Chick Growth Research Articles

Expression of Genes Related to Meat Productivity, Metabolic and Morphological Significance of Broiler Chickens with the Use of Nutritional Phytochemicals.

The study aimed to analyze gene expression linked to skeletal muscle growth and lipid metabolism in broiler chickens fed with plant extracts. Five groups of chickens were formed: four experimental groups and one control group. The diets of the experimental groups were supplemented with different plant extracts: chicory, St. John's wort, maral root, and creeping thyme, whereas the control group received feed without phytobiotic compounds. Weekly weighings were conducted (n = 36). The chickens were slaughtered at day 26 for tissue sampling of four birds from each group. Gene expression (MYOG, MSTN, FASN) related to muscle growth and fatty acid synthesis was analyzed using the β-actin ACTB gene as a reference. Blood samples were taken at day 35 for biochemical analysis and anatomical dissection was performed. The study revealed that using plant extracts from chicory, thyme, and maral root increased MYOG gene activity by 4.21, 7.45, and 8.93 times, respectively. T. serpyllum extract boosted the MSTN gene by 10.93 times, impacting muscle growth regulation. FASN gene expression for fatty acid synthesis increased significantly by 18.22-184.12 times with plant extracts. The best results regarding meat productivity of chickens were obtained when using R. carthamoides extract. The results of the study will serve as a basis for further development of a phytocomposition designed to increase the meat productivity of broiler chickens in the production of environmentally safe poultry products.

Fatty acid composition, lipid profile and oxidative stability of meat of broiler chickens fed diet containing bird eye pepper of varying inclusion level and sieve size.

Nutritional modifications to improve meat quality is targeted by farmers. Bird eye pepper (BEP) contains bio-compounds of physiological significance. The potency of BEP of varying inclusion level and sieve size on meat quality [fatty acid (FA), lipid profile and oxidative stability] of broiler chickens was investigated. A total of 246 birds fed diet-containing BEP [inclusion level (0, 0.15 and 0.3%), sieve size (0.05 and 0.1mm)] were randomized to six treatments replicated 4 times in a 2 by 3 factorial layout. After feeding (31 days), forty-eight birds (two per replicate) were slaughtered and breast muscles harvested. Meat lipid profile and 2-thiobarbituric acid reactive substance (TBARs) were determined on day (d) 0, while TBARs was further assessed on d 3 and 5, but FA on d 10 of refrigeration storage. BEP diet (0.15%) increased (p < 0.05) total monounsaturated FA (MUFA), unsaturated FA (UFA) and n-3 FA, while 0.05mm BEP lowered (p < 0.05) meat index of thrombogenicity (TI) but increased meat hypocholesteromic: hypercholesteromic (HH) value. Dietary 0.15% (0.05mm) BEP yielded low (p < 0.05) SFA but high MUFA: SFA, UFA: SFA and NVI, while 0.15% (0.1mm) BEP diet resulted in high total MUFA and higher (p < 0.05) UFA, n-3 and n-3: n-6 FA. Control, 0.15% and 0.05mm BEP diets reduced (p < 0.05) meat cholesterol value. This study has shown that 0.15% (0.05mm) BEP diet had no deleterious effect on the growth of broiler chickens but improved the NVI, IA, TI, HH, TBARs and cholesterol of the meat - a significance to health-conscious consumers.

The use of partially slatted floor designs as an alternative to littered systems in broiler chickens. I. The effects on the performance, slaughter and carcass traits.

In this study, the effects of fully littered, slatted and their varying combinations on growth, performance, carcass and meat quality characteristics in broiler chickens were investigated. In the experiment, five treatment groups were formed as fully littered (FL), fully slatted (FS), 1/3 littered + 2/3 slatted (2/3 SF), 1/2 littered + 1/2 slatted (1/2SF), 2/3 littered + 1/3 slatted (1/3 SF). Each treatment group included 5 replicates (24 chicks in each) and a total of 600 male-female mixed fast growing broiler chicks (Ross-308) were used during 6 weeks. Weekly body weight (BW, g), feed intake (FI, g), feed conversion ratio (FCR, g.feed intake/g.weight gain), livability (%) and EPEF (European Production Efficiency Factor) were determined as performance characteristics. Carcass yield (CY, %), and the percentages of abdominal fat (AFP, %), edible internal organs (EIOP, %), gizzard (GP, %), breast (BRP, %) and thigh (TP, %) meat were the carcass characteristics. Meat quality measured by pH and color (L*: lightness, a*: redness, b*: yellowness) of breast and thigh meat, and occurrence of white striping and hemorrhaging in breast meat. The weekly BW differences among the floor treatments were significant (P < 0.01), and 1/3SF broilers were the heaviest at slaughter age (3311.6g). The 6-week FCR in FS broilers was significantly worse than the others (1.471), but FI, livability and EPEF were similar among treatments. AFP tended to be higher in FL birds (P = 0.066), while CY, EIOP, GP, BRP and TP did not differ between groups. Breast pH was similar between treatments, with 1/2SF showing the highest (6.34) and FL the lowest (6.24) breast pH (P < 0.01). The partially slatted systems caused lighter, redder and yellower color values in breast meat (P < 0.01) than the fully littered or slatted systems, but did not change the color of the thigh meat. White striping and hemorrhaging in breast meat were not affected by the floor treatments. This study suggests that the use of partially slatted systems in broiler chickens improves meat color without compromising performance traits (body weight, feed efficiency, EPEF), litter moisture and slaughter traits and these systems could be an alternative to fully littered systems.

Effects of shallot (Allium ascalonicum) powder supplementation on growth, intestinal morphology, immune stimulation, and intestinal bacteria in broiler chickens

Background and Aim: Antimicrobial resistance in poultry farms is a significant global public health concern that has led farmers to explore alternative antibiotics, such as prebiotics in poultry production. This study aimed to examine the antimicrobial activity of ethanolic shallot extract (ESE) and the effects of adding shallot powder (SP) to broiler feed on broiler growth, immune response to Newcastle disease virus (NDV) vaccination, and gastrointestinal tract bacteria. Materials and Methods: We determined the antimicrobial effects of ESE against Escherichia coli O157:H7 (EOH) and Lactobacillus acidophilus TISTR 2365 (L2365) using the agar well diffusion method. We used a complete randomized design to assign 120 1-day-old Arbor Acre chicks to six groups with four replicates of five broiler chickens over 42 days. The treatment groups were as follows: T1-basal diet (B) + NDV vaccination (positive control), T2-B (negative control), T3-B + 2 g SP per kg of feed, T4-B + 2 g SP per kg of feed + NDV, T5-B + 4 g SP per kg of feed, and T6-B + 4 g SP per kg of feed + NDV. Results: The minimum inhibitory concentrations of ESE on EOH and L2365 were 62.50 and 125.00 mg/mL, respectively. The body weight gain, average daily gain, and feed conversion ratio in the 4 g SP of T5 and T6 groups were significantly improved compared with the other groups (p &lt; 0.05). The immune organ (IO) and thymus gland weights in the T4 group were significantly greater than those observed in the positive and negative control groups (p &lt; 0.05). The IO weights of the bursae of Fabricius and spleen tended to be greater in the T4 group than in the other groups. T5 group broilers had the highest ratio of villus height to crypt depth. The humoral immunity titers against NDV vaccination were improved in the SP-supplemented groups compared with the non-supplemented groups (p &gt; 0.05). SP supplementation reduced the levels of coliform (p &lt; 0.05) and E. coli in the broiler intestine by adding 4 g of SP per kg of feed. However, L2365 was more tolerant to ESE in vitro and tended to increase in line with increased SP levels. Conclusion: ESE showed strong antimicrobial activity to reduce harmful bacteria, and SP supplementation may exhibit prebiotic effects to increase broiler chicken growth, immunity, and microbial balance. Keywords: broiler chickens, food security, immune stimulation, intestinal bacteria, intestinal morphology, shallot.

Revealing in vivo broiler chicken growth state: Integrating CT imaging and deep learning for non-invasive reproductive phenotypic measurement

The measurement of body dimensions in broiler chickens has long been of great interest to the poultry industry, especially regarding reproductive phenotypes closely linked to breeding traits and the growth status of roosters. Existing measurement methods suffer from subjectivity, destructiveness, and various limitations. Therefore, we propose a novel method for the in vivo measurement of broiler chicken reproductive phenotype based on a three-dimensional medical imaging segmentation network. Leveraging our proposed FDTR medical imaging segmentation algorithm, this method achieves robust segmentation performance on a broiler chicken dataset. However, due to the morphological diversity and extreme class imbalance of broiler chicken reproductive phenotypes, we introduce a meta-learning paradigm and design a specialized decoder path. Ultimately, we establish relationships between the predicted results obtained from the segmentation network and the reproductive phenotypes to achieve phenotypic measurement. To evaluate this method, we collected and constructed the YF2023 broiler chicken reproductive phenotype dataset. Extensive cross-validation experiments demonstrate that the proposed method effectively measures the reproductive phenotypes of live roosters using computed tomography (CT) medical imaging. The proposed segmentation model achieves a mean fold dice similarity coefficient (DSC) of 0.6353, a mean fold Hausdorff distance (HD) of 11.84 mm, and a mean fold average volume distance (AVD) of 1.72 mm3. In addition, we evaluated our model’s generalization performance on unseen data, where the model achieved a DSC of 0.6825, an HD of 7.58 mm, and an AVD of 1.40 mm3. The predicted results exhibit a mean correlation coefficient of 66.18% with the weights of reproductive phenotype. This validates the enormous potential of the method in broiler chicken breeding and provides new insights and solutions for the accurate segmentation of broiler chicken reproductive phenotype. The code is available at https://github.com/Github-XKou/MetaFDTR.

In ovo feeding of l-arginine and selenium nanoparticles influences post-hatch growth, muscle development, antioxidant status, and meat quality in slow-growing chickens.

This study investigated the effects of in ovo feeding (IOF) of l-arginine (L-Arg), selenium nanoparticles (SeNP), and a combination of L-Arg and SeNP on the hatchability, post-hatch growth, muscle development, antioxidant status, and meat quality of slow-growing chickens. On day 18 of incubation, a total of 960 fertilized eggs with similar weights were randomly assigned to 4 treatment groups with 4 replicates of 60 eggs each: (1) non-injected control group (Control), (2) injected with 1% of L-Arg (IOF_L-Arg), (3) injected with 0.3 µg/egg of SeNP (IOF_SeNP), and (4), injected with 1% of L-Arg and 0.3 µg/egg of SeNP (IOF_L-Arg + SeNP). A completely randomized design was used. After hatching, 640 mixed-sex chicks were allocated to 4 treatment groups and split into 4 replicate pens (40 birds per pen). All groups of chicks were fed with commercial feed ad libitum until they reached 63 d of age and were subsequently weighed and slaughtered. The results of the present study showed that hatchability was similar among treatments. Final BW or breast muscle yield was not affected (P > 0.05) by IOF treatment. Chickens treated with IOF_L-Arg + SeNP exhibited decreased feed conversion ratio, drip loss, and increased protein content in breast meat (P < 0.05). The IOF_L-Arg + SeNP group exhibited a higher density of breast muscle fibers than the control group (P < 0.05). Overall, in ovo feeding of L-Arg combined with SeNP resulted in improved feed efficiency and enhanced antioxidant capacity at hatch without any adverse effects on chicken hatchability, health, or subsequent growth. Furthermore, meat from chickens in the IOF_L-Arg + SeNP group exhibited a preferable texture with a higher protein content.

Bacillus amyloliquefaciens TL promotes gut health of broilers by the contribution of bacterial extracellular polysaccharides through its anti-inflammatory potential.

The focal point of probiotic efficacy and a crucial factor influencing poultry cultivation lies in the level of intestinal inflammation. In conventional farming processes, the reduction of intestinal inflammation generally proves advantageous for poultry growth. This study investigated the impact of Bacillus amyloliquefaciens TL (B.A.-TL) on inflammatory factor expression at both tissue and cellular levels, alongside an exploration of main active secondary metabolites. The results demonstrated that broiler feeding with a basal diet containing 4 × 109 CFU/kg B.A.-TL markedly enhanced chicken growth performance, concomitant with a significant decrease in the expression of genes encoding inflammatory cytokines (e.g., CCL4, CCR5, XCL1, IL-1β, IL-6, IL-8, LITAF, and LYZ) in jejunum and ileum tissues. The extracellular polysaccharides of B.A.-TL (EPS-TL) exhibited notable suppression of elevated inflammatory cytokine expression induced by Escherichia coli O55 lipopolysaccharides (LPS) in chicken macrophage-like cells (HD11) and primary chicken embryonic small intestinal epithelial cells (PCIECs). Moreover, EPS-TL demonstrated inhibitory effect on NF-κB signaling pathway activation. These findings suggested that the metabolic product of B.A.-TL (i.e., EPS-TL) could partly mitigate the enhanced expression of inflammatory factors induced by LPS stimulation, indicating its potential as a key component contributing to the anti-inflammatory effects of B.A.-TL.

Age-dependent genetic architectures of chicken body weight explored by multidimensional GWAS and molQTL analyses

Chicken body weight (BW) is a critical trait in breeding. Although genetic variants associated with BW have been investigated by genome-wide association studies (GWAS), the contributions of causal variants and their molecular mechanisms remain largely unclear in chickens. In this study, we construct a comprehensive genetic atlas of chicken BW by an integrative analysis of 30 age points and 5 quantitative trait loci (QTL) across 27 tissues. We find that chicken growth is a cumulative non-linear process, which can be divided into three distinct stages. Our GWAS analysis reveals that BW-related genetic variations show ordered patterns in these three stages. Genetic variations in chromosome 1 may regulate the overall growth process, likely by modulating the hypothalamus-specific expression of SLC25A30 and retina-specific expression of NEK3. Moreover, genetic variations in chromosome 4 and chromosome 27 may play dominant roles in regulating BW during stage Ⅱ (8–22 weeks) and stage Ⅲ (23–72 weeks), respectively. In summary, our study presents a comprehensive genetic atlas regulating developmental stage-specific changes in chicken BW, thus providing important resources for genomic selection in breeding programs.

A Comparison of the Cecal Microbiota between the Infection and Recovery Periods in Chickens with Different Susceptibilities to Eimeria tenella.

To investigate the effect of Eimeria tenella (E. tenella) infection on the cecal microbiota, resistant and susceptible families were screened out based on the coccidiosis resistance evaluation indexes after E. tenella infection. Subsequently, a comparative analysis of cecal microorganisms among control, resistant, and susceptible groups as well as between different periods following the E. tenella challenge was conducted using metagenomic sequencing technology. The results showed that the abundance of opportunistic pathogens, such as Pantoea, Sporomusa, and Pasteurella in the susceptible group and Helicobacter and Sutterella in the resistant group, was significantly higher on day 27 post-inoculation (PI) (the recovery period) than on day 5 PI (the infection period). Additionally, the abundance of Alistipes, Butyricicoccus, and Eubacterium in the susceptible group and Coprococcus, Roseburia, Butyricicoccus, and Lactobacillus in the resistant group showed a significant upward trend during the infection period compared with that in the recovery period. On day 5 PI, the abundance of Faecalibacterium and Lactobacillus was decreased in both the resistant and susceptible groups when compared with that in the control group and was greater in the resistant group than in the susceptible group, while Alistipes in the susceptible group had a relatively higher abundance than that in other groups. A total of 49 biomarker taxa were identified using the linear discriminant analysis (LDA) effect size (LEfSe) method. Of these, the relative abundance of Lactobacillus aviarius, Lactobacillus salivarius, Roseburia, and Ruminococcus gauvreauii was increased in the resistant group, while Bacteroides_sp__AGMB03916, Fusobacterium_mortiferum, Alistipes_sp__An31A, and Alistipes_sp__Marseille_P5061 were enriched in the susceptible group. On day 27 PI, LDA scores identified 43 biomarkers, among which the relative abundance of Elusimicrobium_sp__An273 and Desulfovibrio_sp__An276 was increased in the resistant group, while that of Bacteroides_sp__43_108, Chlamydiia, Chlamydiales, and Sutterella_sp__AM11 39 was augmented in the susceptible group. Our results indicated that E. tenella infection affects the structure of the cecal microbiota during both the challenge and recovery periods. These findings will enhance the understanding of the effects of changes in the cecal microbiota on chickens after coccidia infection and provide a reference for further research on the mechanisms underlying how the intestinal microbiota influence the growth and health of chickens.

Dried Chlorella powder supplementation: Impact on broiler chicken growth, health, and intestinal microflora

The use of dried Chlorella as an immune and growth stimulant to enhance nonspecific host defense mechanisms or as an antimicrobial to inhibit bacterial growth has been reported. This study aimed to assess the effects of dried Chlorella powder (DCP) supplementation on the growth, health, and intestinal microflora of commercial broiler chicks, comparing a diet containing DCP with an antibiotic-based diet. A total of 120 pieces day-old Cobb 500 broiler chicks were reared at Sher-e-Bangla Agricultural University Poultry Farm, Dhaka, and randomly divided into four experimental groups of three replicates each, with 10 chicks per replication. One group was fed a control diet, while the remaining three groups were fed diets with 0.5% and 1.0% DCP, and antibiotics, respectively. Results indicated significant (P&lt;0.05) improvements in body weight and dressing percentage with DCP inclusion compared to control-fed broilers. A linear increase in body weight was observed with higher DCP levels, with birds on the 1% DCP diet achieving superior body weights (1665.13±8.82) compared to the control and antibiotic groups. Feed Conversion Ratio (FCR) and feed consumption were also significantly (P&lt;0.05) improved, with the best FCR at 1% DCP (1.37±0.01) and the highest FCR in the control group (1.45±0.00). The highest feed consumption was noted in the control group. No significant (P&gt;0.05) differences were observed in the relative weight of spleen and bursa among the groups. DCP had no significant (P&gt;0.05) effects on liver, gizzard, intestine, and heart weights. Hematological studies revealed no significant (P&gt;0.05) differences, except for Hemoglobin and Red Blood Cells (RBC), which were significantly (P&lt;0.05) increased by DCP compared to control and antibiotic groups. DCP supplementation significantly (P&lt;0.05) reduced E. coli and Salmonella sp. counts while increasing Lactobacillus sp. counts. Additionally, treatments with DCP significantly (P&lt;0.05) boosted Newcastle disease (ND) titre levels compared to the control group. The study showed that DCP can be effectively replaced antibiotics in broiler diets, enhancing growth, health, and immune response, thereby promoting sustainable and safer poultry production practices.

Effects of Different Photoperiods during Incubation on Post-Hatch Broiler Performance and Stress Response.

This study evaluated the subsequent effect of photoperiods during incubation on post-hatch growth and stress response of commercial broiler chickens. A total of 875 Ross 308 broiler breeder (48 weeks of age) eggs were hatched using different durations (0, 4, 8, 12, 16, 20, and 24 h a day) of dichromatic light [green and red (495 to 750 nm); 2700 K; 250 lux; SUNJIE; China] throughout the whole period of incubation. A total of 50 0-day-old hatched straight run broiler chicks from each photoperiod during incubation were used to evaluate subsequent growth performance (feed intake, body weight, and feed conversion ratio); stress parameters (physical asymmetry, tonic immobility, and vocalization,); welfare traits (feather score and gait score); carcass traits (live weight, dressed weight, carcass yield, liver weight, gizzard weight, heart weight, abdominal fat weight, breast weight, and leg weight); and serum chemistry (globulin, total protein, cholesterol, glucose, and uric acid). There were no influences of photoperiod during incubation on post-hatch growth, stress parameters, welfare, and carcass traits. Heart yield was higher in birds incubated under 20 h light than in those from the 16 h light group. Incubation under different lighting durations also altered blood biochemical profile but did not influence serum globulin and cholesterol levels. It was concluded that under experimental conditions, incubation of broiler eggs under different lighting durations did not impact subsequent post-hatch performance (21-35 d).

Different dietary branched-chain amino acid ratios, crude protein levels, and protein sources can affect the growth performance and meat yield in broilers

Balanced ratios of branched-chain amino acids (BCAAs) can enhance chicken growth, immunity, and muscle synthesis. However, these ratios can be affected by changes in crude protein (CP) levels or the substitution of protein sources, leading to BCAA antagonism. This, in turn, can have a negative impact on chicken growth. In Experiment 1, a total of 960 0-d-old male Cobb 500 broilers were divided into 6 treatments with 8 replicates. Three different BCAA ratios were used in High or Low CP diets as follows: 1) Low Leu group (Low level of leucine with increased valine and isoleucine levels), 2) Med Leu group, and 3) High Leu group (High level of leucine with reduced valine and isoleucine levels) for a total of 6 diets. In Experiment 2, a total of 640 0-d-old male Cobb 500 broilers were divided into 4 treatments with 8 replicates. The four diets had either High or Low CP and one of two protein sources with the same medium levels of BCAAs: 1) the soybean meal (SBM) group, which had SBM as the main protein source (protein bound AA), and 2) the wheat middlings with non-bound AAs (WM+AA) group (non-bound AA), which had additional non-bound AAs to replace SBM. The High Leu diet had a negative effect on overall growth performance, carcass weight, breast muscle weight, and body mineral composition compared to the Low Leu and Med Leu groups, particularly in the High CP diet (P < 0.05). The SBM group showed increased growth performance, breast muscle weight, expression levels of genes promoting muscle growth, and improved bone mineral composition compared to the WM+AA group, and the High CP group intensified the negative effect of the WM+AA diet (P < 0.05). In summary, balanced BCAA ratios and SBM-based diets have positive effects on chicken growth and muscle accretion, whereas excessive leucine and non-bound AA levels in the diets may negatively affect growth performance and meat yield in chickens.

CTGF Inhibits the Differentiation of Chicken Preadipocytes via the TGFβ/Smad3 Signaling Pathway or by Inducing the Expression of ACTG2.

Chicken is the main source of protein for humans in most parts of the world. However, excessive fat deposition in chickens has become a serious problem. This adversely affects the growth of chickens and causes economic losses. Fat formation mainly occurs through preadipocyte differentiation, and excessive fat deposition results from the accumulation of preadipocytes after differentiation. Our previous studies have found that the connective tissue growth factor (CTGF) may be an important candidate gene for fat deposition. However, its function and mechanism in preadipocyte differentiation are still unclear. In this study, the RT-qPCR and Western blot results showed that the expression of CTGF mRNA and protein in the abdominal adipose of lean chickens was significantly higher than that of fat chickens. Therefore, we studied the function and mechanism of the CTGF in the differentiation of chicken preadipocytes. Functionally, the CTGF inhibited the differentiation of chicken preadipocytes. Mechanistically, the CTGF mediated the TGFβ1/Smad3 signaling pathway, thereby inhibiting the differentiation of chicken preadipocytes. In addition, we used the unique molecular identifier (UMI) RNA-Seq technology to detect genes that can be regulated by the CTGF in the whole genome. Through transcriptome data analysis, we selected actin gamma 2 (ACTG2) as a candidate gene. Regarding the function of the ACTG2 gene, we found that it inhibited the differentiation of chicken preadipocytes. Furthermore, we found that the CTGF can inhibit the differentiation of preadipocytes through the ACTG2 gene. In summary, this study found the CTGF as a new negative regulator of chicken preadipocyte differentiation. The results of this study help improve the understanding of the molecular genetic mechanism of chicken adipose tissue growth and development and also have reference significance for the study of human obesity.

Effect of the competitive exclusion culture on the growth, blood parameters, leg health, and innate immunity of broiler chickens

Abstract The primary aim of poultry production is to obtain a high yield and quality end product. To reduce the risk of disease, many direct-fed microbial products have been developed. That appears to be an excellent tool for disease prevention. We evaluated the influence of the commercial, competitive exclusion (CE) product, Broilact®, on the growth rate, hematology, serum biochemistry, and innate immunity in male ROSS-308 chickens, randomly divided into two groups (Broilact® treatment and control) raised for 42 days. The birds’ body weight was determined at 1, 7, 14, 28, 35, and 42 days, and the blood samples were collected at days 22 and 42 of life. We observed lower mortality, better gait score, and higher final body weight in the Broilact® group. At day 22, birds from the treated group presented higher white blood cells counts (WBC) and T cytotoxic lymphocyte (CD8+) counts, higher total protein (TP) (fraction globulin and albumin), and lower triglyceride (TAG) and Ca2+ plasma concentrations. No differences were found in acute phase proteins (APPs). At day 42, only the K+ and Na+ concentrations were higher, while the IL-10 was lower in treated birds’ blood serum. Our results indicate that treatment with one dose of the Broilact® product at day one of life has a beneficial influence, which improves the chickens’ performance, leg health and some serum enzymes activity, maintains electrolyte homeostasis, and influences leukocyte count with the rise of T CD8+ subpopulations.

Impact of long-term feeding a high level of Spirulina combined with enzymes on growth performance, carcass traits and meat quality in broiler chickens.

This study evaluates the effect of prolonged feeding with a high inclusion level of Spirulina, combined with peptidases, on broiler chicken's growth performance, digesta viscosity, carcass attributes and meat quality. The experiment involved 120 male broilers divided into 40 battery brooders, each housing 3 birds. Post 7-day acclimatisation with a corn and soybean-based diet, the birds were provided with one of four diets: a corn and soybean meal-based diet (CON), a mix incorporating 15% Spirulina (SP), a Spirulina-rich mix supplemented with 0.025% of commercial VemoZyme® P (SPV), or a Spirulina-rich mix supplemented with 0.10% of porcine pancreatin (SPP). The CON group had higher body weight and weight gain (p < 0.001) and a lower feed conversion ratio (p < 0.001) from day 7-21, compared to the Spirulina-fed groups. Spirulina-fed chickens significantly increased ileum viscosity (p < 0.05). Spirulina also elevated the weight (p < 0.05) of the duodenum and the length (p < 0.001) of the entire gastrointestinal tract compared to CON. Breast and thigh muscles from Spirulina-fed broilers displayed higher values of yellowness (b*) (p < 0.001), pigments (p < 0.05), and n-3 PUFA (p < 0.01), while n-6/n-3 ratio (p < 0.001) and α-tocopherol (p < 0.001) decreased relative to the CON. In conclusion, the introduction of a high level of Spirulina into broiler diets for an extended duration, has the potential to diminish birds' growth performance, possibly due to increased digesta viscosity. However, it does enhance the nutritional quality of the meat.

APPLICATION OF CRISPR TO INCREASE MEAT YIELD IN CHICKEN

Meat production is one of the major purposes of the poultry industry. Meat is full of protein and accomplishes the protein requirement of the diet. This study was carried out to attempt to use CRISPR-mediated genome editing of chicken to increase meat yield. For this purpose, CRISPR was used to edit the gene sequence and then it was allowed to infect the PGC’s (Primordial germ cells). The successfully edited PGC’s having blocked exon 3 of MSTN gene were then injected into the blood bloodstream of 2.6 days of fertilized egg cells. The eggs were incubated up to hatch. The wild type was taken as control and the Mutated ones as T1. The CRD was used with three replications to find the significance of variation in To and T1. The weight of chicks for T0 (wild type) and T1 (Mutated) was significantly different. The average weight of three replications of each treatment was compared through a bar graph. it was found that the CRISPR-mediated edited chicks were more weighted than that of their wild types. The CRISP-mediated inhibition of MSTN has a significant effect on muscle growth in chickens. The more such genes may be targeted to get more meat yield.

It is good to be average: Ecological correlates of breeding phenology in an Arctic seabird, Alle alle (Dovekie)

Abstract Recognizing the deviation in an animal’s behavior from a population mean is not only necessary to understand the evolution and stability of the whole system but also to predict the future of a population in a changing environment. Arctic seabirds are expected to exhibit high synchronization in timing of breeding at the population level, due to highly seasonal and harsh environmental conditions. Nevertheless, even in such a highly synchronized system, there are always some earlier and later breeders, and the drivers of inter-pair variation remain largely unknown. Using an 8-year dataset on Alle alle (Dovekie), a small Arctic seabird, we examined potential drivers of breeding phenology. We found that A. alle pairs were quite repeatable in their phenology, and preserved their phenological status, with their chicks hatching consistently before, during, or after the population median date for hatching, despite that the calendar position of the median shifted between years. This would suggest that timing of breeding is associated with some pair characteristics, either via properties of the nest and/or some partner’s traits. However, breeding phenology of the pair was not dependent on nest location, pair bond duration or morphological similarity of the partners. Importantly, timing of breeding was negatively associated with chick growth rate, indicating fitness consequences of phenology. A simulation in our study further suggests that the chance of fledgling survival in the context of predation may be the highest for the chicks that hatched during the peak of the hatching period. While our results suggest that the timing of the breeding is important for the reproductive outcome, further research is required to determine the drivers of the consistent breeding phenology within A. alle pairs.

Comparative analysis of the growth differences between hybrid Ningdu Yellow chickens and their parentals

Although the local high quality chicken breed in China has excellent flavor, its growth rate is inferior to that of foreign breeds. To improve the growth rate of local chicken breeds, it is crucial to study the mechanism of chicken muscle development. Herein, Ningdu Yellow chicken was used as the research object, and a new hybrid breed (W) was obtained by crossing the G, H and D lines, which combined the excellent physiological characteristics of its parents. Combined analysis of Ningdu Yellow chickens and their parents was carried out. Chickens from 105-day-old lines (W, G, H) were selected, and breast meat and serum were extracted for transcriptome sequencing and metabolome determination to study their growth differences. The live weight, carcass weight, half-eviscerated weight, eviscerated weight, and breast muscle weight of W were significantly higher than those of G and H. Differential expression analysis identified 1700 differentially expressed genes (DEG), and gene ontology and kyoto encyclopedia of genes and genomes (KEGG) analyses identified 33 and 1 pathways related to growth and development and steroid biosynthesis, respectively. Next, pairwise analysis identified 57 KEGG pathways, among which the MAPK signaling, steroid hormone biosynthesis, tight junction, and PPAR signaling pathways were involved in growth and development. Cluster analysis found that genes highly expressed in the W group were associated with regulation of the actin cytoskeleton, riboflavin metabolism, steroid biosynthesis, and glycerophospholipid metabolism. The top 2 clusters obtained by protein-protein interaction analysis were important for the growth and development of chickens. Finally, the metabolomic analysis found key differentially accumulated metabolites (DAM) that might be account for the growth differences. Further integrated analysis identified key DEGs and DAMs that might be responsible for the observed growth differences. This study identified genes governing growth traits in Ningdu Yellow chickens, laying a theoretical foundation for the development of chicken breeding, the utilization of hybrid supporting lines, and promotion of the Chinese chicken industry.

The Assessment of Mixing Solid Waste from Palm Kernel Cake and Indigofera Zollingeriana as Chicken Feed towards the Free-Range Chicken Growth Rate

The Assessment of Mixing Solid Waste from Palm Kernel Cake and Indigofera Zollingeriana as Chicken Feed towards the Free-Range Chicken Growth Rate

Effects of Moringa oleifera Leaf Powder on the Growth Performance, Meat Quality, Blood Parameters, and Cecal Bacteria of Broilers.

The effect of dietary inclusion of Moringa oleifera leaf powder (MLP) on the growth, meat quality, carcass characteristics, hematobiochemical profile, and cecal bacteria of broiler chicken was investigated in this research trial. In this study, 192-day-old Arbor Acre broiler chicks were assigned in a completely randomized design to three groups: control, antibiotic, and MLP. A standard basal diet was given to the control group, while the antibiotic group received 75 mg/kg chlortetracycline, and the MLP group received 100 mg/kg M. oleifera leaf powder supplemented basal diet. Each group was further divided into eight replicates consisting of eight birds each, and the trial ran for 35 days. Among the groups, the MLP-fed broilers achieved the highest final body weight (FBW), average daily gain (ADG), and average daily feed intake (ADFI). Notably, the FCR for the whole experimental period was lower in the MLP group, indicating a more efficient use of feed for growth. Supplementation of MLP with basal diet significantly increased (p < 0.05) the weight of thighs and drumsticks relative to live weight %, while the spleen and abdominal fat weight (% of live weight) were significantly decreased (p < 0.05). Adding MLP to the diet improved the meat quality of broilers, as indicated by the highest pH of meat at 45 min and the lowest cooking loss (%) observed in this group. MLP exhibited hypocholesterolemic and hypolipidemic effects, with the lowest total cholesterol and triglyceride levels compared to non-supplemented groups. The hematological profile revealed that the MLP group exhibited the highest RBC count and Hb level, while also showing the lowest H/L ratio. Moringa supplementation significantly (p < 0.05) modulated the cecal bacterial population, reducing pathogenic E. coli and Shigella spp. while increasing beneficial Lactobacillus spp. and the total aerobic plate count (TAPC). In conclusion, Moringa oleifera leaf powder (MLP) can be used as a natural feed supplement for promoting the growth, meat quality, healthy blood, and sound health of broilers.