Chromium Methionine Research Articles

Effects of Dietary Chromium Methionine on Growth Performance, Hematological Characteristics and Carbohydrate Metabolic Enzyme Activities of Common Carp (Cyprinus carpio)

A 60-day feeding trial was conducted to evaluate the effects of dietary chromium methionine (Cr-Met) supplementation on growth performance, digestive enzymes, hematological characteristics, and carbohydrate metabolic key enzyme activities in juvenile common carp (Cyprinus carpio). Seven diets (32.2% crude protein, 6% crude lipids of dry matter) were formulated to contain graded levels of Cr3+ (0.31, 0.43, 0.57, 0.73, 1.13, 1.90 and 3.64 mg/kg, respectively). Each diet was randomly assigned to triplicate groups of 60 juvenile common carp (approximately 40.95±4.80 g), which were stocked in plastic tanks. The results indicated that the highest weight gain (WG), specific growth rate (SGR), feed efficiency (FE), and protein efficiency ratio (PER), were observed in fish fed the diet containing 1.13 mg/kg Cr3+. There were no significant differences in the wholebody compositions; however the glycogen levels in the muscle and hepatopancreas in fish fed the basal diet were lower than those fed the other diets. The insulin (INS) and glycogen (GC) concentrations in the serum were not significantly influenced by the dietary Cr-Met levels. However, fish fed the basal diet had higher glucose and cortisol concentrations, and lower insulin receptor (ISR) and LDH concentrations in the serum than those fed diets supplemented with Cr-Met. Fish fed the 1.13 mg/kg Cr3+ diet had significantly higher hexokinase (HK), 6-phosphofructo-1-kinase (6-PFK1), glucose-6-phosphate dehydrogenase (G6PDH), glycogen synthase (GS), and lower phosphoenolpyruvate carboxykinase (PEPCK) activities than those fed the basal diet. Based on the two-slope broken line model analysis between SGR and dietary Cr3+ levels, the optimal dietary Cr3+ supplement level was estimated to be 1.09 mg/kg for juvenile common carp.

PHYSIOLOGICAL RESPONSES OF BROILER CHICKENS AS INFLUENCED BY EARLY AGE HEAT CONDITIONING AND DIETARY ANTIOXIDANT SUPPLEMENTATION

Two hundred and forty 1-d old commercial broiler chicks (Cobb) were allotted to two groups of 120 chicks. The first group was the control(Non heat conditioning). The second one was exposed to 40±1°C for 24h at 5 DOA, (early age heat conditioning). Each group was further subdivided into 4 sub-groups of 30 birds each, the first sub-group was control group, the second was fed basal diet supplemented with 200 IU/kg diet vitamin E and 0.8 mg/kg diet chromium methionine, the third was fed basal diet supplemented with 200 IU/kg diet vitamin E and 0.3 mg/kg diet selenium methionine and the fourth was fed basal diet supplemented with 200 IU/kg diet vitamin E, 0.8 mg/kg diet chromium methionine and 0.3 mg/kg diet selenium methionine, to investigate the effects of early age of heat conditioning and some antioxidants supplementation on somephysiological changes. Results showed that Chicks exposed to early age heat conditioning recorded significantly higher (P< 0.05) BW, BWG, FI and FCR compared with non heat conditioning chicks at 21and 42 DOA. There were significant (P<0.05) effects of dietary supplements on BW, BWG, FI and FCR at 21 and 42 DOA, and also by the interaction between early age heat conditioning and dietary supplements. Early age heat conditioning had significant (P< 0.05) effect on Hb, HT, RBC´S, MCHC and MCV levels at 21 DOA, but MCH values was insignificantly influenced. Significant (P< 0.05) effects of early age heat conditioning significant (P< 0.05) effects on Hb, HT, and RBC´S levels of broiler chicks at 42 DOA, however, MCH, MCHC and MCV levels were not affected. Dietary supplements (regardless early age heat conditioning) significantly increased Hb, HT, RBC´S, MCH, MCHC and MCV levels at 21 DOA and at 42 DOA except MCH, MCHC and MCV which were not significant. The interaction between early age heat conditioning and dietary supplements was significant for most of the hematological parameters studied either at 21 or 42 DOA. Early age heat conditioning had a significant (P< 0.05) effect on H/L ratio, but the effect of dietary supplements alone was not significant at 21 and 42 DOA. Based on the results of the present study it is concluded that early age heat conditioning of broiler chicks and dietary supplements by Vit.E; organic chromium or organic selenium in combination could be recommended for alleviating the negative effects of heat stress during the summer season, on broiler chicks performance.

185 Effects of chromium methionine and zinc source on performance, carcass traits, and meat quality of growing-finishing pigs

185 Effects of chromium methionine and zinc source on performance, carcass traits, and meat quality of growing-finishing pigs

270 Effects of chromium methionine and zinc source on serum metabolites, endocrine parameters, and the antioxidant status of growing–finishing pigs

270 Effects of chromium methionine and zinc source on serum metabolites, endocrine parameters, and the antioxidant status of growing–finishing pigs

Effects of Chromium Methionine Supplementation with Different Sources of Zinc on Growth Performance, Carcass Traits, Meat Quality, Serum Metabolites, Endocrine Parameters, and the Antioxidant Status in Growing-Finishing Pigs.

This experiment was conducted to evaluate the effects of chromium methionine with/without zinc sulfate or zinc amino acid complex on the growth performance, carcass traits, meat quality, serum parameters, endocrine parameters, and antioxidant status of growing-finishing pigs. A total of 180 (32.0±1.7kg body weight, BW) crossbred pigs (Duroc × Landrace × Yorkshire) were used in a completely randomized design with three dietary treatments and 10 replicates per treatment (five pens of barrows and five pens of gilts with six pigs per replicate). Three treatments were corn-soybean meal-based diets supplemented with 100mg Zn/kg from zinc sulfate (ZnSO4), 100mg Zn/kg from ZnSO4+0.2mg Cr/kg from chromium methionine complex (CrMet), or 50mg Zn/kg from ZnSO4+50mg Zn/kg from zinc amino acid complex (ZnAA)+0.2mg Cr/kg from CrMet, respectively. The experiment lasted 105days, of which was divided into three stages including phase 1 (30 to 50kg BW), phase 2 (50 to 80kg BW), and phase 3 (80 to 110kg BW). Results showed that supplementation with CrMet and ZnAA improved (P<0.05) the feed conversion of the pigs in phase 2, phase 3, and the overall experiment. Hot carcass weight, dressing percentage, and a longissimus dorsi muscle area were increased (P<0.05) in pigs fed with diets supplemented with both CrMet and ZnAA compared with pigs fed with diets containing only ZnSO4 (P<0.05). There was also an increase (P<0.01) pH24h in the longissimus dorsi muscle in pigs fed with diets supplemented with CrMet and ZnAA. The concentration of serum glucose in pigs fed with diets containing CrMet and ZnAA was decreased (P<0.05) compared with that in pigs fed with the diet containing ZnSO4. Supplementation with CrMet and ZnAA increased (P<0.05) the circulating levels of insulin and decreased (P<0.05) cortisol. There was an increase (P<0.05) in total serum antioxidant capacity and Cu/Zn superoxide dismutase activity as well as a decrease (P<0.05) in serum malondialdehyde concentrations in pigs fed with diets supplemented with CrMet and ZnAA compared with pigs fed with the diet supplemented only with ZnSO4. In conclusion, supplementation of CrMet only or CrMet together with ZnAA improved feed conversion, carcass traits, and meat quality in the growing-finishing pigs.

Effects of Chromium Methionine Supplementation on Blood Metabolites and Fatty Acid Profile of Beef during Late Fattening Period in Holstein Steers

The objective of this study was to determine the effects of chromium methionine (Cr-Met) chelate supplementation on blood metabolites and fatty acid profile of beef from Holstein steers during late fattening period. Fifteen Holstein steers were allotted randomly into two groups including the control (non Cr-Met feeding, NCM, ave. body weight [BW] = 483±25.7 kg) and the treatment (Cr-Met feeding for 4 months, 4CM, ave. BW = 486±27.5 kg) group. The feeding amount of Cr-Met to animals was limited to 400 ppb/cow/d and was supplemented to total mixed ration. No difference in blood albumin, alkaline phosphatase, urea-nitrogen, calcium, creatine, glucose, total protein, triglyceride, and cholesterol were observed between the treatment groups (p>0.05). The level of high density lipoprotein was higher in the 4CM group than the NCM group, whereas low density lipoprotein was lower in the 4CM group (p<0.05). The fatty acid composition (caprate, laurate, myristate, pentadecanoate, palmitate, palmitoleate, margarate, cis-11 heptadodecanoate, stearate, oleate, trans-vaccenate, linoleate, cis-11 eicosenoate, docosa hexaenoic acid, and docosa pentaenoic acid) of the beef showed no difference between the two groups (p>0.05). The arachidonic acid level tended to be higher in the 4CM than the NCM group (p = 0.07). Cr-Met had no influence (p>0.05) on the ratio of saturated, unsaturated, unsaturated/saturated, monounsaturated/saturated and polyunsaturated/saturated fatty acids whereas the ratio of polyunsaturated fatty acids (PUFA) in the 4CM group was comparatively higher than the NCM group (p<0.05). This study concluded that feeding Cr-Met supplementation in 400 ppb/d to Holstein steers for 4 months during late fattening period can improve some blood metabolites and beef quality by increasing PUFA and gamma-linoleate compositions of beef.

Dietary chromium methionine supplementation could alleviate immunosuppressive effects of heat stress in broiler chicks.

The present study was conducted to investigate the effects of dietary supplementation of chromium methionine (CrMet) on performance, immune responses, and stress status of broiler chicks subjected to heat-stress conditions. A total of 450 day-old Ross 308 broiler chicks were randomly distributed between 5 replicate pens (15 birds each) of 6 experimental treatments according to a 2 × 3 factorial arrangement of treatments including 2 temperature conditions (thermoneutral and heat stress) and 3 supplemental Cr levels (0, 500, and 1,000 μg/kg as CrMet). For induction of heat stress, the house temperature was set at 35 ± 2°C from 15 to 42 d of age. Results showed that the chicks subjected to heat-stress condition had lower (P < 0.01) feed intake, BW gain, and deteriorated (P < 0.05) feed conversion values compared with those kept in the thermoneutral house. Dietary supplementation with CrMet increased (P < 0.01) feed intake and improved (P < 0.01) weight gain and feed efficiency. There were significant Cr level × temperature interactions, so that inclusion of CrMet into the diets was more effective in heat-stressed chicks. Exposure to heat stress suppressed (P < 0.01) cutaneous hypersensivity response to phytohemagglutinin-P injection at 30 d of age, and dietary supplementation of 500 μg Cr/kg induced (P < 0.05) this response, with the greater impacts in heat-stressed chicks, resulting in a significant (P < 0.01) Cr × temperature interaction. Antibody responses against Newcastle and infectious bronchitis disease viruses were diminished (P < 0.01) in heat-stressed chicks. Dietary inclusion of CrMet improved (P < 0.05) antibody responses to different immunostimulants, and this effect was more pronounced in heat-stressed chicks. Exposure to heat stress caused a significant (P < 0.05) decrease in the proportion of helper (CD4+) T lymphocytes and increased cytotoxic (CD8+) T lymphocytes, resulting in a decreased (P < 0.01) CD4+ to CD8+ ratio in peripheral blood circulation. Supplementation of CrMet to heat-stressed chicks modulated (P < 0.01) plasma corticosterone level. The present findings indicate that dietary CrMet supplementation could alleviate heat-stress-induced growth retardation in broiler chicks. Moreover, supplemental CrMet modulated suppressive effects of heat stress on cellular and humoral immune responses.

Effect of high stocking density on performance, egg quality, and plasma and yolk antioxidant capacity in laying hens supplemented with organic chromium and vitamin C

This study was conducted to investigate the effects of dietary supplementation of chromium–methionine (CrMet) and vitamin C on performance, egg quality measurements, and plasma antioxidant capacity in laying hens subjected to high stocking density. A total of 360 Hy-Line W-36 laying hens, 26wk of age, were used in a 2×2×3 factorial arrangement of treatments consisting of 2 cage densities [5 or 7 hens/cage (40×45cm2)], 2 supplemental vitamin C levels (0 and 500mg/kg as l-ascorbic acid), and 3 supplemental Cr levels (0, 500, and 1000μg/kg as CrMet) with 5 replicate cages per treatment. The hens were kept in wire-floor cages in an environmentally-controlled room. After a 2-wk adaptation, the 70-d study was initiated and it was divided into two 35-d periods (28–33 and 33–38wk of age). Results showed that although subjecting hens to high stocking density had no effect on egg production percentage during 28–33wk of age, it decreased (P=0.031) during the 33–38wk of age, resulting in a marked reduction (P=0.038) in egg mass. Dietary Cr supplementation (500 and 1000μg/kg) increased (P<0.01) egg production and egg mass during both 35-d periods, and improved (P=0.005) feed conversion ratio (FCR) during the first 35-d period. There was a stocking density×vitamin C interaction (P=0.018) for FCR values during the first 35-d period, so that supplemental vitamin C improved FCR to a greater extent in high stocking density-challenged hens. Dietary CrMet supplementation (500 and 1000μg/kg) increased (P=0.001) feed intake during the second 35-d period. Shell thickness was greater (P=0.015) in hens under high stocking density challenge during the second 35-d period. Subjecting hens to high stocking density decreased (P=0.007) plasma vitamin C concentration, while plasma vitamin C level was increased (P<0.05) as the result of dietary supplementation of vitamin C. Dietary supplementation of CrMet (500 and 1000μg/kg) increased plasma vitamin C level only in high stocking density-challenged hens, resulting in a stocking density×Cr interaction (P=0.039). Although high stocking density increased (P<0.05) plasma and yolk concentrations of malondialdehyde (MDA), supplemental vitamin C decreased (P<0.05) plasma and yolk MDA contents. Similarly, dietary inclusion of CrMet (500 and 1000μg/kg) decreased (P=0.046) plasma MDA level. The present findings indicate that dietary CrMet supplementation could increase antioxidant capacity in stressed hens, which improve production performance of laying hens.

Effects of Graded Levels of Chromium Methionine on Performance, Carcass Traits, Meat Quality, Fatty Acid Profiles of Fat, Tissue Chromium Concentrations, and Antioxidant Status in Growing-Finishing Pigs.

A 97-day feeding trial was conducted to investigate the effects of dietary chromium methionine (CrMet) on performance, carcass traits, meat quality, fatty acid profiles of fat, tissue chromium concentrations, and antioxidant status in growing-finishing pigs. A total of 180 crossbred pigs with a mean initial body weight (BW) 30.18 ± 0.28kg were allotted to 5 treatments with 6 replicates per treatment and 6 pigs per pen in a randomized complete block design based on BW and sex. Treatments were added with 0 (control), 100, 200, 400, and 800μg/kg chromium as CrMet. Blood samples were obtained from the anterior vena cava on days 97. Carcass characteristics, pork quality, and tissue chromium concentration data were collected from one pig per pen. The results indicated that supplemental CrMet did not significantly affect growth performance, carcass traits, or meat amino acid profiles. Chromium at 100, 400, and 800μg/kg decreased drip loss but increased shear force (P < 0.05). Pigs fed 100 or 400μg/kg had a higher 24-h pH than the control (P < 0.05). While meat color, muscle moisture, crude protein, or crude fat were not affected by CrMet. Supplemental 800μg/kg chromium reduced C18:0 levels in belly fat (P < 0.05), and chromium supplementation increased cis-9, trans 11-conjugated linoleic acid levels linearly (P < 0.05). Dietary CrMet supplementation increased serum, kidney, and muscle chromium contents (P < 0.05) but did not affect liver chromium contents. Besides, tissue chromium concentrations were increased linearly with increased chromium dosage (P < 0.05). Chromium at 400μg/kg increased serum glutathione peroxidase activities (P < 0.05), and chromium at 800μg/kg decreased serum total antioxidant capacity levels (P < 0.05). Nevertheless, liver and kidney antioxidant status were not significantly affected by CrMet. These results indicated that dietary supplementation CrMet did not significantly influence growth and carcass traits, but improved meat quality at the expense of tenderness. Therefore, the long-term exposure to 800μg/kg chromium affected fatty acid compositions and reduced serum antioxidant capacity.

Effects of forage level and chromium-methionine chelate supplementation on performance, carcass characteristics and blood metabolites in Korean native (Hanwoo) steers.

A feeding trial was carried out to determine the effects of chromium methionine (Cr-Met) chelate and forage level over two years, 1st fattening and 2nd fattening period on growth parameters, carcass characteristics and blood metabolites of 46 Korean native (Hanwoo, Bos Taurus, BW = 183 ± 44 kg) steers. Treatments were: 1) Steers in the low forage (LF) group were fed diets that consisted of 60% concentrate and 40% forage; 2) Steers in the high forage (HF) group were fed diets that consisted of 40% concentrate and 60% forage. Following the 1st fattening period, steers (BW = 480 ± 37.6 kg) were randomly assigned to four treatment groups: LF (40 F plus no Cr-Met supplementation in the 2nd fattening period), LFCM (40LF plus added 400 ppb of Cr-Met during the 2nd fattening period), HF (60 F plus no added Cr-Met during the 2nd fattening period) and HFCM (60 F plus added 400 ppb of Cr-Met in the 2nd fattening period). Dry matter intake of the treatment diets did not differ during the raising and 1th fattening period (P > 0.05). The ADG in the raising period showed no difference between the 40 F and 60 F groups (P > 0.05). Carcass characteristics including rib-eye area and meat yield index were higher in HF than the other treatment groups (P < 0.05). The HF group tended to show a higher (P = 0.08) marbling score than the LF group whereas the HFCM group showed a higher marbling score than the LFCM group (P < 0.05). HDL was higher and LDL lower in groups fed with Cr-Met than in other groups whereas glucose showed the lowest value in HF group (P < 0.05). Triglyceride (TG), Cholesterol, PUN and total protein (TP) were the same among all treatment groups (P > 0.05). The Insulin concentration in the blood was significantly higher for the HFCM group than for the LF, LFCM and HF groups (P < 0.05). It is concluded that supplementation of chromium-methionine chelate could improve meat quality in beef steers.

Effects of high-level chromium methionine supplementation in lambs fed a corn-based diet on the carcass characteristics and chemical composition of the longissimus muscle

Twenty-four male lambs (24.93 ± 0.93 kg) were used in order to evaluate the effects of chromium methionine (Cr) supplementation in high-energy finishing diets on the carcass characteristics and chemical composition of the longissimus muscle (LM). Treatments were 0.00, 0.60, 1.20, and 1.80 mg Cr/lamb daily. The experiment lasted 56 days. There were no effects of treatments on dry matter intake, feed to gain ratio, and final weight, which averaged 35.24 ± 1.01 kg. Supplemental Cr linearly decreased fat thickness enough to improve the estimated yield grade from 1.82 to 1.42 with no effect on the other carcass traits measured. Fat concentration in the LM decreased linearly as the level of Cr increased in diets, but protein concentration remain constant and so the protein/fat ratio in the LM increased. It is concluded that Cr supplementation has a modulating effect on carcasses by reducing fat; maximal response was reached at a daily dose of 1.80 mg Cr/head.

Effects of Cr Methionine on Glucose Metabolism, Plasma Metabolites, Meat Lipid Peroxidation, and Tissue Chromium in Mahabadi Goat Kids

This study was designed to investigate the effects of chromium methionine (Cr-Met) on glucose metabolism, blood metabolites, meat lipid peroxidation, and tissue chromium (Cr) in Mahabadi goat kids. Thirty-two male kids (16.5 ± 2.8 kg BW, 4-5 months of age) were fed for 90 days in a completely randomized design with four treatments. Treatments were supplemented with 0 (control), 0.5, 1, and 1.5 mg Cr as Cr-Met/animal/daily. Blood samples were collected via heparin tubes from the jugular vein on 0, 21, 42, 63, and 90 days of experiment. On day 70, an intravenous glucose tolerance test (IVGTT) was conducted. At the end of the feeding trial, the kids were slaughtered, and the liver, kidney, and longissimus dorsi (LD) muscle samples were collected. Plasma glucose, insulin, and triglyceride concentrations were decreased by Cr supplementation (P < 0.05). LD muscle malondialdehyde (MDA) decreased, and plasma and tissue Cr contents increased with increasing supplemental Cr levels (P < 0.05). Plasma glucose concentrations at 30 and 60 min after glucose infusion were lower in the kids fed 1.5 mg Cr diet than the kids fed control diet (P < 0.05). The IVGTT indicated that the kids supplemented with 1.5 mg Cr had higher glucose clearance rate (K) and lower glucose half-life (T½; P < 0.05). Glucose area under the response curve (AUC) from 0 to 180 min after glucose infusion was decreased linearly (P < 0.01) by supplemental Cr. The results suggested that supplemental Cr may improve glucose utilization and lipid oxidation of meat in fattening kid.

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.

Hypoglycemic activity and acute oral toxicity of chromium methionine complexes in mice

The hypoglycemic activity of chromium methionine (CrMet) in alloxan-induced diabetic (AID) mice was investigated and compared with those of chromium trichloride hexahydrate (CrCl3·6H2O) and chromium nicotinate (CrNic) through a 15-day feeding experiment. The acute oral toxicity of CrMet was also investigated in ICR (Institute for Cancer Research) mice by a single oral gavage. The anti-diabetic activity of CrMet was explored in detail from the aspects of body weight (BW), blood glucose, triglyceride, total cholesterol, liver glycogen levels, aspartate transaminase (AST) and alanine transaminase (ALT) levels. The obtained results showed that CrMet had beneficial effects on glucose and lipid metabolism, and might possess hepatoprotective efficacy for diabetes. Daily treatment with 500 and 1000μg Cr/kg BW of CrMet in AID mice for 15 days indicated that this low-molecular-weight organic chromium complex had better bioavailability and more beneficial effects on diabetics than CrCl3·6H2O. CrMet also had advantage over CrNic in the control of AST and ALT activities. Acute toxicity studies revealed that CrMet had low toxicity potential and relatively high safety margins in mice with the LD50 value higher than 10.0g/kg BW. These findings suggest that CrMet might be of potential value in the therapy and protection of diabetes.

Effects of chromium methionine supplementation on performance, carcass traits, and the Ca and P metabolism of broiler chickens under heat-stress conditions

SUMMARY We investigated the effects of different levels of chromium methionine (CrMet) on the performance, carcass traits, and Ca and P metabolism of broiler chickens under conditions of heat stress. A total of 288 male broiler chickens (Ross 308) were allocated to 4 treatment groups (supplementation with 0, 200, 400, or 800 ppb of Cr in the form of CrMet) in a completely randomized design. The experiments were conducted under heat-stress conditions, but all birds were kept below 33 ± 2°C. The BW and feed intake of the broilers supplemented with Cr increased at 800-ppb concentrations of Cr (P 0.05). Chromium supplementation did, however, increase carcass yield and decrease the abdominal fat contents. The serum Ca and P levels of the broilers were unaffected (P > 0.05) by different level of CrMet supplementation, but the alkaline phosphatase activity significantly (P < 0.05) decreased by these treatments. Therefore, supplemental CrMet at the level of 800 ppb can improve both performance and carcass traits in broiler chickens reared under heat-stress conditions.

Effects of Dietary Chromium Methionine on Growth Performance, Carcass Composition, Meat Colour and Expression of the Colour-related Gene Myoglobin of Growing-finishing Pigs.

To investigate the effect of dietary chromium (Cr) as Cr methionine (CrMet) on growth performance, carcass traits, pork quality, meat colour and expression of meat colour-related genes in growing-finishing pigs, 189 crossbred Duroc×(Landrace×Yorkshire) growing-finishing pigs (male, castrated, average initial BW 74.58±1.52 kg) were selected and randomly allocated into four groups. Dietary treatments per kg of feed were as follows: 0 (CT), 0.3 mg/kg (T1), 0.6 mg/kg (T2) and 0.9 mg/kg (T3) Cr (in the form of CrMet; as-fed basis), and each treatment was replicated five times with 8 to 10 pigs per replicate pen. During the 28 d of the experiment, both the ADG and the ADFI increased linearly (p<0.05) as the level of dietary Cr increased. The F/G ratio decreased linearly (p<0.05). As dietary Cr increased, loin muscle areas (linear, p = 0.013) and average backfat thickness (linear, p = 0.072) decreased. Shear force (linear, p = 0.070) and Commission Internationale de I’Éclairage (CIE) redness (quadratic, p = 0.028) were increased. In addition, CIE Lightness (quadratic, p = 0.053) were decreased as dietary Cr increased. As dietary Cr increased, total myglobin (Mb) content (quadratic, p = 0.015) and the mb mRNA levels (quadratic, p = 0.046) in longissimus muscles of pigs were up-regulated. In conclusion, supplementation of dietary Cr improved growth and meat colour, but increased shear force and decreased IMF reduced palatability of longissimus muscles. Moreover, the increasing total Mb content and mb mRNA levels indicated that CrMet dietary supplementation may improve meat colour via up-regulating expression of the mb gene.

Optimization of Reaction Parameters for the Synthesis of Chromium Methionine Complex Using Response Surface Methodology

This study deals with a new and better protocol to prepare chromium methionine using aqueous ethanol solution as the reaction medium. Response surface methodology (RSM) coupled with Box-Behnken design was employed to model and optimize the operational parameters of this protocol. The ethanol content of aqueous ethanol, the molar ratio of methionine and Cr(III), reaction temperature, and reaction time were chosen as independent variables, and their combined effects on the conversion of Cr(III) (response 1) and the yield of chromium methionine (response 2) were investigated. The optimal values of the parameters were found to be the following: ethanol content of aqueous ethanol is 48.5%; n(Met)/n(NaOH)/n(CrCl3·6H2O) = 4.31:4.31:1; reaction time is 127 min; reaction temperature is 81.1 °C; initial Cr(III) concentration is 0.25 mol/L. The conversion of Cr(III) and the yield of chromium methionine are up to 99.79% and 99.23%, respectively, under the optimal conditions. The analysis of variance (ANOVA) and regression with R2 values of 0.9984 for the conversion of Cr(III) and 0.9974 for the yield of chromium methionine illustrate that the experimental results are in good agreement with the predicted values, and the models can be used to predict the synthesis of chromium methionine successfully.

English

&nbsp; This study was conducted to study the effect of supplemental chromium on reproductive performance of dairy cows. Thus, forty multiparous Holstein cows (parity 3) were allocated to two treatments and 20 replicates in a completely randomized design. In this study, treatments consisted of: control group, which received no chromium supplementation and treatment group, which received 6 g/day chromium from chromium methionine. The cows allocated to this experiment from week 3 prior to parturition until 9 weeks thereafter. Reproduction parameters consisted of: insemination index and numbers of open days, clinical metabolic disorders which include acidosis, milk fever, retained placenta and displaced abomasums, and also clinical puerperal complications consisting of: mastitis, endometritis and ovarian cysts were determined. Results indicate that Cr supplementation significantly causes decrease in the numbers of open days (p &lt; 0.05). Clinical metabolic disorders and clinical puerperal complications were not affected by chromium methionine supplementation. The results of this experiment showed&nbsp;that chromium methionine supplementation in multiparous dairy cows diet may improve their reproductive performance in transition period. &nbsp; Key words:&nbsp;Dairy cow, Chromium methionine, reproductive performance

Effects of supplemental chromium-methionine on reproductive performance of dairy cows in transition period

This experiment was conducted to study the effects of supplemental chromium on the reproductive performance of dairy cows. Thus, twenty multiparous Holstein cows (parity 3) were allocated to two treatments groups with ten replicates in a completely randomized design. In this study, the treatment consists of control group which received no chromium supplementation and treatment group which received 5 g/day of chromium from chromium methionine. The cows used for this experiment were within the range of 5 weeks prior to parturition to 12 weeks after parturition. Reproduction parameters consisting of insemination index and numbers of open days, clinical metabolic disorders which included acidosis, milk fever, retained placenta and displaced abomasums, and also clinical puerperal complications consisting of mastitis, endometritis and ovarian cysts, were determined. The results indicated that chromium (Cr) supplementation significantly caused a decrease in the numbers of open days (p < 0.05). Clinical metabolic disorders and clinical puerperal complications were not affected by chromium methionine supplementation. The results of this experiment also showed that chromium methionine supplementation in multiparous dairy cows diet may improve their milk yield and reproductive performance in transition period. Key words: Dairy cow, transition period, chromium methionine, reproduction.

Immune Response of Broiler Chickens Fed Diets Supplemented with Different Level of Chromium Methionine under Heat Stress Conditions.

The objectives of this study were to investigate the immune responses of broiler chickens fed diets supplemented with different level of chromium methionine (CrMet) in heat stress (HS) condition. Two hundred and eighty eight male broiler chickens (Ross 308) were allocated to four treatment groups (supplementation with 0, 200, 400 or 800 ppb Cr in the form of CrMet) in a completely randomized design. The experiment was conducted at heat stressed condition and all birds were kept under temperature of 33±2°C. Antibody titers against Newcastle disease virus (NDV) and infectious bronchitis virus (IBV), heterophil to lymphocyte ratios (H/L), and concentration of plasma cortisol (CPC) were measured at 21 and 42 d. At 42 days of age two birds were chosen randomly from each replicate, slaughtered, spleen and bursa of Fabricius were collected, weighed and expressed as a percentage of live body weight. Antibody titers against NDV and IBV at 21 and 42 days of age in broiler fed supplemental CrMet were higher than in broiler chickens fed control diet (p<0.05). CPC level in broiler chickens fed CrMet were significantly (p<0.05) decreased. Increases in lymphocyte counts and consequently a decrease in heterophil to lymphocyte ratios in broiler chickens fed 800 ppb Cr were observed at 21 and 42 d. Supplementation with CrMet had no significant effect on lymphoid organs of broilers. The results suggest that dietary CrMet supplementation at a level of 800 ppb can improve some immune responses of broiler chickens under heat stress conditions.