Different Levels Of Calcium Research Articles

PSI-41 Tibia attributes in aged Lohmann LSL-lite hens fed corn-soybean meal diet with different levels of calcium and 25-hydroxy vitamin D3.

PSI-41 Tibia attributes in aged Lohmann LSL-lite hens fed corn-soybean meal diet with different levels of calcium and 25-hydroxy vitamin D3.

The effects ofmicrobial phytases and dietary calcium and phosphorus levels on the productive performance and bone mineralization of broilers

Two trials were conducted to evaluate the effects of phytase and different levels of calcium (Ca) in an available phosphorus-limited diet (aP) on the performance, bone mineralization, and Ca and P retention of broilers. In Trial 1, 160 one-day-old male broilers were placed into 40 cages and allocated to five dietary treatments: one positive control [PC, 4.7 and 4.3 g/kg non-phytate P (NPP) and 9.0 and 8.5 g/kg Ca, from 1 to 21 days (d) and from 21 to 35 d of age, respectively] and four negative control [NC, 3.2 and 2.9 g/kg NPP and 7.0 and 6.3 g/kg Ca in starter (1–21 d) and growth (22–35 d) diet] groups comprising 4 concentrations of phytase A (FLF® 1000 FUT, 0, 250, 500 and 1000 FTU/kg). In Trial 2, 300 one-day-old broilers were placed into 60 cages and allocated to 10 dietary treatments, consisting of two NC diets (3.2 g/kg NPP), either 7.0 g/kg Ca (low Ca) or 9.0 g/kg Ca (high Ca), supplemented (0 or 500 FTU/kg) with four different phytases [OptiPhos® 5000 CT (A), Phyzyme® XP10000 TPT (B), Ronozyme® NP (C) and FLF® 1000 FUT (D)] from 1 to 14 d. In Trial 1, the PC group and the group receiving the highest dose of phytase A FLF® 1000 FUT (1000 FTU/kg) yielded significantly higher average daily gains from 1 to 21 d and higher tibia weights and ash contents than the NC, 250, and 500 FTU/kg. In Trial 2, no differences were observed in performances between animals receiving different types of phytase. Low Ca diets improved the feed efficiency from 1 to 7 d and ileal P digestibility. The interaction between Ca:aP and phytase affected (P ≤ 0.05) the feed efficiency from 1 to 7 d and ADG from 7 to 14 d. Based on this study, high levels of phytase (1000 FTU/kg) supplemented in starter (1–21 d) and growth (22–35 d) diets containing 3.2 and 2.9 g/kg NPP and 7.0 and 6.3 g/kg Ca, respectively, may be required to promote performance and bone mineralization in growing broilers. Lowering Ca levels to 7 g/kg in starting diets may exert greater effects on performance and ileal P digestibility than low levels (500 FTU/kg) of phytase.

Effect of Diets with Various Calcium and Boron Levels in Prelaying Period on Growth, Bone Ash and Subsequent Performance and Shell Quality of Laying Hens

This experiment was conducted to determine the effects of diets with three different levels of calcium (% 0.8, 1.6, 3.2) and four different levels of boron (0, 75, 150, 300 mg kg-1) in prelaying period (14-20 weeks) on growth, bone ash and subsequent performance and egg shell quality of laying hens. A total 864 Super Nick pullets at 14 weeks of age were randomly allocated to twelve treatments arranged in a 3x4 factorial design with six replicates of 12 pullets each. Feed and water provided for ad-libitum access. The tibia samples were taken, three pullets and hens from every replicates at 20 and 42 weeks of age, respectively. Results of the present experiment showed that body weights and body weight gains were reduced in high prelay dietary Ca and B as the main factor. Feed intake of the pullets was not significantly influenced by the treatments. There were no detectable difference in feed intake, egg production, egg mass and feed conversion ratio (g, feed/ g, egg mass) and eggshell weight, but interactive effects of dietary Ca and B levels on eggshell thickness, egg specific gravity and shell breaking strength was significant. Shell thickness and breaking strength were significantly higher in hens fed pre-lay diet with 3.2 % Ca and no supplemental B than other treatments and egg specific gravity was significantly reduced by feeding 1.6 % Ca and 75 mg kg-1 B at 36 weeks of age. Bone ash (g or %) of hens at 20 and 42 weeks of age was not changed by Ca levels or interaction dietary Ca and B levels, but pullets receiving the 150 mg kg-1 B as the main factor had significantly higher in bone ash (g or %) values than other dietary B levels.

Effect of Different Levels of Calcium, Phosphor and Vitamin D3 with Fennel Extract on, Performance and Egg Shell Quality in Post Molted Ross Broiler Breeders

Effect of Different Levels of Calcium, Phosphor and Vitamin D3 with Fennel Extract on, Performance and Egg Shell Quality in Post Molted Ross Broiler Breeders

Вплив різних рівнів кальцію та фосфору у комбікормах на мінеральний склад скелету японських перепелів

<p>The authors investigated the effect of different levels of calcium and phosphorus in the mixed fodder on mineral composition of Japanese quail skeleton. Experimental studies were carried out in the conditions of the Problematic Research Laboratory of Mixed Fodder Additives, National University of Life and Environmental Sciences of Ukraine (Kiev, Ukraine). We selected Japanese quail as the material for scientific and economic experience.</p><p>The experiment was conducted by groups-analogues method. Fodder was in the dry loose form. The difference in feeding was due to different levels of calcium and phosphorus in the feed for experimental groups. In the beginning of the experiment the experimental quail were similar regards live weight while in the end we did not detect significant difference in their mass. Nevertheless, we observed little decrease in live weight with increasing of phosphorus up to 1.4 % and calcium up to 3.5 %. We fixed that water content in the quail skeletons from Group 4, 5 and 6th study groups (calcium 4.0 %, phosphorus 0.8, 1,1 and 1,4 % respectively) were smaller in comparison with quails from Control, Group 2 and 3 (calcium content 3.5 % with the same level of phosphorus). We also determined increasing of dry matter content in the skeleton by 2.5 – 2.8 % while increasing the content of calcium and phosphorus in mixed fodder of quails-hens (Group 4, 5 and 6). The phosphorus content in quail skeleton depended on the level of phosphorus in the mixed fodder and can be up to 0.39-0.66 % in the bones. The simultaneous increase in the level of phosphorus and calcium in mixed fodder of experimental groups was accompanied by increase in the concentration of calcium and magnesium in the quail skeleton by 0.85–0.87 and 0.01–0.07 per cent respectively.</p>

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.

БІОХІМІЧНІ ТА МОРФОЛОГІЧНІ ПОКАЗНИКИ КРОВІ ЯПОНСЬКИХ ПЕРЕПЕЛІВ ЗА РІЗНИХ РІВНІВ КАЛЬЦІЮ ТА ФОСФОРУ У КОМБІКОРМАХ

&lt;p&gt;We studied the influence of a different level of a calcium and phosphorus in mixed fodders on morphological and biochemical indexes of a blood of Japanese quail. We selected 240 quails, which were divided into 6 equal groups - control and 5 experimental. Experimental quails were contained in six-fodders cell battery, each cell was 60x40x20 cm and contained of 20 birds (15 females and 5 males). At the beginning of the experiment the experimental quails had similar body weight indicators that were the same in the end of our research. When we fed quails with different levels of calcium and phosphorus wew registered that calcium, magnesium, total protein and alkaline phosphatase activity in their blood was within physiological norm. We identified no significant differences in these indicators. It should be noted that the highest content of phosphorus in the quail blood was observed in female birds of 6th experimental group, which exceeded by 23.1% the values in quails of control group with calcium content of 4.0% and phosphorus of 1.4% (P &amp;lt;0.05). The introduction of different level of a calcium and phosphorus were not significantly affect the blood erythrocytes, leukocytes, and hemoglobin. The ratio of segmented rods, eosinophils, lymphocytes and monocytes in the blood of experimental birds was within the physiological norm of fluctutations. In content, there was a slight deviation (within 1%) was not statistically significant in the blood of the bird experimental and control groups, eosinophils and monocytes. The lymphocyte content was below 8.3% in the blood of all experimental bird groups. It is revealed that a level of a calcium of 4.0 % and phosphorus of 0.8, 1,1, and 1,4 % in rations of quails, promotes rising of a calcium level in skeleton of female quails and does not influence significantly the morphological and biochemical blood indices.&lt;/p&gt;

Response of broiler chickens to different levels of calcium, non-phytate phosphorus and phytase

ABSTRACT1. Five hundred and seventy six-d old Ross 308 broiler chicks (6 cages per diet, 8 birds per cage in 3 × 2 × 2 factorial arrangement) were fed on maize–soybean meal-based diets containing three concentrations of Ca (6, 8 or 10 g/kg), two concentrations of non-phytate phosphorus (NPP) (3 or 4 g/kg) and two levels of exogenous microbial phytase (0 or 500 FTU/kg) from d 0 to 35.2. Body weight (BW), feed intake (FI) and mortality records were collected. Two birds per replicate were killed at 24 d of age to obtain tibia samples.3. Increasing Ca level significantly reduced the FI and body weight gain (BWG) between hatch and 10 and 24 d, especially with the phytase-supplemented diets. However, phytase supplementation of the diet containing 4 g NPP/kg improved the FI and BWG at d 10 and 24. At d 24, phytase supplementation improved feed conversion ratio (FCR) of birds that consumed diets containing high NPP. The overall FCR was better in birds offered the phytase-supplemented, medium-Ca diet.4. There was a significant reduction in length, width and breaking strength of the tibia bone in birds fed on a diet with high Ca and low NPP. Phytase supplementation improved the tibia ash content and bone breaking strength of chicks fed on the diet containing 8 and 4 g/kg Ca and NPP, respectively. The Ca content of the tibia bone was low in birds fed on diets with 6 and 4 g/kg Ca and NPP, respectively, but this was counteracted by phytase supplementation.5. Birds fed on diets with 4 g/kg NPP had the best carcass percentage and parts yield. Phytase supplementation to high-Ca diets significantly reduced the carcass yield of birds.6. These results confirmed the detrimental effect of high dietary Ca on phytase activity and subsequent growth and bone development of birds, especially when NPP is in short supply.

Energy and protein requirements of crossbred Holstein x Zebu steers fed different levels of calcium and phosphorus in the diet

The aim of this study was to determine the energy and protein requirements of crossbred Holstein x Zebu steers fed with or without the supplementation of dicalcium phosphate in the diet. Thirty-two steers with an average initial body weight of 377.5 ± 49.4 kg were used, of which four were initially slaughtered to estimate the empty body weight (EBW) of the animals. Twenty-four steers were fed ad libitum and were distributed in a completely randomized design with two levels of concentrate (30 and 60 %), and diets with or without dicalcium phosphate and four steers were fed at maintenance level, so that the body weight gain was equal to zero. After 84 days the animals were slaughtered. The animal tissues were sampled, and composted by two samples, denominated by “carcass” (bone, muscle and fat) and “non-carcass” (head, limbs, blood, hide, organs and viscera) for determination of the body composition. The net energy requirements (NEm) and metabolizable energy for maintenance (MEm) were obtained while relating heat production (HP) and metabolizable energy intake (MEI); meanwhile, the net energy requirements for gain (NEg) and the net protein requirements for gain (NPg) were obtained as a function of empty body weight (EBW), empty body gain (EBG) and retained energy (RE) in EBW. The daily net and metabolizable energy requirements for maintenance were 76.90 and 119.36 kcal/EBW0.75, respectively. The net energy requirements for gain can be obtained by the following equation: NEg = 0.0568±0.0025 × EBW0.75 × EBG1.095. The efficiencies of use of metabolizable energy for maintenance and gain are 64.4 and 29.68 %, respectively. The metabolizable protein requirements for maintenance are 4.14 g/BW0.75. The net protein requirements for gain can be obtained through the following equation: NPg = 236.36±30.06 × EBG - 19.84±6.14 × RE. We recommend the use of the equations obtained in this experiment to calculate the energy and protein requirements of crossbred Holstein x Zebu steers.

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.

Rooting and growth of chrysanthemum cultivars in response to different levels of calcium

Rooting and growth of chrysanthemum cultivars in response to different levels of calcium

Antioxidant activity and nutrient release from polyphenol-enriched cheese in a simulated gastrointestinal environment.

Green tea polyphenols are recognized for their antioxidant properties and their effects on lipid digestion kinetics. Polyphenols are sensitive to degradation in the intestinal environment. Interactions with dairy proteins could modulate the stability and biological activity of polyphenols during digestion. The objective of this study was to evaluate the release of nutrients (polyphenols, fatty acids and peptides) and the antioxidant activity in polyphenol-enriched cheese containing different levels of calcium in a simulated gastrointestinal environment. The relationship between cheese matrix texture, matrix degradation and nutrient release during digestion was also studied. Green tea extract was added to milk at 0% or 0.1%, and cheeses were produced on a laboratory scale. The level of available calcium was adjusted to low (Ca(low)), regular (Ca(reg)) or high (Ca(high)) during the salting step of the cheese-making process. Cheeses were subjected to simulated digestion. The rate and extent of fatty acid release were 21% lower for Ca(low) cheese than for Ca(reg) and Ca(high) cheeses. The greater adhesiveness of Ca(low) cheese, which resulted in lower rates of matrix degradation and proteolysis, contributed to the reduced rate of lipolysis. The presence of green tea extract in cheese reduced the release of free fatty acids at the end of digestion by 7%. The addition of green tea extract increased cheese hardness but did not influence matrix degradation or proteolysis profiles. The formation of complexes between tea polyphenols and proteins within the cheese matrix resulted in a more than twofold increase in polyphenol recovery in the intestinal phase compared with the control (tea polyphenol extract incubated with polyphenol-free cheese). Antioxidant activity was 14% higher in the digest from polyphenol-enriched cheese than in the control. These results suggest that cheese is an effective matrix for the controlled release of nutrients and for the protection of green tea polyphenol integrity and biological activity in the gastrointestinal environment.

Effect of different levels of calcium and phosphorus and their interaction on the performance of young broilers

A study was conducted to evaluate the interaction among 3 levels of Ca and 4 levels of nonphytate phosphorus (NPP) on broiler performance, bone ash, and whole-body fractional retention of Ca and P. Ross male broiler-chicks (n = 420) were sorted by BW at d 1 posthatch and assigned to 5 cages/diet with 7 birds/cage. Twelve diets were arranged in a 3 × 4 factorial of 3 levels Ca (at 0.5, 0.7, or 0.9%) and 4 levels NPP (at 0.25, 0.31, 0.38, or 0.45%) with a high dose of phytase (1,150 U/kg) in all diets. On d 14, chickens were euthanized and the right tibia was collected from 3 birds/replicate; the rest of the animals were used to measure whole-body Ca and P retention. An interaction was observed between the level of Ca and NPP on feed intake (FI), tibia weight, and bone-ash content (P < 0.05). Increasing the level of NPP from 0.25 to 0.38% increased FI (P < 0.05) on chickens fed the high-Ca diet (0.9%), but not with Ca at 0.5 or 0.7%. Broilers achieved their greatest weight gain (WG) and bone formation with 0.7% Ca and 0.38% NPP. Increasing the dietary Ca decreased its fractional retention from 74% with dietary Ca at 0.5 to 46% with Ca at 0.9%. The increase in the levels of dietary P steadily increased the fractional retention of Ca from 53 to 61%, and increased the whole-body Ca content (g/kg BW). It can be concluded that a dietary level of 0.38% NPP/kg in diets containing a high dose of phytase (1,150 U/kg) and 0.7% Ca are adequate to ensure broiler performance and bone ash of broilers from d 0 to d 14 posthatch.

Effects on performance and eggshell quality of particle size of calcium sources in laying hens' diets with different Ca concentrations

Abstract. The objective of this study was to evaluate the effect of particle size of a dietary Ca source on egg production and eggshell quality when added to hens' diets that have different levels of calcium. The experiment was carried out on 216 ISA Brown hens (25 to 70 weeks of age), allocated to 9 groups of 12 replicates (cages), with two birds in each cage. A 3 × 3 factorial arrangement was used, with three dietary levels of calcium (3.20, 3.70 and 4.20 %) and three levels of dietary substitutions (0, 25 and 50 %) of fine particles of limestone (FPL, diameter 0.2–0.6 mm) with large particles of limestone (LPL, diameter 1.0–1.4 mm) as a Ca source. The level of Ca in the diet had no effect on egg production, mean egg weight, feed intake, feed conversion ratio or eggshell quality parameters (P &gt; 0.05). Substitution of FPL with LPL did not affect laying performance indices or eggshell quality at 30, 43 and 53 weeks of age (P &gt; 0.05); however, it increased (P &lt; 0.05) eggshell percentage, thickness, density and breaking strength in older hens (69 weeks of age). In conclusion, the results of this study demonstrated that a level of 3.20 % Ca in a layer's diet is sufficient through the entire laying cycle to maintain good egg production and eggshell quality and that partial (25 or 50 %) substitution of fine- with large-particle limestone can, irrespective of the level of Ca in the diet, improve eggshell quality in aged laying hens.

Oxalobacter formigenes Colonization and Oxalate Dynamics in a Mouse Model.

Animal and human studies have provided compelling evidence that colonization of the intestine with Oxalobacter formigenes reduces urinary oxalate excretion and lowers the risk of forming calcium oxalate kidney stones. The mechanism providing protection appears to be related to the unique ability of O. formigenes to rely on oxalate as a major source of carbon and energy for growth. However, much is not known about the factors that influence colonization and host-bacterium interactions. We have colonized mice with O. formigenes OxCC13 and systematically investigated the impacts of diets with different levels of calcium and oxalate on O. formigenes intestinal densities and urinary and intestinal oxalate levels. Measurement of intestinal oxalate levels in mice colonized or not colonized with O. formigenes demonstrated the highly efficient degradation of soluble oxalate by O. formigenes relative to other microbiota. The ratio of calcium to oxalate in diets was important in determining colonization densities and conditions where urinary oxalate and fecal oxalate excretion were modified, and the results were consistent with those from studies we have performed with colonized and noncolonized humans. The use of low-oxalate purified diets showed that 80% of animals retained O. formigenes colonization after a 1-week dietary oxalate deprivation. Animals not colonized with O. formigenes excreted two times more oxalate in feces than they had ingested. This nondietary source of oxalate may play an important role in the survival of O. formigenes during periods of dietary oxalate deprivation. These studies suggest that the mouse will be a useful model to further characterize interactions between O. formigenes and the host and factors that impact colonization.

Peak bone strength is influenced by calcium intake in growing rats

In this study we investigated the effect of supplementing the diet of the growing male rat with different levels of calcium (from low to higher than recommended intakes at constant Ca/P ratio), on multiple factors (bone mass, strength, size, geometry, material properties, turnover) influencing bone strength during the bone accrual period. Rats, age 28days were supplemented for 4weeks with high Ca (1.2%), adequate Ca (0.5%) or low Ca level (0.2%). Bone metabolism and structural parameters were measured. No changes in body weight or food intake were observed among the groups. As anticipated, compared to the adequate Ca intake, low-Ca intake had a detrimental impact on bone growth (33.63 vs. 33.68mm), bone strength (−19.7% for failure load), bone architecture (−58% for BV/TV) and peak bone mass accrual (−29% for BMD) due to the hormonal disruption implied in Ca metabolism. In contrast, novel, surprising results were observed in that higher than adequate Ca intake resulted in improved peak bone strength (106 vs. 184N/mm for the stiffness and 61 vs. 89N for the failure load) and bone material properties (467 vs. 514mPa for tissue hardness) but these effects were not accompanied by changes in bone mass, size, microarchitecture or bone turnover. Hormonal factors, IGF-I and bone modeling were also evaluated. Compared to the adequate level of Ca, IGF-I level was significantly lower in the low-Ca intake group and significantly higher in the high-Ca intake group. No detrimental effects of high Ca were observed on bone modeling (assessed by histomorphometry and bone markers), at least in this short-term intervention. In conclusion, the decrease in failure load in the low calcium group can be explained by the change in bone geometry and bone mass parameters. Thus, improvements in mechanical properties can be explained by the improved quality of intrinsic bone tissue as shown by nanoindentation. These results suggest that supplemental Ca may be beneficial for the attainment of peak bone strength and that multiple factors linked to bone mass and strength should be taken into account when setting dietary levels of adequate mineral intake to support optimal peak bone mass acquisition.

13.4: Photoluminescent Properties of MgCaO for High‐Xe PDPs

AbstractUsing synchrotron radiation the photoluminescent spectra of both MgCaO with different levels of calcium, and MgO pellet material were measured. The sensitivity at 147 and 172 nm radiation is compared, including the emission spectra. At room temperature MgCaO material can be resonantly excited at both 172 and 188 nm. At room temperature no UV light is emitted from MgCaO, but after cooling down to 20K there is a strong UV emission at 235 nm.

Exigências de cálcio e de fósforo disponível para codornas japonesas de 26 a 38 semanas de idade

Este experimento foi conduzido com objetivo de avaliar niveis de cálcio e fósforo disponível para codornas japonesas. Foram utilizadas 12 dietas e sete repetições de oito aves por repetição num total de 672 aves, as quais foram distribuídas segundo um delineamento inteiramente casualizado, em esquema fatorial, com três níveis de cálcio (2,0; 2,5 e 3,0%) e quatro de fósforo disponível (0,10; 0,17; 0,24 e 0,31%). Observou-se interação significativa entre os níveis de cálcio e fósforo disponível para o consumo de ração e de cálcio, verificouse efeito quadrático e linear para os níveis de fósforo disponível de codornas que consumiram dietas que continham 2,0 e 2,5% de cálcio, respectivamente, e para dietas que continham 3,0% de cálcio não houve efeito significativo. A produção de ovos comerciais cresceu linearmente, influenciada pelo nível de fósforo disponível das dietas. Verificou-se interação significativa entre o cálcio e fósforo disponível, para os teores de fósforo e cinzas nas tíbias. Aumento dos níveis de fósforo disponível nas dietas proporcionou aumento do teor de fósforo nas tíbias das aves alimentadas com dietas que continham 3,0% de cálcio e, efeito quadrático e linear sobre o teor de cinzas na tíbia das aves que receberam dietas com níveis 2,5 e 3,0% de cálcio, respectivamente. Para o teor de cálcio nas tíbias, verificou-se aumento linear com elevação dos níveis de fósforo disponível nas dietas. O consumo de 555,4mg de cálcio (2,0%) e de 88,18mg (0,31%) de fósforo disponível ave/dia, atende as exigências de codornas japonesas no período de 26 a 38 semanas de idade.

The tolerance levels of Calcium:Phosphorus in the diet of growing grass-cutters

Calcium and phosphorus are important nutrients required for bone formation and they are important constituents of the skeleton and teeth. A twelve weeks feeding trial was conducted to determine the effect of different levels of Calcium: Phosphorus in the diet of grass-cutter (Thryonomys swinderianus) on the performance characteristics of grass-cutters. The grass-cutters were randomly allotted to 3 different treatment groups in a Completely Randomized Design (CRD). The trial consisted of 3 treatments (G1 &ndash; G3) and each treatment was replicated 3 times with 3 grass-cutters per replicate. Grass-cutters in Treatment 1 (G1) were fed a diet containing Ca:P in ratio of 0.5: 0.25 while in Treatment 2 (G2) and Treatment 3 (G3), the grass-cutter were fed diet containing Ca:P in ratio of 1:0.5 and 1.5:0.75 respectively. The parameters measured were feed intake, weight gain .Feed conversion ratio and protein efficiency ratio were calculated. The highest weight gain was recorded in the diet containing 1.5 %Ca and 0.75%P. The feed intake increased as the level of Ca :P in the diet increased . It was observed that there was no poor bone formation, enlargement of the joints, lameness and stiffness across the treatments. Calcium and phosphorus intake increased as the level of Ca :P in the diet increased in the diet. Calcium and Phosphorus digestibility were not significantly affected by the treatment effect (P&gt;0.05). The protein efficiency ratio was not significantly affected the treatment effect Based on the present results, grass-cutter can tolerate 0.5 - 1.5 calcium and phosphorus between 0.25-0.75% in the diet.Keywords: Calcium, feed utilization, Nutrients digestibility, phosphorus, Thryononomys swinderianus

Interaction between dietary conjugated linoleic acid and calcium supplementation affecting bone and fat mass

Dietary conjugated linoleic acid (CLA) has shown wide biologically beneficial effects, such as anticancer, antiatherosclerotic, antidiabetic, immunomodulating, and antiobesity effects. However, the effects of CLA on total body ash, reflective of bone mineral content, have not been consistent. We hypothesized that the inconsistency of the CLA effect on ash may be linked to interaction between CLA and dietary calcium levels. Thus, we investigated the effects of CLA on body ash in conjunction with various calcium levels. Male ICR mice were fed three different levels of calcium (0.01, 0.5, and 1%) with or without 0.5% CLA for 4weeks for Experiment 1 and separate CLA isomers at 0.22% level with 1% calcium in Experiment 2. CLA feeding reduced body fat regardless of dietary calcium level, whereas CLA supplementation increased body ash compared to control only in animals fed the 1% calcium. In Experiment 2 it was confirmed that this observation was associated with the trans-10, cis-12 CLA isomer, but not with the cis-9, trans-11 isomer. CLA administration with 1% dietary calcium significantly improved total ash percent (%) in femurs, confirming that CLA has the potential to be used to improve bone mass.