Dietary Sodium Levels Research Articles

Response of broiler chickens to diets containing different levels of sodium with or without microbial phytase supplementation.

Phytate induced excessive mineral excretion through poultry litter leads to poor performance and environmental pollution. Exogenous microbial phytase supplementation to poultry diets reduce the environmental excretion of nutrient and improve bird’s performance. However, excessive dietary sodium (Na) level may hinder the phytase-mediated phytate hydrolysis and negate the beneficial effects of phytase. Therefore, this experiment was conducted to investigate the effects of different concentration dietary Na on phytase activity and subsequent impact on broiler performance, bone mineralisation and nutrient utilisation. In this study, six experimental diets, consisting of three different levels of Na (1.5, 2.5, or 3.5 g/kg) and two levels of microbial phytase (0 or 500 U/kg) were formulated by using 3 × 2 factorial design. The six experimental diets were offered to 360 day-old Ross 306 male chicks for 35 days, where, each experimental diet consisted of 6 replicates groups with 10 birds. Along with growth performance, nutrient utilization, intestinal enzyme activity, dry matter (DM) content of litter and mineral status in bone were analysed. Dietary Na and phytase had no effect on bode weight gain and feed intake. Birds on the low Na diet showed higher (p < 0.05) feed conversion ratio (FCR) than the mid-Na diets. High dietary Na adversely affected (p < 0.001) excreta DM content. Phytase supplementation to the high-Na diet increased (p < 0.01) the litter ammonia content. High dietary Na with phytase supplementation improved (Na × phytase, p < 0.05) the AME value and ileal digestibility of Ca and Mg. The total tract retention of Ca, P, and Mg was reduced with high Na diet, which was counteracted by phytase supplementation (Na × phytase, p < 0.001). The diets containing mid-level of Na improved (p < 0.001) the function of Na-K-ATPase and Mg-ATPase in the jejunum. The overall results indicate that high dietary Na did not affect phytase activity but influenced the nutrient utilization of birds, which was not reflected in bird overall performance.

Sodium and chloride requirements of yellow-feathered chickens between 22 and 42 days of age

Sodium and chloride are the key factors maintaining normal osmotic pressure (OSM) and volume of the extracellular fluid, and influencing the acid–base balance of body fluids. The experiment was conducted to investigate the effects of dietary Na+ and Cl− level on growth performance, excreta moisture, blood biochemical parameters, intestinal Na+–glucose transporter 1 (SGLT1) messenger RNA (mRNA), and Na+–H+ exchanger 2 (NHE2) mRNA, and to estimate the optimal dietary sodium and chlorine level for yellow-feathered chickens from 22 to 42days. A total of 900 22-day-old Lingnan yellow-feathered male chickens were randomly allotted to five treatments, each of which included six replicates of 30 chickens per floor pen. The basal control diet was based on corn and soybean meal (without added NaCl and NaHCO3). Treatments 2 to 5 consisted of the basal diet supplemented with equal weights of Na+ and Cl−, constituting 0.1%, 0.2%, 0.3% and 0.4% of the diets. Supplemental dietary Na+ and Cl− improved the growth performance (P<0.05). Average daily gain (ADG) showed a quadratic broken-line regression to increasing dietary Na+ and Cl− (R2=0.979, P<0.001), and reached a plateau at 0.1%. Supplemental Na+ and Cl− increased (P<0.05) serum Na+ and OSM in serum and showed a quadratic broken-line regression (R2=0.997, P=0.004) at 0.11%. However, supplemental Na+ and Cl− decreased (P<0.05) serum levels of K+, glucose (GLU) and triglyceride. Higher levels of Na+and Cl− decreased duodenal NHE2 transcripts (P<0.05), but had no effect on ileal SGLT1 transcripts. The activity of Na+ /K+-ATPase in the duodenum decreased (P<0.05) with higher levels of dietary Na+ and Cl−. In conclusion, the optimal dietary Na+ and Cl− requirements for yellow-feathered chickens in the grower phase, from 22 to 42 days of age, to optimize ADG, serum Na+, OSM, K+ and GLU were 0.10%, 0.11%, 0.11%,0.17% and 0.16%, respectively, by regression analysis.

Assessment of Sodium and Potassium Intakes in Children Aged 6 to 18 Years by 24 h Urinary Excretion in City of Rabat, Morocco.

Background The incidence of noncommunicable diseases (NCDs) has greatly increased, mainly due to high level of dietary sodium. Thus, reduction of sodium intake in population has been recognized as one of the most cost-effective strategies to reduce NCDs. The aim of this study was to estimate sodium and potassium consumption in a sample of Moroccan children as a baseline study to implement national strategy for salt intake reduction. Methods The study was conducted on 131 children aged 6–18 years recruited from Rabat and its region. Sodium excretion and potassium excretion were measured on 24 h urinary collection, and the creatinine excretion was used to validate completeness of urine collections. Results The average of urinary sodium was 2235.3 ± 823.2 mg/day, and 50% of children consume more than 2 g/d of sodium (equivalent to 5 g/day of salt), recommended by the WHO. However, daily urinary excretion of potassium was 1431 ± 636.5 mg/day, and 75% of children consume less than adequate intake. Sodium consumption increased significantly with age. Of particular interest, 46.7% of children aged 6–8 years and 49.3% of children aged 9–13 years consume more than the corresponding upper limits. Conclusions Children have high sodium and low potassium status. There is evidence of the urgent need to implement a strategy for reduction of dietary sodium intake in Morocco.

Necrotic enteritis challenge and high dietary sodium level affect odorant composition or emission from broilers.

Necrotic enteritis (NE) challenge and high dietary sodium (from sodium chloride) level on odor flux from broiler litter was investigated using 160 day-old Ross 308 male chicks randomly assigned to 4 dietary treatments with 4 replicates of 10 birds each. A 2 × 2 factorial arrangement of treatments was employed. Factors were: presence or absence of NE challenge and normal (1.6 g/kg) or high (4.0 g/kg) dietary sodium (Na) level. On d 20, odorants were collected from litter headspacewith a flux hood and measured using selected ion flow tube mass spectrometry (SIFT-MS). On d 33, while challenge did not lead to higher mortality, it reduced feed intake by 5.48% (P < 0.05) and body weight gain by 9.02% (P < 0.01) and worsened FCR by 5 points (P < 0.01), indicating subclinical necrotic enteritis occurred in challenged birds. Challenge increased (P < 0.01) litter moisture and litter headspace concentrations of dimethyl sulfide (P < 0.05), propyl mercaptan (P < 0.05), total butanols (P < 0.05), acetoin (P < 0.01), skatole (P = 0.05), butyric acid (P < 0.05), and methyl amine (P < 0.05) and tended to increase concentrations of ethyl mercaptan (P = 0.07), carbon disulfide (P = 0.09), indole (P = 0.10), and formic acid (P = 0.10) compared to the unchallenged group. The birds fed a high Na diet produced higher litter moisture (P < 0.01) and higher litter headspace concentration of sulfur compounds and phenol (P < 0.01) compared to those fed a normal Na diet. In the birds fed a high Na diet, challenge increased the litter flux of some additional odorants, which included 2,3-butanedione (P < 0.05), acetic acid (P < 0.01), propionic acid (P < 0.01), isobutyric acid (P < 0.01), isovaleric acid (P < 0.01), pentanoic acid (P < 0.05), 2-butanone (P < 0.05), and 3-methyl-1-butanol (P < 0.05). These findings suggest that both a high Na diet and sub-clinical NE increase the odor nuisance potential of broiler farms.

Sodium in feline nutrition.

High sodium levels in cat food have been controversial for a long time. Nonetheless, high sodium levels are used to enhance water intake and urine volume, with the main objective of reducing the risk of urolithiasis. This article is a review of current evidence of the putative risks and benefits of high dietary sodium levels. Its secondary aim is to report a possible safe upper limit (SUL) for sodium intake. The first part of the manuscript is dedicated to sodium physiology, with a focus on the mechanisms of sodium homeostasis. In this respect, there is only few information regarding possible interactions with other minerals. Next, the authors address how sodium intake affects sodium balance; knowledge of these effects is critical to establish recommendations for sodium feed content. The authors then review the consequences of changes in sodium intake on feline health, including urolithiasis, blood pressure changes, cardiovascular alterations and kidney disease. According to recent, long-term studies, there is no evidence of any deleterious effect of dietary sodium levels as high as 740mg/MJ metabolizable energy, which can therefore be considered the SUL based on current knowledge.

Postmating Circuitry Modulates Salt Taste Processing to Increase Reproductive Output in Drosophila

To optimize survival and reproduction, animals must match their nutrient intake to their current needs. Reproduction profoundly changes nutritional requirements, with many species showing an appetite for sodium during reproductive periods. How this internal state modifies neuronal information processing to ensure homeostasis is not understood. Here, we show that dietary sodium levels positively affect reproductive output in Drosophila melanogaster; to satisfy this requirement, females develop a strong, specific appetite for sodium following mating. We show that mating modulates gustatory processing to increase the probability of initiating feeding on salt. This postmating effect is not due to salt depletion by egg production, since abolishing egg production leaves the sodium appetite intact. Rather, the salt appetite is induced need-independently by male-derived Sex Peptide acting on the Sex Peptide Receptor in female reproductive tract neurons. Wefurther demonstrate that postmating appetites for both salt and yeast are driven by the resultant silencing of downstream SAG neurons. Surprisingly, unlike the postmating yeast appetite, the salt appetite does not require octopamine, suggesting a divergence in the postmating circuitry. These findings demonstrate that the postmating circuit supports reproduction by increasing the palatability of specific nutrients. Such a feedforward regulation of sensory processing may represent a common mechanism through which reproductive state-sensitive circuits modify complex behaviors across species.

Abstract W P232: High Sodium Diet Did Not Increase Peripheral Blood Pressure in a Transgenic Mouse Model of Alzheimer's Disease

Introduction: The impairment of Ca2+ homeostasis has been connected to the deleterious effect of abnormal beta-amyloid (Ab) on the calcium sensing receptors (CaSR) in Alzheimer’s disease (AD). Elevated extracellular Ca2+ can also induce relaxation of arteries and prevent the development of hypertension. Change in ionic strength reduces the effect of CaSR agonists, such as Ab, and regulates Ca2+ homeostasis. Na+ gradient also increase ionic strength and may regulate Ca2+ homeostasis through CaSR and Na+/Ca2+ antiporter exchange to affect blood pressure. In non-pathological conditions, the elevation of Na+ gradient through high-sodium diet is considered as a reason for imbalance of Na+/Ca2+, and one of the several causes of hypertension and cardiovascular complications. However, the effect of Na+ gradient on AD patients is unclear. The purpose of this study was to test the hypothesis that in AD the increase of Na+ gradient diminishes the Ab ability on activation of CaSR and does not induce the hypertension. Method: We examined the effect of Na+ load on the arterial blood pressure in double transgenic mice harboring Ab precursor protein (APPswe), and presenilin-1 (PSEN1) as mouse model of AD (10-20 weeks, 25-30g). Wild type littermates were used as controls. Four groups: Control + low sodium diet (n=6); Control + high sodium diet (n=12); APP + low sodium diet (n=12); APP + high sodium diet (n=12) were tested for both systolic arterial blood pressure (SAP) and diastolic arterial blood pressure (DAP). Mice were fed a low- (0.08% NaCl) or a high-sodium (4% NaCl) diet for 3 months. Heart rate and SAP and DAP were measured noninvasively using tail blood pressure measurement device after 3 months. Results: Compared with mice fed standard diet (0.08% NaCl), mice fed high sodium diet showed markedly elevated SAP and DAP (134±4.8 compared with 162±2.8 mmHg, and 114±5.0 compared with 137±20 mmHg) (p&lt;0.0001). There was no significant difference in both SAP and DAP between APP mice fed standard (0.08% NaCl) and high-sodium (4% NaCl) diet. SAP and DAP in elevated Aβ mouse were not affected by high dietary levels of sodium. Conclusion: Data from this AD model suggest that APP transgenic mice is resistant to high sodium-induced increase in systolic and diastolic blood pressure.

Effects of dietary electrolyte balance on the performance, plasma biochemistry parameters and immunoglobulin of sows during late gestation and lactation

An experiment was conducted to investigate the effects of dietary electrolyte balance (dEB) on the performance, urine pH, plasma biochemistry parameters, milk composition and immunoglobulin of sows during late gestation and lactation. Forty-eight sows (Landrace×Large white, mean parity 4.1±1.75) were randomly allocated to four dietary treatments, with twelve replicates per treatment and one sow per replicate according to body weight and parity number. The dietary treatments were with dEB values of −100, 0, 162 (control group), and 300mEq/kg from day 90 of gestation to farrowing, transitioning to −100, 0, 198 (control group), and 300mEq/kg dEB, respectively, throughout the subsequent 21 days of lactation. Dietary electrolyte balance values were obtained by manipulating dietary sodium (Na) and chloride (Cl) levels. Calcium (Ca) and phosphorus (P) concentrations were held constant across experimental diets. Blood and urine samples were collected on day 107 of gestation, day of farrowing and weaning (day 21 of lactation). The colostrum and milk samples were obtained on day 0 and day 14 of lactation, respectively. The results showed that average daily feed intake (ADFI) of lactating sows was lower in sows fed a –100mEq/kg diet compared with the other three groups (P<0.05) and other parameters of the sow or litter performance were not different (P>0.05) among dietary treatments. Urine pH values were lower (P<0.05) in sows fed −100 and 0mEq/kg diets compared with the control and 300mEq/kg group, and urine pH of the control group was lower (P<0.05) than that of 300mEq/kg group at all sample periods. Additionally, the pH of the urine was also lower in sows fed −100mEq/kg diet compared with the 0mEq/kg group at the day of weaning (P<0.05). Plasma Cl and Mg concentrations were higher in sows fed −100 or 0mEq/kg diet compared with the control group (P<0.05) at all measurement stages. No differences were observed among dietary treatments in plasma Ca, P concentrations (P>0.05). The percentages of protein, lactose and fat in the colostrum and milk were similar among dietary treatments (P>0.05). The immunoglobulin in plasma, colostrum and milk was higher in sows fed −100 or 0mEq/kg diet compared with the control group (P<0.05). In conclusion, changing dEB during late gestation and lactation did not affect sow or litter performance; or the percentages of protein, lactose, or fat in either colostrum or milk. Decreasing dEB increased plasma Cl and Mg concentrations and enhanced immunoglobulin in plasma, colostrum and milk and reduced urine pH, while, ADFI of lactating sows was lower in sows fed −100mEq/kg diet compared with the other three groups.

A call for quality research on salt intake and health: from the World Hypertension League and supporting organizations.

Extensive research supports the harmful effects of high dietary sodium.[1-11] In several animal species, including chimpanzees, diets with added sodium result in increased blood pressure (BP), and, in all settings, sodium-induced hypertension is harmful.[12] Further, in several animal models, increased dietary sodium directly causes inflammation and vascular, cardiac, and renal target organ damage independent of BP.[1, 13] Increased dietary sodium is a procarcinogen for gastric cancer in animal studies and a probable procarcinogen in humans, as shown in epidemiological studies that have found close associations between sodium intake and gastric cancer.[14, 15] Reducing dietary sodium decreases BP in adults and children,[1] with a linear relationship down to the lowest levels of sodium intake tested in randomized controlled trials (about 1200 mg/d of sodium). Increased dietary sodium is also associated with increased vascular events in healthy populations and was estimated to cause more than 3 million sodium-related deaths in 2010 (http://viz.healthmetricsandevaluation.org/gbd-compare/). Reducing dietary sodium is projected to be one of the most effective (and cost-effective) interventions to improve health.[16] Major health and scientific organizations around the world have recommended that dietary sodium levels be reduced.

Sodium, Potassium, Blood Pressure, and Cardiovascular Disease in Humans

The scientific underpinning for recommended levels of dietary sodium and potassium intake is of great importance to healthcare providers and policy decision-makers. Recent clinical trials and meta-analyses confirm the capacity of dietary sodium reduction and potassium supplementation to reduce blood pressure with no harmful effects on blood lipid levels in customary clinical settings. Blood pressure is thought to be a good surrogate for cardiovascular disease events and the most important preventable risk factor for mortality and disability-adjusted life years. Cohort analyses and related pooling studies that have been used to explore the relationship between dietary Na and CVD were all based on secondary analyses of datasets that were not designed for this purpose. Most are of insufficient quality to provide dependable information. The limited information available from clinical trial experience and cohort studies of higher quality suggests a reduction in dietary Na decreases CVD morbidity and mortality. Modeling studies suggest that a small reduction in dietary sodium would result in a sizable general population health benefit. Some countries have experienced a progressive decline in average dietary sodium consumption. However, there is no evidence of a corresponding trend in the United States, and almost the entire population is failing to meet dietary sodium and potassium guideline recommendations.

Estimation of salt intake by 24-hour urinary sodium excretion: a cross-sectional study in Yantai, China

BackgroundHigh levels of dietary sodium are associated with raised blood pressure and adverse cardiovascular health. To determine baseline salt intake, we investigated the average dietary salt intake from 24-hour urinary sodium excretion with a small sample of Yantai adults in the Shandong province of China.MethodsOne hundred ninety one adults aged 18–69 years were randomly selected from the Yantai adult population. Blood pressure, anthropometric indices and sodium excretion in a 24-hour urine collection were measured. Consumption of condiments was derived from 3-day weighted records. Completeness of urine collections was verified using creatinine excretion in relation to weight.ResultsThe mean Na and K outputs over 24 hours were 201.5 ± 77.7 mmol/day and 46.8 ± 23.2 mmol/day, respectively (corresponding to 11.8 g NaCl and 1.8 g K). Overall, 92.1% of the subjects (96.9% of men and 87.1% of women) had intakes of over 6 g salt (NaCl)/d. The main sources of salt intake from weighed condiments records were from home cooking salt (74.7%) followed by soy sauce (15.0%). Salt intake from condiments and salt excretion were weakly correlated((r = 0.20, p = 0.005).A positive linear correlation between salt intake was associated with systolic blood pressure in all adjusted and unadjusted model (r = 0.16, p = 0.01). Each 100 mmol/day increase in sodium intake was associated with a 4.0 mmHg increase in systolic blood pressure.ConclusionDietary salt intake in Yantai adults was high. Reducing the intake of table salt and soy sauce used in cooking will be an important strategy to reduce sodium intake among Yantai adults.

Dietary Responses to a Hypertension Diagnosis: Evidence from the National Health and Nutrition Examination Survey (NHANES) 2007–2010

Dietary modification has been shown to substantially reduce blood pressure among people with hypertension. This article uses data from the 2007–2008 and 2009–2010 cross-sections of the National Health and Nutrition Examination Survey (NHANES) to examine the extent to which a hypertension diagnosis can influence individuals’ dietary choices. Several models were estimated to clarify the association of a hypertension diagnosis with dietary factors related to hypertension management. A comparison group of individuals at risk for developing hypertension was used. Results suggest that individuals who received a recent diagnosis of hypertension are more likely to have lower intakes of some dietary factors important in blood pressure management, including sodium. The results also highlight a discrepancy between added salt use and dietary sodium intake. While more recent hypertensive patients tended to consume lower levels of dietary sodium, patients diagnosed longer ago tended to use less added salt. Given that those diagnosed were more likely to have lower blood pressure profiles and improved diets, especially close to the time of diagnosis, the results of this study underscore the need for a prompt and accurate diagnosis of hypertension.

What Should We Tell Patients with Heart Failure about Sodium Restriction and How Should We Counsel Them?

This article is a review of current evidence regarding the recommended level of dietary sodium, involvement of family members in adoption of a low sodium diet, and evidence-based strategies to increase patient and family member willingness and ability to a follow a low sodium diet. The available evidence suggests that recommending a 2.5 to 3 g sodium diet will meet nutritional needs and decrease risk of hospitalizations. The best strategy identified for patient success is to fully involve both patients and family members in jointly reducing sodium intake. Motivational interviewing techniques should be used before counseling begins to guide patients and family members toward realization of the need to follow a low sodium diet. Successful counseling starts with determining perceptions, barriers, and individual characteristics that impede adherence. This information is incorporated into theory-based teaching strategies to promote behavior change and successful adoption of a low sodium diet.

Spatial variation of salt intake in Britain and association with socioeconomic status

ObjectivesTo evaluate spatial effects of variation and social determinants of salt intake in Britain.DesignCross-sectional survey.SettingGreat Britain.Participants2105 white male and female participants, aged 19–64 years, from the British National Diet and...

Effect of different levels of dietary sodium from sodium chloride on gastrointestinal tract response, tibia mineralization, and footpad dermatitis incidence in young turkeys

SUMMARY The objective of this study was to determine whether different levels of dietary Na from NaCl affect gut function, tibia mineralization, and footpad dermatitis incidence in young turkeys. Male B.U.T. 9 turkeys (n = 308) were fed diets with very low, low, medium, and high NaCl addition, providing 0.07, 0.12, 0.17, and 0.22% Na and 0.23, 0.30, 0.40, and 0.49% Cl. Only the very low NaCl treatment negatively (P < 0.05) affected the growth rate and feed conversion in 8-wk-old turkeys. Both very low and low dietary NaCl levels adversely affected the density index and the elastic strength of the tibia. Dry matter concentrations in the small intestine and digesta viscosity were found to decrease along with increasing NaCl addition. The moisture content of cecal digesta and excreta was not affected by dietary treatments, although significantly lower footpad dermatitis scores were noted in groups fed the very low and low NaCl diets. A high salt level was associated with an increase in cecal pH, NH3 concentrations, and β-glucuronidase activity (P < 0.05 vs. other groups). It may be concluded that the medium level of NaCl addition seems to be the best dietary option because the other treatments decreased the BW of 8-wk-old turkeys (very low NaCl level), reduced tibia strength (very low and low NaCl levels), or negatively affected cecal metabolism (high NaCl level).

Influence of graded levels of dietary sodium on the development of footpad dermatitis in broiler chickens

SUMMARY An experiment was conducted to investigate the effects of graded levels of dietary Na (0.15, 0.20, 0.25, and 0.30% Na) on the live performance and development of footpad dermatitis (FPD) in broiler chickens reared to 49 d of age. On the day of hatch, 1,280 mixed-sex chicks were randomly allotted to 4 treatments, with 8 replicate pens of 40 broilers per pen. Feed and water consumption were monitored and litter samples were analyzed for moisture. The incidence and severity of FPD were assessed by examining all birds on d 28 and 49. Dietary supplementation of broiler diets with graded levels of Na improved (P < 0.05) FCR on d 14 (linear and quadratic), BW on d 28 and 49 (linear), decreased mortality on d 49 (linear), and increased total water consumption (linear). Litter moisture level also increased (P < 0.001) linearly from 24% (0.15% Na) to 32% (0.30% Na) on d 49. Moreover, the incidence and severity of FPD on d 28 and 49 were increased linearly with Na levels in the diet. On d 49, FPD severity was the most severe for broilers receiving the highest dietary levels of Na. With these results, we confirm earlier reports that high dietary Na can increase litter moisture and can therefore be a direct trigger of FPD development in broiler chickens.

The effect of different dietary sodium levels on blood electrolytes, growth performance and foot pad dermatitis incidence in turkeys

The objective of this study was to determine the effect of different dietary sodium levels on serum macroelement concentrations, growth performance and incidence of foot pad dermatitis (FPD) in female turkeys raised to six weeks of age. The influence of a lowsodium diet (without additional sodium) and diets supplemented with NaCl to increase sodium content by 0.5, 1.0, 1.5, 2.0 and 2.5 g kg–1 was compared. The dietary electrolyte balance (DEB) was high (242-248 mEq kg–1) due to a high potassium content (11.0 g kg–1). Turkeys fed the low-sodium diet were characterized by significantly lower concentrations of chloride (p=0.002) and phosphorus (p<0.001), and significantly higher magnesium levels (p<0.001), compared with the other groups. The lowest dietary inclusion of sodium (0.5 g kg –1 ) contributed to a significant increase in the body weights of turkeys at six weeks of age (p<0.001), and it improved feed conversion efficiency (p<0.001) in comparison with the low-sodium diet. No significant differences in body weight and feed conversion ratio followed experimental treatments with higher dietary NaCl addition. Diets supplemented with different amounts of sodium had no effect on litter moisture content, whereas the incidence of FPD increased significantly following the addition of dietary sodium at 1.0 g kg–1 to 2.5 g kg–1, compared with the low-sodium diet. The results of our study indicate that moderate sodium supplementation (0.5 g kg–1) of a sodium-deficient diet significantly increased the body weights of young

The effect of different dietary sodium levels on blood mineral concentrations and tibia mineralization in turkeys

The objective of this study was to determine the effect of different dietary levels of sodium in diets with and without sodium chloride on mineral metabolism, including blood electrolyte levels and tibia mineralization parameters, in young turkeys (to six weeks of age). The influence of diets with a low (L), medium (M) and high (H) sodium content, at 0.34, 1.34 and 2.82 g/kg respectively, was compared. The content of chloride and potassium in turkey diets (1.7 - 5.9 and 11 g/kg, respectively) was above the recommended levels. The sodium-deficient diet L decreased the serum concentrations of sodium, chloride and phosphorus, and it increased the serum levels of calcium and magnesium in turkeys, compared with groups M and H. Relative to group L, different dietary sodium levels in groups M and H contributed to a similar increase in the body weights of birds (1.06 vs. 1.46 and 1.44 kg, p < 0.001) and in the absolute (4.60 vs. 6.83 and 6.62 g, p < 0.001) and relative tibia weight (0.42 vs. 0.46 and 0.46% body weight, p = 0.031). No significant differences were found between groups with respect to the content of ash, calcium and phosphorus in tibia dry matter. Supplemental sodium increased the bone density index (from 50.6 to 68.4 and 66.3 mg/mm in groups L, M and H, respectively, p < 0.001), the maximum bending moment (from 5.27 to 7.40 and 7.33 N/mm, p = 0.002) and the minimum breaking strength of tibia (from 0.136 to 0.191 and 0.189, p = 0.002). In conclusion, our study indicates that the applied dietary treatment with a moderate sodium level (1.34 g/kg) resulted in a rate of bird growth and tibia mineralization similar to those observed with the treatment with much higher Na content (2.82 g/kg).

Effects of inclusion level and source of dietary sodium on performance and meat characteristics of broiler chickens

The effect of different concentrations of dietary Na from three Na salts (NaCl, NaHCO3 and Na2SO4) was assessed in two experiments carried out on broiler chickens aged from 1 to 35 days. In Exp. 1, diets were supplemented with 0.15, 0.20 and 0.25% Na, which increased the average Na content of the diets to 0.19, 0.24 and 0.30% respectively. In Exp. 2, the amounts of selected Na salts (NaCl and Na2SO4) were reduced and the estimated Na contents of experimental diets amounted to 0.10, 0.13, 0.15 and 0.19%. In view of the risk factors for the development of foot pad dermatitis, our aim was to find an optimum source of Na and to keep dietary Na intake at the minimum level sufficient to support normal growth and acceptable slaughter quality. The present results suggest that the amount of Na required for the undisturbed growth of broilers and adequate feed conversion is not less than 0.15% of additional Na in the starter period (1–14 d), and not less than 0.11% in the grower period (until day 35). Higher dietary Na levels did not lead to further production advantages, and were found to increase the moisture content of droppings. Dry matter concentration of excreta was also affected by Na source. In comparison with NaHCO3, Na2SO4 seemed to be a better alternative for NaCl. Na2SO4 also tended to surpass NaHCO3 as a dietary alternative for NaCl in terms of feed utilisation during the starter period. The applied additional Na levels (0.25 and 0.15%) and Na sources had no effect on the sensory profile and composition of breast meat.

The effect of different dietary sodium levels on the growth performance of broiler chickens, gastrointestinal function, excreta moisture and tibia mineralization

The effect of different dietary sodium levels on the growth performance of broiler chickens, gastrointestinal function, excreta moisture and tibia mineralization