Fecal Ca Research Articles

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.

Impact of faecal DM excretion on faecal calcium losses in dogs eating complete moist and dry pet foods - food digestibility is a major determinant of calcium requirements.

The recommendations for the Ca supply for maintenance of dogs have been reduced by about 75% in the last decades. An important factor for Ca requirements is faecal Ca losses. In previous studies with experimental diets faecal Ca losses depended on Ca intake and on faecal DM excretion. A predictive equation for faecal Ca losses in mg/kg body weight (BW) developed in a fibre model is: faecal losses=-33·8+(13·6 faecal DM excretion (g/kg BW))+(0·78 Ca intake (mg/kg BW)). The present study aimed at testing this equation in pet food with material from trials carried out for other purposes. Digestion trials with twenty-five dry and fifteen moist foods (326 observations in total) were evaluated retrospectively. Faecal DM excretion and faecal Ca losses were significantly correlated (r20·86; P<0·001). There was a highly significant correlation (r20·87; P<0·001) between the experimentally determined faecal Ca excretion and the faecal Ca excretion predicted by the equation of Kienzle et al. The data from the previous fibre model study could be transferred to prepared moist and dry dog food. Faecal DM excretion has a considerable impact on faecal Ca losses in a practical feeding situation. In conclusion, Ca requirements for maintenance may vary with food DM intake and digestibility.

Acidogenic mineral additions increased Ca mobilization in prepartum sows.

Increased sow milk production is associated with an increase in unexplained sow mortality during prepartum and early postpartum periods. This association has led to purported claims of hypocalcemic disorders. Assuming similar responses as dairy cows, feeding anionic mineral salts in late gestation and early lactation may reduce potential hypocalcemia related disorders in sows. Two experiments using CAD-MATE (Granco Minerals, Petersburg, VA), an acidogenic mineral supplement (AMS), were designed to determine the amount required to increase urinary Ca excretion and to identify renal compensatory responses to acid loads in sows. In Exp. 1, 30 multiparous gestating sows (Landrace × Large White) were fed 1 of 6 diets with either 0, 0.5, 1.0, 1.5, 2.0, or 2.5% AMS additions for 14 d. Diets provided a range (33 to -216 mEq/kg) of cation-anion balance, calculated as Na + K - Cl - S. Two 24-h urine samples were collected via bladder catheters for mineral analysis. One venous blood sample was drawn from 2 sows per diet on d 14. In Exp. 2, twelve sows were fed 1 of 3 diets to provide either 0, 1.5, or 2.5% AMS. Three 24-h composites of urine and fecal excreta were collected and analyses were used to calculate apparent mineral retention. Venous blood pH (range 7.41 to 7.33) and base excess (range 5.4 to 0.5 mmol/L) decreased (linear, < 0.10), but blood ionized Ca (range 1.28 to 1.37 mmol/L) increased (linear, < 0.05) proportionally to dietary AMS additions. Blood anion gap was not affected by diet. Urine pH decreased (linear, < 0.10) with additions of AMS (range 7.47 to 5.52). In Exp. 2, urinary SO (range 134 to 396 mEq/d) and NH (range 84 to 323 mEq/d) excretion increased ( < 0.05) with AMS additions. Urinary Mg, Na, and K excretion did not differ among treatments. Fecal excretion of Ca, Mg, and P increased ( < 0.05) in sows fed diets with 2.5% AMS. Fecal K, Na, and Cl excretion did not differ among treatments. Apparent Ca retention decreased ( < 0.05) with AMS additions, but apparent Mg and Cl retention increased ( < 0.05). In conclusion, AMS induced a renal compensated acid load as exhibited by urinary ion excretion patterns and maintenance of blood gas values within physiological ranges. Feeding diets with 1.5 or 2.5% AMS increased urinary and fecal Ca excretion and decreased apparent Ca retention implying an increase in mobilization of body Ca pools in prepartum sows.

An Evaluation of the Contribution of Macro- and Microelements from Colonial Nesting Waterbirds to Surface Water.

Macro- and microelements contained in the feces of cattle egrets () and other colonial birds in heronries can be sources of contamination of nearby waterways. Concentrations of the macroelements potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), sulfur (S) and the microelements zinc (Zn), copper (Cu), iron (Fe), manganese (Mn), and boron (B) were measured in water and fecal samples collected from four locations containing heronries during the breeding seasons of 2011, 2012, and 2013. Nitrogen and phosphorus were measured but not reported in this study. Concentrations of K in feces ranged from 8.19 × 10 ± 4.38 × 10 to 4.88 × 10 ± 7.57 × 10 mg kg, and concentrations in water ranged from 3.92 ± 0.05 to 17.93 ± 0.37 mg L. Similarly, concentrations of Ca in feces ranged from 4.17 × 10 ± 1.84 × 10 to 1.16 × 10 ± 4.14 × 10 mg L, and concentrations in water ranged from 25.28 ± 0.89 to 67.88 ± 2.02 mg L. When birds nested directly over water, concentrations of K, Ca, and Mg in water were significantly higher ( < 0.05) than concentrations in water adjacent to birds nesting on islands. The results from this study show that macroelements from avian feces have the potential to enrich surface water and to negatively affect surface water quality. These results provide information regarding the contribution of nutrients from heronries (comprised primarily by cattle egrets) to watersheds.

Hulled and hull-less barley grains with the genetic trait for low-phytic acid increased the apparent total-tract digestibility of phosphorus and calcium in diets for young swine.

A 35-d experiment was conducted using 63 crossbred pigs (35 barrows and 28 gilts) with an initial average BW of 7.0 kg and age of 28 d to evaluate the efficacy of the low-phytic acid (LPA) genetic trait in hulled or hull-less barley in isocaloric diets. Hulled barleys were the normal barley (NB) cultivar Harrington and the near-isogenic LPA mutant 955 (M955) with P availabilities of 36 and 95%, respectively. Hull-less lines were produced by crossing NB and the LPA mutant 422 line with a hull-less line, producing hull-less NB (HNB) and hull-less mutant 422 (HM422) with P availabilities of 41 and 66%, respectively. Pigs were in individual metabolism cages or pens for Phase 1 (d 0 to 14) and Phase 2 (d 14 to 35). Diets defined as NB, HNB, HM422, or M955 with no added inorganic P (iP) had available P (aP) concentrations of 0.27, 0.28, 0.35, and 0.40% for Phase 1 and 0.15, 0.17, 0.23, and 0.31% for Phase 2, respectively. Only diet M955 was adequate in aP. Therefore, iP was added to the P-deficient diets to make diets NB + iP, HNB + iP, and HM422 + iP with aP equal to that in diet M955. Overall (d 0 to 35), ADG and G:F were greater ( < 0.01) for pigs fed diet M955 or the diets with added iP than for pigs fed the NB diet. Serum tartrate-resistant acid phosphatase activity on d 34 was greater ( < 0.01) for pigs fed the NB or HNB diets than for pigs fed the other diets. Bone breaking strength and P absorption (g/d) were greater ( < 0.01) for pigs fed diet M955 or the diets with iP than for pigs fed the NB or HNB diets. Pigs fed diet M955 absorbed greater ( < 0.01) percentages of P and Ca and had less ( < 0.01) fecal excretion of P (g/d and %) and Ca (%) than pigs fed the other diets. In conclusion, the LPA genetic trait was effective in hulled and hull-less barley in isocaloric diets fed to young pigs. Pigs fed the diet with LPA M955 consumed 31% less P and excreted 78% less fecal P and 30% less fecal Ca than pigs fed the diet with NB + iP that was equal to diet M955 in aP. Therefore, LPA barley, especially M955 with 95% aP, will reduce the use of iP in swine diets, reduce P pollution from swine manure, and support the goal of achieving global P sustainability.

Impact of Increasing Dietary Calcium Levels on Calcium Excretion and Vitamin D Metabolites in the Blood of Healthy Adult Cats

BackgroundDietary calcium (Ca) concentrations might affect regulatory pathways within the Ca and vitamin D metabolism and consequently excretory mechanisms. Considering large variations in Ca concentrations of feline diets, the physiological impact on Ca homeostasis has not been evaluated to date. In the present study, diets with increasing concentrations of dicalcium phosphate were offered to ten healthy adult cats (Ca/phosphorus (P): 6.23/6.02, 7.77/7.56, 15.0/12.7, 19.0/17.3, 22.2/19.9, 24.3/21.6 g/kg dry matter). Each feeding period was divided into a 10-day adaptation and an 8-day sampling period in order to collect urine and faeces. On the last day of each feeding period, blood samples were taken.ResultsUrinary Ca concentrations remained unaffected, but faecal Ca concentrations increased (P < 0.001) with increasing dietary Ca levels. No effect on whole and intact parathyroid hormone levels, fibroblast growth factor 23 and calcitriol concentrations in the blood of the cats were observed. However, the calcitriol precursors 25(OH)D2 and 25(OH)D3, which are considered the most useful indicators for the vitamin D status, decreased with higher dietary Ca levels (P = 0.013 and P = 0.033). Increasing dietary levels of dicalcium phosphate revealed an acidifying effect on urinary fasting pH (6.02) and postprandial pH (6.01) (P < 0.001), possibly mediated by an increase of urinary phosphorus (P) concentrations (P < 0.001).ConclusionsIn conclusion, calcitriol precursors were linearly affected by increasing dietary Ca concentrations. The increase in faecal Ca excretion indicates that Ca homeostasis of cats is mainly regulated in the intestine and not by the kidneys. Long-term studies should investigate the physiological relevance of the acidifying effect observed when feeding diets high in Ca and P.

Demonstration of uniformity of calcium absorption in adult dogs and cats.

A meta-analysis was conducted to understand quantitative aspects of calcium (Ca) and phosphorus (P) absorption in adult dogs and cats. 34 studies in dogs and 14 studies in cats met the criteria for inclusion in the meta-analysis. Intake and faecal excretion values of Ca and P were subjected to a modified Lucas test and subsequent regression analyses. According to the current scientific consensus, Ca true digestibility (absorption) should increase at low Ca intake and decrease at high Ca intake. If true, this should result in a nonlinear relationship between the percentage of Ca excreted and dietary Ca intake. The present meta-analysis showed a highly significant linear relationship (p<0.0001) between Ca intake and Ca excretion suggesting a lack of systematic quantitative adaptation in true Ca digestibility. This finding suggests either that the time period covered by standard digestion trials is too short to induce adaptation mechanisms or that dogs and cats at maintenance will not efficiently alter quantitative Ca absorption percentage according to the amount ingested. If the latter is true, a dietary Ca supply differing greatly from the recommended dietary intake might impair the health of cats and dogs when fed long term. The data plots for P intake and faecal excretion were less uniform suggesting other factors not just dietary intake influence faecal P excretion. In adult cats, the dietary Ca:P ratio strongly influenced the true digestibility of P, whereas this effect was less marked in adult dogs. Faecal P excretion was significantly correlated to faecal Ca excretion in both species (p<0.0001), and surprisingly, the level of P intake did not appear to be an important determinant of true digestibility of P.

Effects of Polycan on calcium bioavailability in two different rat models of osteoporosis

This study evaluated the effects of Polycan, a β-glucan produced by Aureobasidium pullulans SM-2001, on calcium (Ca) bioavailability in an ovariectomy (OVX) model and a thyroparathyroidectomy (TPTX) model of osteoporosis in the SD rat. Polycan (62.5, 125, and 250 mg/kg body weight) was administered daily with an oral gavage for 4 weeks in both the OVX group (beginning 10 weeks following OVX surgery) and the TPTX group (beginning 4 days following TPTX surgery) while a commercial food product containing 1% milk-borne Ca was available ad libitum. After 4 weeks of Polycan administration, all animals were sacrificed and changes in bone mineral density (BMD) in the femur, tibia, and lumbar vertebrae (L6) were analyzed using dual-energy X-ray absorptiometry. Ca intake was calculated based on the amount of food intake during the 24 h period prior to sacrifice and the Ca balance, absorption, and retention ratios were calculated based on Ca intake, urinary and faecal Ca content, and Ca balance. Polycan treatment resulted in a marked increase in the BMD of the femur, tibia, and L6 relative to the OVX and TPTX controls with concomitant increases in Ca bioavailability and decreases in secreted Ca. These findings indicate that Polycan may enhance the absorption and bioavailability of Ca and improve Ca balance.

Effects of 25-(OH)D3 on fecal Ca and P excretion, bone mineralization, Ca and P transporter mRNA expression and performance in growing female pigs

A study was conducted to examine the effects of 25-hydroxyvitamin D3 (25-(OH)D3) on fecal Ca and P excretion, bone mineralization, performance and the mRNA expression of intestinal transporter genes in growing female pigs. Sixty-day old gilts (n = 24) with an average initial BW of 23.13 ± 1.49 kg were randomly allocated to a control diet (diet 1) containing wheat/corn/soybean meal and 150 IU kg−1 of Vitamin D3, diet 1 + 50 μg of 25-(OH)D3 kg−1 (diet 2) and diet 1 + 100 μg of 25-(OH)D3 kg−1 (diet 3). The pigs were housed in an individual pen and had ad libitum access to feed and water for 42 days, and BWG and feed intake were measured weekly. Measures of bone mineralization and expression of Ca and P transporters mRNA were analyzed using Dual Energy X-Ray Absortiometry (DEXA) and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. Data were analyzed using GLM procedure of the Statistical Analysis System (SAS Institute version 9.2). Fecal Ca and P concentration were significantly reduced (P ≤ 0.05) in pigs fed diets 2 and 3 compared with the control diet. Supplementation of 25-(OH)D3 did not significantly improve bone mineralization, animal performance and intestinal transporters mRNA expression except for SLC34A1, a sodium-dependent phosphate transporter 1. In conclusion, supplementation of 25-(OH)D3 in swine nutrition may not improve animal performance but has the potential to reduce environmental pollution by increasing dietary Ca and P retention while reducing their excretion.

Effect of di-calcium phosphate on calcium balance and body condition score of dairy cows fed Napier grass

A research work was undertaken to evaluate the feeding effects of di-calcium phosphate (DCP) on calcium balance and body condition score of dairy cows fed Napier grass. The trial was conducted in the village Alokdiar of Shajadpur upazilla under Sirajgonj district. Twenty crossbred lactating dairy cows of 320 ±15.5 kg live weight were used for the trial. Animals were equally and randomly allocated into four groups, T0 (Napier+concentrate), T1 (Napier+concentrate+100g DCP), T2 (Napier+concentrate+150g DCP) and T3 (Napier+concentrate+200g DCP). Total DMI did not differ significantly (p&gt;0.05) among the groups but highly significant differences (p&lt;0.01) were found in Ca intake. Ca balance; and Ca in feces, Ca in urine, Ca in milk and total Ca excretion differed significantly (p&lt;0.05). No significant difference (p&gt;0.05) was found in DM in feces (%), DM in feces (kg/d) and milk production (L) among the treatment groups except urine excretion. There was a linear increase of body condition score (BCS) with DCP (T1, T2 and T3), but BCS was linearly declined in non DCP diet (T0). Diets with 150g DCP may be suggested for optimizing Calcium balance and body condition score of dairy cows fed Napier grasses.DOI: http://dx.doi.org/10.3329/bjas.v43i3.21648 Bang. J. Anim. Sci. 2014. 43 (3): 197-201

Effect of a combination GOS/FOS® prebiotic mixture and interaction with calcium intake on mineral absorption and bone parameters in growing rats.

Increasing calcium intake is the most effective strategy for avoiding Ca deficit. However, if intake remains inadequate, improving Ca absorption becomes an important tool to optimize Ca homeostasis and bone health. The effect of a mixture of GOS/FOS(®) 9:1 added to a normal- or low-Ca diets on Ca absorption and bone mineralization, density and structure was investigated, in a model of growing rats. Several colonic parameters to help support the findings were also evaluated. Weanling Wistar rats received one of the four experimental AIN-93G diets: C5: 0.5% Ca; C3: 0.3% Ca; P5: 0.5% Ca + 5.3% GOS/FOS(®); P3: 0.3% Ca + 5.3% GOS/FOS(®) until 50 days (T = 50). At T = 50, lactobacillus and cecum weights were higher, whereas cecum pH was lower in P5 and P3 versus C5 and C3 (p < 0.001). At T = 50, fecal Ca, Mg and P were lower and their absorptions (mg/dL) were higher in P5 and P3 versus C5 and C3, respectively (p < 0.05). Ca, Mg and P absorption % was higher in P5 and P3 versus C5 and C3 (p < 0.001). Femur Ca and P content, bone mineral content, trabecular bone mineral density, tibia length, bone volume, osteoblast surface, stiffness and elastic modulus were higher in P5 and P3 versus C5 and C3 (p < 0.05). Despite the lower Ca content, P3 group reached similar values than C5 in all these latter parameters. Supplementing diets with the GOS/FOS(®) mixture increased bone mineralization, density and structure due to an increase in Ca, P and Mg absorptions. Thus, this prebiotic mixture may help to improve bone development in a period of high calcium requirements.

Regulation of intestinal calcium absorption appears to be different in dogs and man (908.9)

The dog is used as a model for human skeletal research, with the assumption that calcium (Ca) and phosphorus (P) metabolism are similar between species. A prior meta‐analysis of Ca intake and faecal excretion suggested that adult dogs are unable to adapt their Ca digestibility to Ca intake, meaning dogs lack the ability to increase Ca digestibility when dietary Ca is low. We wanted to test this hypothesis in vivo with diets reflective of normal feeding.Apparent Ca digestibility and selected Ca metabolism and safety markers were determined at baseline and every 6 weeks for 6 months of low Ca feeding (~60 mg Ca/kg BW^0.75 = Minimum Requirement (MR), Ca/P=0.6) in 11 adult dogs. During low Ca feeding there was no decrease in faecal Ca excretion and apparent Ca digestibility was negative. Markers of bone resorption increased. This study confirmed the results of the meta‐analysis: dogs fed Ca at MR exhibit negative apparent Ca digestibility and increased bone resorption suggesting that Ca regulation in the dog does not utilize changes in Ca digestibility. These data show that Ca homeostasis of the dog differs from human, and thus the dog should not be used as a model animal for human skeletal research.

Urinary Calcium and Oxalate Excretion in Healthy Adult Cats Are Not Affected by Increasing Dietary Levels of Bone Meal in a Canned Diet

This study aimed to investigate the impact of dietary calcium (Ca) and phosphorus (P), derived from bone meal, on the feline urine composition and the urinary pH, allowing a risk assessment for the formation of calcium oxalate (CaOx) uroliths in cats. Eight healthy adult cats received 3 canned diets, containing 12.2 (A), 18.5 (B) and 27.0 g Ca/kg dry matter (C) and 16.1 (A), 17.6 (B) and 21.1 g P/kg dry matter (C). Each diet was fed over 17 days. After a 7 dayś adaptation period, urine and faeces were collected over 2×4 days (with a two-day rest between), and blood samples were taken. Urinary and faecal minerals, urinary oxalate (Ox), the urinary pH and the concentrations of serum Ca, phosphate and parathyroid hormone (PTH) were analyzed. Moreover, the urine was microscopically examined for CaOx uroliths. The results demonstrated that increasing levels of dietary Ca led to decreased serum PTH and Ca and increased faecal Ca and P concentrations, but did not affect the urinary Ca or Ox concentrations or the urinary fasting pH. The urinary postprandial pH slightly increased when the diet C was compared to the diet B. No CaOx crystals were detected in the urine of the cats. In conclusion, urinary Ca excretion in cats seems to be widely independent of the dietary Ca levels when Ca is added as bone meal to a typical canned diet, implicating that raw materials with higher contents of bones are of subordinate importance as risk factors for the formation of urinary CaOx crystals.

Calcium and caffeine interaction in increased calcium balance in ovariectomized rats

OBJECTIVE: This study investigated the effects of caffeine intake associated with inadequate or adequate calcium intake in laparotomized or ovariectomized rats by means of the calcium balance. Forty adults Wistar rats were ovariectomized or laparotomized. METHODS: The animals (n=40) were randomly placed in eight groups receiving the AIN-93 diet with 100% or 50% of the recommended calcium intake with or without added caffeine (6mg/kg/day). The animals were kept in individuals metabolic cages at a temperature of 24°±2ºC, light/dark cycles of 12/12 hours, and deionized water available ad libitum. On the 8th week of the experiment, food consumption was measured and 24-hour urine and 4-day feces were collected to determine calcium balance [Balance=Ca intake-(Urinary Ca+Fecal Ca)]. RESULTS: Animals with adequate calcium intake presented higher balances and rates of calcium absorption and retention (p&lt;0.05) than those with inadequate calcium intake, regardless of caffeine intake (p&lt;0.05). Caffeine intake did not affect urinary calcium excretion but increased balance (p&lt;0.05) in the groups with adequate calcium intake. CONCLUSION: Adequate calcium intake attenuated the negative effects of estrogen deficiency and improved calcium balance even in the presence of caffeine.

Calcium absorption and bone density in immature horses fed two levels of crude protein

Research in other animal models indicate that high protein diets increase urinary calcium (Ca) excretion and may lead to a negative Ca balance and reduced bone density. This study was undertaken to determine the effects of two common levels of dietary protein intake on physiological parameters, Ca absorption, and bone density in immature horses. Sixteen 10-month old horses were blocked by age and sex into two dietary treatments. The control diet (C) was formulated using common ingredients to provide 100% of the National Research Council (NRC) for crude protein (CP), while the high protein diet (H) was formulated at 150% of NRC recommendations. Lower than expected dietary intake resulted in mean protein intake of 769±16 g/d in C and 978±18 g/d in H, equivalent to 91% and 116% of NRC, respectively. Blood, urine, and faeces were collected during the 112-day study to determine pH and mineral balance. Radiographs of the left third metacarpal were used to estimate bone density via radiographic bone aluminum equivalence (RBAE). Although urine pH decreased over time (P&lt;0.001), no change in blood or urine pH was observed due to diet. Faecal pH, normalised to day 0, was significantly lower in H (P&lt;0.02). Faecal Ca loss was greater in H (P&lt;0.005); while Ca absorption and absorption as a percent of intake were lower for H (P&lt;0.02). RBAE of dorsal and palmar cortices increased over time (P&lt;0.001), but no differences were observed between diets. While excess dietary protein decreased faecal pH, increased faecal Ca excretion, and decreased Ca absorption, there appeared to be no effect on bone density over the course of this study.

Mineral deficiency status of ranging zebu (Bos indicus) cattle around the Gilgel Gibe catchment, Ethiopia

Mineral deficiencies in cattle, widespread in East Africa, impair optimal health and production and consequently place a great burden on the farmers' income. Therefore, detection of shortages and imbalances of specific minerals is essential. Our objective was to evaluate the mineral status of grazing cattle around the Gilgel Gibe catchment in Ethiopia and associated factors. In study I, individual animal plasma and herd faecal Ca, P, Mg, Na, K, S, Fe, Zn, Mn and Cu concentrations were determined in adult zebu cattle (Bos indicus; n=90) grazing at three altitudes around the catchment, whilst recording body condition score and sex. In study II, liver samples of adult male zebu cattle (n=53) were analysed for Cu, Zn, Fe, Se and Mo concentrations and inspected for parasitic infections. Plasma and liver analyses revealed a Cu deficiency problem in the area, since 68 and 47 % of cattle, respectively, were Cu deprived according to diagnostic criteria for Bos taurus cattle. High hepatic Mo concentrations in 17 % of cases might reflect excessive dietary Mo intake. Liver Se and plasma Na concentrations were too low in 92 and 80 % of cattle. Plasma Mn concentrations were largely below the detection limit. Plasma Cu as well as Ca concentrations were lower in the lowest altitude compared to the highest altitude group (P<0.05), whereas lean to medium cattle had lower plasma Cu concentrations (P<0.05). No differences in hepatic mineral concentrations were detected between cattle with different types of parasitic infection. In conclusion, bovine mineral deficiencies were present in the Gilgel Gibe area and were associated with grazing altitude and body condition score.

Impact of dried distillers grains with solubles (DDGS) and diet formulation method on dry matter, calcium, and phosphorus retention and excretion in nursery pigs

Phosphorus (P) is an expensive component in swine diets, and dietary P levels above the pig's requirement can result in excess P excreted in manure and potential environmental concerns. Consequently, utilization of dietary P by pigs must be optimized in order to minimize diet cost and P excretion in manure. Phosphorus and calcium (Ca) balance was evaluated in nursery pigs fed a control maize–soybean meal (M–SBM) diet formulated on a total P (TP) basis, and four experimental diets containing maize dried distillers grains with solubles (DDGS; 100 or 200g/kg) formulated on either a TP or available P (AP) basis. Barrow pigs (n=39, initial body weight=10.37±0.37kg) were randomly assigned to one of five diets for a 7d adaptation period followed by a 5d period of total, separate collection of both urine and feces. Compared to the M–SBM diet, dry matter (DM) digestibility coefficients were reduced in pigs fed diets containing 100 or 200g/kg DDGS by approximately 0.02 and 0.04 units, respectively (P<0.01). Feed and total P intake were similar among pigs fed control and DDGS diets, but P intake was lower (P<0.01) for pigs fed diets formulated on an AP compared to TP basis. Fecal P concentration was reduced (P<0.01) when diets contained DDGS compared to the M–SBM diet, and when DDGS diets were formulated on an AP basis compared to a TP basis. Total P excretion, retention, and apparent total tract digestibility coefficients were not affected by diet formulation method (FM) or level of DDGS inclusion (P>0.05). Calcium intake tended to be higher (P=0.06), and fecal Ca concentration and retention were higher (P<0.05) for pigs fed the M–SBM diet compared with those fed the DDGS diets. Feeding the 200g/kg DDGS diets tended to increase (P=0.08) fecal Ca excretion, and reduced (P<0.05) Ca retention, retention coefficient, and apparent total tract digestibility compared to feeding the 100g/kg DDGS diets. There were no significant effects of FM or DDGS×FM for Ca intake, retention, excretion, or apparent total tract digestibility. These results indicate that increasing dietary DDGS inclusion levels for nursery pigs decreases DM digestibility and fecal P concentration, but does not affect P excretion, retention, or digestibility. Formulating DDGS diets (100 or 200g/kg) on a TP or AP basis had no effect on P digestibility or total excretion, but total dietary P content is reduced when diets are formulated on an AP basis.

Effects of boron supplementation to diets deficient in calcium and phosphorus on performance with some serum, bone and fecal characteristics of broiler chickens.

Three levels of boron (0, 30, 60 ppm) were supplemented in practical corn-soybean based starter and grower diets, containing either adequate or inadequate Ca or P. A total of 1,800, 1-day-old sexed broiler chicks were assigned to six dietary treatments and fed with the experimental diets for 42 days. Boron improved the overall feed conversion ratio, but increased body weight only at 21 days of age (p<0.01). Boron decreased feed intake in the case of feeding on a diet deficient in Ca and P, and tended to increase feed intake when birds received a diet adequate in Ca and P, signifying significant boron by Ca-P interaction (p<0.01). Mortality was not influenced by boron (p>0.05). Dietary Ca and P deprivation reduced body weight and feed consumption significantly, but did not influence the feed conversion ratio and mortality (p>0.05). Serum Ca level, ALP and ALT activities were not influenced either by dietary Ca and P deficiency or boron supplementation. Serum P content increased with respect to boron at 30 ppm. Bone breakage strength was not affected by dietary variables. Tibia ash, Ca and P were increased in response to the supplementation diet with 30 ppm boron, whereas 60 ppm showed no effect in most cases. Accordingly, the dietary boron supplementation of 30 ppm significantly decreased fecal Ca and P excretion, while there was a numerical decline in the 60 ppm boron as compared to the 0 ppm boron group. Data presented herein indicated that boron, either at the 30 ppm or 60 ppm supplementation level, was effective in conversion of feed to body weight, whereas only boron at 30 ppm contributed to the mineralization of bone thereby augmenting more Ca and P while excreting less through faeces.

Skeletal Remodeling Following Clinically Relevant Radiation-Induced Bone Damage Treated with Zoledronic Acid

Our aim was to determine if zoledronic acid (ZA) changes (45)Ca pharmacokinetics and bone microstructure in irradiated, ovary-intact (I) and irradiated, ovariectomized mice (OVX), two groups with different patterns of skeletal damage. The hind limbs of I and OVX BALB/c mice received a single 16-Gy radiation dose, simulating pre- and postmenopausal female cancer patients undergoing radiation treatment. All I and OVX mice were radiolabeled with 15μCi (45)Ca. Mice were treated with or without a 0.5mg/kg injection of ZA. The time course of bone mineral remodeling was evaluated using a fecal (45)Ca assay, measured by liquid scintillation. A group of nonirradiated, intact mice were used for the longitudinal evaluation of (45)Ca biodistribution. Distal femur bone histomorphometric parameters were measured using microCT at 50days post-ZA intervention. Most (45)Ca was incorporated into the skeleton and eliminated from the soft tissues within 3-5days postirradiation, attaining a steady state of excretion at 25-30days. ZA intervention in both groups resulted in a rapid decrease in fecal (45)Ca excretion. There was a significant difference in (45)Ca excretion in the OVX±ZA (P=0.005) group but not in the I±ZA (P=0.655) group. The rate of excretion of fecal (45)Ca was slower in the OVX+ZA compared to the I+ZA group (P=0.064). (45)Ca assay is useful to monitor the time course of bone mineral remodeling after an antiresorptive intervention in irradiated mice, providing a basis to investigate bone effects of cancer therapy protocols. For equivalent doses of ZA, recovery may depend on the nature and degree of skeletal damage.