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.     

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.     

Efficacy of dietary supplemental insoluble fibrous materials in ameliorating adverse effects of coccidial challenge in broiler chickens

ABSTRACT

The current experiment was designed to examine effects of dietary supplemental sunflower hulls (SH) and rice hulls (RH) on growth performance, carcass traits, intestinal morphology, lesion score and oocyst shedding in broiler chickens exposed to coccidial challenge. A total of 540 broiler chickens (Ross 308) were assigned to six dietary treatments based on a factorial arrangement (2 × 3) across 1–14, 14–28 and 28-42-d periods. Experimental treatments consisted of broiler chickens without or with coccidial challenge each offered with three different diets: a basal diet or basal diet supplemented with either RH or SH at 40 g/kg diet, respectively. Infection with Eimeria impaired daily weight gain (DWG) and feed conversion ratio (FCR) of broiler chickens during growing period (p < 0.05) while supplementation of SH or RH reduced the adverse effect of coccidiosis so that birds had similar DWG to those fed the basal diet without infection. However, only dietary SH improved the FCR of broilers challenged with coccidiosis. Regardless of coccidial challenge, dietary access to insoluble fibre improved performance of broilers across the growing period (p < 0.05); however, this effect was not observed during the entire rearing period. Relative weights of liver and pancreas were increased in birds subjected to coccidial challenge on d 21 of age (p < 0.05). Moreover, relative weights of the intestinal segments were enhanced (p < 0.05). Furthermore, gizzard weights were higher in birds receiving diets added with fibre (p < 0.05). Infection with coccidiosis decreased villus height and villus height to crypt depth ratio in duodenum of broilers which received the basal diet compared with those fed the same feed without coccidial challenge (p < 0.05). However, supplemental SH could decrease the negative effect of infection on the noted intestinal morphometric attributes. Similarly, a marked reduction was observed for lesion score and faecal oocyst excretion of challenged broilers fed on dietary supplemental fibre (p < 0.05). In conclusion, supplementation of insoluble fibre could ameliorate negative effects of coccidial challenge on DWG of broiler chickens and inclusion of SH in diet of birds exposed to Eimeria infection could be recommended.     

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 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.     

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.     

Vitamin E and selenium supplementation to alleviate cold-stress-associated deterioration in egg quality and egg Yolk mineral concentrations of Japanese quails

The effects of vitamin E (dl-α-tocopheryl acetate) and selenium (Se; Na₂-SeO₃) on egg production, egg quality, and mineral content of egg yolk in Japanese quails reared under a low ambient temperature (6°C) were evaluated. Birds (n=300; 7 wk old) were randomly assigned to 12 treatment groups, 25 birds per group. The birds in a 3×2 factorial design received either three levels of vitamin E (125, 250, and 500 mg/kg diet) or two levels of selenium (0.1 or 0.2 mg/kg diet). After 2 wk on feed, six groups of the birds were maintained at 18°C (thermoneutral temperature [TN]), and the other half were acclimated over 3 d to a decreased environmental temperature of 6°C (cold stress [CS]). The performance, egg quality, and mineral content of egg yolk were not influenced by supplemental vitamin E and selenium in quails not exposed to cold stress (p≥0.09). Two hundred fifty and 500 mg vitamin E/kg diet compared with 125 mg/kg diet and higher dietary selenium inclusions (0.2 vs 0.1 mg/kg) resulted in a better body weight, egg production, and feed efficiency (p=0.01) in quails reared under CS. Similarly, egg weight, egg specific gravity, eggshell thickness, and Haugh unit were positively influenced with vitamin E (p=0.01) and selenium (p≤0.05) supplementation. Egg yolk concentrations of Zn, Fe, and Mn were higher with higher dietary vitamin E (p=0.01) and selenium (p=0.05). There was no interaction detected for parameters measured in the present study (p≥0.3). The results of the present study showed that a combination of 250 or 500 mg vitamin E and 0.2 mg selenium per kilogram of diet provides the greatest effects on performance and egg quality of Japanese quails reared under cold stress and suggest that such a supplementation can be considered as a protective management practice in Japanese quail diets to reduce the detrimental effects of cold stress.     

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.     

Effects of different levels of selenium on growth performance and immunocompetence of broilers under heat stress

An experiment was undertaken to evaluate the effect of dietary selenium (Se) levels on growth performance and immune competence of broilers under heat stress. Birds were raised in either a thermoneutral (TN, 23.9°C constant) or heat stress conditions (HS, 23.9°C to 38°C cycling) and were fed a corn-soybean meal basal diet supplemented with Se at 0, 0.2 and 0.4 mg/kg. A total of 240 one-day-old male broiler chicks were randomly assigned to six groups; each group had four replicates of 10 birds. Body weight and feed intake were not influenced by dietary Se, while feed conversion was significantly improved by a Se-supplementation of 0.2 mg/kg. HS significantly reduced body weight, feed intake and feed conversion. Numbers of abdominal exudate cells (AEC), percentage of macrophages in AEC, phagocytic macrophages, internalized opsonised and unopsonised sheep red blood cells (SRBC) were significantly increased by dietary Se. Both primary and secondary antibody responses were characterised by increasing titres of antibody to SRBC by dietary Se when birds were exposed to HS (p < 0.05). Lymphoid organ weights, antibody responses, incidence of macrophages in AEC, and phagocytic ability of macrophages were also significantly reduced under HS. These results indicated that HS severely reduced growth performance and immunocompetence of broilers, whereas the immune response of broilers improved by dietary Se supplementation under HS.     

Effects of glyceryl polyethylene glycol ricinoleate on nutrient utilisation and performance of broiler chickens

A completely randomised design study with a 2 × 2 factorial arrangement was conducted to observe effects of an emulsifier (glyceryl polyethylene glycol ricinoleate (GPR)) on nutrient utilisation and performance of broiler chickens. A total of 384 male broiler chickens were used to determine the influence of GPR (without addition or added at 0.04% of diet) and two levels of apparent metabolisable energy (AME_N) (according to standard requirements (Diets SE) or energy reduced by 0.4 MJ/kg diet (Diets LE)) on birds’ performance and apparent total tract digestibility (ATTD). ATTD of ether extract (EE) and AME_N were measured on d 14 and 35, and ATTD of neutral detergent fibre (NDF) was measured on d 35. All diets were based on wheat–maize–soybean meal with rapeseed oil and lard (blend of 50:50) as fat sources. During the grower period and the whole trial, birds fed Diets supplemented with GPR were characterised by higher body weight gain (BWG) and lower feed conversion ratio (FCR) compared to chicken receiving diets without GPR (p < 0.05). At the end of experiment, birds fed Diet LE without GPR were characterised by lower BWG and higher FCR (p < 0.05). Supplementation with GPR caused a higher ATTD of EE for diets SE and LE at d 14 and 35 (p < 0.05). Moreover, the GPR addition to Diet LE improved ATTD of NDF at d 35 (p < 0.05). In conclusion, the findings suggest that GPR effects the digestion of a blend of animal fat/rapeseed oil positively, even in a practical maize–wheat-based broiler diet with decreased AME_N level.     

Black soldier fly as dietary protein source for broiler quails: apparent digestibility,excreta microbial load,feed choice,performance, carcass and meat traits

In order to expand with validated scientific data the limited knowledge regarding the potential application of insects as innovative feed ingredients for poultry, the present study tested a partial substitution of soya bean meal and soya bean oil with defatted black soldier fly (Hermetia illucens) larvae meal (H) in the diet for growing broiler quails (Coturnix coturnix japonica) on growth performance, mortality, nutrients apparent digestibility, microbiological composition of excreta, feed choice, carcass and meat traits. With this purpose, a total of 450 10-day-old birds were allocated to 15 cages (30 birds/cage) and received three dietary treatments: a Control diet (C) and two diets (H1 and H2) corresponding to 10% and 15% H inclusion levels, respectively (H substituted 28.4% soya bean oil and 16.1% soya bean meal for H1, and 100% soya bean oil and 24.8% soya bean meal for H2, respectively). At 28 days of age, quails were slaughtered, carcasses were weighed, breast muscles were then excised from 50 quails/treatment, weighed, and ultimate pH (pHu) and L*, a*, b* colour values were measured. Breast muscles were then cooked to assess cooking loss and meat toughness. For the digestibility trial, a total of 15 28-day-old quails were assigned to the three feeding groups. The excreta samples were subjected to chemical and microbiological analysis. The same 15 quails were then simultaneously provided with C and H2 diets for a 10-day feed choice trial. Productive performance, mortality and carcass traits were in line with commercial standards and similar in all experimental groups. With the exception of ether extract digestibility, which was lower in H1 group compared with C and H2 (P=0.0001), apparent digestibility of dry matter, CP, starch and energy did not differ among treatments. Microbial composition of excreta was also comparable among the three groups. Feed choice trial showed that quails did not express a preference toward C or H2 diets. Breast meat weight and yield did not differ among C, H1 and H2 quails. Differently, the inclusion of H meal reduced meat pHu compared with C. In conclusion, this study demonstrated that H. illucens larvae meal can partially replace conventional soya bean meal and soya bean oil in the diet for growing broiler quails, thus confirming to be a promising insect protein source for the feed industry. Further research to assess the impact of H meal on intestinal morphology as well as on meat quality and sensory profile would be of utmost importance.     

Plant extract supplementation as a strategy for substituting dietary antibiotics in broiler chickens exposed to low ambient temperature

ABSTRACT

The present study was conducted to investigate the effects of two plant extracts as alternatives to dietary antibiotics in broiler chickens exposed to low ambient temperature. A total of 300 one-day-old male broiler chickens were randomly assigned to four dietary treatments (5 replicate pens; 15 broiler chickens each) which consisted of starter (d 0 to 10), and grower (d 10 to 28) diets. Dietary treatments included a basal diet (negative control, NC) and three similar diets that were either supplemented with 200 mg/kg of Prosopis farcta extract (PFE), Rhus coriaria L. extract (RCE) or an antibiotic premix containing oxytetracycline (positive control, PC). In order to simulate low ambient temperature, room temperature was maintained at 32°C during the first 3 d of the trial and afterwards, the temperature was gradually reduced by approximately 1.5°C each day to 14°C on d 21. PFE and PC treatments exerted a significant effect on body weight gain at d 28. Diet PFE was effective in reducing mortality when compared with diet NC (p < 0.05). Furthermore, diet PFE caused increases in ileal digestibility of gross energy, dry matter and organic matter when compared with diet NC (p < 0.05). Diets PFE and PC decreased coliforms, total aerobic bacteria and total anaerobic bacteria loads in the caeca when compared with diet NC (p < 0.05). Moreover, the addition of PFE to the diet improved villous height in all small intestinal segments as well as villous height:crypt depth ratio in the duodenum when compared with diet NC (p < 0.05). The results indicated that PFE is not only a valid alternative to oxytetracycline under cold stress conditions, with no antibiotic resistance, but also has the potential to increase the resistance of broiler chickens against ascites syndrome. Moreover, the addition of RCE at the concentration of 200 mg/kg to the diet was not sufficient to improve the performance of broiler chickens (similar to diet PC) but maybe more effective at higher concentrations.     

Carcass and meat quality traits of chickens fed diets concurrently supplemented with vitamins C and E under constant heat stress

The objective of this study was to determine if a diet supplemented simultaneously with vitamins C and E would alleviate the negative effects of heat stress, applied between 28 and 42 days of age, on performance, carcass and meat quality traits of broiler chickens. A total of 384 male broiler chickens were assigned to a completely randomized design, with a 2×3 factorial arrangement (diet with or without vitamin supplementation and two ambient temperatures plus a pair-feeding group) and 16 replicates. Chickens were kept in thermoneutral conditions up to 28 days of age. They were then housed in groups of four per cage, in three environmentally controlled chambers: two thermoneutral (22.5 and 22.6°C) and one for heat stress (32°C). Half the chickens were fed a diet supplemented with vitamins C (257 to 288 mg/kg) and E (93 to 109 mg/kg). In the thermoneutral chambers, half of the chickens were pair-fed to heat stressed chickens, receiving each day the average feed intake recorded in the heat stress chamber in the previous day. Meat physical quality analyses were performed on the pectoralis major muscle. No ambient temperature×diet supplementation interaction effects were detected on performance, carcass, or meat quality traits. The supplemented diet resulted in lower growth performance, attributed either to a carry-over effect of the lower initial BW, or to a possible catabolic effect of vitamins C and E when supplemented simultaneously at high levels. Heat stress reduced slaughter and carcass weights, average daily gain and feed intake, and increased feed conversion. Growth performance of pair-fed chickens was similar to that of heat stressed chickens. Exposure to heat stress increased carcass and abdominal fat percentages, but reduced breast, liver and heart percentages. Pair-fed chickens showed the lowest fat percentage and their breast percentage was similar to controls. Heat stress increased meat pH and negatively affected meat color and cooking loss. In pair-fed chickens, meat color was similar to the heat stressed group. Shear force was not influenced by heat stress, but pair-fed chickens showed the tenderest meat. In conclusion, reduction in growth performance and negative changes in meat color in heat stressed chickens were attributed to depression in feed intake, whereas negative changes in body composition, higher meat pH and cooking loss were credited to high ambient temperature per se. Diet supplementation with vitamins C and E as antioxidants did not mitigate any of these negative effects.     

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.     

Effects of taurine supplementation on productive performance,nutrient digestibility and gene expression of nutrient transporters in quails reared under heat stress

This study was conducted to examine the effects of dietary taurine supplementation on productive performance, nutrient digestibility, antioxidant status, and the gene expression of ileal nutrient transporters in laying quails reared under heat stress (HS). One hundred and eighty laying Japanese quails (Coturnix coturnix japonica) were fed a basal diet or basal diet supplemented with either 2.5 or 5 g of taurine per kg of diet, and reared at either 22 ± 2 °C for 24 h/d (thermoneutral, TN) or 34 ± 2 °C for 8 h/d (HS) for 12 weeks. The quails reared under HS consumed less feed, produced less egg, and had lower dry matter, organic matter and crude protein apparent digestibilities compared with the quails reared under the TN condition (P = 0.001). However, increasing taurine concentrations in the diet improved feed intake and egg production (P = 0.001), but also the apparent digestibilities (P ≤ 0.027) in quails reared under HS. The greater doses (5 g/kg) of taurine resulted in more responses. The quails reared under HS had greater serum and liver MDA concentrations (P = 0.0001) which decreased with dietary taurine supplementations, particularly greater doses. The gene expressions of ileal PEPT1, EAAT3, CAT1, CAT2, SGLT1, SGLT5, GLUT2, and GLUT5 decreased under HS conditions (P = 0.001). However, supplementing taurine, in a dose-dependent fashion, to the diet of quails reared under HS resulted in increases in the gene expressions of the transporters (P < 0.05) except for CAT1. The results of the present work showed that taurine supplementation, particularly with greater doses (5 g/kg), to the diet of laying quails kept under HS acts as alleviating negative effects of HS, resulting in improvements in productive performance and nutrient digestion, and also upregulation of ileal nutrient transporters.     

Activity of supplemental enzymes and their effect on nutrient utilization and growth performance of growing chickens as affected by pelleting temperature

Activity of supplemental enzymes in a barley‐soybean‐maize based diet at 60, 75 and 90°C pelleting temperatures was studied using feed viscosity, in‐vitro enzyme activity and broiler performance data.

High pelleting temperatures increased feed viscosity but supplemented enzymes reduced the viscosity at all three temperatures levels by 11, 14 and 17%, respectively. Water intake and losses in excreta of birds were found to be affected by feed viscosity. Activity of cellulase enzyme, measured using the radial diffusion method, was unaffected at 60 and 75°C, but reduced by 73% in feed processed at 90°C. Enzymes increased the weight gain of broilers by 11.1% at 90°C, but no effect could be seen at low pelleting temperatures possibly due to high dietary protein and energy contents. Feed intake was unaffected by enzymes. Birds consumed 6% more feed and grew 9% faster when the pelleting temperature was increased from 60 to 75°C. Reduced feed intake and daily weight gain observed at 90° C could be fully compensated by the enzyme supplementation. High pelleting temperature reduced energy metabolizability (3.2%) and nitrogen utilization (4%) but enzyme almost compensated them (by 3.3% and 2.6%, respectively). No interaction could be detected between the pelleting temperatures and enzymes.

It is concluded that pelleting temperatures as high as 90°C drastically reduce cellulase activity, energy and nitrogen utilization thus lowering broiler performance. Either the remaining activity of cellulase or other thermostable enzymes can prevent the losses.     

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

Abstract

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 3×3 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).     

In ovo injection with glycerol and insulin-like growth factor (IGF-I): hatchability,intestinal morphometry,performance, and carcass characteristics of broilers

ABSTRACT

The objective of this study was to evaluate the effects of in ovo injection with glycerol (GLY) and insulin-like growth factor (IGF-I) on hatchability, biochemical parameters, intestinal morphometry, performance, and carcass characteristics of broiler chickens. A total of 400 fertilised eggs were distributed into five experimental groups. The treatments were arranged as non-injected (control), saline solution injected (0.9% NaCl solution), GLY solution injected (10 nmol/ml), IGF-I solution injected (100 ng/ml), and GLY + IGF-I solution injected. At 17.5 d of incubation, 0.5 ml of each solution was injected into the amniotic fluid of each egg of the injected groups. The injection of different solutions did not influence the hatchability and incubation time of the eggs. Compared to intact eggs, IGF-I and IGF-I+ GLY increased (p < 0.01) the blood IGF-I at hatching. Higher hepatic glycogen was observed (p < 0.05) with GLY or IGF-I. The tested substances decreased (p = 0.02) the fructose 1,6-biphosfate phosphatase activity but did not affect glycaemia. No difference in performance was observed in the first week. Higher feed intake and weight gain with lower feed conversion ratio was obtained ( p  < 0.05) with IGF-I at 14 d. At 21 d, higher weight gain was obtained (p = 0.05) with IGF-I, GLY, IGF-I, and GLY + IGF-I, resulting (p < 0.01) in birds with greater weight gain at 35 and 42 d of age. GLY provided higher villus height in the ileum at hatching and at 7 d of age. The tested solutions increased the relative weight of the liver at hatching. At 42 d of age, no carcass characteristics were influenced. It is concluded that GLY and IGF-I, together or separately, can be used in the in ovo feeding to improve the post-hatch performance of broilers, without affecting hatchability and carcass composition.     

Effects of dietary L-carnitine and coenzyme Q10 at different supplemental ages on growth performance and some immune response in ascites-susceptible broilers

Abstract

Effects of dietary L-carnitine and coenzyme Q₁₀ (CoQ₁₀) at different supplemental ages on performance and some immune response were investigated in ascites-susceptible broilers. A 3 × 2 × 2 factorial design was used consisting of L-carnitine supplementation (0, 75, and 100 mg/kg), CoQ₁₀ supplementation (0 and 40 mg/kg) and different supplemental ages (from day 1 on and from day 10 on). A total of 480 one-day-old Arbor Acre male broiler chicks were randomly allocated to 12 groups, every group had five replicates, each with eight birds. The birds were fed a corn-soybean based diet for six weeks. From day 10 – 21, all the birds were exposed to a low ambient temperature (12 – 15°C) to increase the susceptibility to ascites. No significant effects were observed on growth performance by L-carnitine, CoQ₁₀ supplementation, and different supplemental ages. Packed cell volume was significantly decreased by L-carnitine supplementation alone, and ascites heart index and ascites mortality were decreased by L-carnitine, CoQ₁₀ supplementation alone, and L-carnitine + CoQ₁₀ supplementation together (p < 0.05). Heart index of broilers was significantly improved by L-carnitine, CoQ₁₀ supplementation alone during 0 – 3 week. Serum IgG content was improved by L-carnitine supplementation alone (p < 0.05), but lysozyme activity was increased by L-carnitine + CoQ₁₀ supplementation together (p < 0.05). A significant L-carnitine by supplemental age interaction was observed in lysozyme activity. L-carnitine supplementation alone had no effects on the peripheral blood lymphocyte (PBL) proliferation in response to concanavalin A (ConA) and lipopolysaccharide, but supplemental CoQ₁₀ alone and L-carnitine + CoQ₁₀ together decreased the PBL proliferation in response to ConA (p < 0.05). The present study suggested that L-carnitine + CoQ₁₀ supplementation together had positive effects on some immune response of ascites-susceptible broilers, which might benefit for the reduction of broilers' susceptibility to ascites.     

Optimal dietary concentration of chromium for alleviating the effect of heat stress on growth,carcass qualities,and some serum metabolites of broiler chickens

This study was conducted to determine the effects of chromium (chromium picolinate, CrPic) supplementation at various levels (0, 200, 400, 800, or 1200 microg/kg of diet) on performance, carcass characteristics, and some serum metabolites of broiler chickens (Ross) reared under heat stress (32.8 degrees C). One hundred fifty old male broilers were randomly assigned to 5 treatment groups, 3 replicates of 10 birds each. The birds were fed either a control diet or the control diet supplemented with either 200, 400, 800, or 1200 microg Cr/kg of diet. Increased supplemental chromium resulted in an increase in body weight (p = 0.01, linear), feed intake (p < or = 0.05, linear), and carcass characteristics (p < or = 0.05, linear) and improved feed efficiency (p = 0.01, linear). Increased supplemental chromium decreased serum corticosterone concentration (p = 0.01, linear), whereas it increased serum insulin and T3 and T4 concentrations (p = 0.01). Serum glucose and cholesterol concentrations decreased (p = 0.01), whereas protein concentrations increased linearly (p = 0.001) with higher dietary chromium supplementation. Results of the present study conclude that a supplementation of diet with chromium at 1200 ppb can alleviate the detrimental effects of heat stress in broiler.