Control Broilers Research Articles

Evaluation of xylanase in low-energy broiler diets

The objective of the current study was to evaluate the effect of feeding a thermo-tolerant xylanase in low-energy broiler diets on performance and processing parameters. Evaluation criteria included average broiler BW, FCR, livability, carcass yield, and fat pad yields. The experimental design consisted of 3 nutrient profiles: positive control, negative control 1 (−66 kcal/kg), and negative control 2 (−132 kcal/kg). Two xylanase inclusion programs were included in the negative control 1 and 2 diets; 60 g/t was included in the starter and grower diets with either 60 or 100 g/t in the finisher and withdrawal diets, yielding a total of 7 treatment groups with 8 replicate pens per treatment each containing 42-d-old straight-run chicks per treatment (2,352 total broilers). Broilers were reared in floor pens through 45 d of age. The dietary program consisted of 5 dietary phases: starter (1–15 d), grower 1 (16–23 d), grower 2 (24–31 d), finisher (32–38 d), and withdrawal (39–45 d). Body weights and feed consumption were determined on days of dietary changes, including d 15, 23, 31, 38, and 45. On d 45, 4 male and 4 female broilers per replicate (448 total) were subjected to an 8-h feed withdrawal period and processed to obtain carcass and fat pad weights. Reducing the dietary energy level increased FCR and decreased the fat pad weight of broilers in the negative control 2 treatment compared with the positive control. Inclusion of xylanase during the starter phase increased d 15 BW and reduced FCR. The inclusion of xylanase continued to reduce FCR throughout the trial, as compared with diets without xylanase inclusion. Within this study, we have demonstrated the effectiveness of xylanase inclusion in reduced-energy diets (−66 and −132 kcal/kg) to improve FCR of broilers to that of broilers fed energy-adequate diets.

Body weight, meat quality and blood metabolite responses to carbohydrate administration in the drinking water during pre-slaughter feed withdrawal in broilers.

This study was conducted to determine weights of body (BW), carcass (CW), gastrointestinal tract (GTW), meat quality and some blood metabolite responses to corn starch, saccharose or glucose administration in the drinking water during pre-slaughter feed withdrawal (FW) in broilers. On day 42 of age, 200 broilers (Ross 308) were allocated randomly to five treatments with four replicates. During a 10-h FW, control broilers (C) were provided with non-treated water and the standard finisher diet ad libitum, whereas fasted broilers provided with non-treated (NFW) or treated water, 3g glucose (G), saccharose (S) or corn starch (CS)/L. Eight birds (four males and four females) per treatment were slaughtered. Birds receiving non-treated or treated water had lower BW and higher carcass yield than the full-fed broilers. The full-fed broilers had higher absolute and relative GTW than the fasted birds. Broilers consumed more readily treated water compared with non-treated water. While the a* value of breast meat from CS birds was higher than that from NFW, the b* value of that was higher than S and C birds. The c* values of breast meat from S birds were lower compared with that from the CS treatment. The thigh meat from NFW broilers had higher h* value than that from C and G broilers. The thigh meats of C and CS broilers had higher c* value than that of G birds. The full-fed broilers had higher plasma triglyceride concentration than NFW, S and G birds. The full-fed broilers had higher plasma uric acid and uric acid nitrogen concentrations than S birds. These results show that carbohydrate administration in the drinking water cannot be a good alternative for the FW period before slaughter due to the fact that the carbohydrates do not reduce BW losses and do not lead to increases in meat quality.

A meta-analysis of the feed intake and growth performance of broiler chickens challenged by bacteria

The aim of this meta-analysis was to determine the effect of a bacterial immune challenge (Clostridium spp., Escherichia coli, and Salmonella spp.) on the ADFI, ADG, and nutrient partitioning (maintenance requirements and feed efficiency) of broiler chickens. The database used for the meta-analysis included 65 articles that were published between 1997 and 2012 concerning a total of 86,300 broilers and containing information on the feed intake, protein intake, methionine intake, and weight gain of broilers that were challenged with Clostridium spp., E. coli, or Salmonella spp. and were fed or not fed feed additives. The results of the ADFI and the ADG of the challenged broilers were transformed into values relative to those obtained in control broilers (δADG and δADFI). The meta-analysis involved 3 sequential analyses: graphical, correlation, and variance-covariance analysis. The results obtained for the birds that were challenged with Clostridium spp., E. coli, or Salmonella spp. indicated that the ADFI was reduced by 16, 7, and 9%, respectively, and the ADG was reduced by 40, 10, and 29%, respectively. When the results for the challenged birds that were treated or nontreated were compared, ADFI reductions of 26.0 and 26.5% and ADG reductions of 2.9 and 21.6% were observed, respectively. Regression analyses of the ADG as a function of the protein or methionine intake of the challenged birds suggested that nutrients were diverted to the immune system. The relationship between the δADG and the δADFI was quadratic in the challenged and nontreated or treated broilers, as well as for each disease. The intercept of the regression-based curves for the data from all of the challenges were different from zero and negative (−2.20, −0.70, and −3.37, respectively), indicating that all of the challenges increased the maintenance requirements. In general, this meta-analysis allowed for the quantification of the effects of bacteriological challenges on the maintenance and feed efficiency of broiler chickens, and the knowledge that was generated in this study is applicable to broiler nutrition and for modeling their nutritional requirements.

김치 유래의 유산균 변이주 Lactobacillus paracasei ML-7의 특성 및 육계 성장에 대한 영향

김치로부터 분리, 선별한 유산균 L. paracasei LS-2에 UV 조사 및 L. paracasei LS-2균주가 성장하지 않는 pH 3.5 MRS agar 배지에서 성장하는 변이주를 선별함으로써 변이주인 L. paracasei ML-7를 선별하였다. 선별된 변이주 L. paracasei ML-7의 유기산 생성능력, 병원성 미생물의 생육 저해 능력, 육계에서의 증체 및 사료 효율 개선효과를 시험하였다. 변이주인 L. paracasei ML-7 는 모균주인 L. paracasei LS-2에 비하여 MRS 배지에서 성장속도가 증가되었으며, 유기산 생성도 증가되었다. 또한 L. paracasei ML-7은 병원성 미생물인 E. coli ATCC 25922 (<TEX>${\alpha}$</TEX>-hemolysin producing E. coli)와 A. flavus ATCC 22546에 대한 생육 저해 능력이 모균주인 L. paracasei LS-2에 비해 증가되는 것을 확인할 수 있었다. 육계를 대상으로 하는 사양시험에서 변이주 L. paracasei ML-7을 급여한 처리구에서 증체량 개선 및 사료효율이 개선됨을 확인하였다. 본 결과로부터 유산균의 인공변이로부터 유기산생산 증가 및 그에 따른 가축 사양 성적 개선이 가능한 변이주의 제작이 가능함을 확인할 수 있었다. A mutant strain of Lactobacillus paracasei (ML-7) was derived by ultraviolet irradiation of the parent L. paracasei LS-2 strain, followed by colony selection on pH 3.5 MRS agar plates, on which L. paracasei LS-2 cannot grow. The L. paracasei ML-7 mutant strain produced an increased amount of organic acids compared to the L. paracasei LS-2 parent strain. Broiler chickens were randomly fed with one of three experimental diets: a basal diet as a control, and basal diets supplemented with 0.3% of the L. paracasei LS-2 and L. paracasei ML-7 strains. When concluding the study, the final body weights of the broilers fed with the supplemented basal diets were found to be significantly higher (1.9% for LS-2 and 6.2% for ML-7) than the control broiler group. Broilers fed with basal diet supplemented with the mutant L. paracasei ML-7 strain showed increased body weight and food intake, compared to broilers fed with the basal diet with or without the parent L. paracasei LS-2 strain.

Comparative proteomic analysis of the breast muscle response to chronic corticosterone administration in broiler chickens showing long or short tonic immobility

Broilers of the same genetic origin were classified as short or long tonic immobility duration (STI and LTI, respectively) phenotypes and treated chronically with vehicle (control) or corticosterone (CORT) dissolved in drinking water between 27 and 42 d of age. Differential expression of proteins and mRNA was examined using 2-dimensional gel electrophoresis and real-time PCR to elucidate the mechanism behind the severe retardation of broiler breast muscle growth caused by LTI and CORT. The majority of the 13 proteins found to be differentially expressed in breast muscle of STI and LTI broilers are involved in either glycolysis (5 proteins) or myofilament formation (5 proteins). Of the 16 proteins differentially expressed in breast muscle following CORT treatment, 6 are structural proteins, 5 are categorized as cellular defense and stress proteins, and 3 (pyruvate kinase, l-lactate dehydrogenase, and creatine kinase) are involved in responses to stress and muscle damage. Real-time PCR results indicated that expression of these proteins is transcriptionally and posttranscriptionally regulated. Protein synthesis capacity, estimated by the RNA-to-protein ratio, was significantly lower in the breast muscle of CORT-treated broilers than in untreated control broilers. The level of Leu, Gly, and Ser in serum was significantly higher in CORT-treated broilers than in the control birds. Therefore, we conclude that CORT treatment retards the growth of skeletal muscle by suppressing protein synthesis and augmenting protein catabolism, paralleling the response to severe stress and muscle damage, and the negative effect of LTI on muscle growth is likely mediated through glucose metabolism. No interaction was observed between CORT and tonic immobility affecting growth performance or any parameter examined in the current study.

Efficacy of zinc in amelioration of aflatoxicosis in broiler chickens

In the present study the effect of zinc supplementation in ameliorating aflatoxicosis in broiler chickens was studied. Day-old broiler chicks (240) were divided into 6 treatment groups containing 5 replicates of 8 birds each (T1–control; T2- T1+ 250 ppb AFB1; T3- T1+ 20 mg Zn/kg; T4- T1+ 40 mg Zn/kg; T5– T2 + 20 mg Zn/kg; T6- T2 + 40 mg Zn/kg diet) and the experiment was conducted from day 1 to 42 days of age. During overall growth period (0–6 weeks), the weight gain of broilers in control (T1) was 1,341.90 g as against 1,123.43 g in aflatoxin (AF) fed group (T2) which was significantly lower. The body weight gain (BWG) in T3, T4 and T6 was statistically similar to that of control, however the BWG in T5 was higher than T2 but could not match with that of control (T1). Supplementation of 40 mg Zn/kg in AF contaminated diet significantly improved the BWG. The overall feed intake (FI) in groups (T3, T4, T5 and T6) was statistically similar to that of control group, however, the FI in group T2 was significantly reduced compared to control. The overall FCR in AF fed group (T2) was higher than that of control. The FCR in all other treatment groups was statistically similar to that of control. AF increased the relative weights of liver and spleen while decreased in weight of bursa. These effects of AF were ameliorated by supplementation of 40 mg Zn/kg feed. It was concluded that aflatoxin contamination (250 ppb) in broiler diet impaired the performance in terms of body weight gain, feed intake and feed conversion efficiency and relative organ weights. Supplementation of 40 mg Zn/kg to the aflatoxin contaminated diet ameliorated the ill effects of aflatoxicosis on performance of the birds.

Influence of cold&amp;ndash;dry (harmattan) season on colonic temperature and the development of pulmonary hypertension in broiler chickens, and the modulating effect of ascorbic acid

Influence of cold&ndash;dry (harmattan) season on colonic temperature and the development of pulmonary hypertension in broiler chickens, and the modulating effect of ascorbic acid Ndazo S Minka,1 Joseph O Ayo2 1Department of Animal Health and Husbandry, College of Agriculture and Animal Science, Division of Agricultural Colleges, Ahmadu Bello University, Mando-Kaduna, Nigeria; 2Department of Physiology, Faculty of Veterinary Medicine, Ahmadu Bello University, Zaria, Nigeria Abstract: The influence of cold&ndash;dry (harmattan) season on colonic temperature (CT) and the development of pulmonary hypertension (PH), as well as the effect of ascorbic acid (AA), were investigated in Anak male broilers during the harmattan season (November&ndash;January) of 2010&ndash;2013. A total of 150 broiler chickens per season served as subjects. At the age of 4 weeks, the broilers were randomly divided into two groups consisting of three replicates of 25 birds each: group I, the control, was not administered AA; group II was AA-treated, administered with 200 mg/kg body weight of AA, every day at 7 am and 7 pm for a period of 3 weeks. The mortality rate and CT of the birds were recorded during the daytime and nighttime. Ten birds from each group were sacrificed at weeks 4, 5, 6, and 7 for the assessment of PH and ascites syndromes. The mean ambient temperature value of 24.3&deg;C&plusmn;0.1&deg;C recorded in the daytime was higher (P&lt;0.05) than the value of 17.2&deg;C&plusmn;0.1&deg;C recorded during the nighttime. The average level of dust was 8.2 mg/m3. The control birds were hypothermic during the nighttime and had high mortality rates compared with the AA-treated birds. Broilers with obvious signs of ascites demonstrated a uniquely continuous increase in CT. At weeks 6 and 7 of age, 80% of the control broilers that were sacrificed exhibited an increase (P&lt;0.05) in the weight of right ventricle to the weight of total ventricles, packed cell volume, and erythrocyte count with low hemoglobin content, which indicated PH syndrome. The remaining 20% of the control birds and those that died had ascites syndrome in addition to the PH syndrome. These syndromes were not observed in the AA-treated birds. In conclusion, the harmattan season induced PH in broilers with no obvious clinical signs; the harmattan may compromise the welfare, health, productivity, and meat quality of the birds, effects which were ameliorated by AA. Keywords: ascorbic acid, broilers, cold&ndash;dry (harmattan), colonic temperature, hypothermia, pulmonary hypertension/ascites

Tissue distribution of B-lymphocyte subsets (IgA, IgG and IgM) in the mucosa and lymphoid tissues of broilers immunized with Gumboro vaccine

The present research was designed to study the histological and immunohistochemical changes of lymphoid organs (bursa of Fabricius and cecal tonsil) and in the ileum (representative mucosal organ) of broiler chickens after immunization with Gumboro vaccine. Two groups (n=24) of Cobb-500 broiler chickens were reared in a same environment A mild vaccine (BUR® 706) followed by a intermediate (Nobilis® Gumboro 228 E) type vaccine was administered for immunization of chickens and samples were collected at 7 days interval for up to 32 days of age. The conventional histological structure of all three organs of the present study was similar to the earlier reports. In addition, in the bursa of Fabricius, the population of lymphocytes and the size of the follicles were found to increase in vaccinated chickens than the control chickens. The Igs positive cells (IgA, IgG and IgM) were distributed principally beneath the capsule, around the follicles and in the cortex and medulla. The frequencies of IgG- and IgM- positive cells were more than the IgA-positive cells in the bursa of vaccinated group. IgM-positive cells became peak at day 25 and started to decline at day 32 in the bursa of Fabricius of vaccinated groups of chickens. In the cecal tonsils and ileum, the Igs positive cells (IgA, IgG and IgM) distributed around the intestinal gland and within the lymphatic nodules of the lamina propria, in the core of the villi, and within the epithelium in both the control and vaccinated chickens. Their frequency per 0.1 mm2 area of the lamina propria and in the epithelium was increased abruptly in the vaccinated group than the control broiler chickens. Like bursa, in the cecal tonsil and ileum of vaccinated chickens, the frequencies of IgG- and IgM-positive cells were also more than IgA-positive cells. The present study suggested that, the Igs positive cells were greatly accelerated in the vaccinated chickens than the control chickens and it may be due to immunomodulatory effect of vaccine.DOI: http://dx.doi.org/10.3329/bjvm.v11i1.14154Bangl. J. Vet. Med. (2013). 11 (1): 13-19

Caspase-1, -2, and -3 gene expression is enhanced in the heart and lung of chickens with pulmonary hypertension (ascites)

To investigate the involvement of apoptosis in the pathogenesis of T3-induced pulmonary hypertension in broiler chickens, caspase-1, -2, and -3 gene expressions were evaluated by semiquantitative RT-PCR in the lungs and left and right heart ventricles. One-day-old fast-growing chickens were randomly divided into 2 equal groups with 3 replicates per group. Chicks were reared for 7 weeks under standard conditions. T3 as a thyroid hormone was added to the ration after week 1 of rearing. Pulmonary hypertension was induced at 49 days based on RV/TV ratio index. The caspase genes were constitutively expressed in the lung and right and left ventricles of intact and pulmonary hypertensive broiler chickens. The relative amount of caspase-1, -2, and -3 mRNA in the lung and right and left ventricles of the heart was higher in pulmonary hypertensive broilers than in control broilers (P < 0.05). It is speculated that increased mRNA levels of caspase in the lungs and hearts of pulmonary hypertensive broilers could be evidence of upregulated apoptosis, which is involved in the pathophysiology of broiler chickens with pulmonary hypertension.

Effects of phytogenic feed additive on growth performance, digestibility, blood metabolites, intestinal microbiota, meat color and relative organ weight after oral challenge with Clostridium perfringens in broilers

A total of 405 mixed sex broilers with a BW of 42±1g (1d of age) were used in a 35-d trial to investigate the effects of phytogenic feed additive (PFA) containing essential oils of thyme and star anise as main active components on growth performance, energy and nutrient apparent total tract digestibility (ATTD), blood metabolites, intestinal microflora, meat color, and relative organ weight after oral challenge with Clostridium perfringens. Broilers were randomly assigned to 1 of 3 treatments (9 replicate pens per treatment with 15 broilers per pen). Dietary treatments were: control (CON); antibiotics (ANT), CON+10mg/kg of avilamycin); and PFA, CON+250mg/kg of PFA. Broilers were oral challenged with 5mL C. perfringens (107cfu/mL) culture suspensions on d 19, 20, and 21. Broilers fed PFA diets had greater (P<0.01) feed conversion ratio than those fed CON and ANT diets during the finisher phase (d 21–35). Broilers fed PFA diet got lower (P<0.01) FCR than those fed CON diet during d 0–35. The chicks fed PFA had greater (P<0.01) ATTD of dry matter, and gross energy than that fed CON and ANT diets at d 21. The ATTD of crude protein and crude ash were increased (P<0.05) by dietary supplementation of avilamycin or PFA at d 21. Dietary supplementation of avilamycin or PFA improved (P<0.05) the ATTD of gross energy at d 35. At d 35, supplementation of PFA reduced (P<0.01) the serum total cholesterol (TC) content and increased (P<0.01) high density lipoprotein-cholesterol (HDL-C) than CON and ANT treatments. The HDL-C concentration was increased (P<0.01) by avilamycin inclusion in the diet compared with that of broilers in CON. The PFA inclusion reduced (P<0.01) C. perfringens and Escherichia coli counts in small and large intestine. The lesion score of small intestine was also reduced (P<0.05) by supplementation of the diet with PFA compared with ANT and CON diets. In conclusion, our results indicated that supplementation of PFA improved growth performance, reduced blood TC, and also inhibited C. perfringens and E. coli proliferation in small and large intestines in broiler chicks under oral C. perfringens challenge.

Diminished gene expression of cardiac heat shock proteins in pulmonary hypertensive chickens

1. The relative expression of heat shock protein (HSP) genes (HSP60, HSP70 and HSP90) was performed using quantitative real-time PCR on tissue from the heart ventricles to investigate the effect of 3,5,3′-l-triiodothyronine (T3)-induced pulmonary hypertension in broiler chickens.2. The ratio of the right ventricle to total ventricle (index of pulmonary hypertension) was increased in the treated groups at 12 and 42 d of age compared to controls but was significant only at 42 d.3. The HSP genes were expressed in the right and left ventricles of control but T3-treated broilers at 12 and 42 d of age. The relative amounts of HSP60 and HSP90 gene expression in the right ventricle of treated groups were significantly increased at 12 d and decreased at 42 d of age compared to controls.4. Variations of HSP60 and HSP90 mRNAs in the left ventricle were not significant. The relative amount of HSP70 mRNA expression in the right and left ventricles of treated groups was significantly decreased at 42 d of age compared to controls. HSP70 mRNA expression did not differ between the right and left ventricles at 12 d of age.5. It is concluded that gene expression of HSPs (i.e. HSP60 and HSP90) was upregulated in the heart of chickens developing pulmonary hypertension syndrome, probably to delay the pathological process of disease. The right ventricle from hearts of pulmonary hypertensive chickens showed considerable reductions of HSP60, HSP70 and HSP90, which is evidence of a loss of compensatory responsiveness in dilated heart.

English

The aim of the study was to investigate the effect of supplemental probiotic preparation on performance indices, serum enzymes and electrolytes of broiler chickens. Two hundred (200) day-old Marshall broiler chicks were randomly selected and distributed based on the level of supplementation into four groups of 50 chicks each (Control, C; E10.5%, E21.5% and E32.0%). Chickens fed 2.0% probiotic had a significantly higher body weight when compared with the control group. Activity of alanine aminotransferase differed significantly in the group E10.5%, and especially (p<0.01) in the group E11.5%. Alkaline phosphatase activity decreased significantly (p<0.05), when compared with that of the control group. Serum calcium and phosphorus concentrations in experimental groups were significantly higher. Potassium concentration in experimental group rose significantly (p<0.05), when compared with that of the control broiler chickens. In conclusion, supplementing broiler feeds with 2.0% yeast probiotic improved performance indices, serum enzyme activities and enhanced the maintenance of electrolyte homeostasis in broiler chickens. Keywords: Body weight, feed conversion ratio, serum biochemistry, Saccharomyces cerevisiae, broiler chicken. African Journal of Biotechnology Vol. 12(35), pp. 5480-5485

Electrolysed reduced water decreases reactive oxygen species-induced oxidative damage to skeletal muscle and improves performance in broiler chickens exposed to medium-term chronic heat stress

1. The present study was designed to achieve a reduction of reactive oxygen species (ROS)-induced oxidative damage to skeletal muscle and to improve the performance of broiler chickens exposed to chronic heat stress. 2. Chickens were given a control diet with normal drinking water, or diets supplemented with cashew nut shell liquid (CNSL) or grape seed extract (GSE), or a control diet with electrolysed reduced water (ERW) for 19 d after hatch. Thereafter, chickens were exposed to a temperature of either 34°C continuously for a period of 5 d, or maintained at 24°C, on the same diets. 3. The control broilers exposed to 34°C showed decreased weight gain and feed consumption and slightly increased ROS production and malondialdehyde (MDA) concentrations in skeletal muscle. The chickens exposed to 34°C and supplemented with ERW showed significantly improved growth performance and lower ROS production and MDA contents in tissues than control broilers exposed to 34°C. Following heat exposure, CNSL chickens performed better with respect to weight gain and feed consumption, but still showed elevated ROS production and skeletal muscle oxidative damage. GSE chickens did not exhibit improved performance or reduced skeletal muscle oxidative damage. 4. In conclusion, this study suggests that ERW could partially inhibit ROS-induced oxidative damage to skeletal muscle and improve growth performance in broiler chickens under medium-term chronic heat treatment.

Content of plasmatic glycerol and activity of hepatic glycerol kinase in broiler chickens fed diets containing different sources and concentrations of glycerine

The objective of this study was to evaluate the effect of three sources of glycerine (crude glycerine from soya bean oil - CGSO, mixed crude glycerine from frying oil and lard--MCG, and a semipurified glycerine from soya bean oil--SPGSO) in four concentrations in the diet (17.5, 35.0, 52.5 and 70.0 g of each type of glycerine per kg of feed) on the levels of plasmatic glycerol and the activity of the hepatic enzyme glycerol kinase in broilers of 22-35 days old (experiment I) and 33-42 days old (experiment II). The highest (p < 0.05) plasmatic glycerol level was detected in broilers fed diet containing CGSO. Independent of the source, increasing the concentration of glycerine led to a linear increase (p < 0.05) in the plasmatic glycerol concentration. In experiment I, all the diets containing glycerine resulted in increased concentrations of plasmatic glycerol, in relation to the control diet without glycerine. However, in experiment II, only the diet containing 17.5 g of CGSO per kg of feed and the diets formulated with any of the three types of glycerine in the inclusion concentrations of 35, 52.5 and 70 g/kg of feed resulted in higher plasmatic glycerol levels than those observed in the control broilers. The source of glycerine influenced the glycerol kinase activity only in experiment II, where the use of CGSO in the diet increased the enzyme activity. For both experiments, the glycerol kinase activity increased with the inclusion of glycerine in the diet. In conclusion, based on the absence of saturation of the glycerol kinase activity for the three glycerine sources and for both rearing periods evaluated, the broilers can metabolize the glycerol (at the level of the phosphorylation of the glycerol to glycerol-3-phosphate in the liver) present in the glycerine when the diet is supplemented with up to 70 g of glycerine per kg of feed.

The effect of dietary supplementation with the natural carotenoids curcumin and lutein on broiler pigmentation and immunity

The objective of this study was to compare the effects of supplementation with 2 carotenoids, curcumin and lutein, on pigmentation and immunity in lipopolysaccharide (LPS)-stimulated broiler chicks. Two hundred forty 1-d-old Arbor Acres broilers were randomly distributed into 3 dietary treatment groups: a basal diet without carotenoid supplementation (control), a basal diet supplemented with 200 mg/kg of curcumin (CRM), or a basal diet supplemented with 200 mg/kg of lutein (LTN) for 42 d. The birds were vaccinated against Newcastle disease (ND) and avian influenza on d 10. At 16, 18, and 20 d of age, half of the chicks in each group were injected in the abdominal region with either LPS (250 mg/kg of BW) or an equal volume of 0.9% NaCl. The intensity of the shank skin color (Roche color fan score) and the b* (yellow) values of the breasts and thighs were highest in lutein-supplemented broilers, followed by curcumin-supplemented and control broilers, whereas the a* (red) value of the thigh muscle was highest in curcumin-supplemented LPS-induced birds. At 42 d, the relative weight of the abdominal fat was lowest in the CRM-supplemented group, followed by the LTN-supplemented and control groups; the spleen weight was lower in the non-LPS-induced LTN-supplemented group than the LPS-induced control group. The ND and avian influenza titers were significantly higher in the CRM-supplemented group than in the other groups at 20 d; at 30 d, the ND titer was significantly higher in the LPS-induced LTN group. Supplementation with curcumin significantly promoted B and T lymphocyte proliferation in both LPS- and non-LPS-induced birds at 21 d. Curcumin also promoted B lymphocyte proliferation in non-LPS-induced birds at 42 d. Curcumin significantly reduced alanine aminotransferase and aspartate aminotransferase activities at 42 d in non-LPS-treated birds, whereas lutein significantly increased the activities of these enzymes in LPS-induced birds. Both carotenoids significantly lowered lipid oxidation in the liver of supplemented birds. Thus, in broiler chickens, lutein-supplemented birds exhibited better pigmentation efficiency, whereas curcumin-supplemented birds exhibited improved immune responses.

Growth performance, carcass yield and intestinal microflora populations of broilers fed diets containing thepax and yogurt

The present study aimed at evaluating the effect of the probiotic thepax and yogurt (as probiotic) on the growth response and intestinal microflora results of broiler chickens. Two hundred forty day-old Ross 308 broilers were equally distributed into 12 floor pens and reared for 42 day. The treatments consisted of yogurt (10, 5 and 2.5% during starter, grower and finisher periods in the drinking water, respectively) and thepax (1000, 500, 250 g/ton-1 in the starter, grower and finisher diets, respectively), resulting three experimental diets and a control group. Each dietary treatment was fed ad-libitum to four replicate group of 20 birds at the beginning of rearing period. Birds and feed were weighed on days 21 and 42. The results of experiment indicate that diets containing feed additives improved broiler performance. The body weight gain and feed conversion ratio improved significantly more (p < 0.05) with the thepax treatment compared with the control broilers during the total rearing period. The highest (p < 0.05) carcass and thigh values were recorded for broilers fed the diet supplemented with thepax and yogurt, respectively. The lowest abdominal fat pad value was obtained in broilers fed the diet supplemented with thepax. On d 21, thepax and yogurt significantly reduced (p < 0.05) cecal Escherichia coli and Clostridium perfringens populations compared with the control group. In conclusion, thepax and yogurt improved broilers growth response and conferred intestinal health benefits to chickens by improving their microbial ecology.

Effects of dietary alternatives (probiotic, green tea powder, and Kombucha tea) as antimicrobial growth promoters on growth, ileal nutrient digestibility, blood parameters, and immune response of broiler chickens

A feeding trial was conducted to study the effects of alternative antimicrobial growth promoters (probiotic, Kombucha tea, and green tea powder) in wet, wheat-based diets on broiler performance, carcass yield, organ weights, immune response, and histomorphological measurements of the small intestine. One hundred and sixty-one-day-old male broiler chicks were randomly assigned to 1 of 4 dietary treatments for 6 weeks. The dietary treatments were: (a) control (1.2 g water/gram of dry feed), (b) control diet supplemented with 1 g/kg probiotic (8 × 105 colony forming units (CFU) of Bacillus subtilis/gram), (c) control diet plus 1.2 g/kg diet Kombucha tea (20 % concentration), and (d) control diet plus 10 g/kg green tea powder. The body weight and feed intake were significantly (P < 0.05) increased by the dietary inclusion of the Kombucha tea compared to the control and green tea-fed broilers. However, an improvement in performance traits was observed in broilers fed with the probiotics. Plasma lipids of birds fed the green tea powder diet consisted of lower cholesterol and TG and higher HDL than those of control birds. Protein digestibility was significantly higher (P < 0.05) for birds given the Kombucha tea supplement compared to that of the control birds. The probiotic diet increased (P < 0.05) the villus height/crypt depth ratio and the villus height in the duodenum. Overall, the results in this work show that Kombucha tea and probiotic supplements in feed display growth promoting effects similar to those of traditional antibiotics; therefore, these products might be alternatives to antibiotic growth promoters.

Influence of Stocking Density on Welfare Indices of Broilers

The current study was conducted to identify the influence of short-term (five days) high stocking density (SD) on broilers’ welfare by assessing several thermophysiological parameters in 32 birds of 43 days of age Ross male broiler chickens. Based on broiler’s body weight, broilers were randomly allotted into two SD rates; control (26.5 kg/m2) or high (45.0 kg/m2). It appears evident that placing broilers at high SD as 45.0 kg/m2had manifested noticeable impacts on their thermophysiological responses. This conclusion was demonstrated by the existence of results of the current study showed a major displacements in broilers’ homeothermic status, high SD broilers experienced pronounced elevations of their body temperatures as well as head, body and shank surface temperatures over the control SD broilers. Additionally, this was further emphasized by the noticeable displacements of body internal, external and total thermal gradients as well as heat loss index of high SD broilers compared to the control broilers. Based on the presented evidences, short-term high SD markedly increased broilers stress and jeopardize their welfare. Measuring broilers’ thermophysiological responses under different rates of SD can be adapted to assess their welfare.

Haplotypes in the coding region of myostatin gene in broiler chicken

A study was designed to explore haplotypes of myostatin gene in control broiler chicken. The single stranded- conformation polymorphism technique was used to find out variants of exon 1, 2 and 3 of myostatin gene and all the variants were sequenced. Total 7 haplotypes were observed in the population where h1 haplotype was the most predominant one. Consequently, 6 haplotype combinations were found in the population of which h1h5 haplogroup was the most frequent one while h1h3 haplogroup was the least frequent one. The sex-wise differences of distribution of haplotypes as well as haplogroups were found as nonsignificant. The broiler population did not follow the Hardy- Weinberg equilibrium for this locus. The differences of nucleotides at several locations were found in the haplotypes. Different demographic parameters were also studied with respect to the haplotype distribution in the population.

Effects of dietary glutamine and gamma-aminobutyric acid on meat colour, pH, composition, and water-holding characteristic in broilers under cyclic heat stress

1. An experiment was conducted to evaluate the effects of dietary glutamine (Gln, 0 and 5 g/kg) and gamma-aminobutyric acid (GABA, 0 and 100 mg/kg) on raw breast meat colour, pH, composition and water-holding characteristic of broilers under cyclic heat stress (HS). 2. A total of 360 21-d-old Arbor Acres male chicks were randomly assigned to 5 treatment groups (6 replicates of 12 birds per cage). The positive control (PC) broilers were kept in a thermoneutral chamber (22–24°C) and fed on the basal diet. The other 4 groups were kept in a cyclic HS chamber (30–34°C) for 9 h (from 09:00 to 18:00). 3. A significant increase was observed in breast meat lightness at 28, 35 and 42 d; and pH values at 28, 35 and 42 d; while a significant decrease was observed in breast meat cooking loss (CL) and contents of moisture, crude protein (CP), crude fat (CF) and crude ash (CA) due to HS. 4. The supplementation with 0·5 g Gln/kg decreased lightness at 28, 35 and 42 d; while increasing redness at 28 d, yellowness at 35 d, contents of CP, CF and CA, thawing loss (TL) and drip loss (DL). The addition of 100 mg GABA/kg decreased lightness at 28 and 35 d, pH value at 28, 35 and 42 d, and TL; while increasing redness at 28 d, 35 and 42 d, contents of moisture, CP and CF. 5. The lightness, redness, and pH value; contents of moisture, CP, CF and CA; and TL, DL and CL of breast meat of broilers fed with the mixture of Gln and GABA under cyclic HS were similar to those of the broilers in the PC group. 6. Significant interactions were found between Gln and GABA for yellowness at 28 and 35 d; pH at 28, 35 and 42 d; moisture content, CP content, water-holding capacity and TL. 7. These results demonstrated that dietary Gln and GABA offer a potential nutritional strategy to prevent cyclic HS-related depression in broiler meat chemical composition and quality.