Poultry Science Journal
Volume:10 Issue: 2, Summer -Autumn 2022

Animal studies have shown the role of gamma amino butyric acid (GABAergic) and Dopaminergic systems in controlling appetite, but their interactions in birds have not yet been investigated . In this study, 6 experiments were carried out to investigate the interactions between GABArergic and dopaminergic systems in fresh laying hens (Each experiment included 4 groups, 11 chicks per group). Chicks received intracerebroventricular (ICV) injections after 3h of starvation in the following form: In 6 experiments; Each experiment has 4 groups. Group 1 (CON): Received Saline as a control group. Group 2 (DOP): Dopamine neurotransmitters include 125 nmol L-DOPA (levo-dihydroxyphenylalanine) as a dopamine precursor. 6-OHDA, 2.5 nmol as a dopaminergic neurotoxin. SCH23390, 5nmol. AMI-193, 5nmol. NGB2904, 6.4nmol and L-741742, 6nmol. (L-DOPA, 6-OHDA, D1 receptor, D2 receptor, D3 receptor and D4 receptor antagonists), respectively (each of them in one of the experiments). Group 3 (GABA): Baclofen, 0.2μm (GABAB agonist). Group 4 (DOP+GABA): Receive Baclofen simultaneously with any of the L-DOPA, 6-OHDA, D1, D2, D3 and D4 antagonists, respectively (each of them in one experiments). Cumulative consumption of food (based on the percentage of body weight) was measured up to 120 minutes after the injection. According to the results, ICV injection of Baclofen alone significantly increased feed intake (P < 0.05). None of the dopamine receptors (L-DOPA, 6-OHDA, D1, D2, D3, D4, as well as dopamine synthesis inhibitors) did not affect food intake (P > 0.05). The co-injection of the L-DOPA, 6-OHDA, D1-D4 receptor antagonists + baclofen (P> 0.05) showed no significant effect. The results of this study showed that dopaminergic and GABAB receptors had no interaction in FD3 neonatal layer-type chicken.

This study aimed to use grape pomace and pomace extract to feed British United Turkey Big 6 (B.U.T.6) and compare its effect with vitamin E-selenium on growth performance, internal organs, and bacterial population of the cecum, and prececal nutrient digestibility. For this purpose, 80 hatched day-old B.U.T.6 were placed in a completely randomized design, including four treatments, four replicates for each treatment, and five birds in each replicate. The turkeys underwent experimental treatments from 31 to 127 days, including control, 3% dietary grape pomace, 150 mL/L aqueous extract of grape pomace, and 0.5 mL/L vitamin E-selenium in the drinking water. The turkeys treated with grape pomace had the highest daily weight gain and final body weight. Grape pomace extract treatment had a negative effect on daily feed intake. Experimental treatments throughout the course did not have a significant effect on the feed conversion ratio. The bacterial population of Escherichia coli in the cecum was lower in the vitamin E-selenium treatment than in other treatments. The population of Lactobacillus bacteria in all experimental treatments was higher than in the control treatment and the highest in the treatment of grape pomace extract. Digestion of dry matter, crude fat, and protein in turkeys treated with grape pomace extract and control were more than in the other treatments. The digestibility of crude fat in turkeys treated with grape pomace was significantly lower than in other treatments. The use of grape pomace in turkey diets is recommended because it increases the overall daily weight gain, final body weight, and the number of beneficial bacteria. In turkeys treated with grape pomace extract, daily weight gain and final body weight can be considered helpful in reducing feed costs.

The aim of this study was to determine the effects of different sound stimulant applied to embryos during the incubation on performance characteristics, fear responses, and developmental stability of Japanese quails. For this purpose, a quiet environment, species-specific relaxing sounds, and species-specific disturbing sounds were applied to quail eggs placed in three homologous incubators in different rooms. A constant sound pressure (65 decibels) was used throughout the incubation, with stimulation for two minutes out of every twenty minutes. There were no differences between the experimental groups in terms of hatch weight and weekly body weights. Similarly, sound stimulation had no positive or negative effects on parameters of the Gompertz growth curve and slaughter-carcass traits. The mean values of tonic immobility duration of quails in both the disturbance and comfort group (72.15 and 71.35 sec, respectively) were higher than that of the control group (51.14 sec, P < 0.05). Moreover, when the developmental stability of the bilateral features was examined, fewer fluctuating asymmetry cases were detected in the disturbance and comfort groups. As a result, it is possible to say that the sound models applied to the embryos during incubation did not affect the performance characteristics, but had negative effects on developmental stability and fear responses.

This experiment was conducted to study the effects of hydroalcoholic extract from Withania somnifera (WS) leaf and fish oil on performance, mineral retention, bone morphological and mechanical characteristics, and Calbindin-D 28K (CALB1) gene expression in broiler chickens. Treatments were arranged in a CRD with a 2 × 3 × 2 factorial arrangement consisted of two dietary Ca levels (low: 30% less than normal Ca level, and adequate: normal Ca level), three concentrations of WS (0, 100 and 200 mg/kg diet) and two concentrations of fish oil (0 and 2 %). A total of 600 one-day-old Ross 308 male broilers were divided into 12 treatments with 5 replicates and 10 chickens in each. At 24 d of age, one bird per replicate was randomly killed, and tibiae were removed. Results showed that dietary supplementation of WS significantly improved feed conversion ratio (FCR) (P < 0.05). Birds fed diets supplemented with WS had significantly higher Ca content in the tibia (P < 0.05). Dietary inclusion of fish oil significantly increased the width of the bone proliferative zone (P < 0.05). In biomechanical properties, dietary supplementation of WS and fish oil significantly increased the shear force (P < 0.05). Synergistic effects of WS and fish oil showed that the addition of WS at 200 mg/kg in birds fed diets containing fish oil led to a significant increase in tibial stiffness (P < 0.05). Low-Ca diet up-regulated duodenal CALB1 mRNA expression (P < 0.05). Supplementation of WS also resulted in a significant up-regulation in the gene expression of CALB1in both duodenum and jejunum (P < 0.001). In conclusion, dietary supplementation of WS may have beneficial effects on bone calcification and strength by increasing the CALB1 gene expression and Ca retention. Also, synergistic effects of WS and fish oil may improve the mechanical properties of the tibia.

The effects of dietary insoluble fiber sources on growth performance, gastrointestinal tract (GIT) traits, nutrient digestibility and intestinal enzyme activity were studied in broilers from 1 to 42 d of age. A total of 480 one-day-old chicks (Ross 308), were allocated in four treatments, six replicates and 20 birds in each, based on a completely randomized design. Dietary treatments were including a corn-soybean meal basal diet (control diet) and other three diets formulated by the inclusion of 30 g/kg of processed wheat straw (WS), sunflower hulls (SFH), or soybean hulls (SBH) in the control diet. From 1 to 10 d of age, broiler chickens fed processed WS tended to have higher feed intake than broilers fed the control diet (P = 0.064) and had higher body weight gain than broilers fed the other treatments (P < 0.05). The relative weight of the GIT organs was not affected by treatments but SFH and SBH decreased the length of the small intestine at 42 d of age (P < 0.05). The pH of different segments of the GIT, carcass traits, dry matter, nitrogen digestibility, and apparent metabolizable energy corrected by nitrogen were not affected by treatments. The activity of amylase and aminopeptidase in the duodenum and jejunum was not affected by the insoluble fiber sources. In conclusion, the dilution of the control diet with the inclusion of 30 g/kg insoluble fiber did not have any negative effect on broiler chickens' performance and marketing weight. Moreover, improved performance was observed with processed WS, particularly during the starter period.

The present experiment studied the effect of a high dose of guanidinoacetic acid (GAA; 2.25 g/kg), with or without trimethylglycine (TMG) on growth performance and physiological variables of broiler chickens. A total of 300 day-old males Cobb 500 were randomly assigned to three dietary treatments with 5 replicates of 10 birds in each. Treatments were including a basal diet (control treatment), the basal diet supplemented with 2.25 g/kg GAA, and the GAA diet with 1 g/kg TMG. All birds received feed and water ad libitum during a 40-days rearing period. Results indicated that weight gain during days 31-40 of the rearing period was impaired by feeding the GAA diet. Feed conversion ratio was impaired in all feeding stages when the high dose of GAA was included in the diet. However, the inclusion of TMG in the GAA diet restored these responses to a comparable level to the control group. The GAA diet caused a significant increase in malondialdehyde concentration in serum compared to the control treatment. Moreover, the use of GAA decreased the heterophil to lymphocyte ratio than other treatments. A high dose of GAA caused higher serum levels of creatine and homocysteine; however, TMG supplementation re-established those responses. In addition, TMG supplement significantly up-regulated hepatic adenosyl homocysteinase and methionine adenosyltransferase II beta genes. In conclusion, feeding a high dose of GAA could impact broiler growth performance, but this effect could be ameliorated by dietary inclusion of TMG supplement, suggesting the negative effects of high doses of GAA were linked to the methyl donor deficiency. The practical implication is to include TMG in diets when a high dose of GAA is going to feed.

This study aimed to investigate the effects of nano-vitamin D3 (NVD3) and micro-vitamin D3 (MVD3) on performance and bone parameters in broiler chickens. A total of 792 one-d-old Cobb 500 male broiler chickens were randomly distributed in a completely randomized design according to a 2×6 factorial arrangement of 12 dietary treatments with six replicates of 11 chicks. The treatments were: basal diet (control); basal diet supplemented with 100, 200, 400, 800, and 1600 (IU/kg diet) commercial MVD3; and a basal diet supplemented with the same levels of NVD3. The basal diet consisted of 0.5% Ca and 0.25% non-phytate phosphorus and was free of vitamin D3 supplement. There were significant differences (P < 0.01) in feed conversion ratio due to supplementation with NVD3 from 4 to 10, 11 to 21, and 4 to 21 days of age compared to those receiving MVD3. The chicks receiving NVD3 had significantly (P < 0.01) higher live body weight (LBW) at 21-d of age and daily weight gain from 4 to 21-d of age compared to MVD3. The chicks receiving NVD3 had a significantly (P < 0.01) higher concentration of ash and Ca content in the tibia. Bone stiffness and strength, tibia weight per length index, tibia weight, tibia diameter, organic matter (OM), OM/ash, and OM/length at 21-d were significantly (P < 0.01) improved in birds fed diets supplemented with NVD3. Relative bioavailability of the NVD3 source to the MVD3 was more efficient according to performance and bone mineralization measurements. There was better growth performance and bone parameters in the 800 and 1,600 IU/kg levels of both kind than at the lowest level. Assessing the data of all experimental indexes showed that 800 IU/kg exhibited significant linear effects, suggesting that it can be the ideal level of supplementation of NVD3, and, on the other side, the rate of 1600 IU/kg could be the maximum supplementation of NVD3 in broiler chickens.

The food security of a country can be harmed if the supply and demand of poultry products are affected due to any disruptions disrupted by factors such as poor growth rates and disease outbreaks. On top of that, with regard to food safety reasons, developed countries have started to prohibit the inclusion of antibiotics in livestock feed. As a result, it is essential to seek alternative preventive substitutes for growth promotion and prophylaxis in poultry rather than depending on antibiotics. Plant extracts are one of the alternatives with anti-microbial and growth-promoting effects on poultry. Saponins have many biological and pharmacological activities like anti-carcinogenic, anti-microbial, anti-parasitic, anti-fungal, anti-inflammatory, hypocholesterolemic, immunomodulatory, and anti-oxidant properties. Because of its growth-promoting effect, immunity enhancer, and microbial capabilities, saponins from diverse sources and quantities could be used as an anti-microbial alternative to synthetic antibiotics in the broiler industry. Additionally, steroidal saponins have been commercialized as supplements for poultry, health foods for human consumption, and potential anti-cancer treatments. Therefore, the present review will critically shed light on the availability of different saponins and the influence on the production performance and immunopathology responses of poultry supplemented with different saponins extract. Information from this review will added knowledge on the usability of different saponins extracts which could be considered as a novel feed additive in the poultry industry.

This study aimed to perform a meta-analysis to combine genetic parameters for economically important traits of Iranian indigenous chickens. A data set of information related to different growth, reproduction, and egg quality traits including 336 heritability estimates and 433 genetic correlations from 45 articles published between 2007 and 2019 were used. Meta-analysis was performed based on a random-effects model to calculate the effect size for genetic parameters. Also, statistic and Q test were used to measure the degree of heterogeneity among studies. The mean heritability for growth traits ranged from 0.222 (body weight at hatch) to 0.34 (body weight at 12 weeks of age). The lowest and highest estimates of the heritability for reproductive traits were 0.181 (number of eggs produced) and 0.449 (age at sexual maturity), respectively. The mean heritability estimate for egg internal quality traits varied from 0.211 (yolk weight) to 0.355 (albumin weight) and for external quality traits of eggs in the range from 0.261 (shell strength) up to 0.332 (Shell weight). Also, the mean genetic correlation estimates between growth traits, and between reproductive traits ranged from 0.297 to 0.878 and -0.678 to 0.788, respectively. Also, the genetic correlation between internal and external quality traits of eggs ranged from -0.069 to -0.979 and -0.012 to -0.856, respectively. The estimates reported in the present study are appropriate to be used in breeding programs when reliable genetic parameter estimates are not accessible for economically important traits in native fowls.

Many scientific researchers reported the significant effect of heat stress (HS) on commercial poultry production. Bird metabolism and blood parameters change during acute and chronic heat stress status. This article reviewed and analyzed the broiler blood parameters under normal thermal and cyclic-chronic heat stress conditions. All the reviewed reports were achieved from Elsevier, PubMed, Web of Science, and Google Scholar those were in English up to January 27, 2022. Outcomes of blood cholesterol (Chol), triglyceride (Tri), glucose (Glu), corticosterone (Cortico), uric acid (UA), sodium (Na+), Potassium (K+), and triiodothyronine (T3) were calculated by standardized mean difference (SMD) with 95% confidence interval (CI). Articles with common metabolite differentiated between 4 or 7 studies with 94-662 chicks in each of them. Chronic HS had no significant effect on blood concentrations of Cortico (5 studies: SMD=1.8153 95% CI=-2.9524; 6.5830), Tri ( studies=7 SMD=0.4559 95% CI=-0.2923; 1.2040), Uric (studies=5 SMD= 0.9590 95% CI= -0.3338; 2.2518), T3 (studies=4 SMD= -9.006 95% CI= -46.1608; 28.1487), K+ (studies=4 SMD= -6.675 95% CI= -20.1400; 6.7898) , but significantly increased Glu (studies=8 SMD= 0.3064 95% CI= 0.0027; 0.6100), Chol (studies=6 SMD= 0.7655 95% CI= 0.2653; 1.2658) and decreased Na+ (studies=4 SMD= -1.723 95% CI= -3.1536; -0.2925) levels. Statistically significant effects of chronic heat stress reflexed as a decrease in serum sodium, increase in cholesterol, and glucose level. But there was no significant difference between triglyceride, corticosterone, uric acid, potassium, and triiodothyronine in the heat stress and normal temperature group. Based on our meta-analysis, high blood glucose, high Cholesterol, and losing electrolyte balance are major problems in chickens during cyclic-chronic heat stress acclimatizing programs.

The aim of this study was to evaluate the effect of a Herbal product (Nutrition Bio-Shield Superfood® (NBS)) supplementation in diets varying in metabolizable energy (ME) and crude protein (CP) contents on the internal egg quality and fatty acid profile of eggs in commercial laying hens. A total of 420 layer hens aged from 63-74 weeks were assigned to 10 treatments with 6 replicates in a completely randomized design with a 5×2 factorial arrangement with 5 dietary levels of NBS (0, 0.5, 1, 1.5, 2 g/kg diet) and 2 concentration of nutrients (standard and 5% diluted for ME and CP). The diluted diet significantly (P < 0.05) increased the shell thickness and shape index compared to the standard diet; however, it decreased shell weight and concentrations of margaric, elaidic, linoleic, docosahexaenoic, polyunsaturated fatty acids, n3, n6, and the ratio of n6:n3 fatty acids in egg yolk compared to the standard diet (P ≤ 0.05). NBS supplementation linearly decreased egg yolk myristic, margaric, and ginkgoic acids concentrations (P < 0.05). In addition, a significant interaction effect was found between diet dilution and NBS supplementation on the haugh unit, shape index, albumen percentage, and egg yolk margaric acid concentration. In general, the reduction of energy and CP in the diet of laying hens by 5% of the standard had no adverse effect on egg quality parameters.

This experiment was conducted to investigate and compare the effects of dietary probiotic and prebiotic with sesame meal processed by bio-fermentation technique (SMP) on production performance, blood metabolites, and gut microbiota population in laying hens. A total of 200 Hy-Line W-36 laying hens, 43-wk-old, were randomly allocated to four experimental treatments with five replicates and ten hens per replicate. Experimental treatments were as follows: 1) corn-soybean meal diet (as control diet; [CON]), 2) control diet + 0.1% probiotic (PRO), 3) control diet + 0.1% prebiotic (PRE), and 4) a diet without additives, in which SMP replaced part of the soybean meal in the control diet (SMP). The bio-fermentation process decreased the pH, phytic acid, and crude fiber and increased the crude protein content and the number of lactic acid bacteria (LAB) in sesame meal (P < 0.05). The feeding trial results showed that hens fed diets containing SMP and PRO had better egg production, egg mass, and feed conversion ratio compared to other treatments (P < 0.05). Lactic acid bacteria population and pH in the crop of birds that received PRO and SMP were higher and lower than in other birds, respectively (P < 0.05). Hens fed diets containing SMP, PRO, and PRE had greater LAB populations and lower coliform count in the ileum and cecal than those fed the CON diet (P < 0.05). Feeding diets containing tested feed additives and SMP decreased serum concentrations of cholesterol and triglycerides (P < 0.05). In summary, the results indicated that using SMP in laying hens' diet improved laying production, gut microbiota balance, and serum lipid profile. Therefore, it can be concluded that bio-fermentation, in addition to providing the possibility of replacing dietary sesame meal for soybean meal in laying hen diets, can be applied as a strategic tool for promoting gastrointestinal hygiene and health in birds.