Fecal Ca Research Articles

Fecal calcium levels of bird nestlings as a potential indicator of species-specific metal sensitivity

Sensitivity of bird species to environmental metal pollution varies but there is currently no general framework to predict species-specific sensitivity. Such information would be valuable from a conservation point-of-view. Calcium (Ca) has antagonistic effects on metal toxicity and studies with some common model species show that low dietary and circulating calcium (Ca) levels indicate higher sensitivity to harmful effects of toxic metals. Here we measured fecal Ca and five other macroelement (potassium K, magnesium Mg, sodium Na, phosphorus P, sulphur S) concentrations as proxies for dietary levels in 66 bird species to better understand their interspecific variation and potential use as an indicator of metal sensitivity in a wider range of species (the main analyses include 39 species). We found marked interspecific differences in fecal Ca concentration, which correlated positively with Mg and negatively with Na, P and S levels. Lowest Ca concentrations were found in insectivorous species and especially aerial foragers, such as swifts (Apodidae) and swallows (Hirundinidae). Instead, ground foraging species like starlings (Sturnidae), sparrows (Passeridae), cranes (Gruidae) and larks (Alaudidae) showed relatively high fecal Ca levels. Independent of phylogeny, insectivorous diet and aerial foraging seem to indicate low Ca levels and potential sensitivity to toxic metals. Our results, together with information published on fecal Ca levels and toxic metal impacts, suggest that fecal Ca levels are a promising new tool to evaluate potential metal-sensitivity of birds, and we encourage gathering such information in other bird species. Information on the effects of metals on breeding parameters in a wider range of bird species would also help in ranking species by their sensitivity to metal pollution.

Supplementing dairy feed by dicalcium phosphate and effect on dry matter intake, digestibility, milk composition, and blood mineral balances in crossbred dairy cows.

The present study was conducted to assess if Dicalcium Phosphate 18% (DCP) supplementation in dairy feed would affect dry matter intake, milk composition, blood mineral balance and milk production in lactating crossbred Dairy Cows). A 4 × 4 double change-over design set as Latin Squares was used to do feeding and digestibility trials. DCP was supplemented at different levels 0; 0.3; 0.6; 0.9% DM/day of DCP for which the experimental groups was respectively designated as T0, T1, T2, T3, The effect of DCP supplementation on parameters of interest was evaluated using blood serum, milk, feed and feed refusals samples. The present study revealed that supplementation of DCP with the concentrate mix improved mean dry matter intake (11.46; 12.81; 14.59, and 15.68 kg DM/d) for T0, T1, T2, T3, respectively, and digestibility of nutrients in lactating dairy cows compared to the controls. Likewise, DCP supplementation improved milk production and composition except solids not fat (SNF) composition. Serum calcium (Ca) composition was significantly in supplemented group (p<0.05). DCP supplementation significantly improved (p<0.05) total Ca intake, Ca in milk, Ca in feces, total Ca excretion. Optimum dairy cow production and productivity was achieved at 0.6% DM/day of DCP supplementation. However, the current results need to be confirmed using large number of lactating dairy animals.

Effect of reduced-calcium and high-calcium cheddar cheese consumption on the excretion of faecal fat: a 2-week cross-over dietary intervention study

PurposeStudies show that dairy fat consumed in the form of cheese reduce LDL-cholesterol concentration (LDL-c) compared to butter and mechanistic suggestions include the calcium content of cheese leading to enhanced faecal fat excretion. The aim of this study was to test the effect of varying the calcium content within a cheese, on faecal fat excretion as a primary outcome, and blood lipid markers, fasting glucose and calcium excretion as secondary outcomes.Methods7 healthy males (BMI 18–25) participated in this randomized, cross-over control intervention, of 3 × 2 week periods. Diets contained 240 g/day cheese; a High Calcium Cheese (HCC) diet, a Reduced Calcium Cheese (RCC) diet, and a control arm: Reduced Calcium Cheese + CaCO3 Supplement (RCC + Supp) diet. Diets differed in calcium content and form but were otherwise controlled for energy and key macronutrients. Blood and 5-day faecal samples were collected.ResultsThere was no significant difference in faecal fat excretion (g/day) between the diets (P = 0.066). Percent fat of faecel excretion was higher after RCC + Supp (P = 0.016). None of the individual fatty acids were different. Fasting LDL-c was significantly lower following the HCC diet vs. the other arms (P = 0.002). Faecal Ca was different across all diets (P = 0.001), lowest after RCC, and greatest after RCC + Supp. No differences were observed for fasting blood parameters or changes in anthropometry.ConclusionVarying the calcium content within a cheese matrix significantly affected fasting LDL-c values. Results did not support higher faecal fat excretion as an underlying mechanism, but the high attrition rate was a limitation.Trial registerer Trial Registered at ISRCTN.org, registration number ISRCTN11663659 on 12.07.2022. Retrospectively registered.

Requirements and Metabolism for Calcium, Phosphorus and Vitamin D3 in the Growing-Furring Blue Foxes.

Simple SummaryThe nutritional needs of mink and foxes have long been clear, not specifically for blue foxes. With the development of technology, the present study aimed to study the effect of dietary calcium, phosphorus, and vitamin D3 supplementation levels on the growth performance, nutrient digestibility, and serum biochemical indicators of the growing hairy blue fox. The results showed that Ca (0.8–1.2%) and vitamin D3 (1327 IU·kg−1) doses have important effects on the growth performance and nutrient digestibility of growing blue foxes and can reduce fecal nitrogen and fecal phosphorus by improving the utilization of protein and phosphorus.A 3 × 3 factorial experiment was conducted to investigate the influence of dietary calcium, phosphorus, and vitamin D3 (VD3) supplement levels on the growth performance, nutrient digestibility, and serum biochemical indices of growing-furring blue foxes. One hundred and thirty-five 120-day-old male blue foxes were randomly allocated into nine groups. The nine treatment diets were supplemented with 0%, 0.4%, or 0.8% Ca, and 1000, 2000, or 4000 IU·kg−1 VD3. The base diet contained 0.8% Ca and 327 IU·kg−1 VD3. The dietary calcium level had a significant effect on the average daily gain (ADG) of blue foxes at 121 to 135 days of age and 136 to 150 days (p < 0.05). The ADG of blue foxes at 121 to 135 days of age was significantly decreased by VD3 level (p < 0.05). The Ca dosage decreased the nutrient digestibility (p < 0.05). The Ca dosage increased the fecal Ca and P and decreased the P digestibility (p < 0.05). Interactions were found between the Ca and VD3 levels, which affected the digestibility of Ca and P (p < 0.05). In conclusion, this research determined the suitable doses of Ca and VD3 for growing-furring blue foxes.

Meta-analysis-based estimates of efficiency of calcium utilisation by ruminants

The most abundant mineral in the body of animals is Ca, which has crucial importance for the regulation of various processes. The maintenance of Ca balance has become more challenging, especially in lactating ruminants, owing to the increased milk yields and thus Ca requirement. To determine the Ca requirement, factors such as Ca secretion via milk or Ca deposition in body tissues and conception products are summed up to the net Ca requirement. Nevertheless, dietary Ca cannot be completely utilised by the animal to cover the net Ca requirement, therefore a value for the efficiency of Ca utilisation is applied, which is the maximum proportion of Ca from the feed that the animal can use for covering the net requirement. However, current estimates for the efficiency of Ca utilisation are inconsistent. Therefore, the objective of the present meta-analysis was to estimate the efficiency of Ca utilisation for ruminants, considering the Ca supply of the animal. A data set of 223 observations was compiled from 37 studies, including data on cattle and small ruminants. Standardised Ca digestibility was calculated from data on Ca intake and faecal Ca excretion, corrected for faecal endogenous losses. Furthermore, a data subset on only lactating ruminants was created. For this subset, Ca excretion via faeces and urine and standardised Ca digestibility were related to the Ca supply of the animal. An exponential function was fitted to standardised digestibility data in response to Ca concentration in the diet and Ca supply, revealing that standardised Ca digestibility decreased with increasing dietary Ca concentration and Ca supply. The median for standardised Ca digestibility was 40%, with a remarkable variation between 9% and 88%. In response to Ca supply, faecal Ca excretion increased in a strong linear manner (slope = 0.76, R2 = 0.96). Excretion of Ca via urine was very low even when Ca supply was very high. To conclude, Ca digestibility is a suitable indicator for the efficiency of Ca utilisation, since excessive Ca is almost completely excreted in faeces; however, Ca digestibility has to be determined at a Ca supply level below the requirement of the animal. To date, only very limited number of data have been reported for such supply conditions. Comparative studies using various Ca sources are suggested for future studies but should be conducted using a marginal Ca supply level.

No Observed Adverse Effects on Health Were Detected in Adult Beagle Dogs When Fed a High-Calcium Diet for 40 Weeks.

Simple SummaryCalcium (Ca) is an essential mineral that plays a vital role in many bodily functions. There is evidence that high levels of dietary Ca for puppies and growing dogs can result in adverse growth and health effects, with certain breeds and dog size categories being most susceptible, for example, large breed sizes or beagles. Until recently, little was known about the health consequences of high Ca diets to adult dog, however, a study in the large sized breed Labrador retriever found no adverse health consequences when feeding diets containing levels of Ca near maximum levels set by pet food regulators (2.5 g per 100 g dry matter) for 40 weeks. This current study fed a similar high Ca diet to adult beagles, a medium sized breed for 40 weeks and monitored the dogs’ health using an extensive suite of health parameters. All dogs remained healthy and did not display any clinically relevant signs of adverse health relating to diet at any point during or following completion of the study.The implications of long-term high calcium (Ca) intake are well documented in growing dogs and in adult dogs of large breed size, however, the consequences on other breeds and breed sizes are yet to be determined. Eighteen neutered adult beagles, nine males and nine females aged 1.4–4.4 years, were randomized to control or test diets providing in g∙4184 kJ−1 (1000 kcal−1): 1.44 and 7.19 total Ca balanced with 1.05 and 4.25 total phosphorus, respectively, for 40 weeks. Health parameters, ultrasound scans, radiographs, glomerular filtration rate, and mineral balance were measured at eight-week intervals. All dogs remained healthy with no measured evidence of orthopedic, urinary, or renal disease. The test diet resulted in a 5.2 fold increase in fecal Ca excretion. Apparent Ca digestibility (%) and Ca balance (g/d) did not significantly (p > 0.05) change from baseline in the test diet group, although dogs displayed a positive Ca balance (maximum at week 8, 1.11 g/d with 95% CI (0.41, 1.80)) before a neutral Ca balance was restored at week 32. Despite an initial positive Ca balance, we can conclude that no measurable adverse health effects were observed as a result of the test diet fed in this study in beagles over a period of 40 weeks.

Formulation of diets for pigs based on a ratio between digestible calcium and digestible phosphorus results in reduced excretion of calcium in urine without affecting retention of calcium and phosphorus compared with formulation based on values for total calcium.

An experiment was conducted to test the hypothesis that formulating diets for pigs based on a ratio between standardized total tract digestible (STTD) Ca and STTD P instead of total Ca and STTD P does not decrease Ca retention, but increases P utilization. Forty barrows (59.4 ± 3.8 kg) were individually housed in metabolism crates and allotted to four corn-soybean meal-based diets in a randomized complete block design with two blocks and five pigs per diet in each block. Diets were formulated using a 2 × 2 factorial design with two diet formulation principles (total Ca or STTD Ca) and two inclusion levels of microbial phytase (0 or 500 units per kg of feed). Phytase was assumed to release 0.11% STTD P and 0.16% total Ca. Diets were formulated based on requirements for total Ca and STTD P or a ratio between STTD Ca and STTD P of 1.25:1. Diets were fed for 11 d and fecal and urine samples were collected from feed provided from day 6 to day 10. Interactions (P < 0.05) between diet formulation principle and phytase level were observed for Ca intake, Ca in feces, Ca absorbed, Ca retained, P digestibility, P absorbed, and P in urine. Phytase increased (P < 0.05) the digestibility of Ca in both total Ca and STTD Ca diets. Without phytase, Ca intake, Ca in feces, and Ca absorbed was greater (P < 0.05) from pigs fed total Ca diets than from pigs fed STTD Ca diets, but P absorbed, P digestibility, and P in urine was greater (P < 0.05) from pigs fed STTD Ca diets than from pigs fed total Ca diets. However, in the presence of phytase, no differences between diet formulation principles were observed in these variables. Regardless of phytase, Ca in urine was lower (P < 0.05) from pigs fed STTD Ca diets than from pigs fed total Ca diets. There were no differences in Ca retention between pigs fed STTD Ca diets and total Ca diets, but pigs fed total Ca diets retained less (P < 0.05) Ca if diets contained phytase. No differences in P retention were observed between diet formulation principles, but pigs fed non-phytase diets retained more (P < 0.05) P than pigs fed diets with phytase. In conclusion, because diets formulated based on STTD Ca contain less Ca than total Ca diets, pigs fed STTD Ca diets excreted less Ca in urine, but retention of Ca was not affected. Formulating non-phytase diets based on STTD Ca instead of total Ca increased P absorption, which confirms the detrimental effect of excess Ca on P digestibility. However, P retention was not improved if pigs were fed STTD Ca diets.

Standardized total tract digestibility of phosphorus in high-protein sunflower meal fed to growing pigs with or without phytase supplementation

The objective of this research was to determine the coefficient of apparent (CATTD) and standardized total tract digestibility (CSTTD) of phosphorus (P) in high-protein sunflower meal (HP-SFM) fed to growing pigs with or without phytase supplementation. Twenty-four pigs (19.5 ± 1.9 kg) were assigned to 1 of 4 diets to give 6 replicates per diet. The experimental diets consisted of a corn-soybean meal-based diet and a diet containing 300 g/kg of HP-SFM, both of which were fed without or with phytase supplementation at 500 phytase units/kg. The CATTD and CSTTD of P in experimental diets were determined and then the CATTD and CSTTD of P in HP-SFM were calculated using the difference method. Pigs were fed their diets at approximately 2.8 times the maintenance energy requirement. Pigs were housed individually in metabolism crates for 15 days including 10 days for adaptation to experimental diets and 5 days for total collection of feces. Phytase supplementation decreased (P < 0.05) both calcium (Ca; 21.4 vs. 13.4 g/kg) and P (44.4 vs. 32.3 g/kg) concentrations in feces in HP-SFM-containing diets. The addition of dietary phytase to the HP-SFM-containing diets also reduced (P < 0.05) daily fecal Ca output from 3.08 to 1.86 g/day and daily fecal P output from 6.41 to 4.51 g/day. The CATTD of Ca and P and CSTTD of P increased (P < 0.05) with phytase supplementation in both basal and HP-SFM-containing diets. There was a tendency (P = 0.061) for phytase supplementation to increase P utilization in HP-SFM, and the CATTD and CSTTD of P in HP-SFM with phytase supplementation were 0.37 and 0.38, respectively, which were higher than for HP-SFM without phytase supplementation (0.18 and 0.19, respectively).

282 Effect of formulating diets based on a ratio between STTD Ca and STTD P and the inclusion of phytase on the calcium and phosphorus balance of growing pigs

Abstract An experiment was conducted to test the hypothesis that formulating diets for pigs based on a ratio between standardized total tract digestible (STTD) Ca and STTD P instead of total Ca and STTD P increases the efficiency of Ca and P utilization. Forty barrows (59.4 ± 3.8 kg) were individually housed in metabolism crates and allotted to 4 corn-soybean meal diets and 2 periods of 11 d in a randomized complete block design. Diets were formulated using a 2 × 2 factorial design with 2 Ca requirement estimates (total Ca or STTD Ca) and 2 inclusion levels of microbial phytase (0 or 500 units/kg). Phytase was assumed to release 0.11% STTD P and 0.16% total Ca. Diets were formulated based on requirements for total Ca and STTD P and the ratio between STTD Ca and STTD P was 1.25:1 in diets formulated based on STTD Ca. Fecal and urine samples were collected from feed provided from d 6 to 9. Data for Ca and P balance were analyzed using a model that included the main effects of diet formulation and phytase level, the interaction between main effects, and the random effect of period. Interactions (P &amp;lt; 0.05) between diet formulation and phytase level were observed for Ca intake, Ca in feces, Ca digestibility, Ca retained as a percentage of intake, P digestibility, P absorbed, and P in urine (Table 1). Despite being provided less (P &amp;lt; 0.05) Ca, pigs fed diets formulated based on STTD Ca did not absorb or retain less Ca than pigs fed total Ca diets, but they absorbed more (P &amp;lt; 0.05) P than pigs fed diets formulated based on total Ca. In conclusion, by formulating diets based on values for STTD Ca, P absorption was increased confirming detrimental effects of oversupplying Ca.

Abstract 5730: A new polyphenol prebiotic isolated from Myrciaria dubia improves gut microbiota composition and increases anti-PD-1 efficacy in murine cancer models

Abstract Introduction The gut microbiota influences immune checkpoint inhibitors (ICI) efficacy, and immunogenic commensals bacteria such as Akkermansia muciniphila (AM) and Ruminoccocus are enriched in ICI responder patients. Therefore, strategies to beneficially shift microbiota composition represent a novel therapeutic avenue. Myrciaria dubia (MD) is a polyphenol-rich berry prebiotic that has been recently shown to improve the gut microbiota composition and dampen inflammation in metabolic diseases. Methods Daily oral administration of MD or water was performed in MCA-205 (PD-1 sensitive) and E0071 (PD-1 resistant) murine tumor models treated with iso-control or anti-PD-1. 16s rRNA gene sequencing and qPCR were used to profile the murine fecal microbiota. Tumor immune infiltration was analyzed by flow cytometry and RNA sequencing. Bile acid levels were measured using liquid chromatography coupled to tandem mass spectrometry in mouse feces and plasma at sacrifice. MD supplementation was also tested in antibiotic-treated mice that had undergone a fecal microbiota transplantation (FMT) using feces from non-responder (NR) and responder (R) non-small cell lung cancer (NSCLC) patients. Finally, to determine the bioactive compound, reverse-phase high performance liquid chromatography was used to isolate fractions that were tested in the MCA-205 tumor model. Results In MCA-205, MD gavage alone significantly reduced tumor size and in both tumor models MD increased the efficacy of anti-PD-1 compared to water + anti-PD-1. The activity of MD was inhibited upon antibiotics administration. FMT using mouse feces previously treated with MD recreated the effect in MD-naïve mice. Increases in alpha diversity, and AM and Ruminococcaceae were observed in the feces of MD supplemented mice. Serum and fecal CA, αMCA primary and HDCA and DCA secondary bile acids were upregulated in mice treated with MD. The combination of MD + anti-PD-1 increased the frequency of CD8+/CD4+ Treg and ICOS+ expression on CD8+ T cells, while the depletion of the CD8+ cells inhibited the anti-cancer activity. Next, we validated that FMT from NSCLC ICI patients recreated the patients' phenotypes in the MCA-205 tumor model (R vs NR). Treatment with MD resorted anti-PD-1 anti-tumor efficacy post FMT from NR patients. Lastly, we isolated the bioactive polyphenol molecule from MD and confirmed its anti-cancer effect in vivo. Supplementation of AM and ruminococcus further increased anti-PD1 activity. Conclusion We isolated the bioactive polyphenol molecule from the MD berry and demonstrated that its potent adjuvant effect on anti-PD-1 was associated with a beneficial shift in microbiome and bile acid composition in a CD8+ T cell dependent manner. The modification of the gut microbiota with polyphenol supplementation provides a new therapeutic approach in immuno-oncology. Citation Format: Meriem Messaoudene, Florent Cauchois, Reilly Piedgeon, Khoudia Diop, Corentin Richard, Thibault Varin, Jocelyn Trottier, Olivier Barbier, Geneviève Pilon, Simon Turcotte, André Marette, Bastien Castagner, Bertrand Routy. A new polyphenol prebiotic isolated from Myrciaria dubia improves gut microbiota composition and increases anti-PD-1 efficacy in murine cancer models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5730.

A Naringin- and Icariin-Contained Herbal Formula, Gushukang, Ameliorated Aged Osteoporosis of Aged Mice with High Calcium Intake.

Traditional herbal formula Gushukang (GSK) was clinically applied to treat primary osteoporosis and showed osteoprotective effect in ovariectomized rodent animals and regulatory action on calcium transporters. This study aimed to determine if GSK could ameliorate aged osteoporosis by modulating serum level of calciotropic hormones and improving calcium balance. 18-month-old male mice were orally administered with either GSK (0.38[Formula: see text]g/kg body weight) or calcitriol (1[Formula: see text][Formula: see text]g/kg body weight) combined with high calcium diet (HCD, 1.2% Ca) for 60 days. The aged mice fed with normal calcium diet (NCD, 0.6% Ca) were a negative control. Trabecular bone and cortical bone properties as well as calcium balance were determined. Treatment with GSK significantly increased 25(OH)D and 1,25-(OH)2D levels in serum, moreover, it markedly attenuated trabecular bone micro-architectural deteriorations and elevated trabecular bone mass as well as strengthened cortical bone mechanical properties shown by the increase in maximal bending load and elastic modulus. Calcium balance, including urinary Ca excretion, fecal Ca level and net calcium retention, was remarkably improved by GSK, which up-regulated TRPV6 expression in duodenum and TRPV5 expression in kidney and down-regulated claudin-14 expression in duodenum and kidney. Additionally, 1-OHase and 24-OHase expression was significantly decreased (vs. NCD group) and increased (vs. HCD group), respectively, in kidney of GSK- and calcitriol-treated mice. Taken together, this study demonstrated the ameliorative effects of Gushukang on aged osteoporosis by effectively stimulating vitamin D production and improving calcium balance of aged mice with high dietary calcium supplement.

The effects of zinc deficiency on homeostasis of twelve minerals and trace elements in the serum, feces, urine and liver of rats

BackgroundZinc deficiency can change the concentrations of minerals and trace elements in the body. However, previous studies still had many limitations.ObjectiveTo reveal the effects of zinc deficiency on homeostasis of 16 minerals and trace elements.MethodsForty-five rats were divided randomly into three groups: normal zinc diet (30 mg/kg), low zinc diet (10 mg/kg), and pair-fed diet(30 mg/kg). The concentrations of 16 minerals and trace elements in serum, feces, urine, and liver were measured by inductively coupled plasma mass spectrometry. The excretion of 16 elements in urine and feces were calculated and compared.ResultsZinc-deficient rats exhibited significant changes in up to 12 minerals and trace elements. The low zinc diet induced decreased excretion of zinc and concentrations of zinc in serum, feces, urine, and liver. Zinc deficiency increased feces concentrations of Mg, Cu, Se, K, Ag, Fe and Mn; decreased the concentrations of Mg, Cu, Se, K in liver and urine, and a diminished amount of Ag was observed in serum. Decreased urinary concentrations of Zn Ca, Mg, Cu, Se, K, Na, As and Cr, suggested that zinc-deficient rats increased the 9 elements’ renal reabsorption. Decreased concentrations of Ca in liver, urine, and feces, decreased excretion in urine and feces and increased serum total Ca suggested that zinc deficiency increased the redistribution of Ca in serum or other tissues. Zinc deficiency increased excretion of Cu, Se, Fe; and decreased the excretion of other 8 elements except for Ag.ConclusionsZinc deficiency changed the excretion, reabsorption and redistribution of 12 minerals and trace elements in rats. Our findings are the first to show that zinc deficiency alters the concentrations of Ag, Cr, and As.Graphical abstract

Metabolic Calcium Balance in Rats with Chronic Renal Failure Assessed Using 42Ca Tracer

Objective: This study's objective is to explore the effect of venous calcium (Ca) load on Ca metabolism using an isotope tracer in both healthy rats and rats with chronic renal failure (CRF). Materials and Methods: The methods included inducing CRF by feeding rats with food that containing 0.75% adenine. Both the rats in the control and CRF group received an intravenous injection of 100 mg/kg CaCl2 mixed with 0.5 mg/kg 42Ca for over 2 minutes in order to induce hypercalcemia. Blood samples, urine, and feces were collected for Ca kinetics and metabolism testing before and 24 hours after the injection. Results: Peak blood Ca levels were presented at 5 minutes in both groups but returned to baseline levels differently: within 3 hours in the CRF group and 1 hour in the control group. 24-hour hypercalciuria and a higher weight-corrected fecal Ca loss were consistently detected in the CRF rats before and after the injection, along with a decrease in the percent fractional Ca absorption and true fractional calcium absorption compared to the control group. The increased fecal Ca in the CRF rats primarily resulted from changes in decreased absorption rate, which indirectly lead to an increase in endogenous fecal Ca (EFC). Body weightcorrected EFC levels in the CRF group were significantly higher than those in the control group (207.58 ± 107.18 mg/kg/day vs. 62.44 ± 20.49 mg/kg/day). In addition, EFC was 22.6% and 26.02% of the total fecal Ca in the CRF group and the control group. Conclusion: These results may be useful in the evaluation of calcium metabolism and may have important implications for stable isotopes that are widely used in exploring calcification studies in the CRF.

Effects of distillers dried grains with solubles and forage dietary concentration in precision-fed dairy heifer diets: Mineral apparent absorption and retention

ABSTRACT Objective The objectives were to determine the effects of feeding different forage-to-concentrate ratios (F:C) and corn distillers dried grains with solubles (DDGS) inclusion rates on mineral apparent absorption (AAb) and retention in precision-fed dairy heifer rations. Materials and Methods A split plot design with F:C as whole plot [50:50 (LF) or 75:25 (HF)] and DDGS concentration as subplot (0, 7, 14 and 21%) was administered in a 4 × 4 Latin square using 8 ruminally cannulated Holstein heifers (12.5 ± 0.5 mo of age and 344 ± 15 kg of BW), and targeted an ADG of 800 g/d. Results and Discussion Mineral intake was affected by F:C and DDGS; there was a linear interaction in DMI. Fecal excretion of Mg, S, and Mn was greater for heifers fed HF diets, and fecal Ca, Mg, P, S, and Mn decreased linearly with increasing DDGS. Urinary excretion of Mg was greater for LF and decreased as DDGS increased. The AAb of Mg, S, and Mn was greater for LF. Linear and quadratic interactions between F:C and DGGS in AAb were observed for S and Mg, respectively. Retention of Mg was greater in LF; no differences were detected for Ca, K, Na, and S retention with F:C or DDGS. Linear interactions between F:C and DGGS were observed in the retention of Mg, P, and S. Linear and quadratic interactions in AAb for Mg and S, respectively, and a linear interaction for Mg, P, and S rentention demonstrate the importance of digestion kinetics when different F:C are used to evaluate dietary manipulations. Implications and Applications There was a linear reduction of Ca, Mg, P, S, and Mn fecal excretion in response to the linear reduction of DMI as DDGS were incorporated in diets. Heifers fed high forage diets had greater DMI and rate of passage resulting in small increases in Mg, S, and Mn excretion in feces. Absorption and retention of most minerals, notably Ca, K, Na, and P, were not affected by dietary levels of DDGS.

Saccharomyces boulardii CNCM I-745 Modulates the Fecal Bile Acids Metabolism During Antimicrobial Therapy in Healthy Volunteers.

Saccharomyces boulardii CNCM I-745 (SB) is a probiotic yeast used to lower the incidence of antibiotic-associated Clostridium difficile (C. difficile) infection, though its mechanism of action remains unclear. Cholic acid is a primary bile acid, which triggers the germination and promotes the growth of C. difficile. The intestinal microbiota transforms primary into secondary bile acids. This study examined (1) the antimicrobial-induced alteration of fecal bile acid content, and (2) whether the concomitant administration of SB influences this transformation. This is an ancillary work from a randomized study, which revealed that SB modulates fecal microbiota dysbiosis during antibiotic treatment. Healthy subjects were randomly assigned to (1) SB only, (2) amoxicillin-clavulanate (AC), (3) SB plus AC, or (4) no treatment. We analyzed fecal concentrations of BA by high performance liquid chromatography/tandem mass spectrometry. Compared to the untreated or the SB-treated groups, AC decreased the percentage of fecal secondary BA significantly (days 3 and 7). When SB and AC were administered concomitantly, this decrease in secondary BA was no longer significant. Following treatment with AC, a significant peak of fecal CA was measured on days 3 and 7, which was prevented by the concomitant administration of SB. AC administered to healthy volunteers altered the microbial transformation of primary BA, decreased secondary BA, and increased CA. The latter was prevented by the concomitant administration of SB and AC, suggesting a potent mechanism protection conferred by SB against post-antimicrobial C. difficile infection.Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT01473368.

Transgenerational endocrine disruption: Does elemental pollution affect egg or nestling thyroid hormone levels in a wild songbird?

Endocrine disrupting chemicals (EDCs) include a wide array of pollutants, such as some metals and other toxic elements, which may cause changes in hormonal homeostasis. In addition to affecting physiology of individuals directly, EDCs may alter the transfer of maternal hormones to offspring, i.e. causing transgenerational endocrine disruption. However, such effects have been rarely studied, especially in wild populations. We studied the associations between environmental elemental pollution (As, Cd, Cu, Ni, Pb) and maternally-derived egg thyroid hormones (THs) as well as nestling THs in great tits (Parus major) using extensive sampling of four pairs of polluted and reference populations across Europe (Finland, Belgium, Hungary, Portugal). Previous studies in these populations showed that breeding success, nestling growth and adult and nestling physiology were altered in polluted zones compared to reference zones. We sampled non-incubated eggs to measure maternally-derived egg THs, measured nestling plasma THs and used nestling faeces for assessing local elemental exposure. We also studied whether the effect of elemental pollution on endocrine traits is dependent on calcium (Ca) availability (faecal Ca as a proxy) as low Ca increases toxicity of some elements. Birds in the polluted zones were exposed to markedly higher levels of toxic elements than in reference zones at the populations in Finland, Belgium and Hungary. In contrast to our predictions, we did not find any associations between overall elemental pollution, or individual element concentrations and egg TH and nestling plasma TH levels. However, we found some indication that the effect of metals (Cd and Cu) on egg THs is dependent on Ca availability. In summary, our results suggest that elemental pollution at the studied populations is unlikely to cause overall TH disruption and affect breeding via altered egg or nestling TH levels with the current elemental pollution loads. Associations with Ca availability should be further studied.

The effect of microbial phytase supplementation of sorghum-canola meal diets with no added inorganic phosphorus on growth performance, apparent total-tract phosphorus, calcium, nitrogen and energy utilization, bone measurements, and serum variables of growing and finishing swine

Two experiments were conducted with growing and finishing swine to determine the effect of phytase supplementation of sorghum-canola meal diets without added inorganic phosphorus (iP) on growth performance, apparent total-tract P, calcium (Ca), nitrogen (N), and energy utilization, bone strength, bone ash, serum Ca and P concentrations, and serum phosphatase activity. For Exp. 1, 42 crossbred barrows in individual metabolism cages were fed a P-deficient diet for 7 d before starting a 28-d experiment at 24.8 kg body weight (BW). Experiment 1 had 7 treatments that were a negative control (NC) diet supplemented with 0, 400, 800, 1200, or 1600 U of Aspergillus niger (AN) phytase/kg, a positive control (PC) diet, and the PC diet supplemented with 1200 U of AN phytase/kg. Fecal and urine collections were made from d 21–26. Blood samples were collected on d 0, 14, and 28. For Exp. 2, 126 growing-finishing crossbred swine with an initial BW of 21.6 kg were group-fed (3 pigs/pen) in 3 phases (grower, early-finisher, and late-finisher). Experiment 2 had 6 treatments that were a NC diet for each phase supplemented with 0, 200, 400, 600, or 800 U of AN phytase/kg and a PC diet. Fecal collections were made from d 49–54. Blood samples were collected on d 35, 63, and 91. For both experiments, 400 U of AN phytase/kg of diet was adequate (P ≤ 0.05) for growth performance compared with the PC treatment groups. For Exp. 1, apparent total-tract P absorption and retention plateaued at 1200 U of AN phytase/kg of diet (P < 0.01), with fecal Ca and P excretion reduced 22.4% and 28.6%, respectively, compared with the PC treatment group. However, pigs fed the PC + 1200 U of AN phytase/kg absorbed and retained more P (g/d, P < 0.01) than any other treatment group. For Exp. 2, apparent total-tract P absorption, bone strength, and bone ash weight plateaued at 600 U of AN phytase/kg of diet (P < 0.01), with fecal P excretion reduced 29.4% compared with the PC treatment group. For both experiments, the AN phytase treatments did not increase Ca, N, or energy absorption (amount/d or % of intake), and had no effect on serum Ca and P concentrations, or the serum activity of alkaline phosphatase, total acid phosphatase, or tartrate-resistant acid phosphatase.

Effects of extrusion and microbial phytase on the apparent and standardized total tract digestibility of phosphorus in hemp hulls fed to growing pigs.

An experiment was carried out to determine the apparent total tract digestibility (ATTD) and the standardized total tract digestibility (STTD) of P and the effects of extrusion and microbial phytase on ATTD and STTD of P in hemp hulls (HH). Thirty-six pigs (30.3 ± 2.7 kg) were randomly allotted to 1 of 6 experimental diets in a complete randomized design with 6 replicates per diet. A corn-soybean meal (SBM)-based basal diet was formulated. Two additional diets were formulated by replacing 40% of corn and SBM (on a 100% of total diet basis) with HH or extruded HH (EHH). The test ingredients, corn, and SBM were the only sources of P in the diets. Three additional diets were also prepared by supplementing 500 unit/kg of microbial phytase to the initial 3 diets (the corn-SBM basal diet and diets containing test ingredients). Pigs were fed experimental diets at 3 times the maintenance energy requirement (197 kcal ME/kg BW0.60). Results indicated that fecal P concentration and daily P output were reduced (P < 0.05) from pigs fed diets with dietary phytase compared with pigs fed diets without dietary phytase. The ATTD and STTD of P in experimental diets were not different. However, the ATTD and STTD of P in experimental diets supplemented with dietary phytase were increased (P < 0.05) compared with the diets without phytase. The ATTD and STTD of P in HH were 18.8% and 22.0%, respectively, whereas respective values for EHH were 22.5% and 26.3%. Extrusion had no effects on ATTD and STTD of P in HH. However, the ATTD and STTD of P in HH and EHH increased (P < 0.05) when dietary phytase was added to the diets. The concentration of Ca in feces and daily Ca output were reduced (P < 0.05) as a result of phytase supplementation. Addition of dietary phytase increased (P < 0.05) the ATTD of Ca in all experimental diets. In conclusion, the ATTD and STTD of P in HH fed to growing pigs were 18.8% and 22.0%, respectively. Respective values for EHH were 22.5% and 26.3%. Extrusion did not affect the ATTD and STTD of P in HH. However, the addition of microbial phytase to experimental diets increased the ATTD and STTD of P in diets and test ingredients and decreased fecal P output from pigs fed experimental diets. There was no interaction between extrusion and dietary phytase supplementation.

True is more additive than apparent total tract digestibility of calcium in limestone and dicalcium phosphate for twenty-kilogram pigs fed semipurified diets.

Two experiments were conducted to determine the Ca digestibility of limestone and dicalcium phosphate (DCP) and if values for Ca digestibility are additive in mixed diets for pigs. In Exp. 1, 48 barrows with an average initial BW of 19.2 ± 1.1 kg were assigned to 1 of 6 dietary treatments in a 2 × 3 factorial arrangement of 2 Ca sources, including limestone or DCP, and 3 dietary Ca concentrations of 0.54, 0.74, or 0.94%. Diets were fed for a 5-d adjustment period followed by a total collection period of 5 d with chromic oxide and ferric oxide as markers to determine the initiation and termination of fecal collection, respectively. Results indicated that the increased dietary Ca concentration linearly increased ( < 0.01) Ca intake, digested Ca, and retained Ca but did not affect the apparent total tract digestibility (ATTD) of Ca or Ca retention of intake (%). The ATTD of P and P retention of intake were linearly increased ( < 0.05) as dietary Ca and P increased. In Exp. 2, 72 barrows with an average initial BW of 20.8 ± 1.3 kg were assigned to 1 of 9 dietary treatments in a 3 × 3 factorial arrangement of 3 Ca sources, including limestone, DCP, or the mixture of the 2 at a ratio of 1:1, and dietary Ca concentrations of 0.40, 0.50, or 0.60%. Feeding and sample collection procedures were as in Exp. 1. The results also showed that increased Ca concentration linearly increased ( < 0.001) Ca intake, fecal Ca output, and Ca absorbed but did not affect the ATTD of Ca within each Ca source. The average ATTD were 66.46, 70.34, and 69.32% for the limestone, DCP, and mixed diets, respectively. By regressing daily digested Ca against daily Ca intake, the true total tract digestibility (TTTD) of Ca was determined to be 70.06, 76.42, and 73.72% for the limestone, DCP, and mixed diets, respectively. The predicted TTTD for Ca in the mixed diets of limestone and DCP was calculated to be 72.67% based on the Ca contribution coefficient of 0.59 for limestone and 0.41 for DCP. The predicted Ca TTTD (72.67%) in the mixed diets was not different from the Ca TTTD (73.72%) determined using the regression method. It is concluded that although the ATTD of limestone and DCP were not affected by the Ca concentration in the diet, TTTD is recommended for evaluation of Ca digestibility because of its additivity in a mixed diet.

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.