Performance, serum characteristics, carcase traits and lipid metabolism of broilers as affected by supplement of chromium picolinate

Effects of dietary supplementation of chromium methionine chelate on growth performance, oxidative stress, hematological indices, and carcass traits of broiler chickens

This study was conducted to evaluate the dietary effects of chromium methionine (Cr-Meth) chelate on growth performance, oxidative stress parameters, blood biochemistry, and carcass traits of broiler chickens. An experiment was conducted on 34,000 1-day-old straight-run broiler chicks (Indian River; 42.0 ± 0.03) at a commercial farm. The chicks were divided randomly into 3 groups; the first group contained 17,000 birds, which used as a control, whereas the second and third groups consisted of 7000 and 10,000 birds, respectively, with 5 replicates per group. A completely randomized design was used. The birds were fed the experimental diets containing graded levels of Cr-Meth chelate: 0 (control), 50, and 100 g/ton. This compound consisted of chromium (0.4%) chelated with methionine, and it supply the diets with 200 and 400 ppb Cr for the used levels of 50 and 100 g/ton feed, respectively. Growth performance indices (body weight, body weight gain, feed intake, and feed conversion ratio) were measured throughout the experiment. At the end of experiment, 10 birds per treatment were slaughtered, and the carcass yield with relative weight of the internal organs was determined. Also, blood samples were taken and analyzed for glutathione peroxidase activity, malondialdehyde, ALT, AST, total protein, albumin, glucose, urea, creatinine, triglycerides, and total cholesterol. It was found that Cr-Meth improved the body weight, weight gain, feed intake, and feed conversion ratio of broilers. Moreover, it reduced the mortality rate of birds. The chelated chromium can alleviate the oxidative status of birds by increasing the plasma glutathione peroxidase activity and reducing the serum malondialdehyde level. It was observed that the effects of 100 g/ton Cr-Meth chelate on performance indices, mortality rate, and oxidative stress parameters were better than that of 50 g/ton inclusion rate. Supplementation of Cr-Meth increased the total protein level, but reduced the glucose, total cholesterol, and triglyceride concentrations in the blood serum. In addition, it increased the carcass yield and reduced the abdominal fat percentage of the birds’ carcass. Therefore, chromium can be included in diets of broilers at a rate of 200 to 400 ppb, and the higher concentration was more effective than the lower one. So, it can be recommended to use Cr-Meth chelate in broiler diets at 100 g/ton to improve the productive performance and reduce the oxidative stress of birds.

Effects of Dietary Chromium Picolinate on Gut Microbiota, Gastrointestinal Peptides, Glucose Homeostasis, and Performance of Heat-Stressed Broilers

The current research was devoted to evaluating the effects on gut microbiota, gastrointestinal peptides, and glucose homeostasis of chromium picolinate applied to heat-stressed broilers. In a 14 d experiment, 220 28-day-old AA broilers were randomly assigned into one thermal-neutral and three high-temperature groups dietary-supplemented with 0, 0.4, or 0.8 mg/kg of chromium as chromium picolinate. The temperature for the thermal-neutral group was set at 21 °C, while that for the other three groups (high temperature) was set at 31 °C. The results showed that the average daily gain and average daily feed intake of the 0.4 mg/kg chromium-supplemented group significantly increased compared with the high-temperature groups (p < 0.05). The content of cholecystokinin in the 0.4 mg/kg group significantly decreased, and the gastric inhibitory polypeptide level was significantly elevated in jejunum (p < 0.05). The cecal microbiota of heat-stressed broilers was substantially different from that of the thermal-neutral group. After diet-supplemented chromium, compared to the high-temperature groups, the 0.4 mg/kg chromium supplemented group was characterized by a reduction of Actinobacteriota and Proteobacteria at the phylum level. The Bacilli were elevated, while proportions of Coriobacteria and Gammaproteobacteria were reduced significantly at the class level. The proportions of Lactobacillaceae, Christensenellaceae, and Erysipelotrichaceae were elevated significantly, while that of Clostridiaceae was reduced significantly at the family level. The proportion of Turicibacter was elevated significantly and the proportions of Olsenella and Ruminococcus were reduced significantly at the genus level (p < 0.05). Compared to the high-temperature groups, in the 0.4 mg/kg chromium-supplemented group, the insulin concentration and insulin resistance index were reduced (p < 0.05), and sodium-glucose transporter 1 expression was up-regulated in jejunum (p < 0.05). Performance, microbiota, gastrointestinal peptides, or serum parameters of the 0.8 mg/kg group were almost unaffected by chromium compared with the high-temperature groups. In conclusion, diet supplemented with 0.4 mg/kg Cr improved performance, insulin resistance and sodium-glucose transporter 1 expression and altered gut microflora structure and secretion of gastrointestinal peptides, thus showing that supplementation with chromium is beneficial to maintain glucose homeostasis and alleviate heat stress.

Effects of dietary chromium picolinate supplementation on broiler growth performance: A meta-analysis

Objective

A meta-analysis was conducted to assess the effects of dietary chromium picolinate (CrPic) supplementation on broiler growth performance and to determine whether such effects are regulated by broiler strains, sex, environmental stress, or contextual factors including study area and years.

Methods

Eligible studies were identified by searching the Web of Science, Springer, Elsevier, ScienceDirect, Taylor & Francis Online databases. Weighted average differences with corresponding 95% confidence intervals were computed with a random-effects model. We performed subgroup analysis stratified by study area, published years, broiler strains and sex, and environmental stress. Publication bias was assessed with Egger’s test method. A total of 15 studies eligible for inclusion.

Results

The results indicated that CrPic supplementation significantly improved broiler growth performance and subgroup analysis confirmed this conclusion. We also found that Ross 308 or male broilers might be more sensitive to CrPic supplementation and showed better growth performance. A model was used to obtain the amount of chromium addition under the optimal growth performance, which suggested that the maximum value of average daily gain (ADG) was reached when chromium addition was 1810 μg/kg. The results of the sensitivity analysis showed low sensitivity and high stability of the meta-analysis.

Conclusions

CrPic supplementation had a positive effect on the growth performance of broilers, and this meta-analysis provides a more accurate value of chromium addition, which may be beneficial for the practice of the broiler industry.

Improvement in the growth status and carbohydrate utilization of Labeo rohita (Hamilton, 1822) fingerlings with dietary supplementation of chromium picolinate

A 60-day feeding experiment was conducted to evaluate the effects of dietary chromium (Cr) on carbohydrate utilization and growth performance of Labeo rohita fingerlings. Fishes were fed with four high carbohydrate (53%), isonitrogenous (crude protein 35%), and isocaloric (415 Kcal, 100 gm^-1) experimental diets containing different levels of dietary chromium picolinate (Cr-Pic) viz.0, 400, 800, and 1200 μg kg^-1 diet. Weight gain (WG%), specific growth rate (SGR), feed efficiency ratio (FER), and protein efficiency ratio (PER) were significantly increased at 800 μg kg^-1 diet chromium supplementation (P < 0.05). Cr-Pic supplementation (800 μg kg^-1) also significantly (P < 0.05) enhanced the protein: DNA ratio in muscle, while DNA: RNA and DNA: tissue ratios were significantly (P < 0.05) decreased indicating higher growth. Significantly higher amylase, protease, and lipase activities were recorded in 800 μg Cr-Pic kg^-1 diet fed fishes (P < 0.05), while any of the experimental groups showing no significant (P > 0.05) change in hexokinase activity, indicating normal glycolysis in all. Furthermore, significant (P < 0.05) decrease of glucose-6-phospatase activity in 800 μg Cr-Pic kg^-1 diet fed group, showcasing an evidence for protein-sparing action with Cr-Pic supplementation. Significantly (P < 0.05) higher serum insulin and liver glycogen in 800 μg Cr-Pic kg^-1 diet fed fishes denote an improvement in carbohydrate metabolism. However, significantly (P < 0.05) higher ATPase and SOD activities were also observed when chromium supplementation was more than 800 μg kg^-1 diet, indicating stress at higher level. The present study indicates that growth and carbohydrate utilization can significantly (P < 0.05) be improved by feeding the L. rohita fingerlings with Cr-Pic (800 μg kg^-1 diet) supplemented diet in laboratory condition.

Obesity, insulin resistance, adiponectin, and PPAR-γ gene expression in broiler chicks fed diets supplemented with fat and green tea (Camellia sinensis) extract

Adipose tissue is an active endocrine organ secreting several adipokines, especially adiponectin, that play an important role in regulating insulin function in the body of mammals. Therefore, this study was aimed to investigate the association between abdominal fat deposit, insulin resistance, peroxisome proliferator-activated receptor gamma (PPAR-γ), and adiponectin gene (AG) expression in broiler chicks fed diets high in unsaturated fat supplemented with green tea extract (GTE). A total of 300 one-day-old female Ross 308 broiler chicks were allocated to 6 dietary treatments in a completely randomized design with a factorial arrangement of two levels of GTE (0 and 500 mg/kg diet) × three levels of fat inclusion [without fat (control group), soybean oil (SO), and tallow (Ta)]. Each treatment was replicated five times. At the end of the experiment (day 49), two chicks from each replicate weighing an average of pen weight were bled and then slaughtered for further analysis. Abdominal fat percentage, fasting concentration of blood glucose, triglyceride and insulin, glycogen reserves of breast and liver tissues, and PPAR-γ and AG expression were determined. The insulin resistance index of the Quantitative Insulin Sensitivity Check Index (QUICKI) was calculated using the fasting plasma glucose and insulin concentrations. The highest abdominal fat percentage and the lowest carcass yield were obtained in chicks fed SO-supplemented diet (P < 0.05). Chicks fed diet supplemented with SO showed the highest PPAR-γ gene expression (P < 0.05). SO-rich diets suppressed AG expression in chickens' abdominal fat tissue, and the birds fed with SO-supplemented diet showed a significant decrease in AG expression compared with the control (P < 0.05). Chicks fed diet supplemented with SO showed lower QUICKI and breast glycogen reserve compared with the control group (P < 0.05). A significant increase in blood glucose and triglyceride concentrations was observed in birds fed SO-supplemented diets (P < 0.05). AG and PPAR-γ expression increased and decreased by GTE, respectively. QUICKI tended (P = 0.09) to be greater in GTE-supplemented chicks; however, the effect of GTE supplementation on carcass yield, abdominal fat percentage, and blood insulin and glucose concentration was not significant. The findings of this study showed that SO-rich diets via increased PPAR-γ gene expression and decreased AG expression in abdominal fat may lead to insulin resistance in female broiler chicks.

Chromium propionate improves performance and carcass traits in broilers

There is evidence to suggest that poultry may have a dietary requirement for metabolically available chromium (Cr) that exceeds the amount provided through wheat soybean meal diets. The objective of the present study was to investigate the effects of dietary supplemental organic Cr from Cr propionate at different dose levels (control = 0 μg/kg, T1 = 200 μg/kg, T2 = 400 μg/kg) on the growth performance, carcass traits, and meat quality of broilers. Weight gain and feed intake of each treatment were recorded at the start and after 14, 28 and 35 d, and feed conversion ratios (FCR) were calculated accordingly. At 35 d of age, birds were randomly selected and euthanized for carcass evaluation. Results of the first trial indicate that both Cr propionate treatments increased final body weight (P < 0.05), feed efficiency (P < 0.05) and body weight gain (P < 0.0001). Furthermore, Cr propionate supplementation improved (P < 0.0001) all carcass characteristics. Interestingly, with increased Cr dosage, carcass yield, dressing percentage and breast meat yield increased linearly (P < 0.0001). The second study reveals that the feed intake in the control group was significantly higher compared to both Cr propionate supplemented groups (T1 & T2). Furthermore, the Cr propionate supplemented T2 group displayed a significantly lower FCR than the control and T1 group (P = 0.027). Finally, Cr propionate supplementation increased the dressing percentage compared to control birds (P < 0.0001). In the third experiment, Cr propionate supplementation (T1 & T2) increased final body weight and decreased FCR compared with the control treatment. These effects were highly significant (P < 0.0001) throughout all feeding phases of the trial. Cr propionate supplementation also increased (P < 0.0001) carcass yield, dressing percentage, breast meat yield, leg and thigh weights compared with the control treatment. In conclusion, growth performance, feed conversion, carcass yield, breast and leg meats of broiler birds can be significantly improved by dietary inclusion of Cr propionate. Cr propionate can be supplemented to broiler birds from 1 d old of age at a level that provides 200 or 400 μg/kg organic Cr and can increase the efficiency of broiler production.

Evaluation of Heavy Metal Content in Feed, Litter, Meat, Meat Products, Liver, and Table Eggs of Chickens

We assessed the concentrations of Fe, Cu, Zn, Mn, Se, Co, Cr, Pb, Cd, and Ni in chicken meat and meat products, feed, and litter, as well as laying hens' eggs, feed and litter to monitor the quality of products on the market and their safety for human consumption as judged by recommended daily allowance (RDA) and tolerable upper levels. Samples were chosen as the most popular poultry products in Saudi Arabia. A total of 45 broiler samples of frozen or fresh meat, liver, burger, or frankfurter were chosen from the same brand. Additionally, 60 table eggs from four commercial brands were collected, and the edible parts of these were used to determine levels of minerals and toxic elements. Furthermore, 30 feed and litter samples were collected from the starter, grower, and layer diets of broilers and laying hens. The results indicated that there were significant levels of most of the trace elements and heavy metals in the different meat sources. Furthermore, the liver contained the highest levels of elements, except for Cr, Co, and Ni. The highest Cr level was detected in the fresh meat, followed by frozen meat. Trace elements (Mn and Co) and heavy metals (Ni and Pb) were not detected in either the frozen or the fresh meat. The chicken burger and the frankfurter exhibited similar trace-element and heavy-metal contents, except for Zn and Mn, as the frankfurter showed higher concentrations than the burger. Differences in most of the trace and toxic elements among the different sources of eggs were not found to be significant, except for Zn. Differences between the broiler meat and table eggs were only substantial for Fe and Zn. Fe was significantly higher in meat than in eggs, and the opposite trend was found for Zn. The liver contained higher heavy metals than the eggs, except for Cr. In addition, the burger had higher concentrations of essential (Cu and Co) and heavy metals (Pb and Ni) than the eggs but had lower levels of Zn and Cr. The frankfurter exhibited significantly higher levels of Fe, Cu, Mn, Co, Pb, and Ni than the eggs but lower levels of Zn and Cr. To summarize, Cd, Pb, As, and Se were not detected in the broiler meat or eggs, indicating no risks from these toxic elements. Conversely, the liver exhibited the highest content of heavy metals, except for Cr, indicating that the intake of Pb and Cd was above the recommended daily allowance (RDA) for adults. The meat products exhibited higher Pb, Cd, and Ni levels than the broiler meat and the table eggs, suggesting that they posed a health threat to humans, and the intake of Pb in the meat products was higher than the RDA. Thus, chicken meat and table eggs, which are primary protein sources, are safe sources of human nutrition, while liver and meat products may present potential health hazards through the food chain.

Effects of dietary inclusion of chromium propionate on growth performance, intestinal health, immune response and nutrient transporter gene expression in broilers

The intent of the present study was to evaluate the effect of chromium (Cr³⁺) as chromium propionate on growth performance, organ index, immune response, intestinal morphology and nutrient transporter gene expression in broilers. One-day-old broiler chicks (n = 756) were divided into six experimental groups of 126 chicks; each group was further divided into 7 replicates (18 chicks/replicate). All birds were offered corn-soybean diets supplemented with Cr³⁺ at 0, 0.10, 0.15, 0.20, 0.25 or 0.30 mg/kg. Dietary inclusion of Cr³⁺ at various levels yielded significantly better growth performance and organ index in birds. Similarly, antibody titre against Newcastle disease and avian influenza H5 at various ages was found to be significantly higher in birds that received 0.15 mg/kg Cr³⁺ in the diet. Significant results with respect to villus height (VH), crypt depth (CD) and VH:CD were observed in all groups that received Cr³⁺ in the diet compared to control. Moreover, it was observed that different levels of Cr³⁺ supplementation of the diet also increased the expression of the nutrient transporter genes SGLT1, GLUT2, rBAT and CAT1 in broilers. The findings of the present study suggest that dietary inclusion of Cr³⁺ at various levels may have beneficial effects on growth performance, immunity, intestinal morphology and nutrient transporter gene expression in broilers. Supplementation of the diet with Cr³⁺ at a level of 0.15 mg/kg could yield better performance in broiler production.

The Effect of Chromium Nanoparticles and Chromium Picolinate in the Diet of Chickens on Levels of Selected Hormones and Tissue Antioxidant Status

Simple Summary

We have postulated that supplementation with Cr can increase serotonin levels and improve the antioxidant status of chickens, with no adverse effect on the secretion of other hormones. Obtaining such results may be beneficial in high-density rearing of poultry exposed to many stressors. The studies compared the effects of two forms of Cr (Cr-Pic and Cr-NP) found at two doses 3 and 6 mg/kg. It was found that at the dose of 3 mg/kg, the expected beneficial results can be obtained (increase in serotonin and decrease in norepinephrine level), however, due to the deterioration of the antioxidative system, these studies should be continued to verify these results. Due to the adverse effect of Cr at 3 mg/kg on the antioxidant status of chickens, this level of Cr should not be considered in both forms Cr-Pic and Cr-NP as a feed additive for broiler chickens. In the future, studies on the potential beneficial effects of Cr on the organism should take into account doses lower than 3 mg/kg.

Abstract

We have postulated that supplementation with Cr can increase serotonin levels and improve the antioxidant status of chickens, with no adverse effect on the secretion of other hormones. The study aimed to determine what form and dose of Cr more favorably affect the level of selected hormones (insulin, glucagon, serotonin, dopamine, noradrenaline, histamine, T3 and T4) and the antioxidant status (level of malondialdehyde and lipid peroxides, activity of superoxide dismutase and catalase) of chicken tissues. The experiment was carried out on chickens randomly divided into five treatment groups. The basal diets (control group) were supplemented with two levels of Cr (3 and 6 mg/kg) and two Cr sources: Cr-picolinate (Cr-Pic) and Cr-nano (Cr-NP) to obtain four experimental diets: 3 mg/kg Cr-Pic, 6.0 mg/kg Cr-Pic, 3.0 mg/kg Cr-NP. and 6.0 mg/kg Cr-NP. The addition of Cr in both forms increased the level of serotonin at a dose of 3 mg/kg and, at the same time, reduced the level of noradrenaline. The addition of Cr at 3 mg/kg, irrespective of the form used, regulated the level of hormones of carbohydrate metabolism (increasing insulin levels and reducing glucagon levels) and had an adverse effect on the antioxidant status of the liver and breast muscle. Due to the adverse effect of Cr at 3 mg/kg on the antioxidant status of chickens, this level of Cr should not be considered in both forms Cr-Pic and Cr-NP as a feed additive for broiler chickens. In the future, studies on the potential beneficial effects of Cr on the organism should take into account doses lower than 3 mg/kg.

Effects of Chromium-Loaded Chitosan Nanoparticles on the Intestinal Electrophysiological Indices and Glucose Transporters in Broilers

The present study aimed to evaluate the effect of chromium-loaded chitosan nanoparticles (Cr-CNPs) on the electrophysiological indices, gene expression of glucose transporters, and tissue glycogen in broilers. A total of 200 one-day-old broilers were randomly divided into five groups, with each having five replicates (n = 8). Group A was fed a corn-soybean meal diet, while the diets of groups B, C, D, and E were supplemented with 200, 400, 800, and 1200 µg/kg of Cr as Cr-CNPs, respectively. On day 35, the jejunum was collected for electrophysiological study, gene expression of glucose transporters, and tissues glycogen determination. The basal short-circuit current and tissue conductance before the addition of glucose was the same in all groups. Following the addition of glucose, the change in short-circuit current decreased (p < 0.05) in the jejunal tissues of birds supplemented with 400 and 1200 µg Cr-CNPs compared with the control group. Gene expression of SGLT-1 and GLUT-2 remained unaffected with supplementation. The serum glucose and liver glycogen concentration decreased (p < 0.05) linearly with supplementation, while no effect was observed on muscle glycogen. In conclusion, Cr-CNPs supplementation decreases the glucose absorption and liver glycogen content, without affecting the gene expression of glucose transporters.

Effects of dietary chromium propionate on growth performance, metabolism, and immune biomarkers in heat-stressed finishing pigs1

Study objectives were to determine the effects of chromium (Cr) propionate (Cr propionate 0.04%; 0.5 g/kg of feed to deliver 200 parts per billion Cr/d; KemTRACE Cr, Kemin Industries, Inc., Des Moines, IA) on growth performance, metabolism, and health biomarkers in heat-stressed and nutrient-restricted pigs. Crossbred barrows (n = 96; 105 ± 1 kg BW) were enlisted in an experiment conducted in two replicates, blocked by initial BW, and randomly assigned to one of six dietary-environmental treatments: (i) thermoneutral (TN) and fed ad libitum a control diet (TNCtl), (ii) TN and fed ad libitum a Cr supplemented diet (TNCr), (iii) TN and pair-fed a control diet (PFCtl), (iv) TN and pair-fed a Cr supplemented diet (PFCr), (v) heat stress (HS) and ad libitum fed a control diet (HSCtl), or (vi) HS and ad libitum fed a Cr supplemented diet (HSCr). The study consisted of three experimental periods (P). During P0 (5 d), all pigs were housed in TN conditions (21.3 ± 0.1 °C, 56.8 ± 0.3% relative humidity [RH]) and fed the control diet ad libitum. During P1 (5 d), pigs were fed their respective dietary treatments ad libitum and kept in TN conditions. During P2 (35 d), HSCtl and HSCr-treated pigs were fed ad libitum and exposed to progressive cyclical HS conditions (27 to 31 °C, 50 ± 0.3% RH), while TNCtl, TNCr, PFCtl, and PFCr pigs remained in TN conditions and were fed ad libitum or pair-fed to their respective HSCtl and HSCr counterparts to eliminate the confounding effects of dissimilar feed intake. Overall, HS pigs had increased (P < 0.01) rectal temperature, skin temperature, and respiration rate (0.3 °C, 3.8 °C, and 32 breaths per minute, respectively) relative to TN pigs. Overall, HS decreased ADFI and ADG (20 and 21%, respectively; P < 0.01) compared with TN controls. Final BW tended to be increased in HSCr (2.7 kg, P = 0.06) compared with HSCtl pigs. Similarly, ADG tended to be increased during P2 in HSCr relative to HSCtl-treatment (0.77 vs. 0.72 kg/d; P = 0.10). There were no effects of Cr on most production parameters, but ADFI tended to be increased in Cr relative to Ctl-fed pigs (3.19 vs. 3.09 kg/d; P = 0.08). No effects of Cr supplementation were detected on circulating glucose, insulin, NEFA, cholesterol, triglycerides, or lipopolysaccharide binding protein. However, blood neutrophils were increased in HSCr (37%; P < 0.01) relative to HSCtl pigs. In summary, these results suggest Cr supplementation may benefit growth performance during HS.

Effect of dietary niacin supplementation on performance, total tract nutrient retention, carcass yield and meat lipid profile of growing turkeys

A study was conducted to investigate the influence of dietary high or recommended nicotinic acid (niacin) supplementation on growth performance, total tract nutrient digestibility, hematology, serum chemistry, and lipoprotein concentrations in the serum and meat of growing turkeys. Turkeys were assigned to three treatments on weight equalisation basis with five replicates of eight turkeys in each group. Experimental diets were: no supplemental niacin (Control), a diet supplemented with 60 mg/kg niacin termed as recommended niacin supplementation and a diet supplemented with 180 mg/kg niacin termed as high niacin supplementation (HNS). The experiment lasted for the grower (Day 56–84) and finisher phases (Day 84–112) of the birds. Dietary inclusion of HNS increased (P &lt; 0.01) bodyweight gain, metabolisable energy (Days 84 and 112), dressing percentage and retail cut parts of turkeys (Day 112) in relation to the Control-fed turkeys. Furthermore, least white blood cell count and higher concentrations of packed cell volume, red blood cells and hemoglobin (P &lt; 0.01) were found in turkeys fed HNS on Days 84 and 112. Similarly, turkeys in the HNS group had improved serum constituents including serum protein, uric acid, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphate. The blood and meat lipid profile analysis showed that low density lipoprotein and total cholesterol were least (P &lt; 0.05) in turkeys fed HNS. Collectively, dietary high supplementation of niacin (180 mg/kg) improves production performances, reduces serum and meat fat content and improve indicators of stress resistance ability in growing turkeys.

Dietary supplementation of organic or inorganic chromium modulates the immune responses of broilers vaccinated with Avian Influenza virus vaccine

Dietary supplementation with the organic chromium (Cr) has been shown to positively affect the immune function of poultry. However, to our knowledge, no experiment has been done to directly compare the impacts of Cr chloride and chromium picolinate (CrPic) on the immune responses of broilers vaccinated with Avian Influenza (AI) virus vaccine. Therefore, the present experiment was conducted to investigate the effects of supplemental Cr sources (Cr chloride and CrPic) and levels on the growth performance and immune responses of broilers vaccinated with AI virus vaccine so as to provide an effective nutritional strategy for improving immune function of broilers. A total of 432 1-day (d)-old male broiler chicks were used in a 1 plus 2×4 design. Chickens were given either a diet without Cr supplementation (control) or diets supplemented with 0.4, 0.8, 1.6, or 3.2 mg Cr/kg as either Cr chloride or CrPic for 42 d. Compared to the control, dietary Cr supplementation had no effect (P&gt;0.05) on average daily gain, average daily feed intake and gain : feed of broilers during the starter and grower phases, but increased (P&lt;0.05) the relative weights of bursa of fabricius on d 21 and thymus, spleen, or bursa of fabricius on d 42, serum antibody titers against AI virus on d 21, 28, 35 and 42, blood T-lymphocyte transformation rate on d 28 and 42, blood T-lymphocyte percentage on d 42, and serum interleukin-2 contents on d 28. Broilers fed the diets supplemented with the inorganic Cr chloride had higher (P&lt;0.05) weights of thymus, spleen and bursa of fabricius than those fed the diets supplemented with the CrPic on d 42. In addition, broilers fed the diets supplemented with the CrPic had higher (P&lt;0.05) antibody titers against AI virus than those fed the diets supplemented with the inorganic Cr chloride on d 21 and 35. These results indicate that dietary Cr supplementation improved immune responses of broilers vaccinated with AI virus, and the inorganic Cr chloride was more effective than the CrPic in increasing the relative weights of lymphoid organs, however, the CrPic was more effective than the inorganic Cr chloride in enhancing the serum antibody titer against AI virus.

Effects of chromium picolinate supplementation on growth, body composition, and biochemical parameters in Nile tilapia Oreochromis niloticus

A feeding trial was conducted to evaluate the effects of chromium picolinate (Cr-Pic) on growth performance, body composition, and biochemical parameters in Nile tilapia Oreochromis niloticus. Five experimental diets were formulated with high-protein diet (HP), low-protein diet (LP), and LP + 0.6, 1.2, or 1.8 mg kg^-1 Cr, respectively. Each diet was randomly assigned to four replicate groups of 30 fish per aquarium in a water-circulated rearing system for 60 days. Dietary 1.2 or 1.8 mg kg^-1 Cr inclusion significantly affects the final body weight, weight gain rate, specific growth rate, feed efficiency rate, and protein efficiency ratio of tilapia compare to the LP diet. The Cr inclusion significantly decreased the content of blood urea nitrogen and the blood glucose level generally with increasing Cr inclusion levels. The Cr content of gill tissue was higher than that of back muscle in all treatments, and the addition of 1.2 or 1.8 mg kg^-1 Cr significantly enhanced the Cr contents of back muscle. The cold stress test results showed that adding Cr significantly enhanced the serum T3 concentration and reduced the activity of serum creatine kinase and the serum cortisol level. These results indicated that the supplementation of chromium picolinate can improve the growth performance and reshape the serum protein and carbohydrate metabolism profile and has the potentiality to alleviate the detrimental effects of cold stress in Nile tilapia. The low-protein diet with 1.8 mg kg^-1 Cr obtained the same growth performance as the high-protein diet.

Effects of the supplemental chromium form on performance and metabolic profile in laying hens exposed to heat stress

This experiment was conducted to compare the effect of the supplemental chromium (Cr) form on performance, egg quality, and metabolic profile in laying hens exposed to heat stress (HS). Laying hens (n = 1800; 16-wk-old; Lohmann LSL-Lite) were kept in cages in temperature-controlled rooms at either 22 ± 2°C for 24 h/d (thermoneutral, TN) or 34 ± 2°C for 8 h/d, from 08:00 to 17:00 h, followed by 22°C for 16 h (HS) for 12 wks. Hens reared under both environmental conditions were fed 1 of 3 diets: a basal diet and the basal diet supplemented with either 1.600 mg of chromium-picolinate (CrPic, 12.43% Cr) or 0.788 mg of chromium-histidinate (CrHis, 25.22% Cr) per kg of diet, delivering 200 μg elemental Cr per kg diet. Data were analyzed by 2-way ANOVA. Exposure to HS caused decreases in feed intake (P < 0.0001), egg production (P < 0.0001), egg weight (P < 0.0001), eggshell weight (P < 0.0009), eggshell thickness (P < 0.0001), eggshell strength (P < 0.0001), and Haugh unit (P < 0.0001), deterioration in feed conversion ratio (P < 0.0001), increases in serum glucose and cholesterol concentrations (P < 0.0001 for both), decreases in serum and egg yolk Cr concentrations (P < 0.0001 for both), and decreases in serum Na (P < 0.002) and K (P < 0.01) concentrations. Both Cr sources were equally effective in alleviating performance variables under the HS condition. However, neither Cr sources alleviated deteriorations in egg quality parameters and serum electrolytes. Both Cr sources decreased serum glucose and cholesterol concentrations and increased serum and egg yolk Cr concentrations under the HS condition. In conclusion, HS adversely affected laying performance, egg quality, and metabolic profile. Both CrPic and CrHis partially alleviated the adverse effect of HS on these parameters. Inclusion of either Cr source could be a part of nutritional management strategies to overcome the adverse effects of HS performance and metabolic profile in laying hens.

Effects of the supplemental chromium form on performance and oxidative stress in broilers exposed to heat stress

This experiment was conducted to investigate effects of the organic complex form of supplemental chromium (Cr) on performance, oxidative stress markers, and serum profile in broilers exposed to heat stress (HS). A total of 1,200 10-day-old boilers (Ross-308) was divided into one of the 6 treatments (2 environmental temperatures x 3 diets with different Cr forms). The birds were kept in temperature-controlled rooms at either 22 ± 2°C 24 h/d (thermoneutral, TN group) or 34 ± 2°C for 8 h/d, 08:00 to 17:00 h, followed by 22°C for 16 h (HS group) and fed either a basal diet (C) or the basal diet supplemented with Cr (200 μg/kg) through 1.600 mg of CrPic (12.43% Cr) and 0.788 mg of CrHis (25.22% Cr). Feed intake and body weight were recorded weekly. After cervical dislocation, liver samples were harvested to analyze Cr concentration and glucose transporter-2,4 (GLUT-2,4) expression. The breast meat also was sampled for the concentration of Cr and expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa B (NF-κB). Data were analyzed by 2-way ANOVA. Heat stress caused depressions in feed intake (12.1%) and weight gain (21.1%) as well as elevations in feed conversion (11.2%) and abdominal fat (32.8%). It was also associated with depletion of Cr reserves and increases in serum concentrations of glucose, cholesterol, creatine, and enzymes. Exposure to HS was accompanied by suppression of the expressions of Nrf2 and GLUT-2 in muscle and GLUT-4 in the liver and amplification of the expression of NF-κB in muscle. Both Cr sources partially alleviated detrimental effects of HS on performance and metabolic profile. The efficacy of Cr as CrHis was more notable than Cr as CrPic, which could be attributed to higher bioavailability. In conclusion, CrHis can be added into the diet of broilers during hot seasons to overcome deteriorations in performance and wellbeing related to oxidative stress.

Dietary Supplementation of Chromium Can Alleviate Negative Impacts of Heat Stress on Performance, Carcass Yield, and Some Blood Hematology and Chemistry Indices of Growing Japanese Quail

The main objective of this work was to investigate the impact of dietary chromium supplementation on growth indices, carcass yield, and some hematological and biochemical blood parameters of growing Japanese quails subjected to heat stress. A total of 360 unsexed 2-week-old Japanese quail chicks were used in a 2 × 3 factorial arrangement that had two ambient temperatures (23 ± 2 and 33 ± 2 °C) and three dietary chromium (0.00, 500, and 1000 μg Cr/kg diet as chromium picolinate). For induction of heat stress, the room temperature was set at 33 ± 2 °C from 2 to 6 weeks of age. Results showed that body weight, body weight gain, and feed intake were decreased for birds subjected to heat stress condition during 2 to 4 and 2 to 6 weeks of age. Feed conversion was not significantly (P > 0.05) affected by high ambient temperature throughout the experiment. Carcass, dressing, liver, and heart percentages were not influenced by the ambient temperature or dietary chromium or their combinations. Significant temperature × chromium combinations were observed for hemoglobin value (P = 0.025) and packed cell volume (P = 0.001). Cholesterol and glucose in plasma were increased (P = 0.004 or 0.022) in quails subjected to heat stress condition. Plasma measurements of total proteins, albumin, globulin, lipids, glucose, and A/G ratio of quail chicks were not influenced (P > 0.05) by chromium, while cholesterol was increased with increasing chromium level (P = 0.033). High ambient temperature or dietary chromium levels or their interactions did not (P > 0.05) affect plasma levels of aspartate transaminase (AST), alanine transaminase (ALT), triiodothyronine (T3), thyroxin (T4), or T3/T4 ratio of growing quails. From these observations, it can be concluded that dietary chromium supplementation of growing Japanese quail subjected to heat stress condition could beneficially affect growth performance and carcasses, as well as modulate the hematological and biochemical blood parameters, probably through modulating stress status.

Effects of Chromium-Loaded Chitosan Nanoparticles on Glucose Transporter 4, Relevant mRNA, and Proteins of Phosphatidylinositol 3-Kinase, Akt2-Kinase, and AMP-Activated Protein Kinase of Skeletal Muscles in Finishing Pigs

The study was conducted to evaluate the effects of chromium-loaded chitosan nanoparticles (Cr-CNP) on glucose transporter 4 (GLUT4), relevant messenger RNA (mRNA), and proteins involved in phosphatidylinositol 3-kinase (PI3K), Akt2-kinase, and AMP-activated protein kinase (AMPK) of skeletal muscles in finishing pigs. A total of 120 crossbred barrows (BW 65.00 ± 1.26 kg) were randomly allotted to four dietary treatments, with three pens per treatment and 10 pigs per pen. Pigs were fed the basal diet supplemented with 0, 100, 200, or 400 μg/kg of Cr from Cr-CNP for 35 days. After the feeding trials, 24 pigs were slaughtered to collect longissimus muscle samples for analysis. Cr-CNP supplementation increased GLUT4 messenger RNA (mRNA) (quadratically, P < 0.01) and total and plasma membrane GLUT4 protein contents (linearly and quadratically, P < 0.001) in skeletal muscles. Glycogen synthase kinase 3β (GSK-3β) mRNA was decreased linearly (P < 0.001) and quadratically (P < 0.001). Supplemental Cr-CNP increased insulin receptor (InsR) mRNA quadratically (P < 0.01), Akt2 total protein level linearly (P < 0.01) and quadratically (P < 0.001), and PI3K total protein was increased significantly (P < 0.05) in 200 μg/kg treatment group. The mRNA of AMPK subunit gamma-3 (PRKAG3) and protein of AMPKα₁ was significantly increased (P < 0.001) with the addition of Cr-CNP. The results indicate that dietary supplementation of Cr-CNP may promote glucose uptake by leading to recruitment of GLUT4 to the plasma membrane in skeletal muscles, and these actions may be associated with the insulin signal transduction and AMPK.

Recent advances in role of chromium and its antioxidant combinations in poultry nutrition: A review

Poultry is reared in open side houses in most of the tropical countries, which results in huge temperature variation in shed causing stress resulting in increased demand of antioxidant supplementation. Since cooling of poultry houses or environment control is very expensive, thus methods focused on nutritional modifications appears to be the much logical approach. Stress increases mineral and vitamin mobilization from tissues and their excretion. Effect of some minerals and vitamin supplements such as chromium (Cr) and ascorbic acid to elevate the negative effects of environmental stress is well documented. Cr functions as an antioxidant and its deficiency are said to disrupt carbohydrate and protein metabolism. Cr has been utilized for weight gain, to improve feed conversion ratio, increase relative organ weight, muscle development, decrease cholesterol, increase high-density lipoprotein cholesterol, and improve nutrient digestion. Therefore, the present review discusses the beneficial aspects of Cr with its effect in different doses and antioxidant combinations to explore and promote its optimum utilization in poultry nutrition and production.

Effects of chromium supplementation from inorganic and organic sources on nutrient utilization, mineral metabolism and meat quality in broiler chickens exposed to natural heat stress

One hundred 1-day-old Ven Cobb chicks were used to study the effect of supplementation with 0-2 mg chromium (Cr) per kg diet from potassium chromate (T1), chromium chloride (T2) and chromium-yeast complex (T3). The control group (C) received no supplemental chromium. Each experimental group consisted of five replicates of five birds each and the supplementation was continued for 35 days. The weekly live-weight gain, food conversion ratio and the live-weight gain: food intake ratio were unaffected by the treatments. Metabolizability of the organic nutrients increased in the Cr supplemented groups compared with the C group and significantly higher values were observed in the T3 group indicating beneficial effects of Cr-yeast complex. Intake of the trace elements (copper, zinc, iron and manganese) fulfilled the requirements specified for broiler chickens. Retention of all these trace elements was higher (P < 0-001 for Cu, Zn and Fe, P <0-01 for Mn) in all the Cr supplemented groups compared with that in the C group. Furthermore, in the T3 group the retention of copper, zinc, iron and manganese was higher (P < 0001) than that in the T1 and T2 groups. Two birds were slaughtered from each replicate at the end of 21 and 35 days of feeding to observe Cr in the liver; this was higher (P < 0-01) after 35 days feeding only. Despite supplementation, liver Cr was lower (P < 0-01) in T1 T2 and T3 groups. Cr concentration in the plasma was higher (P < 0-05) in the T3 and T3 groups than that in the C group although its concentration did not change with the age of the birds. Higher (P < 0-01) plasma concentrations of copper were observed in the T1 T2 and T3 groups titan those in the C group. The differences between the Cr supplemented groups in this respect were not significant, however. Liver copper was higher (P < 0-001) in C while liver iron was the lowest (P < 0-05) in that group. The concentrations of copper, iron (P < 0-01) and zinc in the liver (P < 0-05) were higher after 35 than after 21 days while those of manganese were not affected by slaughter age. Protein accretion in the meat tended to be increased in the Cr supplemented groups while deposition of fat in the meat was lower but these differences were not significant (P > 0-05). Other meat quality parameters including sensory evaluation scores improved due to Cr supplementation and Cr-yeast complex was found to have exerted significantly greater effects on these parameters. It was concluded that the supplementation of 0-2mg Cr per kg food dry matter would improve the performance of broiler chickens in terms of metabolizability of organic nutrients, retention of trace elements and meat quality.

Chromium propionate in broilers: effect on insulin sensitivity

The objective of this study was to evaluate the effects of dietary chromium (Cr), as chromium propionate, on measures of insulin sensitivity. Liver and muscle glycogen, and plasma glucose and non-esterified fatty acid (NEFA) concentrations were used as indicators of insulin sensitivity. In total, 288 newly hatched male Ross broilers were divided into 4 dietary treatments consisting of 0 (control diet analyzed 0.43 to 0.45 mg Cr/kg), 0.2, 0.4, or 0.6 mg supplemental Cr/kg diet, resulting in 4 treatments with 9 replicate pens per treatment containing eight birds per pen. At d 21, 2 birds per cage were removed based on the greatest deviation from pen mean BW, resulting in each pen containing 6 birds for the final analyses. Final BW were taken on d 40, and on d 42 two birds from each pen were sampled for plasma NEFA, glucose, and muscle and liver glycogen determination at the initiation and termination of a 22 h fast. The remaining 2 fasted birds were sampled after a 30 min refeeding period. No differences were observed in feed intake, BW gain, or feed efficiency on d 21 or d 40. Liver glycogen tended (P=0.10) to be greater in Cr-supplemented chicks in the fed state, and muscle glycogen concentrations tended (P=0.07) to be greater in Cr-supplemented chicks compared with controls following fasting and refeeding. Plasma glucose concentrations were not affected by dietary Cr in the fed, fasted, or refed state. Plasma NEFA levels were not affected by treatment in fed or fasted birds. However, plasma NEFA concentrations were lower (P<0.01) in chicks supplemented with Cr than in controls following fasting and refeeding, suggesting that Cr increased insulin sensitivity. No differences were detected among birds supplemented with 0.2 or 0.4 mg Cr/kg, and among those receiving 0.4 or 0.6 mg Cr/kg. Results of this study indicate that Cr propionate supplementation of a control diet containing 0.43 to 0.45 mg Cr/kg enhanced insulin sensitivity.

Effects of Supplemental Chromium Source and Concentration on Growth, Carcass Characteristics, and Serum Lipid Parameters of Broilers Reared Under Normal Conditions

An experiment was conducted to investigate the effects of dietary chromium (Cr) source and concentration on growth performance, carcass traits, and some serum lipid parameters of broilers under normal rearing conditions for 42 days. A total of 252 1-day-old Cobb 500 commercial female broilers were randomly allotted by body weight (BW) to one of six replicate cages (six broilers per cage) for each of seven treatments in a completely randomized design involved in a 2 × 3 factorial arrangement of treatments with three Cr sources (Cr propionate (CrPro), Cr picolinate (CrPic), Cr chloride (CrCl3)) and two concentrations of added Cr (0.4 and 2.0 mg of Cr/kg) plus a Cr-unsupplemented control diet. The results showed that dietary Cr supplementation tended to increase the breast muscle percentage compared with the Cr-unsupplemented control group (P = 0.0784), while Cr from CrPic tended to have higher breast muscle percentage compared with Cr from CrCl3 (P = 0.0881). Chromium from CrPic also tended to increase the breast intramuscular fat (IMF) compared with Cr from CrCl3 (P = 0.0648). In addition, supplementation of 0.4 mg/kg Cr tended to decrease low-density lipoprotein cholesterol (LDL-C) (P = 0.0614). Compared with the control group, broilers fed Cr-supplemented diets had higher triglyceride (TG) (P = 0.0129) regardless of Cr source and Cr concentration. Chromium from CrPro and CrPic had lower total cholesterol (TC) compared with Cr from CrCl3 (P = 0.0220). These results indicate that dietary supplementation of Cr has effects on carcass characteristics and serum lipid parameters of broilers under normal rearing conditions, while supplementation of organic Cr can improve carcass characteristics and reduce the cholesterol content in serum.

Monitoring of heavy metal burden in mute swan (Cygnus olor)

Concentrations of heavy metals (especially arsenic, cadmium, chromium, copper, mercury and lead) were measured in the contour (body) feathers of mute swans (Cygnus olor) and in its nutrients (fragile stonewort [Chara globularis], clasping leaf pondweed [Potamogeton perfoliatus], Eurasian watermilfoil [Myriophyllum spicatum], fennel pondweed [Potamogeton pectinatus]) to investigate the accumulation of metals during the food chain. The samples (17 feathers, 8 plants) were collected at Keszthely Bay of Lake Balaton, Hungary. Dry ashing procedure was used for preparing of sample and the heavy metal concentrations were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES). Copper (10.24 ± 2.25 mg/kg) and lead (1.11 ± 1.23 mg/kg) were detected the highest level in feathers, generally, the other metals were mostly under the detection limit (0.5 mg/kg). However, the concentrations of the arsenic (3.17 ± 1.87 mg/kg), cadmium (2.41 ± 0.66 mg/kg) and lead (2.42 ± 0.89 mg/kg) in the plants were low but the chromium (198.27 ± 102.21 mg/kg) was detected in high concentration.

Dietary Inorganic Chromium in Summer-Exposed Buffalo Calves (Bubalus bubalis): Effects on Biomarkers of Heat Stress, Immune Status, and Endocrine Variables

The aim of this study was to evaluate the effect of different levels of inorganic chromium (Cr) on heat stress, immune response, and hormonal variation in Murrah buffalo calves during the summer season. Twenty-four growing Murrah buffalo calves were randomly allocated into four treatments for a period of 120 days. Feeding regimen was same in all the groups, except the buffalo calves in treatment groups were additionally supplemented with 0.5, 1.0, and 1.5 mg of inorganic Cr/kg dry matter. Buffalo calves were monitored daily for physiological variables and dry matter intake (DMI) and fortnightly for body weight change. Blood samples were collected at day 0, 15, 30, 45, 60, 75, 90, 105, and 120 and analyzed for heat shock protein 70 (Hsp 70), lymphocyte proliferation, neutrophil phagocytic activity, immunoglobulin, ferric reducing antioxidant power (FRAP) assay, insulin, cortisol and thyroid hormones, and Cr levels. Dietary Cr supplementation did not have any effect on DMI, growth performance, and physiological variables. However, lymphocyte proliferation, neutrophil phagocytic activity, plasma immunoglobulin, FRAP value, and plasma Cr concentration increased significantly (P < 0.05) with increase in levels of Cr. Adding Cr to the diet of summer-exposed buffalo calves did not show any effect on plasma levels of thyroid hormone, while concentration of insulin, cortisol, and Hsp 70 decreased (P < 0.05). Supplementation of inorganic Cr to the diet of buffalo calves reared under high ambient temperature improved heat tolerance, immune status without affecting nutrient intake, and growth performance.

Effects of dietary organic chromium and vitamin C supplementation on performance, immune responses, blood metabolites, and stress status of laying hens subjected to high stocking density

The present study was carried out to investigate the effects of dietary supplementation of chromium-methionine (CrMet) and vitamin C (VC) on performance, immune response, and stress status of laying hens subjected to high stocking density. A total of 360 Hy-Line W-36 leghorn hens (at 26 wk old) were used in a 2×3×2 factorial arrangement that had 2 cage densities (5 and 7 hens per cage), 3 Cr levels (0, 500, and 1,000 ppb as CrMet), and 2 dietary VC levels (0 and 500 ppm as L-ascorbic acid). The trial lasted for 12 wk. The first 2 wk were for adaptation (26 to 28 wk of age), and the remaining 10 wk served as the main recording period. In addition to performance, immune response to Newcastle disease virus (NDV) was assessed at d 7 and 14 postvaccination. Also, the birds' stress status was evaluated by analyzing appropriate plasma metabolites. The results showed that hens in cages with higher stocking density had lower hen-day egg production, egg mass, and feed intake compared with those in normal density cages (P<0.05). Dietary CrMet supplementation caused significant increases in egg production and egg mass (P<0.01). There were significant Cr × VC interactions related to egg production and feed conversion efficiency (P<0.01); dietary CrMet supplementation was more effective in improving egg production and feed conversion ratio in VC-unsupplemented diets. Although plasma concentrations of triglycerides and high-density lipoproteins were not influenced by dietary treatments, supplemental CrMet decreased plasma cholesterol levels (P<0.05). Plasma insulin and glucose levels of hens kept at a density of 7 hens/cage were significantly higher than those of hens in normal cage density (P<0.01), and dietary CrMet supplementation decreased plasma concentrations of insulin (P<0.001) and glucose (P<0.01), with higher impacts in high stocking density-challenged hens. While high stocking density caused a marked increase in plasma corticosterone (P<0.01), both supplemental CrMet and VC decreased it to near normal levels. There were significant stocking density×Cr interactions related to plasma insulin and corticosterone concentrations (P<0.01); supplemental CrMet was more effective in lowering these hormones in high stocking density-challenged hens. The high stocking density challenge suppressed NDV antibody response (P<0.001), while dietary supplementation of CrMet improved antibody titers against NDV at d 14 post vaccination particularly in hens kept at a density of 7 hens/cage (P<0.01). From the present observations, it can be concluded that CrMet can improve laying performance largely because it alleviates harmful responses to stressful conditions.

Effects of chromium methionine supplementation on growth performance, serum metabolites, endocrine parameters, antioxidant status, and immune traits in growing pigs

The effects of dietary chromium methionine (CrMet) on growth performance, serum metabolites, endocrine parameters, antioxidant status, and immune traits in growing pigs were investigated. A total of 180 crossbred pigs (30.18 ± 0.28 kg initial body mass) were randomly divided into five groups, each group with six pens, six pigs per pen. Pigs were fed on the same basal diet supplemented with 0 (control), 100, 200, 400, and 800 μg/kg Cr from CrMet for 35 days. The results showed that supplemental CrMet did not affect growth performance. Cr at 200-800 μg/kg significantly decreased serum glucose levels (P < 0.05), while other serum metabolites were unaffected by Cr supplementation. Serum growth hormone (GH) levels were significantly decreased by Cr addition (P < 0.05). Furthermore, serum insulin-like growth factor I (IGF-I) levels were linearly decreased with increased Cr dose, and a significant reduction was observed in pigs fed 800 μg/kg Cr diets (P < 0.05). Serum immunoglobulin A, G, and M concentrations were increased linearly with increased Cr dosage, and pigs fed 400 μg/kg Cr had greater serum immunoglobulin M contents (P < 0.05). Cr at 400 μg/kg significantly increased serum superoxide dismutase and total antioxidant capacity activities (T-AOC) (P < 0.05). However, Cr at 800 μg/kg increased serum catalase activities, while decreasing serum T-AOC contents (P < 0.05). Additionally, there was a significant increase in serum malondialdehyde levels for pigs fed 800 μg/kg Cr diets (P < 0.05). These results indicated that dietary supplementation CrMet decreased serum glucose, GH, and IGF-I levels. Besides, supplemental 400 μg/kg Cr as CrMet improved serum antioxidant status and immune responses, but additional 800 μg/kg Cr resulted in lipid peroxidation in growing pigs.

Effects of supplemental vitamin C and chromium on metabolic and hormonal responses, antioxidant status, and tonic immobility reactions of transported broiler chickens

Three hundred female broilers were assigned to five groups with six replicates and were fed with either a basal diet (two control groups) or the basal diet supplemented with 800-mg vitamin C/kg (Vit C group), 1,200-μg Cr(+3) from chromium (Cr) chloride/kg (Cr group) or 800-mg Vit C and 1,200-μg Cr(+3) from Cr chloride/kg (Vit C + Cr group) from 42 to 49 days of age. Treatments did not affect performance. Transport decreased insulin level in the control and Cr groups and increased glucose/insulin (G/I) ratio in the groups. The level of insulin was higher in the Vit C + Cr group than those in the control and Cr groups after the transport. The G/I ratio was lowest in the Vit C + Cr group after the transport. The transport significantly decreased triiodothyronine (T3) concentration in the groups except the Vit C + Cr group and only increased thyroxin (T4) concentration in the Vit C + Cr group. The T3/T4 ratio was significantly decreased in the groups except the Cr group by transport. The T3/T4 ratio was greatest in the Vit C + Cr group before the transport. Alkaline phosphatase activity was decreased in the Vit C + Cr group due to transport. Transport decreased triglyceride levels in the groups and also decreased low-density lipoprotein cholesterol levels in the Vit-C-supplemented groups. Transport increased malondialdehyde concentration in the control and Vit C groups and also increased glutathione peroxidase (GPx) activity in the Cr-fed groups. The GPx activity was higher in the Vit C + Cr group than those in the control and Cr groups after the transport. Ferric reducing/antioxidant power (FRAP) value was decreased in the Vit C and Cr groups by transport. Either alone or in combination, Cr increased the FRAP value before the transport. Neither transport nor treatments had significant effects on the duration of tonic immobility (TI) and number of inductions to induce TI.

Effect of feeding inorganic chromium on growth performance, endocrine variables, and energy metabolites in winter-exposed buffalo calves (Bubalus bubalis)

We investigated the effect of chromium (Cr) supplementation on the growth performance, energy metabolites, and hormonal variation in winter-exposed buffalo calves. Twenty-four female buffalo calves were randomly allotted to four dietary treatments (n = 6) for a period of 120 days. Feeding regimen was the same in all the groups, except the animals in the four respective groups were additionally supplemented with 0.0, 0.5, 1.0, and 1.5 mg of Cr/kg DM in the form of CrCl3.6H2O. Calves were monitored daily for physiological variables and dry matter intake (DMI). Blood samples were collected at fortnightly intervals from each buffalo calves to measure concentrations of hormones (insulin, cortisol, and growth hormone), energy metabolites (glucose and non-esterified fatty acids), and plasma mineral levels. After 120 days of feeding trial, buffalo calves fed with Cr had lower (P < 0.05) circulating plasma concentrations of glucose, insulin, and cortisol hormones, whereas plasma thyroid hormone and non-esterified fatty acids concentrations were found similar (P > 0.05) among all the treatments. The results suggested that dietary Cr supplementation influenced plasma Cr levels without affecting the plasma concentrations of other trace minerals. However, physiological variables, nutrient intake, and growth performance of buffalo calves did not differ among all treatments (P > 005). In summary, the current study showed that supplementation of Cr at the level of 1.0 and 1.5 mg of Cr/kg DMI was more effective in improving glucose utilization by increasing potency of insulin hormone and reducing concentration of cortisol hormone. Results also suggested that supplemental Cr also improves blood plasma Cr levels.

Solexa sequencing of microRNAs on chromium metabolism in broiler chicks

AIM

The aim of this study was to determine the effect of chromium picolinate (CrPic) on the differential expression of the known microRNAs (miRNAs) in broiler skeletal muscle.

METHODS AND RESULTS

A total of 288 1-day-old male Arbor Acres broilers were randomly assigned to one of four dietary treatments supplemented with 0, 0.4, 2.0, or 10.0 mg·kg(-1) CrPic, respectively. Dietary CrPic supplementation at 10.0 mg·kg(-1) increased the average daily feed intake in broilers (p < 0.05). On day 42, the serum total protein level was highest in animals treated with 2.0 mg·kg(-1) (p < 0.05) and 10.0 mg·kg(-1) CrPic (p < 0.05). Dietary supplementation with 10.0 mg·kg(-1) CrPic decreased the levels of serum glucose (p < 0.05) on day 42 and of serum triglyceride (p < 0.05) on days 21 and 42. To further identify miRNAs from broiler skeletal muscles, we sequenced two small RNA libraries using the Solexa sequencing approach, and 57 miRNAs were found to be significantly differentially expressed (p < 0.05). Among them, 6 upregulated and 2 downregulated miRNAs were validated by real-time qPCR (p < 0.05).

CONCLUSIONS

The results of the present study provide a valuable clue regarding the role of miRNA target genes in the mechanism of the dietary CrPic effect on protein synthesis in skeletal muscles of broilers.

Lack of effect of dietary chromium supplementation on growth performance and serum insulin, glucose, and lipoprotein levels in broilers reared under heat stress condition

This study evaluated the effects of supplemental dietary chromium (Cr) on the performance, carcass traits, and some serum parameters of broilers under a heat stress (23.9 to 37 °C cycling) condition. A total of 150 1-day-old broiler chicks (Cobb 500) according to a completely randomized design were assigned into five treatment groups. Each treatment consisted of three replicates and each replicate contained ten chicks. Treatments were supplemented with 0 (control), 600, and 1,200 μg kg(-1) Cr in the form of Cr chloride (CrCl3) and Cr L-methionine from 1 to 49 days of age. Blood samples were collected from two birds in each replicate to determine serum parameters at 35 and 49 days of age. The body mass, feed intake, and conversion ratio were not influenced by dietary Cr (P > 0.05). Dietary supplementation of Cr from either CrCl3 or Cr L-methionine caused increased serum concentrations of Cr (P < 0.05), but had no effect on serum insulin and glucose concentrations at both sampling times (P > 0.05). Serum triglycerides, very low-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol were also not significantly affected (P > 0.05) by dietary treatments, whereas total cholesterol concentration decreased in chicks fed Cr L-methionine compared to the control (P < 0.05).

Nutritional interventions to alleviate the negative consequences of heat stress

Energy metabolism is a highly coordinated process, and preferred fuel(s) differ among tissues. The hierarchy of substrate use can be affected by physiological status and environmental factors including high ambient temperature. Unabated heat eventually overwhelms homeothermic mechanisms resulting in heat stress, which compromises animal health, farm animal production, and human performance. Various aspects of heat stress physiology have been extensively studied, yet a clear understanding of the metabolic changes occurring at the cellular, tissue, and whole-body levels in response to an environmental heat load remains ill-defined. For reasons not yet clarified, circulating nonesterified fatty acid levels are reduced during heat stress, even in the presence of elevated stress hormones (epinephrine, glucagon, and cortisol), and heat-stressed animals often have a blunted lipolytic response to catabolic signals. Either directly because of or in coordination with this, animals experiencing environmental hyperthermia exhibit a shift toward carbohydrate use. These metabolic alterations occur coincident with increased circulating basal and stimulated plasma insulin concentrations. Limited data indicate that proper insulin action is necessary to effectively mount a response to heat stress and minimize heat-induced damage. Consistent with this idea, nutritional interventions targeting increased insulin action may improve tolerance and productivity during heat stress. Further research is warranted to uncover the effects of heat on parameters associated with energy metabolism so that more appropriate and effective treatment methodologies can be designed.

Toxicity evaluation of chromium picolinate nanoparticles in vivo and in vitro in rat

The toxicity of nanoCrpic is still not understood and needs further investigation. Thus, this study investigated the effect of chromium picolinate nanoparticles (nanoCrpic) on the toxicity in vivo and in vitro in rat. In the in vivo study, 36 rats (Wistar, 8-week-old) were randomly divided into the control group (fed basal diet), the low-dose (300 ppb, μg/kg), and high-dose (1,000 ppb) nanoCrpic groups. The trial was conducted for 2 months; at the final stage of the trial, the rats were sacrificed, liver and kidney were examined, and samples of tissues were taken for histological examination. Hepatocytes isolated from 10-week-old Wistar male rats were used for in vitro study to examine the degree of DNA damage following exposure to 0 and 0.294 mM of H(2)O(2) for 30 min. Incubation medium was supplemented with 0 (control), 100, and 300 ppb nanoCrpic. In vivo study indicated that no lesions of liver or kidney were detected in 300 and 1,000 ppb nanoCrpic fed rats. The in vitro study evaluated DNA damage according to the percentage and distance of the fragments migration and revealed that there was insignificant difference between the nanoCrpic and control groups (p > 0.05). This study indicated that nanoCrpic at 300-1,000 ppb in vivo and at 100-300 ppb in vitro showed no signs of toxicity to rats.

Effect of dietary supplementation of organic chromium on performance, carcass traits, oxidative parameters, and immune responses in commercial broiler chickens

An experiment was conducted to study effect of supplementing graded concentrations (0, 100, 200, 300, or 400 μg/kg diet) of organic chromium (Cr) on performance, carcass traits, oxidative stress, and immune responses in commercial broiler chickens reared in open-sided poultry house under tropical climatic conditions. Each diet was fed ad libitum to eight replicates consisting of six birds in each pen from 1 to 42 days of age. Body mass gain and feed efficiency at 21 and 42 days of age and relative mass of liver, abdominal fat, and ready to cook yields at 42 days of age were not affected (P > 0.05) by supplementing organic Cr in broiler diet. Body mass loss during pre-slaughter holding period (12 h) reduced and relative breast mass increased nonlinearly (P < 0.01) with concentration of Cr in diet. Lipid peroxidation decreased, while activities of glutathione peroxidase and glutathione reductase in plasma increased nonlinearly with Cr supplementation. The ratio between heterophyl and lymphocyte was not affected (P > 0.05) with Cr supplementation in broiler diet. Relative mass of lymphoid organs (bursa, spleen, and thymus) and antibody production to Newcastle disease vaccination were not affected (P > 0.05) by the treatments employed. The cell-mediated immunity (lymphocyte proliferation ratio) increased nonlinearly with dietary Cr concentration. The results of the present study indicated that supplementation of organic Cr did not influence body mass and feed efficiency. However, supplementation of the Cr reduced pre-slaughter holding losses, increased the relative mass of breast, and increased antioxidant status and lymphocyte proliferation in broilers reared in tropics.

Chromium supplementation can alleviate the negative effects of heat stress on growth performance, carcass traits, and meat lipid oxidation of broiler chicks without any adverse impacts on blood constituents

This study was conducted to determine the effects of dietary supplementation with Cr nicotinate and Cr chloride and their optimum inclusion rate on performance, carcass traits, meat oxidative stability, serum metabolites, hematological parameters, and liver chromium concentration in heat-stressed broilers. A total number of 420, 1-day-old male broiler chicks were randomly assigned to seven treatments with four replicates of 15 chicks. The dietary treatments consisted of the basal diet supplemented with 0 (control), 500, 1,000, and 1,500 μg/kg Cr in the form of Cr nicotinate and Cr chloride. Chicks were raised for 6 weeks in heat stress condition (33 ± 2°C). Supplements of organic and inorganic Cr particularly at 1,500 μg/kg incorporation increased feed consumption (P < 0.05) and body mass gain of broilers (P < 0.01). Cr supplementation increased carcass yield and decreased abdominal fat (P < 0.01). Supplementation of 1,500 μg/kg Cr nicotinate (P < 0.05) enhanced liver Cr concentration. Storage time increased lipid oxidation of meat (P < 0.01). Cr decreased lipid oxidation of breast and thigh muscles over 2 (P < 0.01) or 6 (P < 0.05) days of storage time. Birds fed 1,500 μg/kg Cr nicotinate, had lower concentration of serum glucose and triglyceride at 21 days (P < 0.05). Hematological parameters tested at 21 and 42 days, were not influenced. The results suggested that dietary Cr supplementation regardless of its source have a positive effect on productive, and carcass traits, also enhances oxidative stability of refrigerated meat in broilers reared under heat stress conditions.

The effect of different levels of organic and inorganic chromium supplementation on production performance, carcass traits and some blood parameters of broiler chicken under heat stress condition

A total of 250 broilers in a completely randomized design selected to evaluate the effect of different levels of chromium (Cr) supplementation on performance, carcass traits and some blood parameters of heat-stressed broiler chicks. All birds were kept under heat stress temperature (33 ± 3°C) and divided into five treatments groups. Each treatment consisted of five pens with 10 birds in each pen. The basal diets were supplemented with 0 ppb (control), 800 ppb Cr-L-Met (T(1)), 1,200 ppb Cr-L-Met (T(2)) or 800 ppb CrCl(3) (T(3)), and 1,200 ppb CrCl(3) (T(4)). The feed intake and body mass were measured at 10, 21, and 42 days of age. Blood samples were collected from two birds in each replicates to determine biological and hematological values at 28 and 42 days of age. There were no significant difference in mass gain and feed conversion of broilers that received Cr supplementations compared with controls. The serum glucose concentration decreased in broilers received organic chromium methionine supplements compared with other treatments groups. Slight but not significant increases were observed in serum high-density lipoprotein (HDL) concentration of treated groups than controls while the mean serum HDL concentration was significantly higher in T(2) group compared with control group. Serum low-density lipoprotein level decreased in broiler received organic Cr supplements (p < 0.05).

Effects of supplemental copper and chromium on the serum and egg traits of laying hens

1. This study investigated the effects of supplemental copper and chromium on the serum and egg traits of laying hens using 144 forty-five-week-old White Leghorn layers. The hens were randomly assigned into 9 groups to conduct this 3 copper (0, 125 and 250 mg/kg as copper sulphate) x 3 chromium (0, 800 and 1600 microg/kg as chromium picolinate) factorial trial. 2. Egg yolk cholesterol was significantly reduced by supplementary copper (Cu) and chromium (Cr) and there was an interaction between Cu and Cr supplementation. Egg production, egg weight, eggshell strength and eggshell thickness were not influenced by Cu or Cr supplementation. 3. Serum cholesterol concentration was decreased by Cu supplementation and very low-density lipoprotein (VLDL) was reduced markedly by both Cu and Cr. On the other hand, high-density lipoprotein (HDL) was significantly increased by Cu and Cr. Interaction occurred between Cu and Cr in the VLDL and HDL parameters. Supplmentary Cu also reduced VLDL-cholesterol (VLDL-C) and enhanced HDL-cholesterol (HDL-C), while supplemental Cr had a contrary effect on these two parameters. 4. If minimum egg cholesterol content is the criterion, this study suggests that 125 mg/kg of Cu together with 800 to 1600 microg/kg of Cr provide adequate supplementary concentrations for laying hens.

Effect of dietary chromium picolinate on growth performance and blood parameters in grass carp fingerling, Ctenopharyngodon idellus

An experiment was conducted to investigate the effect of dietary chromium picolinate supplement on growth and haematology parameters of grass carp, Ctenopharyngodon idellus. Six diets with increasing dietary chromium picolinate levels 0, 0.2, 0.4, 0.8, 1.6 and 3.2 mg kg(-1) were fed to triplicate groups of 20 fish (initial weight of 12.78 +/- 1.16 g, mean +/- SD) in a flow water system for 10 weeks. Fish fed the diet supplemented with 0.8 mg Cr kg(-1) had significantly improved weight gain (WG), feed efficiency ratio (FER), protein efficiency ratio (PER) and protein retention (PR). Fish fed high-chromium diets exhibited lower whole-body crude lipid contents than fish fed low-chromium diets. Liver glycogen concentrations for fish fed the diet with 0.2 mg Cr kg(-1) was the highest (77.67 mg g(-1)). Fish fed the diet supplemented with 1.6 and 3.2 mg Cr kg(-1) had significantly lower liver glycogen concentrations than other groups (P < 0.05). The highest serum insulin concentrations were observed in fish fed the diet supplemented with 0.8 mg Cr kg(-1), but serum insulin concentrations decreased (P < 0.05) when dietary supplementation of chromium was higher than 0.8 mg Cr kg(-1). Cholesterol concentrations decreased in direct proportion to dietary chromium level and achieved the lowest level when the fish were fed the 0.8 mg Cr kg(-1) diet, but increased when the fish were fed the diet with more than 0.8 mg Cr kg(-1) (P < 0.05). Fish fed the diet supplemented with 0.8 mg Cr kg(-1) had higher triglyceride and high-density lipoprotein cholesterol (HDL-C) concentrations compared to other treatments. The results of the present study suggested that chromium picolinate could modify serum carbohydrate and lipid metabolism profile, and that the optimal dietary chromium level was 0.8 mg kg(-1) for grass carp according to growth.

Níveis de cromo orgânico em rações para frangos de corte mantidos sob estresse por calor no período de um a 42 dias de idade

Avaliou-se o efeito da suplementação de cromo sobre o desempenho e o rendimento de cortes de frangos, mantidos em ambiente de alta temperatura, no período de um a 42 dias de idade. Foram utilizados 400 frangos de corte, machos, da linhagem Cobb, em um delineamento experimental inteiramente ao acaso, com cinco tratamentos, 0, 350, 700, 1.050 e 1.400ppb de cromo na ração, oito repetições e 10 aves por repetição. Nos períodos de um a 21 e de um a 42 dias de idade, não houve influência dos tratamentos sobre o ganho de peso, o consumo de ração e a conversão alimentar das aves, mas observou-se que o consumo de cromo aumentou de forma linear. Os tratamentos não influenciaram os pesos absoluto e relativo de nenhum dos cortes, peito, coxa e sobrecoxa, avaliados aos 42 dias de idade. A suplementação de até 1.400ppb de cromo na ração não influenciou o desempenho e o rendimento de cortes nobres de frangos de corte mantidos em estresse por calor, no período de um a 42 dias de idade.