Dietary chromium supplementation for heat-stressed broilers

Effects of the combined use of a probiotic and chromium methionine chelate on the functional state of broiler chickens

Background and Aim

An increase in the productivity of broiler chickens is possible when creating an optimal food base that provides birds with all of the nutrients and biologically active substances required for the fullest realization of their genetic potential. In this regard, we examined the effects of the addition of a water-based probiotic and a chelated form of chromium (Cr) to the diet of birds.

Materials and Methods

Sixty 14-day-old male Arbor Acres broilers were used in this study. The birds were assigned to two groups of 30 birds according to their body weights. The control broilers received distilled water with the basal diet, and the experimental group received a probiotic preparation in drinking water and Cr methionine chelate (Cr-Met) in the diet. The feeding period lasted 28 days. Growth performance indices were measured throughout the experiment. At the end of the experiment, blood sampling was performed to assess blood biochemical parameters, antioxidant system indicators, and trace elements.

Results

We found that the introduction of a probiotic preparation and a chelated form of Cr into the diet of broiler chickens had a positive effect on meat productivity, which was characterized by a 17% increase in the average daily gain of birds (p = 0.05) and a 14% increase in body weight (p = 0.01). Consequently, the yield of the slaughtered carcass increased by 5.8% (p = 0.05). Against the background of the consumption of the developed diet, broiler chickens exhibited a 14% decrease in feed conversion accompanied by an increase in the level of digestibility of dietary nutrients. In addition, glucose levels were decreased by 20% (p = 0.03) against the background of a 76% increase in the total protein concentration (p = 0.01). Superoxide dismutase and glutathione peroxidase activities were increased by 13% (p = 0.02) and 7.5% (p = 0.03), respectively. Elemental analysis of blood serum revealed a 99% decrease in the Fe level versus the control (p = 0.02) and a 31% increase in the Zn level (p = 0.02).

Conclusion

We conclude that feeding broiler chickens is a multicomponent probiotic supplement combined with Cr-Met promotes growth and nutrient absorption, and optimizes metabolic processes.

The Impact of Bacillus subtilis PB6 and Chromium Propionate on the Performance, Egg Quality and Nutrient Metabolizability of Layer Breeders

The objective of this study was to evaluate the effects of Bacillus subtillis PB6, chromium propionate or a combination of the two on the performance, egg and eggshell quality, nutrient metabolizability and serum biochemistry of layer breeders. White Plymouth Rock and Red Rhodes Island breeder hens at 55 weeks of age were allocated in individual cages using a completely randomized block design with 16 replicates. Hens were fed control, control + probiotic (500 g/ton of Bacillus subtilis PB6), control + CrProp (50 g/ton of chromium propionate) and control + probiotic + CrProp diets from 55 to 70 weeks of age. Productive parameters and eggshell quality as well as cortisol and blood biochemistry were grouped each 28 d as well as for the overall period. The metabolizability of nutrients and energy was determined at 70 weeks of age. In the overall period, hens fed the control + probiotic or control + probiotic + CrProp diets had significantly higher egg production, egg mass, shell percentage, thickness and shell strength. The metabolizability of dry matter, nitrogen and energy increased in hens that were fed the control + probiotic + CrProp diet. In conclusion, diets supplemented with Bacillus subtillis PB6 and chromium propionate resulted in improved productive performance, eggshell quality and nutrient metabolizability of layer breeders, without modifying serum cortisol, albumin and triglycerides.

Comparative effects of dietary functional nutrients on growth performance, meat quality, immune responses, and stress biomarkers in broiler chickens raised under heat stress conditions

Objective

The objective of the present study was to investigate the comparative effects of dietary functional nutrients including glutamine (Gln), chromium picolinate (Cr picolinate), vitamin C (Vit C), betaine (Bet), and taurine (Tau) on growth performance, meat quality, immune responses, and stress biomarkers in broiler chickens raised under heat stress conditions.

Methods

A total of 420 21-d-old Ross 308 male broiler chickens (initial body weight = 866±61.9 g) were randomly allotted to 1 of 7 treatment groups with 6 replicates. One group was kept under thermoneutral conditions and was fed a basal diet (PC, positive control). Other 6 groups were exposed to a cyclic heat stress condition. One of the 6 groups was fed the basal diet (NC, negative control), whereas 5 other groups were fed the basal diet supplemented with 0.5% Gln, 500 ppb Cr picolinate, 250 mg/kg Vit C, 0.2% Bet, or 1.0% Tau. The diets and water were provided ad libitum for 21 d.

Results

Broiler chickens in NC group had decreased (p<0.05) growth performance and immune responses measured based on cutaneous basophil hypersensitivity (CBH), but increased (p<0.05) stress responses measured based on feather corticosterone concentrations and blood heterophil:lymphocyte than those in PC group. However, none of dietary functional nutrients had a positive effect on growth performance of broiler chickens. Dietary supplementation of 250 mg/kg Vit C improved (p<0.05) CBH responses of broiler chickens, but other functional nutrients had no such an improvement in CBH responses. All functional nutrients decreased (p<0.05) stress responses of broiler chickens.

Conclusion

Functional nutrients including Gln, Cr picolinate, Vit C, Bet, and Tau at the supplemental levels used in this study decrease stress responses of broiler chickens to a relatively similar extent. However, this reduction in stress responses could not fully ameliorate decreased productive performance of broiler chickens raised under the current heat stress conditions.

Dietary chromium-methionine supplementation and broiler (22–43 days) responses during heat stress. 1. Growth performance and carcass yield, metabolisable energy and serum biochemistry

Context Chromium (Cr) is considered a beneficial trace element. It has been reported that supplementation with Cr in the diet promotes improvements in the productive variables of broilers reared under heat stress (HS). Aim The study aimed to evaluate dose response of Cr as chromium-methionine (CrMet) supplementation on metabolisable energy, serum biochemistry, growth performance and carcass yield of broilers. Methods Three hundred and thirty-six 22-day-old male broiler chickens were randomly assigned to four blocks, six treatments (0, 0.10, 0.20, 0.40, 0.80 and 1.20 mg/kg dry matter (DM) Cr as CrMet), eight repetitions with seven birds per experimental unit, subjected to HS (33°C for 12h/day) from 22 to 43 days. The supplemented CrMet level for each variable studied was estimated using linear and quadratic regressions. Key results The bodyweight was quadratically affected at 35 and 43 days (P &lt; 0.01), as well as bodyweight gain (P = 0.02) and feed conversion ratio (P = 0.01) from 22 to 43 days. A linear improvement (P = 0.03) was observed in the feed conversion ratio from 22 to 28 days and bodyweight gain for 22 to 35 days (P = 0.02). The nitrogen-corrected apparent metabolisable energy and the coefficient of metabolisation of energy were quadratically affected (P &lt; 0.01 and P &lt; 0.01, respectively) by CrMet levels in the diet. A quadratic response was observed on total serum cholesterol (P &lt; 0.01), serum glucose (P = 0.07) and triacylglycerol (P &lt; 0.01). The abdominal fat deposition was quadratically affected (P &lt; 0.01) by CrMet levels in the diet. Conclusions The supplementation of 0.77 mg/kg DM Cr as CrMet improves performance, carcass characteristics and serum biochemistry parameters of broiler chickens reared under heat stress. Implications The results indicate that CrMet can be supplemented in the diet for broilers reared under heat stress to improve productivity of broiler chickens.

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.