British Poultry Science

Article	Citations
Impact of extended lairage periods on physio-metabolic status and meat quality in commercial broilers	41
Combined effects of encapsulated raspberry powder and phosphate on the lipid oxidation, microbiological properties and shelf life of modified atmosphere packaged chicken nuggets during chilled storage	28
Genome-wide DNA methylation and transcriptome analyses reveal important epigenetic genes associated with valgus-varus deformity in broilers	18
Genome-wide association analysis of neck ring traits in NongHua ma male ducks	16
Effects of overfeeding on liver lipid metabolism in mule ducks based on transcriptomics and metabolomics	14
Photohydroionisation for disinfection of poultry litter	13
Stimbiotic and wheat bran inclusion in maize or wheat-based diets for broiler chickens; effects on jejunal histomorphology, digesta oligosaccharides and caecal short-chain fatty-acids profiles	12
Supplemental phosphorus can be completely replaced with microbial phytase in White Leghorn layer diets	12
Digestibility and nutritional parameters of maize ethanol coproducts and xylanase for broiler diets	12
Characterization of circRNA expression profiles associated with non-Mendelian inheritance in feather growth of chickens	11
Use of wheat dilution to improve digestive function in broilers: application in low protein diets	10
Inhibition ofSalmonalla entericaby a novel strain ofBacillus subtilisisolated from the faeces of healthy chickens	10
Bone characteristics, pre-caecal phytate degradation, mineral digestibility and tissue expression were marginally affected by zinc level and source in phytase-supplemented diets in 21-day-old broiler	10
miR-199-3p suppresses cellular migration and viability and promotes progesterone production in goose ovarian follicles before selection through regulating ITGB8 and other ECM-related genes	9
Adenovirus type D and type E infection in broiler chickens: the effect on CD4 and CD8 T cell response, cytokines expression and their immunopathology	9
Metagenomic reconstructions of caecal microbiome in Landes, Roman and Zhedong White geese	9
Biofilm formation, antibiotic resistance and genotyping of Shiga toxin-producing Escherichia coli isolated from retail chicken meats	9
Marination with aronia, grape and hawthorn vinegars affects the technological, textural, microstructural and sensory properties of spent chicken meat	9
Fibre-based feed supplements – fermentation and moisture characteristics, edibility and particle size influence cage-reared laying hens’ preference based on feed consumption and time at the feeder	9
Evaluation of the potential growth and body composition of the Cobb 700 genotype	9
Chicken liver morphology as affected by feed withdrawal time and dietary aflatoxins	9
Dynamic transcriptome profiling reveals essential roles of the receptor tyrosine kinases (RTK) family in feather development of duck	9
miR-181a-5p can inhibit the proliferation and promote the differentiation of chicken primary myoblasts	8
Two novel InDels within the promoter of SIRT1 are associated with growth traits in chickens	8
Effects of dietary calcium and microbial phytase on the bioavailability of two sources of zinc in broilers	8

Developmental potential of cryopreserved gonadal germ cells from 7-day-old chick embryos recovered using the PBS(-) method	8
Effect of goose-derived adiponectin peptide gADP3 on LPS-induced inflammatory injury in goose liver	7
Phenotypic and molecular characterisation of Salmonella spp. isolates in healthy poultry	7
Egg laying performance and egg quality with Paracoccus carotinifaciens supplementation containing high astaxanthin levels	7
Food safety control in poultry industry: prevalence and antimicrobial susceptibility of Escherichia coli isolated from raw chicken and the potential use of <	7
Catalase, superoxide dismutase and butylated hydroxytoluene benefit mid-term storage of red-legged partridge sperm ( Alectoris rufa )	7
Effects of calcium pidolate on performance, carcass traits, bone biomechanical properties and mineralisation and jejunum histomorphology in broilers	7
An approach for goose egg recognition for robot picking based on deep learning	7
Temporal variation characteristics of microbial aerosols in the goose house environment	7
Comprehensive analysis of changes in expression of lncRNA, microRNA and mRNA in liver tissues of chickens with high or low abdominal fat deposition	7
Transcriptome profiling reveals morphogenesis-related candidate genes and pathways in the chick embryonic small intestine	7
RETRACTED ARTICLE: Effects of emulsifier, betaine and l-carnitine on growth performance, immune response, gut morphology and nutrient digestibility in broiler chickens exposed to cyclic hea	7
The potential post-hatching growth of domestic birds is sufficiently described by the Gompertz function	7
Controlling microbial population in poultry industry using acidic and slightly acidic electrolysed water as a potential non-thermal food sanitizer	6
Genetic parameter estimation for traits related to the immune system against sheep red blood cells in Japanese quail	6
Gga-let-7a-3p inhibits the proliferation and differentiation of chicken intramuscular preadipocytes	6
Dietary cholecalciferol and 25-hydroxycholecalciferol supplementation interact to modulate reproductive performance, egg quality, serum antioxidant capacity, intestinal morphology and tibia quality of	6
Evaluating the genetic components of growth in ostriches with multi-trait and random regression models	6
FEDM: a convolutional neural network based fertilised egg detection model	6
Efficacy of maize differing in particle size in low-density protein diets fed to broilers from day 1 to 21 of age	6
Performance of broiler chicken on dietary supplementation of protected organic acids blend	6
N-acetyl-L-cysteine improves the performance of chronic cyclic heat-stressed finisher broilers but has no effect on tissue glutathione levels	6
Avian sperm-borne RNAs: optimisation of a new isolation protocol	6
De-oiled soy lecithin positively influenced growth performance, nutrient digestibility, histological intestinal alteration, and antioxidant status in turkeys fed with low energy diets	6
Biomarker discovery and authentication of cold-slaughtered chicken through classical analytical procedures and mass spectrometry based proteomic approaches	6
The effect of fermented rapeseed meal on production performance, egg quality and hatchability in broiler breeders after peak production	5
Lack of reproducibility compromises conclusions on the effects of three Bacillus species on Salmonella enterica Enteritidis colonisation i	5
Influence of particle size and inclusion level of oat hulls on retention and passage in the anterior digestive tract of broilers	5
Propolis extract reduces heterocyclic aromatic amine formation in chicken thigh meat	5
Transcriptome profiling of morphogenetic differences between contour and flight feathers in duck	5
Pigment concentrations in eggshell and their related gene expressions in uterus of Changshun blue eggshell chickens	5
Genome-wide methylation and transcriptome differential analysis of skeletal muscle in broilers with valgus-varus deformity	5
Investigation on adaptations of broiler chickens to high dietary free amino acid levels in nitrogen utilisation and plasma amino acid concentrations	5
Statement of Retraction: Effects of emulsifier, betaine and L-carnitine on growth performance, immune response, gut morphology and nutrient digestibility in broiler chickens exposed to cyclic heat str	5
Genetic parameter estimation and genetic evaluation of important economic traits in white and yellow broilers	5
Air-classified faba bean protein fraction as a substitute to soybean meal in pelleted and extruded broiler diets	5
Investigation of a potential electrogenic transport-system for myo-inositol in the small intestine of laying hens	5
Feed emulsifier improves the performance and nutrient digestibility in broiler chicken fed diets without antibiotic growth promoter	5
Dietary high-protein distiller’s dried grains with solubles can fully replace soybean meal in diets for meat quails without affecting growth performance	5
Assessment of crop usage in ad libitum fed birds and short-term phytase efficiency as affected by acid addition	5
Expression of genes related to ileal barrier function in heritage and modern broiler chickens	5
Effect of 25-hydroxycholecalciferol supplementation with different dietary available phosphorus levels for broilers	5
Cloning, characterisation and expression of the SERPINB14 gene, and association of promoter polymorphisms with egg quality traits in layer chicken	5
The apparent metabolisable energy and ileal amino digestibility of black soldier fly ( Hermetia illucens ) pre-pupae meal for broiler chickens	5
Comparative analysis of the morphology, chemistry and structure of the tibiotarsus, humerus and keel bones in laying hens	5
A comparison of immersion-based and spray-based crate washing systems on the impact of Campylobacter spp. reduction	4
Alpha-tocopherol acetate and alpha lipoic acid may mitigate the development of wooden breast myopathy in broilers at an early age	4
Integument, mortality, and skeletal strength in extended production cycles for laying hens – effects of genotype and dietary zinc source	4
Association between antimicrobial resistance and biofilm forming ability of Salmonella enterica serotypes from commercial broiler farms in Brazil	4
Factors affecting cryopreservation-associated damages in sperm motility of cockerels (Gallus gallus domesticus)	4

Dynamic changes in protein concentrations of keratins in crop milk and related gene expression in pigeon crops during different incubation and chick rearing stages	4
The fatty acid profile in the yolk and yolk sac from incubated goose eggs depends on the breeder age and laying period	4
The response of turkeys to dietary balanced protein during two periods of growth	4
Epidermal growth factor receptors and their ligands are expressed in the spleen of the Japanese Quail (Coturnix coturnix japonica) during the post-hatch period	4
How are they really doing? Animal welfare on organic laying hen farms in terms of health and behaviour	4
Oxidative stress mediated immunosuppression caused by ammonia gas via antioxidant/oxidant imbalance in broilers	4
Tissue oxidative stress and expression of chicken UCP and ANT mRNA in laying hens exposed to acute cold stress	4
Integrated analysis of mRNA and microRNA expression pattern reveals differential transcriptome signatures in RIPK2 over-expressing chicken	4
Identification of key candidate genes for wing length-related traits by whole-genome resequencing in 772 geese	4
Effects of testis testosterone deficiency on gene expression in the adrenal gland and skeletal muscle of ducks	4
Investigating possible impact, and interaction, of phytase supplementation during pre-experimental and experimental phases on assay of true phosphorus pre-caecal digestibility and total tract retentio	4
miR-30a-3p can inhibit the proliferation and promote the differentiation of chicken primary myoblasts	4
Single and multiple oral amoxicillin treatment in geese: a pharmacokinetic evaluation	4
The relationship of MITF gene expression and promoter methylation with plumage colour in quail	4
Construction of miRNA-mRNA network in the differentiation of chicken preadipocytes	4
Genome-wide association study for reproduction-related traits in Chinese domestic goose	4
PHGDH promotes the proliferation and differentiation of primary chicken myoblasts	4
Editorial	4
Practices and issues of moulting programs for laying hens: a review	4
Non-invasive classification of single and double-yolk eggs using Vis-NIR spectroscopy and multivariate analysis	3
Effect of temperature manipulation during incubation on body weight, plasma parameters, muscle histology, and expression of myogenic genes in breast muscle of embryos and broiler chickens from two com	3
Antiviral effect of palmatine against infectious bronchitis virus through regulation of NF-κB/IRF7/JAK-STAT signalling pathway and apoptosis	3
Effect of increasing dose level of a novel consensus bacterial 6-phytase variant on phytate degradation in broilers fed diets containing varied phytate levels	3
Potential of accelerometer tags for monitoring of Japanese quail ( Coturnix japonica ) reproductive behaviour	3
Growth performance, real-time gizzard pH and calcium solubility in the gut of broiler chickens is dependent on the interaction between dietary calcium concentration and limestone particle size	3
Birchen and Blue Leonesa sperm cryopreservation: a new technique for evaluating the integrity of cockerel sperm membranes	3
Tolerability of graded levels of tall oil fatty acids as a nutritional additive for broiler chickens: a 45-day target animal safety study	3
Prediction of raw meat texture and myopathic severity of broiler breast meat with the wooden breast condition by hyperspectral imaging	3
New primers for sex identification in the Chukar partridges ( Alectoris chukar )	3
Nutritional and technological potential of chicken feathers for the food industry	3
Transcriptome analysis of the bursa of Fabricius and thymus of laying ducks reveals immune gene expression changes underlying the impacts of stocking densities	3
Identification of potential candidate genes for the Huoyan trait in developing Wulong goose embryos by transcriptomic analysis	3
Holo-analysis of the effects of xylo-oligosaccharides on broiler chicken performance	3
Development of an in vivo radiographic method with potential for use in improving bone quality and the welfare of laying hens through genetic selection	3
Insights of dietary electrolyte balance in broilers raised under natural heat stress conditions	3
Screening and bioinformatics analysis of cellular proteins interacting with chicken bromodomain-containing protein 2 in DF-1 cells	3
Mass spectrometry-based metabolic profiling for identification of biomarkers related to footpad dermatitis in ducks	3
Establishing the tolerability to broiler chickens and laying hens of nonanoic acid at practical levels of use as a feed flavouring	3
Examining the relationship between different naturally-occurring maxillary beak shapes and their ability to cause damage in commercial laying hens	3
Short- and long-term sex-dependent effects of a nutritional supplement after hatching on growth, metabolism and gut microbiota in broiler chickens	3
PLGA nanoparticle with Amomum longiligulare polysaccharide 1 increased the immunogenicity of infectious bursal disease virus VP2 protein	3
Phytate degradation and phosphorus utilisation by broiler chickens fed diets containing wheat with increased phytase activity	3
Low dietary phosphorus impairs keel bone health and quality in laying hens	2
Ante-mortem glutathione peroxidase 4 inhibition by RSL3 affects post-mortem meat quality in broiler chickens	2
Dietary soluble non-starch polysaccharide level and composition influences grower and finisher phase performance, excreta moisture content and total tract nutrient digestibility in broilers	2
Properties of encapsulated raspberry powder and its efficacy for improving the pH, colour quality and shelf life of modified atmosphere packaged chicken nuggets	2
Effects of different stocking densities on the development of reproductive and immune functions in young breeder pigeons during the rearing period	2
Expression of genes associated with nutrient uptake in intestines of chickens with different growth potentials show temporal changes but are not correlated with growth	2
Cereal type and conditioning temperature altered protein and carbohydrate molecular structure, nutrient retention and performance in broilers fed pellet diets during starter and grower period	2
Effects of coated sodium butyrate on growth performance, intestinal morphology, and caecal short-chain fatty acids of growing Pekin ducks	2
Effects of graded levels of dietary microbial 6-phytase on performance, intestinal histomorphology, caecal microbial population and short-chain fatty acid composition of Lohmann white-classics	2
Supplementation of Beltsville extender with quercetin improves the quality of frozen-thawed rooster semen	2
In vivo estimation of chicken breast and thigh muscle weights using multi-atlas-based elastic registration on computed tomography images	2
miRNA-mRNA associations with inosine monophosphate specific deposition in the muscle of Jingyuan chicken	2
Morin protects chicks with T-2 toxin poisoning by decreasing heterophil extracellular traps, oxidative stress and inflammatory response	2
Polymorphism in the 5ʹ regulatory region of CTNNB1 gene and association with age at first lay and egg production	2
Identification and functional analysis of circRIPK2 in lipopolysaccharide induced chicken macrophages	2
Characteristics of antioxidant substances and identification of antioxidant peptides in duck embryo eggs	2
Refining the metabolisable energy value of field beans for turkeys	2
Temperature manipulation during incubation: effect on embryo development and incidence of white striping and expression of related genes in broiler chickens from two commercial breeds	2
Influence of different dietary fibre contents in the diet on feather pecking, locomotor activity and performance of laying hens	2
Relationships between models and data in growing poultry	2
Energy cost of physical activities in growing broilers	2
Expression of FOXO3 in the skin follicles of goose embryos during embryonic development	2
Effects of access to feed, water, and a competitive exclusion product in the hatcher on some immune traits and gut development in broiler chickens	2
Effects of oleanolic acid on acute liver injury triggered by lipopolysaccharide in broiler chickens	2
Pharmacokinetics of tolfenamic acid in ducks ( Anas platyrhynchos domestica ) after different administration routes	2
Sunflower and rapeseed meal as alternative feed materials to soybean meal for sustainable egg production, using aged laying hens	2
Avian pathogenic Escherichia coli alters complement gene expression in chicken erythrocytes	2
Novel sfericase protease improves amino acid digestibility of soybean meal and rapeseed meal in broiler chickens	2
Effects of embryo injected with ochratoxin A on growth performance, jejunal morphology and barrier of ducklings	2
Effect of dietary supplementation with algae extracts on growth performance and caecal microbiota of broiler chickens	2
Are slow-growing broiler chickens actually better for animal welfare? Shining light on a poultry welfare concern using a farm-scale economic model	2
Effect of grinding method and extent of pelleting of broiler diets on performance, feeding behaviour and digestive tract functionality	2
Factors associated with keel bone damage – a longitudinal study of commercial layer flocks during the laying period	2
Effect of limestone particle size and microbial phytase on phosphorus and calcium digestion kinetics along the gastrointestinal tract in laying hens	2
Effects of monensin sodium and live attenuated oocyst vaccine as coccidiosis management programs on productive performance, bone quality and mineral utilisation in broiler chickens	2
The ameliorative effects of Nigella sativa, thymoquinone, and bentonite against aflatoxicosis in broilers via AFAR and Nrf2 signalling pathways, and down-regulation of caspase-3	2
Novel circular RNA Sestrin 1 promotes chicken myoblast proliferation and differentiation via circSesn1/miR-16-5p/SESN1 pathway	2
Easier said than done! Organic farmers consider free-ranging important for laying hen welfare but outdoor areas need more shelter – important gaps between research and practice	2

Contamination of chicken carcasses and the abattoir environment withListeria monocytogenesin Taiwan	2
CircSUCO promotes proliferation and differentiation of chicken skeletal muscle satellite cells via sponging miR-15	2
Application of principal component analysis with instrumental analysis and sensory evaluation for assessment of chicken breast meat juiciness	2
Effect of dietary supplementation of organic and inorganic Se on performance and antioxidant response in commercial broiler chickens	2
Increasing digesta viscosity altered nutrient transporter gene expression and decreased nutrient utilisation in Eimeria -challenged birds	2
Exploring the expression and preliminary function of chicken regulator of G protein signalling 3 (RGS3) gene in follicular development	2
Crossbreeding impacts on caecal bacterial count and antibody titres in chickens	2
Effects of diet density and feeding frequency during the rearing period on broiler breeder performance	2
Feed form and perch design do not interact to production performance, gastrointestinal tract traits, behaviour and welfare of laying hens reared in enriched cages	1
Growth, not digestibility, in chickens receiving reduced-protein diets is independent of non-specific amino-nitrogen sources when the essential-to-total-nitrogen ratio is constant and lower than 50%	1
Influence of in-ovo vitamin E and ascorbic acid injections on chick development, hatching performance and antioxidant content in different tissues of newly-hatched quail chicks	1
Effects of betaine supplementation on reproductive performance of breeding geese	1
Succession of the microbial communities and metabolic functions in composting or deep burial processing of dead chickens	1
Dietary energy:protein ratio influences the efficiency of utilisation of dietary protein by growing turkeys	1
The effect of delayed feeding post-hatch on caeca development in broiler chickens	1
Age-related changes in carcass composition, physicochemical properties, texture and microstructure of meat from White King pigeons	1
Runs of homozygosity analysis reveals population characteristics of yellow-feathered chickens using re-sequencing data	1
High frequency of non-susceptibility to ciprofloxacin in nontyphoid Salmonella recovered from Brazilian broiler chicken	1
Carcase characteristics, meat quality, nutrient composition, serum biochemistry and oxidant/antioxidant status in white striping-affected broiler chickens fed diets based on maize-soybean meal	1
Disturbance of mitochondrial dynamics in myocardium of broilers with pulmonary hypertension syndrome	1
miR-7 regulates the apoptosis of chicken primary myoblasts through theKLF4gene	1
Response to letter to the editors by Behnam Saremi referring to the article ‘Feeding guanidinoacetic acid to broiler chickens can compensate for low dietary metabolizable energy formulation’ by Pirgoz	1
Statement of Removal	1
Transcriptomic analysis of long non-coding RNA and mRNA in pigeon squab pectoralis muscle development	1
Effects of the early incubation temperature on the muscle physiology, meat quality, bone strength and gait score in Ross broilers	1
Effect of the physicochemical properties of zinc oxide sources on their bioavailability in broilers	1
Effect of blue and red monochromatic light during incubation on the early post-embryonic development of immune responses in broiler chicken	1
The Gordon Memorial Lecture: genotype, phenotype, selection and more: improving the skeletal health of laying hens	1
Phenotypic correlations between feed efficiency, growth, and meat quality of slow-growing chickens	1
Effect of moderate intensity pulsed electric field on shelf-life of chicken breast meat	1
Impact of the arginine silicate inositol complex on bone metabolism in broiler chickens with tibial dyschondroplasia caused by manganese deficiency	1
Effects of dietary calcium and phosphorus restrictions on growth performance, intestinal morphology, nutrient retention, and tibia characteristics in broiler chickens	1
The oxidation status of three types of duck meat (conventional, organic, wild) during refrigerated storage under air and vacuum-packaged atmospheres	1
Transcriptional regulation of the chicken ASMT gene – a preliminary analysis	1
Effects of faecal microbiota transplantation supplemented with inulin on early immunity and immune organ histomorphology in chickens	1
Feeding dihydroquercetin in wheat-based diets to laying hens: impact on egg production and quality of fresh and stored eggs	1
The effects of outdoor access and stocking density on the performance of broilers reared under tropical conditions	1
A meta-analysis of the sources of variation in the environmental impacts of different broiler production systems	1
MDA5 attenuate autophagy in chicken embryo fibroblasts infected with IBDV	1
Composition of feathers and pulp of two broiler genotypes	1
Effects of emulsifier, betaine, and L-carnitine on growth performance, immune response, gut morphology, and nutrient digestibility in broiler chickens exposed to cyclic heat stress	1
A novel 27-bp indel in the intron region of the YBX3 gene is associated with growth traits in chickens	1
Is oviposition time and oviposition interval associated with the deposition of cuticle on the hen’s egg?	1
Influence of LED light spectra and photoperiods on performance, bone characteristics and related genes expression in broiler breeders	1
Dietary stinging nettle ( Urtica dioica ) improves carotenoids content in laying hen egg yolk	1
Clonal diversity and zoonotic potential of MDR Escherichia coli isolated from poultry at different age intervals	1
Effect of chelated source of additional zinc and selenium on performance, yolk fatty acid composition, and oxidative stability in laying hens fed with oxidised oil	1
Comparison of the apparent ileal calcium digestibility of limestone in broilers and layers	1
Detection and differentiation of Salmonella Enteritidis and Salmonella Typhimurium by multiplex quantitative PCR from different poultry matrices	1
Thyroid hormone-responsive protein mediates the response of chicken liver to fasting mainly through the cytokine-cytokine receptor interaction pathway	1
Feed withdrawal influences egg production, egg quality and antioxidant variables in White Leghorn layers reared during the tropical summer season	1
Effects of fully or partially slatted flooring designs on the performance, welfare and carcass characteristics of broiler chickens	1
Infectious bronchitis virus infection in chicken: viral load and immune responses in Harderian gland, choanal cleft and turbinate tissues compared to trachea	1
Transcriptome analysis of oviduct in laying ducks under different stocking densities	1
Development of real time reverse transcription loop-mediated isothermal amplification assay for rapid detection of genotype VII of Newcastle disease viruses	1
Whole genome analysis of Salmonella Gallinarum strains isolated from a fowl typhoid outbreak in southern Brazil	1
Effects of intermittent lighting program and light colour on ocular health variables as welfare indicators in broiler chickens	1
Effects of high-level ghrelin on intestinal epithelial cell proliferation, nutrient transport and intestinal mucosal immune barrier in chickens	1
Analysis of growth performance and carcass and meat quality of different crossbreeds of Cherry Valley duck	1
Dietary supplementation of Solanum aethiopicum and Solanecio biafrae leaves alters stress and immune responses, antioxidant status, and meat quality in broilers raised in a hot-dry envir	1
Association of keel bone morphometry with keel bone damage and skeletal quality in the laying hen	1
A new method for molecular sex identification in the emu ( Dromaius novaehollandiae )	1
Effects of different feeding strategies on egg production, eggshell quality, tibial mass and intestinal calcium transporter expression in laying hens	1
Transcriptome analysis of long non-coding RNA associated with embryonic muscle development in chickens	1
A 2-bp deletion in intron 1 of TMEM182 is associated with TMEM182 mRNA expression and chicken body weight	1
Comprehensive estimation of overfeeding influence on goose meat quality	1
Black soldier fly larvae meal and fat as a replacement for soybeans in organic broiler diets: effects on performance, body N retention, carcase and meat quality	1
Expression of chicken epidermal growth factor (cEGF) in Escherichia coli regulates the microflora structure of the duodenum to improve growth performance and intestinal	1
High-throughput sequencing reveals crucial miRNAs in skeletal muscle development of Bian chicken	1
A novel Lactobacillus bulgaricus isolate can maintain the intestinal health, improve the growth performance and reduce the colonization of E. coli O157:H7 in broilers	1
The potential effect of microbiota in predicting the freshness of chilled chicken	1
Comparative transcriptomic analysis reveals candidate genes for seasonal breeding in the male Lion-Head goose	1
Effects of protease supplementation and diet type on jejunal and ileal digestibility and total tract metabolisability of nitrogen, starch, and energy in broilers	1