Dietary Ca Level Research Articles

Influence of different levels of calcium, non-phytate phosphorus and phytase on apparent metabolizable energy, nutrient utilization, plasma mineral concentration and digestive enzyme activities of broiler chickens

ABSTRACTThe study investigated the effect of different levels of dietary Ca, non-phytate phosphorus (NPP) and phytase on the nutrient utilization of broiler chickens. A total of 576 day-old broiler chicks (Ross 308) were offered diets containing 3 concentrations of Ca (6, 8 or 10 g/kg diet), 2 concentrations of NPP (3 or 4 g/kg) and 2 concentrations of exogenous microbial phytase (0 or 500 FTU/kg). Diets with high Ca (10 g/kg) reduced (p < .001) the ileal digestibilities of P and protein. The digestibility of Ca and P was negatively (p < .001) affected by high Ca and low NPP (3 g/kg) diet supplemented with phytase. Phytase improved (p < .001) the digestibility of protein and P and also the retention of P and Ca. Phytase supplemented to diets containing 8 g Ca/kg improved (p < .030) the tissue protein content of jejunal mucosa, but reduced (p < .009) the Ca-ATPase activity. Supplemental phytase elevated the plasma P level, especially in birds fed diets containing 6 g/kg Ca and 4 g/kg NPP. In conclusion, phytase supplementation of diets reduced the excretion of minerals by improving their digestibilities; however, this response was dependent on the concentration of dietary Ca and NPP.

Boron Supplementation Influences Bone Mineralization by Modulating Expression of Genes Regulating Calcium Utilization

The influence of dietary boron (B) supplementation on bone mineralization in rats with or without dietary calcium (Ca) restriction was studied in a feeding trial of 90d. Wister strain male rats (n=84; ∼34 wks of age) were divided into seven dietary groups (4 replicates of 3 each) namely, Normal-Ca (100%) basal diet alone (NC, control; 1.69 ppm B) or supplemented with B at 5 (NCB-5), 10 (NCB-10), 20 (NCB20) and 40 ppm (NCB-40) levels; low-Ca (50%) basal diet alone (LC) or supplemented with 40 ppm B (LCB-40). After 90d of experimental feeding, a 5d digestibility trial was conducted to estimate gut absorption of minerals. Eight rats from each group were sacrificed to collect blood for estimation of minerals, femur bone for assessment of minerals, bone breaking strength and radiography, and liver for appraisal of relative mRNA abundance of calmodulin (CAL), vitamin D binding protein (VDBP) and thyroid receptor binding protein (TRBP). Boron supplementation to Ca adequate diets improved (P<0.05) the gut absorption efficiency of Ca (at 5 and 10 ppm B) and Ca content in serum (at 20 at 40 ppm B). The Ca content in femur bone, its (bone) breaking strength and cortical index were observed to be lowest (P<0.05) in the LC group, and were improved (P<0.05) with B-supplementation (40 ppm). Supplementation of B improved (P<0.01) the relative mRNA expression levels for VDBP (at 10 ppm B) and CAL (at 10, 20 and 40 ppm B) in liver tissue as compared to control. The present study indicates a positive and supportive role of B in Ca utilization with both normal and restricted level of dietary Ca and bone mineralization which was mediated through modulation of Ca regulating genes.

Effect of dietary calcium level and source on mineral utilisation by piglets fed diets containing exogenous phytase

Calcium and phosphorus are essential minerals, closely linked in digestive processes and metabolism. With widespread use of low P diets containing exogenous phytase, the optimal dietary Ca level was verified. The 40-day study evaluated the effects of Ca level (4, 7 and 10g/kg diet) and Ca source (Ca from CaCO3 and from Lithothamnium calcareum) on mineral utilisation in 72 piglets (7.9±1.0kg BW) fed an exogenous phytase containing diet with 2.9g digestible P/kg. Measured parameters were growth performance, stomach mineral solubility, bone breaking strength and urinary, serum and bone mineral concentration. The apparent total tract digestibility of minerals was also assessed in the two diets with 7g Ca/kg, using 12 additional pigs. Regardless of Ca source, increasing dietary Ca impaired feed conversion ratio, increased urinary pH, increased serum and urinary Ca, decreased serum and urinary P, decreased serum Mg and increased urinary Mg, increased serum AP activity, decreased bone Mg increased bone Zn. Bone breaking strength was improved with 7 compared to 4g Ca/kg. Compared to CaCO3 , Ca from Lithothamnium calcareum increased serum Mg and with, 10g Ca/kg, it limited body weight gain. The dose response of Ca in a diet with 2.9g digestible P/kg and including exogenous phytase indicated that: (i) a low dietary Ca was beneficial for piglet growth, but was limiting the metabolic use of P; (ii) a high dietary Ca level impaired P utilisation; (iii) the optimal P utilisation and bone breaking strength was obtained with a dietary Ca-to-digestible P ratio of 2.1 to 2.4:1; (iv). Increasing dietary Ca reduced Mg utilisation, but not Zn status, when fed at adequate level. Finally, Ca from Lithothamnium calcareum had similar effects on Ca and P metabolism as CaCO3 , but impaired growth when fed at the highest inclusion level.

Effects of dietary calcium and phosphorus on reproductive performance and markers of bone turnover in stall- or group-housed sows.

Increasing productivity and new housing standards necessitate a reevaluation of nutrient requirements for sows, including minerals. The objective of this study was to determine if the recommended levels of dietary Ca and P are adequate for sows housed in groups and that, therefore, have the potential for increased mobility. A total of 180 multiparous sows and gilts were assigned to 1 of 6 treatments. Treatments, arranged as a 3 × 2 factorial, included the main effects of dietary Ca:P-0.70:0.55% Ca:P (as-fed basis; control), 0.60:0.47% Ca:P (as-fed basis; Low CaP), and 0.81:0.63% Ca:P (as-fed basis; High CaP)-and housing-stalls or groups. The trial was initiated when sows were moved from the breeding stalls to the gestation room at wk 4 or 5 after breeding. Sows were initially fed 2.3 kg/d. This allotment was increased to 3.0 kg/d 2 wk prior to farrowing. Group-housed sows, fed in individual stalls, were allowed access to a loafing area after feeding. Serum samples were collected at the start of the trial and on d 100 of gestation, and both serum and milk samples were collected at mid lactation and prior to weaning. Neither diet nor housing had an effect on the total number of piglets born, ADG from birth to weaning, or weaning weight ( > 0.10). The number of live-born piglets and birth weight were unaffected by diet ( > 0.10) but were improved by group housing relative to stalls ( < 0.05). In late gestation, group-housed sows fed the Low CaP diet had reduced serum Ca (diet × housing interaction, = 0.02), and the greatest reduction (between d 28 and 100 of gestation) in serum P level was observed in group-housed sows fed the Low CaP diet (diet × housing interaction, = 0.04). Osteocalcin and pyridinoline, markers of bone formation and resorption, respectively, were unaffected by diet or housing ( > 0.10). Results from these studies imply that the level of dietary Ca and P recommended by the NRC is adequate for sows of modern genetics, whether housed in stalls or groups.

The Effect of Calcium and Available Phosphorus Levels on Performance, Egg Quality and Bone Characteristics of Japanese Quails at End of the Egg-Production Phase

Calcium (Ca) and available phosphorus (avP) requirements for egg production are different between the beginning and the end of the egg-production cycle. The objective of this study was to estimate the Ca and avP requirements of Japanese quails at end of the production phase. In total, 256 Japanese quails with 48 weeks of age were randomly distributed in 2 x 2 factorial arrangement consisting of two Ca levels (29 and 38 g/kg) and two avP levels (1.5 and 3.0 g/kg), totaling four treatments with eight replicates of eight hens each. The variables evaluated were feed intake (FI); egg production (EP); marketable egg production (MEP); egg weight (EW); egg mass (EM); feed conversion ratio per egg mass (FCRM); feed conversion ratio per dozen eggs (FCRD); livability (L); yolk weight (YW), albumen weight (AW), eggshell weight (SW); yolk percentage (YP), albumen percentage (AP), eggshell percentage (SP), specific egg weight (SEW); bone calcium percentage (BCa), bone phosphorus percentage (BP), bone ash weight (Bash) and bone ash percentage (PBash). There was no interaction between Ca and avP levels for any of the evaluated parameters, except for SEW. Quail performance was not influenced by the treatments, except for MEP. Bone characteristics were not influenced by the tested dietary Ca and avP levels. However, SW and SP increased and AP decreased as dietary Ca level increased. The dietary supplementation of 38 g Ca/kg and 3.0 g avP/kg may increase marketable egg production and the egg quality of Japanese quails at end of the production cycle.

Effects of dietary calcium levels on growth and tissue mineralization in Japanese seabass,Lateolabrax japonicus

A feeding trial was conducted to investigate the effects of different levels of calcium (Ca) on growth and tissue mineralization in Japanese seabass, Lateolabrax japonicus. Six experimental diets were formulated to contain different levels of Ca (2.9, 4.2, 6.5, 7.9, 10.2 and 31.0 g kg−1) from dietary ingredients and Ca-lactate·5H2O. The diets were fed to three triplicate groups of Japanese seabass (initial weight, 12.5 ± 0.0 g) for 56 days. Dietary Ca had no significant effect on survival or feed efficiency; however, the highest Ca (31.0 g kg−1) diet significantly reduced weight gain, feeding rate and whole-body and muscle protein and lipid contents, as well as serum Ca concentration and alkaline phosphatase activity. A significant reduction in vertebral Ca, P, Zn, Fe and Mn contents and scale Ca, P, Mg and Mn contents was observed in Japanese seabass as dietary Ca level increased. Deformed fish were primarily found in the 2.9 and 31.0 g Ca kg−1 groups, indicating that these fish had poor bone mineralization.

Effects of 1.25-Dihydroxycholecalciferol and Hydroalcoholic Extract of Withania Coagulans Fruit on Bone Mineralization and Mechanical and Histological Properties of Male Broiler Chickens

An experiment was conducted to investigate the effects of hydroalcoholic extract of Withania coagulans (WC) fruit and 1.25-dihydroxycholecalciferol (1.25-(OH)2 D3) on bone mineralization, mechanical and histological properties of male broiler chickens at 21 and 42 d of age. A total of six hundred male day-old Ross 308 broiler chickens were randomly distributed according to a completely randomized experimental design in a 2×3×2 factorial arrangement with 12 treatments of five replicates of 10 birds each. Treatments consisted of two basal diets (positive control with adequate Ca level and negative control with 30% less Ca), three levels of WC (0, 100, or 200 mg/kg diet), and two levels of 1.25-(OH)2 D3 (0 or 0.5 µg/kg diet). Birds were housed in floor pens. The diets were fed ad libitum from one to 42 days of age. On day 21 and 42, one bird per replicate was sacrificed and its tibiae were removed. Both Ca and P retention increased when dietary Ca level was reduced (p<0.001). The addition of 200 mg WC/kg to positive control diet increased Ca retention (p<0.01). Except for tibia diameter, no significant main effects of experimental treatments were observed on tibia physical characteristics or on bone mineralization. The diet with 30% Ca reduction decreased tibia diameter at 42 days of age (p<0.05). The dietary addition of 1.25-(OH)2 D3 increased tibia fracture energy, width of tibia mineralized zone, and serum Ca at 42 days of age (p<0.05). At 21 days of age, supplementation of 100 mg WC/kg increased cortical thickness (p<0.05). At 42 days of age, supplementation of 100 mg WC/kg increased tibia shear force (p<0.05) and fracture energy (p<0.01). The results of this experiment showed that supplementation of 100 mg/kg hydroalcoholic extract of WC fruit increased tibia cortical thickness, shear force, and fracture energy.

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.

Effects of Dietary Calcium Levels on Productive Performance, Eggshell Quality and Overall Calcium Status in Aged Laying Hens.

This study was conducted to investigate the effects of diets with varying levels of calcium on egg production, shell quality and overall calcium status in aged laying hens. A total of five hundred 70-wk-old Hy-Line Brown layers were divided five groups and fed one of the five experimental diets with 3.5%, 3.8%, 4.1%, 4.4%, or 4.7% Ca, for 10 weeks. There were no significant differences in feed intake, egg production and egg weight among groups. The cracked eggs were linearly reduced as dietary Ca levels increased to 4.7% (p<0.01). A significant linear improvement for eggshell strength and thickness were determined with increasing dietary Ca levels (p<0.01). The contents of serum Ca and phosphorus were not affected by dietary Ca levels. With increase in dietary Ca levels, the tibial breaking strength slightly increased. There were no significant differences in the tibial contents of ash, Ca and phosphorus among groups. In conclusion, eggshell quality, as measured by appearance, strength and thickness of eggshell, were influenced by dietary Ca content as expected (p<0.05). These results suggested that aged laying hens require relatively higher level of Ca than required levels from current Korean feeding standards for poultry.

Effects of calcium to non-phytate phosphorus ratio and different sources of vitamin D on growth performance and bone mineralization in broiler chickens

ABSTRACT - A 7 × 2 factorial experiment was designed to test the effects of calcium (Ca) to non-phytate phosphorus (NPP) ratio (1.14, 1.43, 1.71, 2.00, 2.29, 2.57, and 2.86) and different sources of vitamin D (1α-hydroxycholecalciferol (1α-OH-D3) and 25-hydroxycholecalciferol (25-OH-D3)) on growth performance and bone mineralization in 1- to 42-d-old broiler chickens. On the day of hatch, 700 female Ross 308 broilers were weighed and randomly assigned to 14 treatments with five stainless steel cages of 10 birds each. Dietary Ca levels were 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, and 10.0 g kg−1 and the NPP content was 3.5 g kg−1. The dose of 1α-OH-D3 or 25-OH-D3 was 5 µg kg−1. Diets were not supplemented with cholecalciferol (vitamin D3). Results showed that the Ca to NPP ratio, vitamin D source, and their interaction affected body weight gain (BWG), feed intake (FI), feed efficiency (FE), and carcass and breast yields, as well as tibia weight and length and ash weight in broiler chickens from 1 to 42 d of age. Broilers fed 1α-OH-D3 had higher BWG and FI as well as tibia breaking strength, weight, length, diameter, and ash weight than birds fed 25-OH-D3 at 42 d of age. The Ca to NPP ratio had a quadratic effect on BWG, FI, mortality, as well as tibia breaking strength, weight, length, ash weight, and ash and P contents in 42-d-old broilers. Broiler chickens at 42 d of age obtain optimal growth performance and bone mineralization at the Ca to NPP ratio of 2.32 when 1α-OH-D3 or 25-OH-D3 are used as the vitamin D source.

An optimal dietary non-phytate phosphorus level of broilers fed a conventional corn–soybean meal diet from 4 to 6 weeks of age

It is imperative to evaluate precise nutrient requirements of animals in order to optimize productivity and minimize feed cost and nutrient excretions. The current non-phytate phosphorus (NPP) recommendation for broilers is based on the papers published 30 years ago. However, today’s commercial birds are quite different from those before 30 years. Therefore, the present experiment was conducted with growing male broiler chickens to evaluate an optimal dietary NPP level of broiler chickens fed a conventional corn–soybean meal diet from 4 to 6 weeks of age. The 1-day-old chicks were fed corn–soybean meal diet containing 0.39% NPP from 1 to 3 weeks of age. At 22 days of age, 360 birds were selected and randomly allotted by BW to one of 10 dietary treatments with six replicate cages of six birds per cage for each treatment. Birds were fed the P-unsupplemented corn–soybean meal basal diet and the basal diet supplemented with inorganic P as CaHPO4·H2O ranging from 0.00% to 0.45% with 0.05% increment from 4 to 6 weeks of age. The dietary NPP levels were 0.09%, 0.14%, 0.20%, 0.24%, 0.30%, 0.34%, 0.38%, 0.45%, 0.49% and 0.54%, respectively, and the dietary Ca level was fixed at 0.90% for all treatments. The results showed that average daily gain, serum inorganic P concentration, tibia bone strength, tibia ash percentage and P percentage, tibia bone mineral content (BMC) and density (BMD), middle toe ash percentage and P percentage, middle toe BMC, total body BMC and BMD were affected (P<0.0001) by dietary NPP level, and increased linearly (P<0.0001) and quadratically (P<0.003) as dietary NPP levels increased. Optimal dietary NPP levels estimated based on fitted broken-line models (P<0.0001) of the above indices are 0.21%, 0.29%, 0.29%, 0.29%, 0.29%, 0.31%, 0.29%, 0.30%, 0.27%, 0.29% and 0.28%, respectively. It is suggested that the total body BMC and BMD, and middle toe ash P and BMC might be new, sensitive and non-invasive criteria to evaluate the dietary NPP requirements of broilers. The optimal dietary NPP level would be 0.31% for broiler chickens fed a conventional corn–soybean meal diet from 4 to 6 weeks of age.

Evaluation of dietary calcium requirements for laying Longyan shelducks

To establish the dietary Ca requirements for laying ducks during their peak laying period, 5 Ca levels (2.8, 3.2, 3.6, 4.0, and 4.4%) were used, and laying performance, eggshell quality, serum variables, and bone quality were examined. A total of 1,620 Longyan shelducks with similar BW at 20 wk of age were fed for 13 wk in 5 treatment groups, each with 4 replicates of 81 birds. Dietary Ca increased egg production and egg mass (linear, P < 0.01) and reduced the feed conversion ratio (FCR), but egg weight was not affected. Dietary Ca level did not affect eggshell properties or any reproductive organ index except for shell weight (highest with the 4.0% Ca diet, P < 0.05). Serum concentrations of Ca and calcitonin increased with dietary Ca level (linear, P < 0.01), and a quadratic response (P < 0.01) was seen in alkaline phosphatase activity; the highest values were in ducks fed the 3.6% Ca diet. Tibial fresh weight was affected by dietary Ca (linear and quadratic, P < 0.05) with tibiae from the 2.8% Ca ducks weighing less than those from ducks fed any other Ca level. Other tibial measurements were unaffected by dietary Ca. According to the regression model, the Ca levels required for laying Longyan shelducks during their peak laying period are 3.4 and 3.2% for maximal serum alkaline phosphatase activity and tibial fresh weight, respectively. The results showed that diets containing 3.2 to 3.6% Ca provide for superior productive performance and bone quality in laying Longyan shelducks during their peak laying period.

Starfish (Asterias rubens) as feed ingredient for piglets

The effects of including starfish meal (SM) as an alternative protein source in diets for piglets on performance, faeces characteristics and plasma parameters were investigated. Four diets were formulated to contain different protein sources: fish meal (FM), extruded soybean meal (ESBM) and two levels of SM (SM50 and SM100). All diets contained 174.4g soybean meal/kg feed and were supplemented by up to 166-172g standardised ileal digestible crude protein/kg feed with either FM, ESBM, SM or a combination giving rise to two SM+ESBM diets with different levels of SM and ESBM. One wk after weaning, 96 pigs with a body weight of 9.6±0.4kg were housed individually and allocated to one of the four diets (n=24) and fed ad libitum for a 14 d period. Average daily feed intake (ADFI), average daily gain (ADG) and gain to feed ratio (G:F) were determined. Pigs fed the SM100 diet had a 23–28% lower (P<0.001) ADG than pigs fed the FM, ESBM and SM50 diets, despite the fact that they ate the same amount of feed. Faeces characteristics were evaluated by scoring during 5 d, and no differences were observed, indicating no effect of the diet on diarrhoea. Blood samples were collected on d 15. Plasma urea nitrogen in SM100 was higher (P<0.003) than the concentrations in ESBM and SM50 but not FM. Plasma Ca concentration was higher (P<0.001) in pigs receiving SM100 compared to FM, ESBM and SM50. The opposite was the case with P where the concentration was lower (P<0.001) in SM100 compared to FM, ESBM and SM50. In conclusion, feeding 50g SM/kg resulted in a performance equal to pigs fed the control diets. Inclusion of 100g SM/kg in the diet affected performance negatively due to a wide Ca:P affecting digestibility and absorption of P negatively. Thus, the determining factor for the maximum inclusion level of SM in diets for piglets may be the dietary Ca level and the resulting Ca:P in relation to the nutritional requirements.

Effects of dietary boron and phytase supplementation on growth performance and mineral profile of broiler chickens fed on diets adequate or deficient in calcium and phosphorus

1. Two experiments were designed to determine the effect of dietary boron (B) in broiler chickens. In Experiment 1, a 2 × 4 factorial arrangement of treatments was used to investigate the effect of dietary calcium (Ca) and available phosphorus (aP) (adequate or deficient) and supplemental B (0, 20, 40, and 60 mg/kg diet). In Experiment 2, B, at 20 mg/kg, and phytase (PHY) (500 FTU/kg diet) were incorporated into a basal diet deficient in Ca and aP, either alone or in combination.2. The parameters that were measured were growth performance indices, serum biochemical activity as well as ash and mineral (i.e. Ca, P, Mg, Fe, Cu and Zn) content of tibia, breast muscle and liver.3. Results indicated that both supplemental B and dietary Ca and aP had marginal effects on performance indices of chickens grown for 42 d.4. There were positive correlations (linear effect) between B concentrations of serum, bone, breast muscle and liver and the amount of B consumed.5. Serum T3 and T4 activities increased linearly with higher B supplementation.6. Increasing supplemental B had significant implications on breast muscle and liver mineral composition. Lowering dietary Ca and aP level increased Cu content in liver and both Fe and Zn retention in breast muscle. Tibia ash content and mineral composition did not respond to dietary modifications with either Ca–aP or B.7. The results also suggested that dietary contents of Ca and aP do not affect the response to B regarding tissue mineral profile. Dietary combination with B and PHY did not create a synergism with regard to growth performance and bioavailability of the minerals.

INTERACTION BETWEEN DIETARY MINERAL AND PHYTASE ON BIOLOGICAL PERFORMANCES OF JAPANESE FLOUNDER, Paralichthys olivaceus. PART II. MINERAL DIGESTIBILITY AND VERTEBRAL MINERAL CONTENT

Interactive effects between dietary inorganic phosphorus (IP) and phytase (P) on mineral digestibility and vertebral mineral content were investigated in a 30 days feeding trial followed by three weeks digestibility trial with Japanese flounder, Paralichthys olivaceus. Eight experimental diets were formulated based on two levels of dietary Ca at 0% and 0.2% combined with either 0% or 0.25% of dietary IP and either with 0 and 2,000 fytase unit (FTU)/kg of phytase in diet, respectively. Result indicated that digestibility of total phosphorus significantly increased by three dietary compounds where the highest was observed in fish fed diet contained 0.25% IP and 2,000 FTU phytase/kg and dietary Ca also included in diet. Significant interaction was only detected between dietary IP and P on this parameter. Supplementation of IP and Ca not phytase significantly improved Ca digestibility. Ca digestibility was very poor when dietary IP and Ca were not supplemented in diet even with when phytase supplemented in diet. There was significant interaction between dietary IP and Ca on Ca digestibility. Vertebral total phosphorus, Ca, and Mg content as well as Ca:P ratio were significantly enhanced by dietary IP and phytase. Dietary Ca has significant effect only on vertebral total phosphorus. Interaction between dietary IP and Ca was significantly found on vertebral Ca content and Ca:P ratio. No significant second-order interaction was observed among the three dietary mineral on overall parameters. Based on total phosphorus and Ca digestibility as well vertebral phosphorus content found in this study, dietary IP, Ca, and phytase at rate of 0.25%, 0.2%, and 2,000 FTU phytase/kg diet, respectively are needed to supplement in diet for a better mineral absorption and bone mineralization.

Reducing calcium and phosphorus in crossbred beef cattle diets: impacts on productive performance during the growing and finishing phase

Forty 3/4 Bos indicus × 1/4 Bos taurus bulls (initial bodyweight = 214 ± 4 kg; 11 ± 0.2 months) were used in the study. Four bulls were slaughtered as reference and the other 36 bulls were allowed ad libitum consumption of treatment diets following a completely randomised 3 × 3 factorial design. The design included three diet concentrations of calcium (Ca) and phosphorus (P): standard, 50% of standard, and 75% of standard and three periods of feedlot confinement: 8, 16, and 24 weeks with four bulls per treatment combination. The diets were isonitrogenous and consisted of 60 : 40 corn silage to concentrate. Dry matter intake, crude protein, ether extract, organic matter, non-fibrous carbohydrates, Ca, and P, expressed as kg/day, were greater (P &lt; 0.05) for bulls confined for longer periods. Nutrient digestibility and average daily gain was not affected (P &gt; 0.05) by Ca and P concentration of diet or by feedlot phase. Dressing were decreased (P &lt; 0.05) for bulls that remained in confinement for a shorter period. The daily maintenance requirements of Ca and P were 13.66 and 21.51 mg/kg empty bodyweight, respectively, and the absorption coefficients of Ca and P were 0.70 and 0.67, respectively. We concluded that for crossbred cattle in the feedlot, dietary levels of Ca and P recommended by BR-CORTE (2010), NRC (2000), and AFRC (1991) could be reduced by 62%, 66%, and 57%, respectively, for Ca and by 14%, 15%, and 43%, respectively, for P with significant savings in costs. This study shows that Ca and P can be reduced to 1.8 and 2.2 g/kg DM respectively, in the diets for crossbred cattle in feedlot.

계란 난황 레시틴 추출 부산물이 사료 내 Ca 함량을 조절한 산란계의 생산성과 Ca 흡수에 미치는 영향

A 3-weeks feeding trial with 288 laying hens were conducted to determine the efficacy of lecithin-free egg yolk at different levels of dietary Ca on performance and Ca absorption. Laying hens were divided into 6 groups according to calcium level and testing agent; 0% calcium feed (A), 0.2% calcium feed (B), 0.4% calcium feed (C, normal feed), 0.6% calcium feed (D), 0.4% calcium feed + 0.2% egg byproduct (C+ 0.2), 0.4% calcium feed + 0.4% egg byproduct (C+0.4). The final body weight gain of C+0.2 and C+0.4 groups were higher by 1.5% and 7.4% respectively than group C. Tibia ash contents did not show significantly difference, but calcium contents increase (p<0.05) in C+0.2 and C+0.4 groups. Parallel undecalcified tibia joint sections were stained for calcium absorption by the von Kossa’s stain. This result show that lecithin free egg byproduct supplementation to normal calcium feed improved growth performance and calcium utilization in laying hens.

Dietary calcium, phosphorus, and phytase effects on bird performance, intestinal morphology, mineral digestibility, and bone ash during a natural necrotic enteritis episode

The objective of this study was to evaluate the effects of dietary Ca, P, and phytase on performance, intestinal morphology, bone ash, and Ca and P digestibility during a necrotic enteritis (NE) outbreak. The 35-d trial was designed as a 2 × 2 × 2 factorial, which included 2 Ca levels (0.6 and 0.9%), 2 P levels (0.3 and 0.45%), and 2 levels of phytase [0 and 1,000 phytase units (FTU)/kg]. Birds were placed on litter from a previous flock that exhibited clinical signs of NE. Birds and feed were weighed on d 12, 19, and 35, and BW gain, feed intake, and feed conversion were calculated. Mortality was recorded daily, and gastrointestinal pH was measured. Tibias and ileal digesta were also collected. Birds began exhibiting clinical signs of NE on d 9, and NE-associated mortality persisted until d 26. Dietary Ca supplemented at 0.9% or inclusion of 1,000 FTU/kg of phytase significantly increased mortality compared with 0.6% Ca or 0 FTU/kg of phytase, respectively. From d 0 to 12, birds fed 0.9% Ca and 0.45% available P with phytase had greater BW gain compared with birds fed 0.6% Ca, 0.45% available P, and phytase. From d 0 to 19, birds fed diets with 0.9% Ca and 0.3% available P had decreased feed intake and improved feed conversion compared with birds fed 0.9% Ca and 0.45% available P. Calcium at 0.9% increased gizzard (d 19) and jejunum (d 12) pH. Phytase supplementation significantly increased Ca digestibility regardless of Ca and P levels of the diets. In addition, diets containing 0.6% Ca and 1,000 FTU/kg of phytase resulted in a significant increase in P digestibility. The results suggest that dietary Ca level may influence NE-associated mortality. In addition, bird performance was affected by interactions of Ca, P, and phytase during the exposure to Clostridium perfringens and the subsequent NE outbreak. Results showed improvements in bird performance when birds were fed 0.6% Ca and 0.3% P in diets supplemented with phytase, which was likely consequent to the influence of Ca in NE pathogenesis.

탈지분유 함유 식이를 섭취하는 흰쥐에서 칼슘과 비타민 D 수준이 무기질 대사에 미치는 영향

The purpose of this study was to investigate the effect of calcium (Ca) and vitamin D (vit. D) levels on metabolism of various minerals such as Ca, P, Mg, Fe, Zn, Cu, and Cr. The comparison was made on the rats that were placed on diet containing powdered skim milk with different Ca and vit. D levels for 5 weeks. A total of 42 5-week-old Sprague-Dawley rats were divided into 7 groups as follows: Control group consisted of normal Ca and normal vit. D (0.5% Ca, 1,000 IU vit. D); Experimental groups were divided into low (0.25%) and high (1.0%) calcium levels; and vit. D group was divided into low (10 IU), normal (1,000 IU), and high (5,000 IU) subgroups. The weight gain and food efficiency ratios of the rats were not significantly different with increasing dietary Ca levels. The absorption rates of 7 minerals (Ca, P, Mg, Fe, Zn, Cu, and Cr) were significantly decreased with increasing dietary Ca levels. Also, fecal excretion of P significantly increased with increasing dietary vit. D levels (p<0.05), and urine excretion of Fe was significantly increased with increasing dietary vit. D levels (p<0.001). The result indicated that higher Ca intake affected on bioavailability of other minerals, due to interactions among minerals in the process of intestinal absorption. However, vitamin D intake had no effect on bioavailability of several minerals. Therefore, it could be suggested that adequate Ca intake is important for balance of the minerals.

Explorative study of metabolic adaptations to various dietary calcium intakes and cereal sources on serum metabolome and hepatic gene expression in juvenile pigs

Daily calcium (Ca) intake is critical for bone health and energy metabolism, but less is known about its metabolic role at young ages. We used targeted electrospray ionization liquid chromatography–mass spectrometry-based metabolomics and candidate gene expression to compare the effect of dietary Ca level (high vs. adequate intake), as influenced by dietary cereal composition (wheat–barley vs. corn grains), on postprandial serum metabolome profiles and hepatic expression of genes related to glucose, lipid and amino acid metabolism in juvenile pigs (n = 32; 7-weeks of age). Explorative analysis of 132 metabolites demonstrated that postprandial serum of pigs fed high Ca contained greater (p < 0.05) concentrations of hexoses, 13 amino acids, 3 polyamines and 33 phosphatidylcholines compared to pigs fed adequate Ca. Partial-least-squares-discriminant analysis and cereal–Ca interactions indicated that the dietary cereal source may modulate the metabolic Ca response to a meal. Hepatic responses showed trends for upregulation of PPARG and SRBEF1 expression with high versus adequate Ca diets. Present data are consistent with the concept that dietary Ca modifies systemic metabolic processes in young animals. Targeted metabolomics provided greater insight into the complex metabolic responses related to dietary Ca than previously reported.