Body Weight Of Chickens Research Articles

Effect of In Ovo Ornithine-á-Ketoglutarate Feeding on Early Body Weight and Pectoral Muscle Development of Chicks

This study investigated the effects of in ovo ornithine-á-ketoglutarate feeding on body weight and pectoral muscle development of chicks. On day 18 of incubation, 198 hatching eggs were randomly divided into three treatment groups each with three replicates of 22 eggs each. The treatment groups consisted of a non-injected control group and two treatments with 1 ml of saline each, containing either 0.2% (treatment group I) or 0.4% ornithine-á-ketoglutarate (treatment group II). The chicks were fed after hatching for seven days. Hatchability was reduced due to in ovo feeding of 0.4% ornithine-á-ketoglutarate. However, in ovo feeding of different levels of ornithine-á-ketoglutarate increased the daily gain, the body weight, the diameter and cross-sectional area of the pectoral muscle fibers, the cross-sectional area of the pectoral muscle fiber bundles, the proportion of proliferating cells in the pectoral muscle. It is concluded that, in ovo ornithine-á-ketoglutarate feeding can promote early growth and development of pectoral muscles in chicks.

The Short Communication: Polymorphism of myostatin gene and its association with body weight traits in a hybrid of GAMA chicken (Gallus gallus domesticus Linn. 1758)

Abstract. Tanjung A, Saragih HTSSG, Trijoko, Soenarwan HP, Widianto S, Mahardhika IWS, Daryono BS. 2019. Polymorphism of myostatin gene and its association with body weight traits in a hybrid of GAMA chicken (Gallus gallus domesticus Linn. 1758). Biodiversitas 20: 3207-3212. An experiment was conducted to detect SNP of the myostatin gene and its association with the body weight of hybrid chicken crossbreed from F1 Kamper and BC1 Broiler. Four F1 Kamper hens were crossbred with BC1 Broiler rooster. Day old chick (DOC) hatched were maintained for 49 days with body weight measurement every seven days. The blood samples from 49 days old chicken were taken for DNA isolation by Chelex 5% method and then amplification of the myostatin gene. PCR products were sequenced, and sequence alignment was performed using Clustal Omega to obtain SNP. The SNP obtained was analyzed by the Pearson correlation test with the body weight of forty nine-days-old chickens. The body weight of the hybrid chicken is higher than of Pelung chicken but lower than the Broiler. There are 7 SNPs in myostatin gene exons included 2 Adenine insertions, 1 Guanine deletion, and four substitutions (C2244G, G2283A, T4842G, G7378T) that yield nine haplotypes. Six haplotypes had different protein sequences with Myostatin protein, while three haplotypes were identical to Myostatin protein. The correlation analysis showed that there was a strong positive correlation (r = 0.736) between normal Myostatin protein and mutant to chicken body weight at 49-days-old. Adenine insertion to nucleotide 2099-2100 of myostatin gene had a very strong positive correlation (r = 0.800) to 49-days-old chicken body weight, although T4842G substitution had a strong negative relationship (r = -0.773) to 49-days-old chicken body weight. Adenine insertion to nucleotide 2099-2100 of myostatin gene could be a genetic marker of heavier body weight of the hybrid chicken.

Genetic analysis on body weight at different ages in broiler chicken raised in commercial environment.

A multivariate model was developed and used to estimate genetic parameters of body weight (BW) at 1-6weeks of age of broilers raised in a commercial environment. The development of model was based on the predictive ability of breeding values evaluated from a cross-validation procedure that relied on half-sib correlation. The multivariate model accounted for heterogeneous variances between sexes through standardization applied to male and female BWs differently. It was found that the direct additive genetic, permanent environmental maternal and residual variances for BW increased drastically as broilers aged. The drastic increase in variances over weeks of age was mainly due to scaling effects. The ratio of the permanent environmental maternal variance to phenotypic variance decreased gradually with increasing age. Heritability of BW traits ranged from 0.28 to 0.33 at different weeks of age. The direct genetic effects on consecutive weekly BWs had high genetic correlations (0.85-0.99), but the genetic correlations between early and late BWs were low (0.32-0.57). The difference in variance components between sexes increased with increasing age. In conclusion, the permanent environmental maternal effect on broiler chicken BW decreased with increasing age from weeks 1 to 6. Potential bias of the model that considered identical variances for sexes could be reduced when heterogeneous variances between sexes are accounted for in the model.

Effects of the MC4R, CAPN1, and ADSL genes on body weight and purine content in slow-growing chickens

Consumer preference for slow-growing broiler chickens is rising because of increased demand for high-quality poultry products. Korat chicken (KRC) is a slow-growing chicken generated in Thailand. A goal of the KRC breeding program is to produce meat with a low purine content to benefit an aging population, without interfering with growth performance. Thus, this study aimed to investigate the effects of genes encoding melanocortin 4 receptor (MC4R), calpain 1 (CAPN1), and adenylosuccinate lyase (ADSL) on body weight, muscle fiber, and content of purine and its derivatives (i.e., adenine, guanine, hypoxanthine, and xanthine), to develop molecular markers for breeding programs. Genotypes of MC4R, CAPN1, and ADSL were obtained from 583 KRCs by PCR-single-strand conformation polymorphism. The body weight and purine contents of the KRCs were measured every 2 wk until the KRCs reached market weight at 10 wk of age. A significant association between the MC4R genotype and body weight at 2, 4, and 10 wk of age was detected. KRC possessing the BB genotype of CAPN1 showed significantly heavier body weight at 6 wk of age and guanine content at 4 wk of age, and a smaller muscle fiber diameter in the breast muscle at 10 wk of age, compared with those of the other genotypes. In addition, high expression levels of the CAPN1 and ADSL genes were detected in the breast muscle at 2 wk of age. Although higher purine contents were detected at a young age, no significant associations with the MC4R, CAPN1, and ADSL genes were detected. Our results indicate that MC4R and CAPN1 could be used as genetic markers for growth and meat quality in the slow-growing chicken breeding program.

Effects of Addition of Noni Fruit Juice (Morinda Citrifolia) Into Drinking Water on Final Body Weight, Carcass Percentage, Abdominal Fat and Meat Cholesterol of Sentul Debu Chicken Phase Growth

The purpose of research to determine the effect of addition Noni fruit juice into drinking water on body weight, percentage of carcass, abdominal fat and meat cholesterol on sentul debu chicken phase growth. The research used 120 day old chicks of Sentul chicken and were raised until 12 weeks old. The research were conducted using a completely randomized design with six levels of noni fruit juice into the drinking water, P0 (without the addition of noni juice into drinking water), P1 (1 ml of noni juice/1 liter of drinking water), P2 (2 ml of noni juice/1 liter of drinking water), P3 (3 ml of noni juice/1 liter of drinking water, P4 (4 ml of noni juice/1 liter of drinking water and P5 (5 ml of noni juice/1 liter of drinking water) and four replications, each replication consisted of five sentul chickens. The observed variables were final body weight, carcass percentage, abdominal fat and meat cholesterol on sentul chicken. Data were statistically analyzed for variance using a Duncan’s Multiple Range test. The results showed that the addition of noni juice until 3 ml/1liter into drinking water gave no significant effect on the final body weight, percentage of carcass and abdominal fat and meat cholesterol,but the addition of noni juice 4 -5 ml into drinking water was decreases the final body weight, carcass percentage and meat cholesterol of sentul chicken. It can be concluded that the addition of noni juice into drinking until 3 ml/1 liter the best result on final body weight, carcass percentage, abdominal fat and meat cholesterol Sentul Debu chicken phase growth.

Use of genomic information to exploit genotype-by-environment interactions for body weight of broiler chicken in bio-secure and production environments

BackgroundThe increase in accuracy of prediction by using genomic information has been well-documented. However, benefits of the use of genomic information and methodology for genetic evaluations are missing when genotype-by-environment interactions (G × E) exist between bio-secure breeding (B) environments and commercial production (C) environments. In this study, we explored (1) G × E interactions for broiler body weight (BW) at weeks 5 and 6, and (2) the benefits of using genomic information for prediction of BW traits when selection candidates were raised and tested in a B environment and close relatives were tested in a C environment.MethodsA pedigree-based best linear unbiased prediction (BLUP) multivariate model was used to estimate variance components and predict breeding values (EBV) of BW traits at weeks 5 and 6 measured in B and C environments. A single-step genomic BLUP (ssGBLUP) model that combined pedigree and genomic information was used to predict EBV. Cross-validations were based on correlation, mean difference and regression slope statistics for EBV that were estimated from full and reduced datasets. These statistics are indicators of population accuracy, bias and dispersion of prediction for EBV of traits measured in B and C environments. Validation animals were genotyped and non-genotyped birds in the B environment only.ResultsSeveral indications of G × E interactions due to environmental differences were found for BW traits including significant re-ranking, heterogeneous variances and different heritabilities for BW measured in environments B and C. The genetic correlations between BW traits measured in environments B and C ranged from 0.48 to 0.54. The use of combined pedigree and genomic information increased population accuracy of EBV, and reduced bias of EBV prediction for genotyped birds compared to the use of pedigree information only. A slight increase in accuracy of EBV was also observed for non-genotyped birds, but the bias of EBV prediction increased for non-genotyped birds.ConclusionsThe G × E interaction was strong for BW traits of broilers measured in environments B and C. The use of combined pedigree and genomic information increased population accuracy of EBV substantially for genotyped birds in the B environment compared to the use of pedigree information only.

Effects of Sweet Potato Leaves, Roselle Calyces and Beetroot on Body Weight, Selected Hematological and Biochemical Parameters in Broiler Chicken

The study was conducted to assess the effects of sweet potato leaves, roselle calyces and beetroot tubers on body weight, selected hematological and biochemical parameters in broiler chickens. Eighty four (84) broiler chickens aged four weeks were randomly assigned into six groups of 14 chickens each. The first group (G0) remained as untreated control while the other groups were the treated groups which received 25% of ground sweet potato leaves (G1), rosella calyces (G2), beetroot tubers (G3) and their mixtures (G4 and G5) for 28 days. Following inclusion of these different vegetables, blood samples were collected and analyzed for selected hematological and biochemical parameters on day 0, 7, 14, 21 and 28. Results showed that consumption of the three vegetables caused significant decreases (p < 0.05) in body weight, serum glucose and cholesterol. On the other hand, hemoglobin concentration, packed cell volume (PCV) and total white blood cell (WBC) counts were shown to increase significantly (p < 0.05) compared to the control group. It is concluded that the hypoglycemic and hypocholesteremic effects in chickens following consumption of the three vegetables together with their positive effects on PCV and WBC counts are important qualities which can be utilized in the management of conditions such as obesity, diabetes mellitus, hyperlipidemia and cardiovascular diseases (atherosclerosis and coronary disease) in humans. Further studies in other animals are recommended.

Chemical Composition and Antioxidant Activities of Polysaccharides from Yingshan Cloud Mist Tea.

The study was designed to investigate the chemical composition and antioxidant activities of polysaccharides from Yingshan Cloud Mist Tea. The chemical composition of green tea polysaccharides (GTPS) was analyzed by Fourier-transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), thermogravimetric (TGA), gas chromatograph (GC), and high-performance gel-permeation chromatography (HPGPC). Then, the antioxidant activities in vitro of GTPS, effects of GTPS on body weight, and the antioxidant activities in chickens were studied. The results showed that GTPS were composed of rhamnose (Rha), arabinose (Ara), xylose (Xyl), mannose (Man), glucose (Glu), and galactose (Gal) in a molar ratio of 11.4 : 26.1 : 1.9 : 3.0 : 30.7 : 26.8 and the average molecular weight was 9.69 × 104 Da. Furthermore, GTPS exhibited obvious capacity of scavenging DPPH radical, hydroxyl radical, and superoxide radical and enhanced the ferric-reducing power in vitro. Last, GTPS significantly increased the body weight of chickens, enhanced the T-AOC, SOD, and GSH-Px level, and decreased the content of MDA in chickens. The results indicated that GTPS might be a kind of natural antioxidant, which had the potential application in feed industry.

The effect of two different green lighting schedules during embryogenesis on myogenesis in broiler chickens

Abstract Light is one of the factors that interfere with avian development as early as during embryogenesis. The aim of this study was to determine the effect of monochromatic green light on hatchability, body weight and breast muscle myogenesis in broiler chickens, as expressed by breast muscle weight, muscle fibre thickness and number of satellite cells (Pax7 +) on d 1, 4 and 8 of life. Lighting programmes investigated were two different light cycles of 30 minutes of light and 30 minutes of darkness (L1 30/30), 12Â h of light and 12Â h of darkness (L2 12/12) and one control group (C) of continuous darkness applied throughout embryogenesis until day 18 of incubation. Green light was found to have a positive effect, resulting in significantly greater body weight of the exposed chickens (group: L2 12/12 – on d 4 of age; group L1 30/30 – on d 8 of age), and highly significantly greater fibre thickness in breast muscle in group L1 on d 8 of age. Photo-stimulation exerted a significant effect on the number of Pax7 + cells per unit of muscle cross-sectional area in broiler chickens on d 4 of life. However, higher body weight tended to be accompanied by a decrease in the number of Pax7 + satellite cells, calculated per unit of muscle area. This indicates the fusion of satellite cells with existing muscle fibres, which leads to an increase in their diameter. Based on the obtained results, we conclude that there is a potential opportunity to regulate the growth and development of chicken skeletal muscle by light during embryogenesis. This may further increase the effectiveness of chicken meat production. However, more research is needed in order to find the most optimal lighting treatment.

Does in Ovo Injection of Two Chicken Strains with Royal Jelly Impact Hatchability, Post-Hatch Growth Performance and Haematological and Immunological Parameters in Hatched Chicks?

Simple SummaryThe present investigation examined improvements in egg hatchability and the growth performance of hatched chicks of two strains upon injection with increasing concentrations of royal jelly (RJ). The results showed positive effects of RJ injection on all parameters. Limited impacts of the different chicken strains were observed on the tested parameters. The study revealed that varying the chicken strain could alter the response to the in ovo injection with RJ.The hypothesis of the present work was that the effects of in ovo injection may differ in different chicken strains. The influence of in ovo royal jelly (RJ) injection on hatching, growth and blood parameters in two chicken strains (Dokki-4 and El-Salam as example for different strains) was evaluated. A total of 1080 eggs were used. On the seventh day of incubation, the eggs were randomly allocated into six experimental groups in a 2 × 3 arrangement that included the two chicken strains and three concentrations of RJ (0, 0.25 and 0.5 mL RJ/egg). Injection with 0.5 mL RJ/egg improved hatchability compared to the other treatments. The El-Salam strain exhibited significantly higher body weight and body weight gain than the Dokki-4 strain. Injection with 0.5 mL RJ/egg significantly (p < 0.05) improved chicken body weight and daily weight gain compared to the control treatment. RJ injection decreased blood lipid profile parameters and the numbers of monocytes and eosinophils and increased total protein, globulin, haemoglobin (Hb) and lymphocyte levels compared to the control treatment. The Dokki-4 strain showed significantly higher antibody titres against avian influenza virus (AIV) (p < 0.05) and sheep red blood cells (SRBCs) (p < 0.0001) than the El-Salam strain and RJ injection enhanced antibody titres against AIV, Newcastle disease virus (NDV) and SRBCs. Therefore, the Dokki-4 strain was superior to the El-Salam strain for the tested parameters and injection with 0.5 mL RJ/egg produced the best hatching parameters, growth performance and health-related traits. RJ in ovo injection was much more effective in the Dokki-4 strain than in the El-Salam strain, which supported the hypothesis of the study that varying the chicken strain could alter the response to the in ovo injection with RJ.

Effect of Spirulina and Canthaxanthin Injection into Hatching Eggs on Hatchability Traits and Subsequent Growth Performance of Chicks

This work aimed to analyze the result of in-ovo injection at the 14th day of hatching period on hatchability, embryonic mortality (%) and subsequent growth performance additionally physiological status for hatched chicks. A 540 hatching Sinai eggs were collected, weighted (52 ± 1 g), distributed into 6 groups and incubated. At the 14th day of incubation, all eggs were candled then total fertile eggs of each group spliced into equal 3 replicates. Experimental groups were organized as follow: negative control (NC) without injection while the other groups were injected with sterile distilled water alone as a positive control (PC), spirulina (SP) with 2.5 and 5.0 mg/egg, canthaxanthin (CX) with 0.025 and 0.050 mg/egg, respectively. Results indicated that the highest value of hatchability (%) of fertile eggs was achieved by injected eggs with 0.050 mg CX/egg followed by in-ovo injection with 2.5 mg SP/egg in comparison with the PC and NC groups. In-ovo injection with 0.050 mg CX/egg resulted in a heavier chick body weight at 8 days after hatch and relative heart weight than other treatments and the control groups. Chicks produced from the eggs injected with 0.050 mg CX / egg recorded a significant improvement in BW at 28 days of age and subsequent BWG than other injected groups and NC during 0-28 days of age. The highest value of the survival ratio percentage was recorded for chicks produced from injected eggs with 2.5 mg SP/ egg. Total protein, globulin and HDL recorded higher (P≤0.01) values in chick's serum by injected hatching eggs with 0.025 and 0.050 mg CX/egg in comparison with NC group, however, total cholesterol and LDL recorded the lower value. It was concluded that, in-ovo injection Sinai hen's eggs with spirulina and canthaxanthin could be used to improve hatchability and decrease embryonic mortality (%) and enhance subsequent growth performance additionally physiological situation of hatched chicks.

The effects of fermented milk products (kefir and yogurt) and probiotic on performance, carcass characteristics, blood parameters, and gut microbial population in broiler chickens.

This study was conducted to determine the effects of fermented milk products and probiotic on performance, carcass characteristics, blood parameters, and gut microbial population in broiler chickens. A total of 480 one-day-old Ross 308 broilers were allocated to 30 floor pens in a completely randomized design with six treatments, five replicates, and 16 chicks (eight males and eight females) in each replicate. On the first day, the male and female chicks were weighed and divided by the feather sexing method so that the average body weight of chicks was approximately equal in each pen. Treatments consisted of six groups (including control): group 1 had a basal diet and normal drinking water, group 2 had a basal diet and probiotics (PrimaLac®) in drinking water as recommended by the manufacturer, group 3 had a basal diet and 2 % yogurt in drinking water, group 4 had a basal diet and 4 % yogurt in drinking water, group 5 had a basal diet and 2 % kefir in drinking water, and group 6 had a basal diet and 4 % kefir in drinking water. Chemical and microbiological characteristics of kefir and yogurt were measured after each production. The results showed that 4 % kefir, yogurt, and probiotic at the recommend level in water improved body weight gain, feed intake, and feed conversion ratio compared with other groups (). The results indicated that treatment had a significant effect on the carcass yield, intestinal length, thigh yield, and abdominal fat in male and female chickens (). There were no effects on total bacteria population but the lactobacilli and coliform bacteria populations showed increasing and decreasing trends, respectively, with 4 % kefir, yogurt, and probiotic supplementation at 28 and 42 d (). In addition, blood glucose and total protein increased when using a high levels of kefir, yogurt, and probiotic in water, while cholesterol and LDL (low-density lipoprotein) concentrations were lower in 4 % kefir, yogurt, and probiotic at the recommended level. Consequently, the results of this study showed that the use of 4 % kefir, yogurt, and probiotic at recommended level in water had beneficial effects on the growth performance, intestinal bacteria population, and blood biochemical parameters in male and female broiler chickens.

Oral administration of Lactobacillus reuteri expressing a 3D8 single-chain variable fragment (scFv) enhances chicken growth and conserves immune homeostasis.

The present study was aimed to investigate the effects of 3D8 scFv-secreting Probiotic Lactobacillus reuteri (L. reuteri) on growth performance, inflammatory responses, and intestinal microbial flora in chickens. To this end, a total of 14 healthy wild-type chickens were divided into two experimental groups. Each group was orally administrated with a daily dose of 109 colony-forming units (CFU) of 3D8 scFv-producing L. reuteri or wild-type (WT) for 35days. Administration of L. reuteri/3D8 scFv significantly improved the body weight of chickens when compared to L. reuteri/WT group. The bacterial taxonomic composition of the fecal microbiota was determined by pyrosequencing of 16S rRNA gene amplicons. Firmicutes, Actinobacteria, and Proteobacteria were dominant phyla in two experimental groups. However, in 3D8 L. reuteri treatment groups at genus level, the Lactobacillus was highly abundant, being represented by 18.12%. In addition, serum levels of primary cytokines such as IL-6, IL-8, TNF-α, IFN-γ, IL-4, and IGF1 were markedly reduced in the probiotic L. reuteri 3D8 group. In summary, our results indicate that the administration of L. reuteri expressing 3D8 scFv has a modulatory effect on inflammatory responses, improves weight gain while not affecting the common microbial composition of the chicken intestine.

Effect of In Ovo Injection of L-Arginine in Different Chicken Embryonic Development Stages on Post-Hatchability, Immune Response, and Myo-D and Myogenin Proteins.

Simple SummaryIn the current study, we hypothesized that the in ovo injection of L-arginine (L-Arg) at different stages of embryonic development, which would have positive effects on the survival rate, hatching rate, immunoglobulin M (IgM) levels, heat shock proteins (HSPs) such as HSP-47, HSP-60, and HSP-70, and muscle development markers as well: Mainly, myoblast determination protein (myoD) and myogenin in pectoral muscles. As indicated, the in ovo injection of L-Arg resulted in an increased hatch rate and weight, survival rate, higher levels of IgM, and myogenin and MyoD expression in the muscles. At the same time, a decrease in the level of HSP-47, HSP-60, and HSP-70 expressions in the tissues was observed on the 14th day of injection compared to the eighth and 18th day of the injection period. In addition, the in ovo injection of L-Arg decreased the serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT) concentration in serum as well micronuclei and nuclear abnormality in the blood on the 14th day of the incubation period. Hence, the 14th day would be a suitable day for the injection of L-Arg to promote the hatching rate and muscle growth of broiler chickens.The aim of this study was to evaluate the effect of in ovo injection with different ratios of L-arginine (L-Arg) into Ross broiler eggs at three different embryonic developmental stages (eighth day (d), 14th day, and 18th day) on the survival, hatchability, and body weight (BW) of one-day-old hatched chicks. Additionally, we have analyzed the levels of serum glutamate oxaloacetate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT), the protein expression of heat shock proteins (HSPs), and we have also determined micronuclei (MN) and nuclear abnormality (NA). In addition, the genotoxic effect was observed in peripheral blood cells such as the presence of micronuclei and nuclear abnormalities in the experimental groups. The results showed that survival and hatching rates as well as body weight were increased on the 14th day of incubation compared to the eighth and 18th day of incubation at lower concentrations of L-Arg. Moreover, the levels of SGOT and SGPT were also significantly (p < 0.05) increased on the 14th day of incubation at the same concentration (100 μg/μL/egg) of injection. In addition, immunoglobulin (IgM) levels were increased on the 14th day of incubation compared to other days. The protein expressions of HSP-47, HSP-60, and HSP-70 in the liver were significantly down-regulated, whereas the expression of myogenin and myoblast determination protein (MyoD) were significantly up-regulated on the 14th day after incubation when treated with all different doses such as 100 μg, 1000 μg, and 2500 μg/μL/egg, namely 3T1, 3T2, and 3T3, respectively. However, the treatment with low doses of L-Arg down-regulated the expression levels of those proteins on the 14th day of incubation. Histopathology of the liver by hematoxylin and eosin (H&E) staining showed that the majority of liver damage, specifically intracytoplasmic vacuoles, were observed in the 3T1, 3T2, and 3T3 groups. The minimum dose of 100 μg/mL/egg on the 14th day of incubation significantly prevented intracytoplasmic vacuole damages. These results demonstrate that in ovo administration of L-Arg at (100 μg/μL/egg) may be an effective method to increase chick BW, hatch rate, muscle growth-related proteins, and promote the immune response through increasing IgM on the 14th day of the incubation period.

Effect of Some Organic Acids on Body Weight, Immunity and Cecal Bacterial Count of Chicken during Heat Stress

Effect of Some Organic Acids on Body Weight, Immunity and Cecal Bacterial Count of Chicken during Heat Stress

Use of probiotics instead of antibiotics in broiler production

Effects of different available commercial probiotics on growth performance and blood parameters were evaluated. To achieve the objectives, a total of 198 one-day-old Hubbard Isa Starbro broiler chicks were raised over 28 days. Chicks were wing-banded, weighed individually and randomly allocated into six equally major groups each having three replicates. Broilers of group T1 (control group) were fed the starter and finisher diets. The broilers of groups T2 was fed the control starter and finisher diets supplemented with antibiotic and groups T3-T5 were fed 4 different commercially available probiotics (T3-Guardizen-M, T4-Protexin and T5-Poultry star sol in drinking water. Weekly body weight, feed consumption and feed conversion were recorded during experimental period. Blood parameters at 4 weeks of age including packed cell volume (PCV), haemoglobin (Hb), total protein, albumin, triglycerides, high density lipoprotein (HDL), uric acid, cholesterol, glucose, intestinal microflora, pH and color properties of meat were determined. All birds were kept under similar environmental, managerial and hygienic conditions. Probiotic supplementation significantly increased the body weight and daily weight gain of broiler chicks at 28 days (p&lt;0.05). Improved feed conversion was noticed in birds fed a diet supplemented with probiotic. The effects of probiotics on carcass and some internal organs were measured and results shows that feeding broilers with probiotics have significant effects (P &lt; 0.05) on dressed carcass weight, abdominal fat, breast, thigh and liver while it appeared insignificant on gizzard (P&gt; 0.05). The lower percent of abdominal fat and the higher percent of dressed carcass, breast and thigh were observed in experimental probiotic(s) groups. pH and meat color did not affect among treatments. There was lower mortality rate in probiotics among groups. Moreover, there was no significant change for Hb, PCV, total protein and albumin concentrations among different groups. Also, total protein, lipids and albumin concentrations were not affected by probiotic(s) supplementation. In addition, different probiotics showed a significant decrease (p&lt;0.05) in triglycerides, cholesterol and uric acid concentration compared to control group. Birds supplemented with probiotics had higher number of lactobacilli but lower number of colibacilli compared to the control. It can be concluded that use of selected commercial probiotic(s) resulted in improved growth performance and carcass yields, and reduced serum cholesterol and uric acid in broiler chickens. Moreover, supplementation of the probiotic(s) to broilers had no detrimental effect on their growth performance and blood parameters. Therefore, usage of these probiotic(s) bacteria as antibiotic alternatives in poultry nutrition can be recommended.&#x0D; Progressive Agriculture 29 (4): 359-370, 2018

Mapping of QTL for chicken body weight, carcass composition, and meat quality traits in a slow-growing line

Slow-growing chicken lines are valuable genetic resources for the development of well-perceived alternative free-range production. While there is no constraint on increasing growth rate, breeding programs have to evolve in order to include new traits improving the positioning of such lines in the growing market for parts and processed products. In this study, we used dense genotyping to fine map QTL for chicken growth, body composition, and meat quality traits in view of developing new tools for selection of a slow-growing line. The dataset included a total of 836 birds (10 sires, 87 dams, 739 descendants) and 40,203 SNP. QTL for the 15 traits analyzed were detected by 3 different methods, i.e., linkage and linkage disequilibrium haplotype-based analysis (LDLA), family-based single marker association (FASTA), and Bayesian multi-marker regression (Bayes Cπ). After filtering for QTL redundancy, we found 16, 16, and 9 QTL when using the FASTA, LDLA, and Bayes Cπ methods, respectively, with a threshold of 2.49 × 10-5 for FASTA and LDLA, and a Bayes factor of 150 for the Bayes Cπ analysis. They comprised 17 QTL for body weight, 9 QTL for body composition, and 15 QTL for breast meat quality or behavior at slaughter. The 3 methods agreed in the detection of highly significant QTL such as that detected on GGA24 for body weight at 3, 6, and 9 wk, and the 2 QTL detected on GGA17 and GGA18 for breast meat yield. Several significant QTL were also detected for the different components of breast meat quality. This study provided new locations for investigation in order to improve our understanding of the genetic architecture of growth, carcass composition, and meat quality in the chicken and to develop molecular tools for the selection of these traits in a slow-growing line.

Target gene identification and functional characterization of miR-1704 in chicken

MiRNAs are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. SNPs in miRNA genes may lead to phenotypic variation by altering miRNA expression and their targets. In this study, miR-1704 expression profiles in nine tissues at 1 d, 6 weeks and 16 weeks old Gushi chickens were detected. MiR-1704 was widely expressed in the detection of tissues. The expression in 1 d and 6 weeks old was low abundance, while its expression at 16 weeks was very high. An rs14668705 (C > G) SNP was detected within the pre-miR-1704 in an F2 resource population of Gushi chicken crossed with Anka broiler. Bioinformatic analysis indicated that the C > G mutation could introduce a base-pair mismatch and cause the change of free energy. Experiments further revealed that the rs14668705 in precursor miR-1704 could significantly affect mature miR-1704 biogenesis and was significantly associated with body weight at the age of 0, 6, 8, 10, and 12 weeks, shank circumference at 4, 8, and 12 weeks, carcass weight, and semi-evisceration weight (p < 0.05). Insulin receptor 2 (IRS2) gene, one of the potential targets of miR-1704 was identified and further confirmed. These data suggested that miR-1704 targeted IRS2 and have an effect on body weight in chicken.

Two insertion/deletion variants in the promoter region of the QPCTL gene are significantly associated with body weight and carcass traits in chickens.

Glutaminyl-peptide cyclotransferase-like (QPCTL) is an isoenzyme of glutaminyl-peptide cyclotransferase (QPCT). QPCTL and QPCT catalyze the formation of N-terminal modified pyroglutamate-fractalkine and the chemokine CCL2. The objective of this study was to investigate the association between insertions/deletions in the chicken QPCTL promoter region with growth traits in chickens. We first detected two insertion/deletion variants of QPCTL via whole-genome resequencing analysis of DNA samples from Xichuan chickens. A total of 1896 individuals from 12 breeds were genotyped for 52- and 224-bp insertions/deletions. We found two novel insertions/deletions in the promoter region of the chicken QPCTL gene and studied their association with chicken body weight and carcass traits. Our findings show that QPCTL can be a molecular marker for chicken genetics and breeding programs.

Review Work on Body Weight and Egg Production Performance of Chickens in Ethiopia

Different breeds of exotic chickens were imported to Ethiopia with the aim of improving chicken productivity. Moreover, one way of improving low genetic potential of local chickens is crossbreeding programs of local chickens with exotic chicken breeds. For further improvement in production traits, understanding performance of economic traits in chicken is important for the formulation of breeding plans. Therefore, the objective of this review paper is to review egg and body weight performance of chickens in Ethiopia. Breed of chicken used, environmental conditions, and management practices are the main factor that affects chicken productivity. The average egg production and body weight performance of chickens is higher in exotic breed followed by cross and local ones. However, poor performance of exotic chickens is observed in situations where the breeds are poorly managed. The performance of crossbreds reduces gradually as the percent of genes goes beyond 50 but the management gets down. With regard to local ones, better management and proper breeding technique do have a chance for upgrading. Therefore, better management, proper breeding activities and regulatory laws should be imposed to enhance chicken productivities. Keywords: Egg, Body weight, Local, Exotic, Crossbreed, Chicken DOI : 10.7176/JBAH/9-8-03 Publication date : April 30 th 2019