Effects of dietary chromium propionate on laying performance,egg quality,serum biochemical parameters and antioxidant status of laying ducks under heat stress

Recent studies have shown that chromium (Cr) could alleviate the negative effects of heat stress on livestock and poultry, but there is little information available to laying ducks. This study aimed to investigate the effects of dietary addition of chromium propionate on laying performance, egg quality, serum biochemical parameters and antioxidant status of laying ducks under hot (average 32 °C) and humid (average 75% relative humidity) summer conditions. A total of 900 66-week-old weight- and laying-matched Shanma laying ducks were randomly divided into five treatments, each with 6 replicates of 30 individually caged birds. The birds were fed either a basal diet or the basal diet supplemented with either 200, 400, 600, or 800 μg/kg Cr as chromium propionate. All laying ducks were given feed and water ad libitum for 5 weeks. The results showed that dietary supplementation with chromium propionate significantly increased the laying rate and yolk colour score (P < 0.05). Treatment with 400 μg/kg Cr as chromium propionate significantly decreased the feed/egg ratio by 5.4% (P < 0.05). Increased supplemental Cr from 0 to 800 μg/kg resulted in an increase in albumen height and the Haugh unit linearly (P < 0.05). Increased supplemental Cr decreased serum cortisol (P < 0.001, linear; P = 0.008, quadratic), heat shock protein-70 (P < 0.001, linear; P = 0.007, quadratic) and glucose (P = 0.007, linear), whereas it increased serum insulin (P = 0.011, Linear), total protein (P = 0.006, linear; P = 0.048, quadratic) and albumin (P = 0.035, linear; P = 0.088, quadratic). Dietary Cr levels increased the activities of superoxide dismutase and glutathione peroxidase, the total antioxidant capacity linearly and quadratically (P < 0.05). A linear and quadratic (P < 0.05) decrease of the malondialdehyde concentrations in response to dietary Cr level was observed. These results indicated that dietary supplementation of Cr as chromium propionate, particularly at 800 μg/kg could beneficially affect the laying rate, egg quality and antioxidant function, as well as modulate the blood biochemical parameters of laying ducks under heat stress conditions.     

Effects of dietary chromium and zinc on egg production, egg quality, and some blood metabolites of laying hens reared under low ambient temperature

This experiment was conducted to evaluate the effects of chromium (chromium picolinate, CrPic) and zinc (ZnSO₄·H₂O) on egg production, egg quality, and serum insulin, corticosterone, glucose, cholesterol, and total protein concentrations of laying hens reared under a low ambient temperature (6.8°C). One hundred twenty laying hens (Hy-Line; 32 wk old) were divided into 4 groups, 30 hens per group. The laying hens were fed the control diet (T1) or the control diet supplemented with either 400 μg of Cr/kg of diet (T2), 30 mg of Zn/kg of diet (T3), or 400 μg of Cr plus 30 mg of Zn/kg of diet (T4). Although the dry matter intake (DMI) was similar (p>0.05) for all treatment groups, supplemental chromium and zinc either individually or together increased live-weight change, egg production, and improved feed efficiency (p<0.05). However, no significant differences were observed between T4 and T2 or T3. Compared to T1, supplemental chromium and zinc increased egg weight, eggshell weight, eggshell thickness, egg specific gravity, and Haugh unit (p<0.05) in T2, T3, and T4 groups, among which there was no significant difference. Serum insulin concentration increased (p<0.05) and corticosterone concentration decreased (p<0.05) with dietary chromium and zinc supplementation. Serum glucose and cholesterol concentrations decreased (p<0.05) and protein concentrations increased (p<0.001) with dietary chromium and zinc supplementation in all treatment groups. The results of this study indicated that either supplemental dietary chromium or zinc increased plasma insulin and decreased corticosterone concentrations and that had a positive effect on performance of laying hens under low ambient temperature.     

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.     

Effects of dietary chromium and ascorbic acid supplementation on digestion of nutrients,serum antioxidant status,and mineral concentrations in laying hens reared at a low ambient temperature

This experiment was conducted to evaluate the effects of chromium (chromium picolinate, CrPic) and vitamin C (l-ascorbic acid) supplementation on the digestion of nutrients and serum concentration of some antioxidant vitamins and minerals of laying hens (Hy-Line) reared at a low ambient temperature (6.8°C). One hundred twenty laying hens (32 wk old) were divided into 4 groups, 30 hens per group. The laying hens were fed either a basal diet or the basal diet supplemented with either 400 μg of Cr/kg diet, 250 mg of l-ascorbic acid/kg diet, or 400 μg of Cr plus 250 mg l-ascorbic acid/kg diet. The digestibility of nutrients (DM, OM, CP, and EE) increased by the supplementation of chromium and vitamin C (p<0.05). Supplemental chromium and vitamin C also increased serum vitamin C and E but decreased malondialdehyde concentrations (p<0.05). Additionally, supplemental chromium and vitamin C caused an increase in the serum concentrations of Fe, Zn, Mn, and Cr (p<0.05) but a decrease in Cu concentration. The results of the present study showed that each dietary supplement influenced most of the parameters measured in a similar way. Also, a combination of the two supplements resulted in an additive effect, and supplementing a combination of vitamin C (250 mg/kg of diet) and chromium (400 μg Cr/kg diet) may offer a potential protective management practice in preventing cold-stress-related depression in the performance of laying hens.     

Effects of dietary combination of chromium and biotin on growth performance, carcass characteristics, and oxidative stress markers in heat-distressed Japanese quail

Environmental stress causes adverse effects in performance and antioxidant status of poultry. Dietary chromium supplementation promotes the growth rate and feed efficiency of growing poultry and these beneficial effects of chromium appear to be greater under stress. Biotin, a member of the vitamin B complex, is involved in the metabolism of carbohydrates, fats, and proteins. In a previous experiment, we examined the effects of chromium picolinate (CrPic) as a chromium source in birds subjected to high environmental temperature and the data showed that supplementation with CrPic ameliorated the deletorious effect of stress. The study was conducted to determine the effects of a supplementation of combination of CrPic and biotin (Diachrome^TM) on performance, carcass characteristics, levels of oxidative stress markers, serum cholesterol, and glucose concentrations in Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature of 34°C. Two hundred forty Japanese quail (10 d old) were randomly assigned to 8 treatment groups consisting of 10 replicates of 3 birds. The birds were kept in a temperature-controlled room at 22°C (thermo-neutral [TN] groups) or 34°C (for 8h/d; 09.00 am to 05.00 pm; heat-stress [HS] groups). Birds were fed either a basal (control) diet (TN and HS) or the basal diet supplemented with either 1, 2 or 4 mg of Diachrome/kg of diet. Heat exposure decreased performance when the basal diet was fed (p=0.001). Diachrome supplementation increased feed intake (p=0.001), body weight (p=0.05), feed efficiency (p=0.01), and carcass traits (p≤0.05) variables linearly in birds reared under HS conditions. Serum vitamin C (p=0.05) and vitamin E (p=0.03) concentrations increased, whereas malondialdehyde (MDA) levels in serum and the liver (p=0.01), thigh muscle (p=0.05), and serum cholesterol and glucose concentrations (p=0.05) decreased in supplemented birds reared at a high temperature. It should be noted that when birds were kept at the thermo-neutral temperature, Diachrome supplementation did not affect (p>0.05) the variables measured, with the exception of a reduction in serum cholesterol and glucose. Results of the present study suggest that Diachrome can be considered a protective dietary supplement by reducing the negative effects of high environment temperature on performance and oxidative stress in quail.     

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?相似文献   

Performance,Egg Quality Traits,and Serum Metabolite Concentrations of Laying Hens Affected by Dietary Supplemental Chromium Picolinate and Vitamin C Under a Heat-Stress Condition

A 3?×?2 factorial experiment consisting three levels (0, 200, and 400 μg/kg) of chromium (chromium picolinate) and two levels (0 and 250 mg/kg) of vitamin C was employed to evaluate the effects of these dietary supplements on performance, egg quality traits, and serum biochemical parameters of heat-stressed laying hens (Lohmann LSL-Lite) from 66 to 74 weeks of age. Feed intake increased when birds were given either 400 μg/kg chromium or 250 mg/kg vitamin C (P?<?0.05), but the birds that received both chromium and vitamin C consumed feed similar to those that received only chromium. Dietary treatments had no effect on egg production, egg mass, egg volume, feed conversion ratio, and body mass (P?>?0.05). The birds that fed on diet with chromium or vitamin C produced eggs with higher shell mass and thickness compared to the control. Both eggshell mass and thickness decreased when vitamin C and chromium were supplemented simultaneously, and birds given the diet supplemented with 400 μg/kg chromium and 250 mg/kg vitamin C had eggshell mass and thickness similar to those of the control group. The serum concentration of chromium increased due to increasing level of dietary chromium (P?<?0.05). The birds that received diet with chromium and vitamin C had higher serum concentrations of chromium compared to those that received only chromium (P?<?0.05). Similarly, the hens that received chromium and vitamin C had higher serum concentrations of calcium and phosphorus compared to the hens fed with other treatments (P?<?0.05). The birds given with supplemental chromium exhibited lower serum glucose, total cholesterol, and triglycerides concentrations but higher serum albumin and total protein concentrations compared to the other groups (P?<?0.05).     

Effects of dietary genistein on nutrient use and mineral status in heat-stressed quails.

Genistein is a powerful antioxidant and plays a role in calcium and bone metabolism. We evaluated the efficacy of dietary supplementation with genistein on the nutrient use and mineral concentrations in tibia and serum of quails reared at high environmental temperature (34 degrees C). Two hundred and forty Japanese quails (10 days old) were randomly assigned to 8 treatment groups consisting of 10 replicates of 3 birds. The birds were kept in a temperature-controlled room at 22 degrees C (Thermoneutral, TN groups) or 34 degrees C (for 8 h/d; 09.00 am-05.00 pm; Heat stress, HS groups). Birds were fed either a basal diet (TN and HS) or the basal diet supplemented with 200, 400 or 800 mg of genistein/kg of diet. Heat exposure decreased apparent nutrient digestibility and bone mineralization when the basal diet was fed (P < 0.001). Apparent digestibility of dry matter (DM) (P < 0.05), crude protein (CP) (P < 0.05) and ash (P < 0.01) was significantly improved by genistein supplementation. However, this improvement was not in direct proportion to increased doses of supplement since there was no difference when diets included either 400 or 800 mg genistein/kg of diet (P < 0.05) in birds reared under heat stress. The amounts of Ca, P, Mg, Mn, Zn, Fe and Cu in the excreta decreased (P < 0.01), while Ca, P, Mg, Mn, Zn and Cu concentrations in tibia ash increased in quails reared under heat stress conditions (P < 0.01) with genistein supplementation. Ca and P concentrations in tibia ash were also increased in birds kept under thermoneutral conditions with genistein supplementation. Increased serum alkaline phosphatase activity (P < 0.01) was associated with increasing dietary genistein in all groups. In conclusion, genistein supplementation to the basal diet improved digestibility of CP, DM and ash and levels of Ca and P and bone mineralization in quails reared under heat stress conditions.     

The effect of genistein supplementation on performance and antioxidant status of Japanese quail under heat stress

Genistein, a phytoestrogen found in soybeans, is a powerful antioxidant. We evaluated the effects of genistein supplementation on performance, carcass characteristics, levels of malondialdehyde (MDA), homocysteine, vitamins C, E, A in Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature of 34 degrees C. Two hundred and forty Japanese quails (10 d old) were randomly assigned to eight treatment groups consisting of 10 replicates of three birds. The birds were kept in an environmental controlled room either for 24 h/d at 22 degrees C with (thermoneutral, TN groups) or for 16 h/d at 22 degrees C and for 8 h/d (09.00 am to 05.00 pm) at 34 degrees C (heat stress, HS groups). Birds were fed either a basal (control) diet (TN and HS) or the basal diet supplemented with 200, 400 or 800 mg of genistein per kg of diet. Heat exposure decreased birds' performance when basal diet was fed. Increase in feed intake and body weight, and improvement of feed efficiency and carcass traits were found in genistein-supplemented quails reared under heat stress conditions. Growth rate and feed efficiency improved in quails reared under thermo-neutral conditions as well. Concentration of serum vitamins C, E, and A increased in supplemented birds reared at high temperature, while non-significant changes occurred in TN groups. With genistein supplementation homocysteine levels in serum and MDA levels in serum and liver decreased in all birds of both TN and HS groups. Effects of genistein were relatively greater in heat-stressed quails than in quails kept under thermo-neutral conditions. Results of the present study suggest that supplementation with genistein can be considered to be protective by reducing the negative effects of oxidative stress induced by heat stress in quail.     

Supplemental zinc and vitamin A can alleviate negative effects of heat stress in broiler chickens

This experiment was conducted to evaluate the effects of zinc (ZnSO₄H₂O) and vitamin A (retinol) supplementation on performance, carcass characteristics, and serum concentrations of glucose, cholesterol, total protein, and malondialdehyde (MDA) as an indicator of lipid peroxidation in broiler chickens (Ross) reared at a high temperature (34°C). One hundred twenty 10-d-old male broilers were randomly assigned to 4 treatment groups, 3 replicates of 10 birds each. The birds were fed either a basal diet or the basal diet supplemented with either 30 mg Zn/kg diet, 4.5 mg (15,000 IU) retinol/kg diet, or 30 mg Zn+4.5 mg retinol/kg diet. Supplemental zinc and vitamin A significantly increased live weight gain and improved feed efficiency (p<0.05). However, a combination of zinc and vitamin A, rather than each separately, provided a greater performance. Hot and chilled carcass weights and yields and the weights of internal organs with the exception of abdominal fat were greater for each supplement (p<0.05) compared to the control group. Abdominal fat decreased (p<0.05) upon dietary zinc and vitamin A supplementation. Supplemental treatments resulted in an increased total serum protein but decreased glucose, cholesterol, and MDA concentrations. The results of the study show that, separtely or as a combination, zinc and vitamin A supplementation resulted in an improved live weight gain, feed efficiency, and carcass traits, as well as a decrease in serum MDA concentrations. The results of the present study also suggest that zinc and vitamin A have similar effects and that a combination of zinc and vitamin A may offer a potential protective management practice in preventing heat-stress-related depression in performance of broiler chickens.     

Effects of source and level of magnesium on catalase activity and its gene expression in livers of broiler chickens

The effects of dietary supplemental magnesium oxide (MgO), magnesium-L-aspartate (MgAsp) and monomagnesium-di-L-aspartate (MgdiAsp) on hepatic catalase (CAT) activity and its mRNA expression were investigated. A total of 360 one-day-old male Abor Acre broiler chickens were allocated to ten treatments, i.e. control plus 9 treatments from 3 x 3 factorial arrangement (Mg source, Mg level), each treatment with six replicates of 6 chickens. The birds were fed with the basal diet alone or supplemented with magnesium (Mg) at 0.9, 1.8, 2.7 g/kg of the diet from MgO, MgAsp or MgdiAsp. Results showed that hepatic Mg concentration increased quadratically as MgO or MgAsp supplementation increased (p < 0.01). Hepatic CAT activity increased linearly in birds fed with MgAsp or MgdiAsp (p < 0.01) and quadratically in birds fed with MgO (p < 0.05) as dietary Mg supplementation level increased. Hepatic CAT mRNA was linearly correlated with the dietary Mg supplementation level (p < 0.01). There were positive correlations among hepatic CAT activity, its mRNA expression level and hepatic Mg concentration (p < 0.01). No effect of Mg2+ on the purified CAT activity was detected in vitro enzymatic reaction system (p > 0.05). Supplemental MgAsp or MgdiAsp was more efficient to increase hepatic Mg concentrations, enhance hepatic CAT activity and its mRNA expression than MgO (p < 0.01). It can be concluded that dietary Mg supplementation could increase hepatic Mg concentration, enhance CAT mRNA expression and consequently enhance CAT activity, and the organic Mg (MgAsp or MgdiAsp) is much more efficient than the inorganic form (MgO).     

The effect of genistein supplementation on performance and antioxidant status of Japanese Quail under heat stress

Genistein, a phytoestrogen found in soybeans, is a powerful antioxidant. We evaluated the effects of genistein supplementation on performance, carcass characteristics, levels of malondialdehyde (MDA), homocysteine, vitamins C, E, A in Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature of 34°C. Two hundred and forty Japanese quails (10 d old) were randomly assigned to eight treatment groups consisting of 10 replicates of three birds. The birds were kept in an environmental controlled room either for 24 h/d at 22°C with (thermoneutral, TN groups) or for 16 h/d at 22°C and for 8 h/d (09.00 am to 05.00 pm) at 34°C (heat stress, HS groups). Birds were fed either a basal (control) diet (TN and HS) or the basal diet supplemented with 200, 400 or 800 mg of genistein per kg of diet. Heat exposure decreased birds' performance when basal diet was fed. Increase in feed intake and body weight, and improvement of feed efficiency and carcass traits were found in genistein-supplemented quails reared under heat stress conditions. Growth rate and feed efficiency improved in quails reared under thermo-neutral conditions as well. Concentration of serum vitamins C, E, and A increased in supplemented birds reared at high temperature, while non-significant changes occurred in TN groups. With genistein supplementation homocysteine levels in serum and MDA levels in serum and liver decreased in all birds of both TN and HS groups. Effects of genistein were relatively greater in heat-stressed quails than in quails kept under thermo-neutral conditions. Results of the present study suggest that supplementation with genistein can be considered to be protective by reducing the negative effects of oxidative stress induced by heat stress in quail.     

In vivo antioxidant properties of vitamin e and chromium in cold-stressed Japanese quails

An experiment was conducted to determine if vitamin E (α-tocopherol acetate) and chromium (chromium picolinate, Cr Pic) supplementation attenuate the negative effects of cold stress on egg production, egg quality, serum metabolites, and antioxidant status in Japanese quails (Coturnix coturnix japonica). One hundred and fifty laying Japanese quails (50-day-old) were divided into five groups, 30 birds per group. The laying quails kept at 6°C for 12 h/d (08.00 p.m. to 08.00 a.m.) were fed either a basal diet (low temperature-basal diet, CS group) or the basal diet supplemented with either 400 μg of Cr/kg of diet (Cr group), 250 mg of α-tocopherol-acetate per kg of diet (Vit. E group) or 400 μg of Cr plus 250 mg of α-tocopherol-acetate per kg of diet (Vit. E + Cr group) while quails kept at 18°C were fed a basal diet (thermo-neutral-basal diet, TN group). Performance and egg quality were significantly reduced in CS group compared with TN group. Supplemental chromium and vitamin E significantly increased live weight change, egg production, and improved feed efficiency in cold-stressed laying hens compared with the group fed the basal diet at 6°C. Egg production and egg weight were also greater (P < 0.05) in each supplemental group compared with the CS group. However, a combination of vitamin E and chromium, rather than each separately, provided the greatest performance. Supplemental vitamin E and chromium also increased serum vitamin C and E but, decreased malondialdehyde (MDA) concentrations (P < 0.05); the combination of vitamin E and chromium resulted in the highest levels of serum vitamin C and E within the cold-stressed quails. Results of the present study indicate that combined antioxidant supplements increased performance, egg quality and serum antioxidant levels while lowering MDA in cold-stressed quails.     

Antioxidant properties of chromium and zinc: in vivo effects on digestibility,lipid peroxidation,antioxidant vitamins,and some minerals under a low ambient temperature

The effects of chromium (chromium picolinate, CrPic) and zinc (ZnSO(4)H(2)O) supplementation on serum concentrations of malondialdehyde (MDA) (an indicator of lipid peroxidation) and serum status of some antioxidant vitamins and minerals of laying hens (Hy-Line) reared at a low ambient temperature (6.8 degrees C) were evaluated. One hundred twenty laying hens (Hy-Line; 32 wk old) were divided into 4 groups, 30 hens per group. The hens were fed either a basal diet or the basal diet supplemented with either 0.4 mg Cr/kg of diet, 30 mg Zn/kg of diet, or 0.4 mg Cr plus 30 mg Zn/kg of diet. Digestibility of nutrients (dry matter [DM], organic matter [OM], crude protein [CP], and ether extract [EE]) increased by supplementation of chromium and zinc (p < 0.05). Supplemental chromium and zinc increased serum vitamins C and E but decreased MDA concentrations (p < 0.05). Additionally, supplemental chromium and zinc caused an increase in the serum concentrations of Fe, Zn, Mn, and Cr (p < 0.05). The present study showed that low ambient temperature causes detrimental effects on the digestibility of nutrients and antioxidant status and that such detrimental effects caused by low ambient temperature can be alleviated by chromium and zinc supplementation, particularly when Cr and Zn were simultaneously included into the diet. Data obtained in the present study suggest that such supplementation can be considered as a protective management practice in a diet of laying hens for alleviating negative effects of cold stress.     

Eucalyptus leaves powder,antibiotic and probiotic addition to broiler diets: effect on growth performance,immune response,blood components and carcass traits

The study was conducted to investigate the effects of different levels of eucalyptus powder (EP), virginiamycin and probiotic on performance, immunity, blood components and carcass traits of broiler chickens. A total of 250, 1-day-old male broiler chickens (Ross 308) were randomly allocated to five treatments with five replicates and 10 chicks each, as a completely randomized design. The dietary treatments consisted of: basal diet (BD), BD+0.25% EP, BD+0.5% EP, BD+0.01% of diet probiotic (Protexin), BD+0.02% of diet antibiotic (virginiamycin). Dietary supplementation did not affect feed intake, BW gain (BWG) and feed conversion ratio (FCR) during starter and grower phases, but BWG and FCR were affected during the finisher and whole periods (P<0.05).The highest BWG and lowest FCR were obtained in birds fed with virginiamycin and 0.5% EP. Dietary supplementation significantly increased the relative weight of carcass and breast (P<0.05). Treatments had no effect on relative weights of internal organs and small intestine except for bursa that increased by treatments. Relative length of jejunum also increased by treatments (P<0.05). Antibody production against sheep red blood cells did not changed in primary titer (day 35), but it significantly increased in secondary titer (day 42) by 0.5% EP. White blood cell counts were increased and cholesterol decreased by dietary supplementation (P<0.05). In conclusion, the results of this study showed that 0.5% EP served as a useful replacement for antibiotic and would improve performance and immune response of broiler chickens.     

Melatonin supplementation can ameliorate the detrimental effects of heat stress on performance and carcass traits of Japanese quail

Melatonin, the major pineal hormone, modulates growth in poultry by influencing hormones involved in growth. We investigated the effects of dietary melatonin supplementation on performance, carcass characteristics, and excretion of nitrogen and some minerals in broiler Japanese quails (Coturnix coturnix japonica) exposed to high-ambient-temperature stress (34°C). One hundred twenty Japanese quails (10 d old) were randomly assigned to 4 treatment groups, 3 replicates of 10 birds each. The birds were kept in either an environment-controlled room at a constant 22°C or were kept at 22°C for 16 h/d and at 34°C for 8 h/d (9:00 am to 5:00 pm). At both temperatures birds were fed either a basal diet or the basal diet supplemented with 40 mg of melatonin per kilogram of diet. The experiment lasted for 32 d. Melatonin improved feed efficiency in both temperatures groups compared with their corresponding controls. Although feed intake was similar in all groups, the improvement in feed efficiency was more noticable in melatonin-fed quails kept at high temperature (p<0.01). Supplemental melatonin significantly increased live weight gain and carcass characteristics under stress conditions (p<0.01) but did not show the same effect at thermoneutral conditions (p>0.05). Heat exposure increased excretion of N, Ca, P, Zn, Fe, and Cr and decreased retention rates for them. Dietary melatonin supplementation returned these values to normal (p<0.01). No interactions between melatonin and temperature were found in the parameters measured. The results of the study show that melatonin supplementation attenuated the retardation in performance as well as the excretion of minerals caused by heat stress in broiler quails. Our data suggest that melatonin might offer protection against heat-stress-related depression in the performance of broiler quails.     

Effects of dietary combination of chromium and biotin on egg production, serum metabolites, and egg yolk mineral and cholesterol concentrations in heat-distressed laying quails

Chromium picolinate is used in the poultry diet because of its antistress effects in addition to the fact that the requirement for it is increased during stress. This study was conducted to determine if the negative effects of high ambient temperature (34°C) on egg production, egg quality, antioxidant status, and cholesterol and mineral content of egg yolk could be alleviated by combination of chromium picolinate and biotin (0.6/2.0; Diachrome^™, as formulated by Nutrition 21 Inc.), in laying Japanese quails (Coturnix coturnix japanica), Quails (n=240; 50 d old) were divided into 8 groups, 30 birds per group. The quails were fed either a basal diet or the basal diet supplemented with 2, 4, or 8 mg of Diachrome/kg diet. Birds were kept at 22°C and 53% relative humidity (RH). At 14 wk of age, the thermoneutral (TN) group remained in the same temperature as at the beginning of experiment, whereas the heat stress (HS) group was kept in an environment-controlled room (34°C and 41% RH) for 3 wk. Heat exposure decreased performance when the basal diet was fed (p=0.001). Diachrome supplementation at 4 and 8 mg/kg diet, increased feed intake (p=0.05), egg production (p=0.05), feed efficiency (p=0.01), egg weight (p=0.05), and Haugh unit (p=0.01) in quails reared under heat stress conditions. Heat exposure increased concentrations of serum malondialdehyde (MDA) (p=0.001), glucose, and cholesterol (p=0.01), which were elevated by supplemental Diachrome (p≤0.05). Egg yolk Cr, Zn, and Fe (p=0.01) concentrations increased linearly, whereas MDA and cholesterol concentrations decreased (p=0.05) as dietary Diachrome supplementation increased in HS groups. Similar effects of supplementation on serum levels of glucose and cholesterol (p=0.05) and egg yolk concentrations of cholesterol (p=0.05) and Cr (p=0.01) were observed in TN groups. No significant differences in other values were observed in the TN groups. Results of the present study suggest that supplementation with Diachrome protects the quail by reducing the negative effects of heat stress.     

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).     

Effects of l-carnitine and niacin supplied by drinking water on fattening performance,carcass quality and plasma l-carnitine concentration of broiler chicks

The present study was initiated to determine whether dietary supplemental L-carnitine and niacin affect growth performance, carcass yield, abdominal fat and plasma L-carnitine concentration of broiler chicks. One-day-old broiler chicks (COB500) were used in the experiment. A two by two factorial arrangement was employed with two levels (0 and 50 mg/l) of supplemental L-carnitine and two levels (0 or 50 mg/l) of supplemental niacin in drinking water as main effects. Body weight gain was significantly improved by L-carnitine, or L-carnitine + niacin supplementation during the first 3 weeks. However, supplemental L-carnitine and niacin did not change body weight gain during the last 3 weeks of the experimental period. Supplemental L-carnitine significantly improved feed intake during the first 3 weeks. Supplemental L-carnitine or niacin did not influence carcass weight, carcass yield and abdominal fat weight. L-carnitine content in the plasma was significantly higher in the groups receiving supplemental L-carnitine and L-carnitine + niacin. It is concluded that dietary supplemental L-carnitine or L-carnitine + niacin could have positive effects on body weight gain and feed intake during the early stages of growing. However, supplemental L-carnitine or L-carnitine + niacin were not of benefit regarding the complete growth period.     

Effects of dietary chromium supplementation on performance, carcass traits, serum metabolites, and tissue chromium levels of Japanese quails

This study was conducted to investigate the effects of various levels of dietary chromium supplementation on performance, carcass traits, blood chemistry, and tissue distribution of chromium (Cr³⁺) in quails. Two hundred forty 1-d-old Japanese quails were divided into five groups with four replicates and were fed a basal diet or the basal diet supplemented with 20, 40, 80, or 100 mg/kg Cr (CrCl₃·6H₂O) until 38 d of age. Chromium supplementation decreased carcass fat percentage, serum low-density lipoprotein (LDL), and glucose and increased serum magnesium (Mg) and Cr content of kidney, liver, and muscle. In conclusion, 20, 40, 80, or 100 mg/kg Cr supplementation to quail diet had no effect on performance, chemical composition of carcass except fat percentage, serum protein, calcium (Ca), and inorganic phosphorus (Pi) levels, but reduced serum glucose, LDL and fat percentage of carcass. Chromium is accumulated mainly in the kidneys and liver.