucidation of Blood Pressure Control Function of Essential Hypertension Candidate Gene Lpin1

We have found that the LPIN1 is the candidate gene for essential hypertension (EHT) by genome-wide association analysis in 2007. Mice characterized by loss of body fat, fatty liver, insulin resistance and peripheral neuropathy were discovered in nature and named fatty liver dystrophy (fld) mice in 2000. Recently, the fld mice were shown that they exhibit few LPIN1 genes, and the LPIN1 gene was proved as the cause of phenotype of fld mice. However, the blood pressure (BP) and the alteratios of the vasoactive factors in fld mice have not yet been elucidated. Therefore, to clarify the BP and the effects of LPIN1 gene defeciency, we analyzed the BP and regulatory factors of the fld mice. Furthermore, we transplanted the fat to fld mice, and clarify the importance of adipocytokine on BP in the model mice. The BP were measured by the tail cuff method and the telemetry method. We performe fat grafting or sham surgery on fld mice, and systolic BP (SBP) was measured by tail cuff method 8 weeks after surgery. We confirmed that the SBP of fld mice were higher than that of CO by the tail cuff method( fld 134±5 vs CO 111±4 mmHg P<0.05). Furthermore, SBP of the fld mice were higher than that of CO (fld 167.7±9.8 vs CO 133.5±10.9 mmHg P<0.01) by the telemetry method. It was confirmed that the adrenalin and noradrenalin excretions in the urine of fld mice were higher than those of CO(fld 0.133±0.067 vs CO 0.038±0.013 μg/day P<0.01 )(fld 0.980 ±0.313 vs CO 0.364±0.080 μg/day P<0.001). There is no significant difference in plasma aldosterone concentration between two groups( fld 434±276.7 vs CO 781±469.5 pg/mL n.s).The SBP tended to decrease with the fat trasplantation in fld mice ( fat transplanted 103.7±4.41 vs sham 114.7±7.67 mmHg P=0.056). We confirmed that fld mouse exhibits higher SBP by both tailcuff method and telemetry method. Because the fld mice exhibit higher PR and high levels of CA concentration and excretion in urine, it was suggested that the sympathetic nervous systems of fld mice were activated. Sympathetic nervous system activity may be related to an increase in BP of fld mouse, and further research is under way. Since it showed that BP decreased by fat grafting, the visceral fat are essential for fld mice to BP control. The implications of adipokine and other fats are under consideration.

Comparative evaluation of daily rhythm of urinary excretion in Equus caballus and Bos taurus by means of fractional clearance

ABSTRACTThe aim of this study was to evaluate the daily variations of urinary excretion of the main electrolytes in Equus caballus and Bos taurus maintained under natural photoperiod. Animals were housed in individual indoor stalls under natural conditions. Urine and blood samples were taken from all the subjects every 4 h for 24 h period and were analyzed to assess the creatinine, calcium, phosphorus, magnesium, and chloride concentration. The fractional excretions of Na (%CrNa), K (%CrK), Cl (%CrCl), P (%CrP), Ca (%CrCa), and Mg (%CrMg) were calculated. Daily oscillations with nighttime acrophases of %CrNa, %CrK, and %CrCl are observed in horse; the acrophases of the parameters which resulted periodic in cow, including %CrNa, %CrCa, and %CrMg, are verified during the light phase. This study brings a contribution to the knowledge of the periodic phenomenon of the urinary excretion in the equine and bovine species. The results suggest that horse and cow are characterized by different circadian patterns for renal fractional clearance and that in these species, in addition to the external circadian stimuli, the renal excretion rhythms are also controlled by a self-sustained intrinsic renal clock that contribute to define the temporal patterns (daytime and nighttime).

Calcium particle size effects on plasma, excreta, and urinary Ca and P changes in broiler breeder hens.

An experiment was conducted using non-colostomized and colostomized broiler breeder hens to determine the effects of feeding limestone of 2 different mean particle sizes (185 microns and 3490 microns) on P excretion, total P and Ca retention, and urinary P and Ca excretion during a 6-week feeding study. Additionally, changes in plasma inorganic P (iP) and ionic Ca (Ca++) and urinary excretion of P and Ca were determined in one egg laying cycle of 24hours. One-hundred-fifty non-colostomized and 6 colostomized broiler breeder hens, 30 wk of age, were divided into 2 groups and fed broiler breeder diets supplemented with either small particle or large particle limestone. Two % acid insoluble ash (Celite) was added to the feed as a marker. Diets, excreta, and urine samples were analyzed for total P and Ca by ionic coupling plasma (ICP) analysis. The non-colostomized breeders fed large particle limestone compared to small limestone particles produced a significant increase in percent tibia ash (P < 0.0001) and egg specific gravity (P = 0.0382), but P excretion approached a tendency of being reduced (P = 0.1585). The urinary total P and Ca (∼18 and 9%, respectively) of total P and Ca excretion for breeders fed both sizes of limestone was not significantly different in the colostomized breeders. In plasma, both iP and Ca++ reached a peak during 18 to 20h and 20 to 24h post oviposition for smaller and larger particle sized limestone fed groups, respectively. The maximal excretion of urinary P was found during 11 to 20h post oviposition, whereas urinary Ca peaked during 0 to 11h post oviposition for both smaller and larger particle sized limestone supplemented groups. In summary, the findings indicate that the particle size (smaller and larger) of calcium source did not significantly influence the quantitative total urinary excretion of Ca and P but did influence the timing of Ca and P excretion.

Calcium and Magnesium Urinary Excretion in Dairy Cows with Different Fee of Glucose Metabolization

Background: The post-partum period in dairy cows is accompanied by a low glucose metabolism in adipose tissue and skeletal muscle tissue, being glucose conducted to the milk production. In humans, low glucose metabolism is associated with metabolic syndromes, the high glucose levels reduce tubular reabsorption of Magnesium (Mg) and Calcium (Ca), leading to hypomagnesemia and hypocalcemia. These minerals are important to the dairy cow, as their decrease leads to diseases. The aim of this study was to evaluate the relationship between glucose metabolism rate with the urinary excretion of Ca and Mg in multiparous dairy cows during the post-partum period.Materials, Methods &amp; Results: Twenty dairy cows were used from a commercial farm southern Brazil, in the semi-extensive system. Glucose tolerance tests were performed (TTG) on day 9 relative to calving. The cows were categorized into three groups according to the glucose metabolism rate (area under the glucose curve, glucose half-life and glucose consumption rate): High Glucose Metabolization (GA); Intermediate Glucose Metabolizing (GI); and Low Glucose Metabolization (GL). Blood and urine samples were collected on days 0, + 3, + 6, + 9, +16 and +2 3 in relation to calving for to determine the levels of Ca, Mg, insulin (Ins), non-esterified fatty acids (NEFA) and Glu. In urine was evaluated the excretion of Ca and Mg. The cows were milked twice a day (at 3:00 a.m. and 3:00 p.m.) and the milk yield (kg/cow) was recorded daily and averages were generated every five days from day 15 to day 60 postpartum. The statistical analyses were performed with the MIXED procedure to assess the main effect of group, time (in days) and their interaction by using version 9.2 SAS software. The influence of the different rates of glucose metabolism on milk production was observed, the GB group had a production than GH group (30.88 ± 1.44 kg vs 23.96 ± 1.43 kg, P &lt; 0.01), but did not differ from GI. The GL group showed higher levels of Glu compared to GA (P &lt; 0.05). The plasma Ca levels were higher in GL (P &lt; 0.05) compared with GH. The NEFA, insulin, and excretion of minerals did not differ between groups (P &gt; 0.05).Discussion: The low glucose metabolism in humans causes an increase in the excretion of Ca and Mg urine, however, in the animals studied, these changes were not observed. This result can be attributed to the fact that insulin resistance is transitory in dairy cattle. The higher glucose levels in the GL group are related due to the lower capacity of glucose entry in the peripheral tissues (adipose and skeletal muscle), which reflected in the higher milk production observed this group. However, the higher calcium concentrations were not expected, since the release of insulin by β-pancreatic cells is dependent on calcium. Possibly, these higher calcium levels in GB, are related to higher milk production, requiring a greater amount of calcium for the production of casein, increasing bone mobilization, intestinal absorption. The energy metabolites, non-esterified fatty acids and insulin, did not differ between groups, suggesting that the animals did not present different metabolic conditions. We conclude that multiparous dairy cows with low glucose metabolism rate (GB) have higher levels of glucose after delivery and increased milk production. The metabolism rate of glucose did not influence the excretion of the Ca and Mg minerals.

The influence of selected feed additives on mineral utilisation and bone characteristics in laying hens

Abstract The trial with 240 caged ISA Brown laying hens was performed to evaluate the effect of selected feed additives on mineral utilisation as well as biomechanical (breaking strength, yielding load, stiffness) and geometrical (cortex thickness, cross-section area, weight, length) indices of tibia and femur bones. At 26 wks of age the layers were randomly assigned to 10 treatments with 12 replicates (cages) of two birds. In the study a 2 × 5 experimental scheme was used i.e. to 70 wks of age, the layers were fed isocaloric and isonitrogenous experimental diets containing reduced (3.20%) or standard (3.70%) Ca level. The diets with both Ca levels were either not supplemented, or supplemented with the studied feed additives i.e. sodium butyrate, probiotic bacteria, herbal extract blend and chitosan. There were no statistically significant effects of the experimental factors on the indices of the tibia bones. However, the diet with reduced Ca level decreased bone breaking strength, yielding load, stiffness, and mineralisation of the femur bones (P&lt;0.05). The majority of used feed supplements, i.e. probiotic, herb extracts, and chitosan, increased biomechanical indices (breaking strength and yielding load) and mineralisation of the femur bones (P&lt;0.05). Neither dietary Ca level nor feed additives affected dry matter, organic matter, ether extract, N-free extracts, crude fibre and ash digestibility, and P retention and excretion; however, Ca excretion and retention was lower in the hens fed the diets with reduced Ca level (P&lt;0.05). Relative Ca retention (Ca retained as % of Ca intake) was improved by diet supplementation with probiotic, herb extracts and chitosan (P&lt;0.05). In conclusion, this study has shown that decreased Ca dietary level (3.20%) can negatively affect bone quality in layers, while probiotic, herb extracts and chitosan addition may improve the selected biomechanical indices of the femurs, irrespective of Ca dietary concentration.

MP24-11 LONG-TERM TREATMENT OF VITAMIN D INSUFFICIENCY OR DEFICIENCY IN POSTMENOPAUSAL WOMEN WITH HYPERCALCIURIA DOES NOT INCREASE URINARY CALCIUM EXCRETION

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology II1 Apr 2018MP24-11 LONG-TERM TREATMENT OF VITAMIN D INSUFFICIENCY OR DEFICIENCY IN POSTMENOPAUSAL WOMEN WITH HYPERCALCIURIA DOES NOT INCREASE URINARY CALCIUM EXCRETION Kristina L. Penniston, Karen E. Hansen, Abigail C. Staples, Stephen Y. Nakada, and R. Allan Jhagroo Kristina L. PennistonKristina L. Penniston More articles by this author , Karen E. HansenKaren E. Hansen More articles by this author , Abigail C. StaplesAbigail C. Staples More articles by this author , Stephen Y. NakadaStephen Y. Nakada More articles by this author , and R. Allan JhagrooR. Allan Jhagroo More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2018.02.764AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Vitamin D (VD) repletion in calcium (Ca) stone formers is sometimes questioned, especially if long-term and/or in those with hypercalciuria (>250 mg/d). We assessed the effect of VD repletion for 1 year on urinary Ca excretion. METHODS The study was randomized, double-blind, placebo-controlled, and IRB-approved. Postmenopausal women with low VD status [serum 25(OH)D <30 ng/mL; n=90; 61±6 y; BMI 30.8±6.8) were randomized to placebo, low-dose (LD) VD (800 IU daily), or high-dose (HD) VD (50,000 IU for 15 d followed by 50,000 IU twice/month for 1 y). Prefilled 31-day pill boxes were dispensed; remaining capsules were counted at study visits (60, 120, & 365 days) to assess compliance. Multiple-day weighed diet records prior to intervention were completed by all to establish individuals′ usual nutritional intake. To reduce dietary confounders in 24-h urine collections, dietary intake was reproduced for energy and nutrient composition for each participant during her baseline and 1 y visits, during which 24-h urine collections were collected. RESULTS Median baseline urinary Ca excretion was 209 mg/d. Compliance with treatment was estimated at approximately 100% across all arms. Overall, urinary Ca excretion was unchanged at 1 y (228±70 to 219±92 mg/d; P=0.25, paired t-test). Only women in the HD group achieved 25(OH)D ≥30 ng/mL (21±3 to 56±12 ng/mL; P<0.001). Despite this rise in VD status, urinary Ca excretion did not increase in this group (256±86 to 250±131 mg/d; P=0.74). Nor did urinary Ca excretion change in the other groups (P≥0.27 for within-group pairwise comparisons from baseline to 1 y). Among hypercalciuric women across all groups (figure; n=28), Ca excretion did not change (312±60 to 273±130 mg/d; P=0.07), but tended to be lower. Hypercalciuria was resolved at 1 y in 40%, 57%, and 50% in HD, LD, and placebo groups, respectively. The incidence of new hypercalciuria at 1 y was 6.7%, 19%, and 12%, respectively. CONCLUSIONS Despite a significant rise in VD status, VD repletion at 50,000 IU twice monthly for 1 y, following a loading dose, did not increase urinary Ca excretion in postmenopausal women with or without hypercalciuria. VD repletion at lower doses also did not increase urinary Ca, and goal VD status was not achieved. Evidence suggests the risk for hypercalciuria is low following VD repletion in patients with low VD status. © 2018FiguresReferencesRelatedDetails Volume 199Issue 4SApril 2018Page: e294 Advertisement Copyright & Permissions© 2018MetricsAuthor Information Kristina L. Penniston More articles by this author Karen E. Hansen More articles by this author Abigail C. Staples More articles by this author Stephen Y. Nakada More articles by this author R. Allan Jhagroo More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Oleanolic Acid Exerts Osteoprotective Effects and Modulates Vitamin D Metabolism.

Oleanolic acid (OA) is a triterpenoid with reported bone anti-resorption activities. The present study aimed to characterize its bone protective effects in vivo and to study its effects on vitamin D metabolism, both in vivo and in vitro. OA significantly increased bone mineral density, improved micro-architectural properties, reduced urinary Ca excretion, increased 1,25(OH)2D3 and renal CYP27B1 mRNA expression in mature C57BL/6 ovariectomised (OVX) mice. OA also improved bone properties, Ca balance, and exerted modulatory effects on renal CYP27B1 and CYP24A1 expressions in aged normal female Sprague–Dawley rats. In addition, OA significantly increased renal CYP27B1 mRNA and promoter activity, and suppressed CYP24A1 mRNA and protein expressions in human proximal tubule HKC-8 cells. OA exerted bone protective effects in mature OVX mice and aged female rats. This action on bone might be, at least in part, associated with its effects on Ca and vitamin D metabolism. The present findings suggest that OA is a potential drug candidate for the management of postmenopausal osteoporosis.

High Protein Diet that Cause Weight Loss and Lower Blood Glucose Level Have a Serious Impact on the Kidney Functions of Male Diabetic Obese Albino Rats

Background: High protein (HP) diets are increasingly being recommended as one of the management strategies for weight control in overweight and obese individuals. The health benefits of high protein diets are well-established, but the mechanisms of action on body systems responsible for the changes in body weight and glycaemic control are not well-clear. Objective: The present study aimed to examine the effect of HP diets on the kidney functions of diabetic obese albino rats. Material and Methods: Eighty male adult male albino rats were used in this study. The animals were divided into eight equal groups (10 rats for each). Type 2 DM and obesity were induced. At the end of the 12 weeks, samples were collected for biochemical analysis. Results: The high protein diet led to significant decrease in BW, FI, BG, TC, LDL, TG, Lactate dehydrogenase, albumin, urine pH and urine citrate; while serum insulin, HDL, urea, creatinine, total protein, urine volume and urinary excretion of Ca were significantly higher in high protein diet groups. Conclusion: A high protein intake in diabetic obese albino rats for 12 weeks led to changes in the serum and urine levels of markers of renal function which indicated abnormalities in the functions of the kidney.

A comparative meta-analysis on the relationship of faecal calcium and phosphorus excretion in mammals.

To investigate the relationship between faecal calcium (Ca) and phosphorus (P) excretion in different mammalian species, a meta-analysis on digestibility data derived from the literature was conducted. Seventy-three studies on carnivores, omnivores, large and small hindgut fermenters, ruminants and hippos (a total of 21 mammalian species, precondition for inclusion dietary Ca/P ratio 1.5/1 - 3.0/1) were analysed for Ca and P digestibility. Dietary Ca/P ratios were lower than faecal Ca/P ratios in carnivores, omnivores, ruminants and hippos. In hindgut fermenters, dietary Ca/P ratios were higher than faecal Ca/P ratios, indicating higher intestinal Ca absorption in these species. In all species investigated, there was a significant positive relationship between Ca intake and faecal Ca excretion and between P intake and faecal P excretion. In the biologically relevant range, these equations predicted lower faecal Ca losses in hindgut fermenters than ruminants, for faecal P vice versa. In all species, faecal Ca and P excretion correlated significantly. In carnivores, this highly linear correlation was exceptionally strong (R²=.92). Yet, the linearity of the correlation was questionable in omnivores and ruminants. Possibly, the strong linear correlation of faecal Ca and P excretion in carnivores is due to the formation of insoluble Ca/P complexes in their relatively short and simple gastrointestinal tract. Another hypothesis is that in carnivores, Ca homeostasis relies on modifying bone turnover to a higher degree than on changes in intestinal Ca absorption. For the formation of bone matrix, a constant ratio of Ca and P absorption is of advantage.

Plasma calcium concentrations are decreased at least 9 hours before parturition in multiparous Holstein-Friesian cattle in a herd fed an acidogenic diet during late gestation

Calcium homeostatic mechanisms are challenged in periparturient multiparous dairy cattle due to the rapid transport of large amounts of calcium into the mammary gland associated with colostrogenesis, resulting in decreased plasma total calcium concentration ([Ca]). An unresolved issue is the timing of the decrease in plasma [Ca] relative to the time of parturition, with the consensus view being that plasma [Ca] does not decrease until after parturition. The objective of this study, therefore, was to characterize the change in plasma [Ca] over time in periparturient dairy cattle. Plasma and mid-stream urine samples were collected daily starting 3 d before calving from 104 periparturient Holstein-Friesian dairy cows in a herd fed an acidogenic total mixed ration during the late dry period. Mixed-models ANOVA and linear and multivariable regression analyses were conducted. Plasma [Ca] decreased in periparturient multiparous cattle (n = 70) but not in primiparous cattle (n = 34). Compared with mean values approximately 72 h before parturition ([Ca] = 2.32 mmol/L), mean plasma [Ca] in multiparous cattle first decreased at 9 h before parturition (2.13 mmol/L) and remained decreased for up to 48 h after parturition, with the lowest mean value (1.87 mmol/L) occurring at 28 h after parturition. Mean 24-h urine Ca excretion was calculated to decrease by 3.5 to 3.8 g in periparturient multiparous cattle. Regression analysis indicated that plasma [Ca] in the 12-h period before and 24-h period after parturition was strongly and negatively associated with age but was also negatively associated with milk production indices. We conclude that plasma [Ca] was decreased at least 9 h before parturition in multiparous dairy cattle fed an acidogenic diet in late gestation, and that calcium homeostasis was disrupted for 2 to 3 d around parturition.

Different sources of calcium for starter pig diets

Abstract The study was conducted to determine the true Ca absorption coefficients and growth performance of piglets fed diets containing different sources of Ca. In the metabolism study, 30 piglets uncastrated, with initial weight averages of 20.52 ± 1.84 kg, were assigned to 5 treatments with 6 piglets per treatment in a randomized complete block design. A basal diet was formulated to meet the piglets nutritional requirements, except to Ca (0.09%), and was supplemented with different source of Ca (limestone, monodicalcium phosphate, calcined bone meal, and oyster meal) to provide 0.64% total Ca. A low-Ca diet (0.018%) and 6 additional piglets were used to estimate the endogenous Ca excretion in the feces. Total feces and urine were collected to determine the apparent and true absorption of Ca. After the adaptation period (7 d), the excreted feces were collected twice daily, weighed, stored in plastic bags in freezer (−18 °C) until the end of the collection period (5 d). The volume of the urine collected for 24 h was measured and a 20% aliquot was stored in glass containers in refrigerator (3 °C) until the end of the collection period (5 d). Experimental diets, feces and urine were analyzed for Ca. To determine the effect of different Ca sources on the growth performance, 160 piglets were assigned, to 2 sexes (males intact and females) and 4 sources of Ca (the same ones used in the metabolism study), in a 2 × 4 factorial arrangement and randomized complete block design with 4 pens per treatment and 5 intact males or 5 females per pen. At the end of the study (22 d), blood samples were collected of the all piglets and 5 piglets per treatment were selected randomly regardless of sex to collect samples of organs. All samples were stored at −18 °C. Response criteria were: weight gain, feed intake, feed efficiency, Ca deposition in organs, bone strength, weight and size of the third metatarsal bone, and serum in Ca. The sources of Ca and direct or indirect collection method did not affect the absorption coefficients. There was no interaction among the sources of Ca and sex of the piglets for the performance variables. The piglets growth performance was similar among treatments. Calcined bone meal and oyster meal resulted in a greater content of mineral matter in the kidney (P = 0.013). The bone meal resulted in a greater Ca concentration in the piglets hearts (P

Effect of urine pH and magnesium on calcium oxalate saturation.

Hypomagnesiuria is a common biochemical finding in patients with calcium oxalate (CaOx) nephrolithiasis. Clinical trials using Mg supplements as therapy against CaOx stones have shown mixed results. We tested the effect of Mg administration in healthy subjects under conditions of controlled urine pH (UpH) on urinary Ca excretion rate (UCaV) and CaOx saturation. This is a 4-phase, double blind, placebo-controlled, metabolic crossover study performed in healthy volunteers. Mg lactate (MgLact2) was used as Mg supplement. High UpH and low UpH were achieved by administration of potassium citrate (K3Citrate) and ammonium chloride (NH4Cl), respectively, with potassium balance maintained by KCl. Eight participants completed 4 phases of study. The interventions successfully modulated 24-h UpH (7.0±0.4 vs. 5.7±0.6 in high vs low pH phases; P<0.001). Administration of MgLact2 increased UMgV [175.8±40.2 vs 93.4±39.7mg/day (7.2±1.7 vs 3.8±1.6mmol/day), high vs low Mg phase; P<0.001], and increased pH both at low (5.6±0.5 to 5.8±0.7; P=0.02) and high UpH (6.9±0.4 to 7.0±0.3; P=0.01). At a given urine pH, Mg supplementation marginally increased UCaV, but did not alter UOxV or CaOx saturation. Provision of an alkali load significantly lowered UCaV and saturation of CaOx at any level of UMgV. Compared to changes in UMgV, changes in UpH play a more significant role in determining urine CaOx saturation in healthy subjects. Mg supplements are likely to reduce CaOx saturation if they also raise urine pH.

Effect of increasing Buttiauxella phytase dose on nutrient digestibility and performance in weaned piglets fed corn or wheat based diets

Two experiments were carried out to determine the effect of increasing phytase levels on apparent total tract digestibility (ATTD) of nutrients, P and Ca retention and growth performance in weaned piglets fed corn or wheat based diets. Five treatments were tested including a positive control (PC) meeting piglet nutrient requirements; a negative control (NC) formulated with a reduction in digestible P (−1.4g/kg and −1.5g/kg in Exp. 1 and 2 respectively) and Ca (−1.5g/kg in both studies); and NC supplemented with a Buttiauxella phytase at 500, 1000 or 2000 phytase units (FTU)/kg feed. One FTU is defined as the amount of enzyme required to release 1μmol of iP (inorganic phosphorus) per minute from sodium phytate at pH 5.5 at 37°C. A complete randomized design was used in both studies, with individual piglets housed in metabolic crates as the experimental unit. There were 2 runs in Exp. 1 and 4 runs in Exp. 2. Each treatment consisted of 8 replicates (1 piglet/replicate) in Exp. 1 and 12 replicates in Exp. 2. Diets based on wheat and soybean meal in Exp. 1 and corn and soybean meal in Exp. 2 were fed in pelleted form; feed and water were supplied ad libitum to the piglets (mean initial BW of 11±1.5kg) during the 14day period. Urine and feces production were collected from each crate during d 10 to14. The ATTD of P, Ca, DM, N and energy, and retention of P and Ca were measured using TiO2 as an indirect marker. In both Exp, increasing phytase dose from 0 (NC) to 2000 FTU/kg linearly increased (P<0.05) ADG and G:F. Phytase at 2000 FTU/kg improved ADG and G:F compared to NC. A linear response was seen for ATTD of P, Ca and GE (P<0.05) in Exp. 1, and for ATTD P and Ca in Exp. 2, with increasing phytase dose. Also there was a tendency for increasing phytase dose to result in a linear increase (P≤0.10) in ATTD of DM in Exp.1, and ATTD of DM and N in Exp. 2. Increasing phytase dose linearly reduced P and Ca excretion and increased the retention of these nutrients in both experiments. The results showed that increasing Buttiauxella phytase dose up to 2000 FTU/kg may provide environmental and production benefits in weaned piglets fed either wheat or corn based diets.

Vitamin D status in growing dairy goats and sheep: Influence of ultraviolet B radiation on bone metabolism and calcium homeostasis

The aim of this study was to investigate how controlled UVB irradiation in combination with reduced nutritional vitamin D (vitD) supply affects vitD status and Ca metabolism of growing goats and sheep. The hypothesis was that, like dairy cows, goats and sheep are able to compensate for the missing nutritional supply of vitD through endogenous production in the skin, with the consequence of a high vitD status and a balanced Ca homeostasis. Sixteen lambs and 14 goat kids aged 3 and a half months were housed in an UVB free environment and fed hay and a vitD-free concentrate over a period of 13 wk. One group of each species was exposed to UVB lamps daily during individual feeding; the other groups served as controls. Serum, urine, and feces samples were taken at the start and at a monthly interval. Serum was analyzed for vitD metabolites, bone markers, growth hormone, insulin-like growth factor I, Ca, and P. Apparent digestibility and urinary excretion of Ca and P were determined. The left metatarsus was analyzed by peripheral quantitative computer tomography for bone mineral density before starting and at the end of the trial. In wk 13, all animals were slaughtered and samples of skin, rumen, duodenum, kidney, and bone (metatarsus) were collected. Content of sterols of vitD synthesis in the skin, Ca flux rates in rumen and duodenum, expression of vitD receptor in duodenum and kidney, renal and intestinal gene expression of Ca transport proteins, and renal enzymes related to vitD metabolism were determined. The UVB exposure led to lower 7-dehydrocholesterol content in the skin and a better vitD status (higher serum 25-hydroxyvitamin D), but no signs of vitD deficiency were seen in the control groups and no effect of irradiation was detected in the analyzed parameters of Ca homeostasis. Differences between the 2 species were detected: lambs had a higher increase of bone mineral density, lower values of bone markers, growth hormone, and insulin-like growth factor I in serum and higher tachysterol and lower lumisterol content in skin compared with goat kids. The results indicated that growing lambs and goat kids are able to compensate for a vitD-reduced diet by cutaneous vitD synthesis when exposed to UVB irradiation and therefore to keep a high vitD status. In contrast, when a reduced vitD diet is combined with missing UVB exposure, the vitD status drops, but the experimental time was probably too short to induce a vitD deficiency or an effect on Ca homeostasis.

Respon Sistem Homeostasis Kalsium Tikus Ovariektomi yang Mengkonsumsi Kombinasi Calcitriol dengan Raloxifene

Normal range of calcium (Ca) level in the blood is maintained by Ca homeostasis in the intestinal, kidney and bone. The objective of this research was to study the response of calcium homeostasis system ovariectomized rats consuming combination of calcitriol and raloxifene by calcium balance study. Twenty five female Wistar rats at 8 weeks of age were divided into five groups of five: normal control (NK), ovariectomy control (OVK), ovariectomy+calcitriol (OVD ), ovariectomy+ raloxifene (OVR), and ovariectomy+calcitriol+ 20raloxifene supplementation (OVDR), of five each. Seven weeks after the surgery, each rats was placed into individual metabolic cages for Ca balance studies (Ca consumption, feces and urine Ca excretion, and intestinalCa absorption). In 5 to 8 days of the balance studies, the remaining food, urine, and feces were collected every day for Ca analyses. The results showed that Ca consumption, feces and urine Ca excretion, and intestinal Ca absorption of OVDR rats were higher than OVK rats. Consumption and feces Ca excretion of OVDR rats were higher than OVK rats which informed the decrease of estrogen hormone. Intestinal Ca absorption of OVDR rats was higher than OVK rats which informed the decrease of parathyroid hormone. Meanwhile, urine Ca excretionof OVDR rats was higher than OVK rats which informed the decrease of parathyroid hormone and estrogen. In conclusions, the response of calcium homeostasis system in ovariectomized rats consuming combination ofcalcitriol and raloxifene for 8 weeks was marked by increasing Ca absorption in intestine and Ca excretion in urine.

(−)-Epiafzelechin Protects against Ovariectomy-induced Bone Loss in Adult Mice and Modulate Osteoblastic and Osteoclastic Functions In Vitro

The present study was designed to characterize the bone protective effects of (−)-epiafzelechin (EAF), a flavan-3-ol, in mature ovariectomized mice model and its ability to stimulate osteoblastic activity and inhibit osteoclastic activity. Mature C57BL/6 mice (three to four months old) were either ovariectomised (OVX) or sham-operated and subjected to treatment (vehicle, 17β-oestradiol (E2, 200 μg/kg/day) or EAF (500 μg/kg/day) orally for six weeks. EAF and E2 significantly reduced urinary calcium (Ca) excretion, serum osteocalcin (OCN), and urinary deoxy-pyridinoline (DPD); increased bone mineral density (BMD); and improved micro-architectural properties in OVX mice. EAF significantly increased cell viability, alkaline phosphatise (ALP) activity, and collagen content, as well as runt-related transcriptional factor 2 (Runx2) mRNA expression in murine osteoblastic MC3T3-E1 cells. In addition, EAF significantly reduced the viability of osteoclast precursor murine leukemia monocyte RAW 264.7 cells and tartrate-resistant acid phosphatase (TRAP) activities in mature osteoclastic RAW 264.7 cells. EAF is a bioactive flavan-3-ol that protects estrogen deficiency-induced bone loss in OVX mice and exerts direct modulating effects in bone cells in vitro.

Dietary maifanite supplementation did not affect the apparent total tract digestibility of calcium and phosphorus in growing pigs.

ObjectiveThis study was conducted to determine the effects of dietary maifanite supplementation and fecal collection method on the apparent total tract digestibility (ATTD) of calcium (Ca) and phosphorus (P) and blood parameters in growing pigs.MethodsThirty-six growing barrows (Duroc×Landrace×Yorkshire; 27.0±2.6 kg) were allotted to six dietary treatments with 6 pigs per treatment according to body weight in a completely randomized design. The experimental treatments were: i) Low Ca+cornstarch (2.25%), ii) Low Ca+maifanite (2.25%), iii) Medium Ca+cornstarch (1.42%), iv) Medium Ca+maifanite (1.42%), v) High Ca+cornstarch (0.64%), and vi) High Ca+maifanite (0.64%). Feces were collected by the total collection (TC) and indicator method (IM). At the beginning and the end of the experiment, blood samples were collected from each pig.ResultsFor the TC method, there were no difference in Ca intake, fecal Ca output, Ca retention and the ATTD of Ca between cornstarch and maifanite diets at the same dietary Ca level. However, urinary Ca excretion was lower (p = 0.01) in pigs fed low Ca diets without maifanite supplementation compared with other dietary treatments. Dietary maifanite supplementation had no effect on the P metabolism in growing pigs. For the IM method, there was no difference in Ca digestibility between cornstarch and maifanite diets at the same dietary Ca level. The ATTD of P was greater (p<0.01) in pigs fed the high Ca diet with maifanite supplementation compared with the high Ca diet with cornstarch treatment. Dietary inclusion of maifanite had no effect on blood parameters in growing pigs.ConclusionDietary maifanite supplementation had no effect on the ATTD of Ca and P and serum parameters in growing pigs. The IM resulted in lower digestibility values than the TC method.

Adult dogs are capable of regulating calcium balance, with no adverse effects on health, when fed a high-calcium diet.

Although the implications of long-term high Ca intakes have been well documented in growing dogs, the health consequences of Ca excess in adult dogs remain to be established. To evaluate the impact of feeding a diet containing 7·1 g/4184 kJ (1000 kcal) Ca for 40 weeks on Ca balance and health parameters in adult dogs, eighteen neutered adult Labrador Retrievers, (nine males and nine females) aged 2·5-7·4 years were randomised to one of two customised diets for 40 weeks. The diets were manufactured according to similar nutritional specifications, with the exception of Ca and P levels. The diets provided 1·7 and 7·1 g/4184 kJ (1000 kcal) (200(SD26) and 881(SD145) mg/kg body weight0·75 per d, respectively) Ca, respectively, with a Ca:P ratio of 1·6. Clinical examinations, ultrasound scans, radiographs, health parameters, metabolic effects and mineral balance were recorded at baseline and at 8-week intervals throughout the study. Dogs in both groups were healthy throughout the trial without evidence of urinary, renal or orthopaedic disease. In addition, there were no clinically relevant changes in any of the measures made in either group (all P>0·05). The high-Ca diet resulted in a 3·3-fold increase in faecal Ca excretion (P0·05). Ca intakes of up to 7·1 g/4184 kJ (1000 kcal) are well tolerated over a period of 40 weeks, with no adverse effects that could be attributed to the diet or to a high mineral intake.