British Poultry Science最新文献

{"title":"Temporal variation characteristics of microbial aerosols in the goose house environment.","authors":"Z Chen, C Lou, W Zheng, B Wu","doi":"10.1080/00071668.2024.2360621","DOIUrl":"10.1080/00071668.2024.2360621","url":null,"abstract":"<p><p>1. Preventing disease is important in poultry production systems, but this has mainly been studied in chickens. The aim of this study is to explore the impact of microbial aerosols in intensive goose house environments.2. To evaluate the environmental quality of geese housing, fine particulate matter (PM2.5) was collected using an ambient air particulate matter sampler. High-throughput sequencing was used to analyse bacterial diversity and relative abundance. Results showed that the number of general and operational taxonomic units (OTUs) were 1,578 and 19 112 in all PM2.5 samples. <i>Firmicutes</i>, <i>Bacteroidota</i>, <i>Proteobacteria</i>, <i>Acidobacterota</i> were the four most abundant phyla in PM2.5.3. Compared with bacterial phyla in the PM2.5 from chicken houses, those in the genus <i>Acidobacterota</i> were increased in goose housing. There are various genera of bacteria present in PM2.5, and their composition was similar across different samples. No significant change was observed in the diversity of microbiota in the PM2.5, although multiple pathogenic bacteria were detected.4. A prediction function showed that a variety of bacterial phyla correlated positively with the human diseases.5. In summary, the microbial aerosols in the goose shed pose significant risks to the health of the geese. Regular monitoring of the composition of microbial aerosols is important for the healthy growth of geese and disease prevention and control.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"538-545"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141589712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"FEDM: a convolutional neural network based fertilised egg detection model.","authors":"Z Gong, M Wang, J Song","doi":"10.1080/00071668.2024.2356656","DOIUrl":"10.1080/00071668.2024.2356656","url":null,"abstract":"<p><p>1. The production of goose eggs holds significant economic value on a global scale and the quality of fertilised eggs is crucial for the successful hatching and sustained development of the poultry industry. Developing a low-cost fertilised egg identification system that is suitable for large-scale testing is of great significance. However, existing methods are expensive and have high environmental detection requirements, which limit their promotion.2. To address this issue, an improved object detection model called FEDM based on YOLOv5 is proposed, which has been shown to be outstanding among nine models. The main network of YOLOv5 is enhanced with the SENet attention mechanism to improve the feature selection capability. The C3_DCNv3 is introduced to enhance the detection ability of blood vessels in the fertilised eggs. The application of Dyhead significantly improved the representation capacity of the object detection head without any computational overhead. The loss function is replaced with MPDIoU to simplify the calculation process.3. Experimental results from the augmented dataset showed that the average precision of the FEDM reached 96.7%, which is a 5.5% improvement compared to the YOLOv5s model. FEDM exhibited better detection performance on eggs from different shooting angles than the YOLOv5 algorithm and achieves high detection speed.4. The FEDM secured significant advancement on the detection rate of the fourth day fertilised egg compared to the YOLOv5 algorithm. Based on this result, savings and space utilisation can be made, which has practical application value.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"546-558"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141198628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of maize differing in particle size in low-density protein diets fed to broilers from day 1 to 21 of age.","authors":"M Naeem, E J Burton, D V Scholey, A Alkhtib, S Broadberry","doi":"10.1080/00071668.2024.2356655","DOIUrl":"10.1080/00071668.2024.2356655","url":null,"abstract":"<p><p>1. This study evaluated the efficacy of maize differing in particle size in low-density protein diets on performance, the digestive tract and litter characteristics in broilers. Four dietary treatments; control commercial diet with a typical crude protein content 22.50% (CON); CON + 20% maize with particle size 350 µm (M350), crude protein 19.90%; CON + 20% maize with particle size 2600 µm (M2600), crude protein 19.90%; CON + 20% whole maize (WM), crude protein 19.90%, were fed <i>ad libitum</i> to broiler chicks up to 21 d of age.2. No differences in body weight gain, feed intake and FCR were found between the WM and CON. WM increased body weight gain compared to M350 and M2600. M350, M2600 and WM increased (<i>p</i> = 0.004) gizzard relative weight compared with CON on day 14. Both WM and M2600 reduced (<i>p</i> = 0.001) gastric isthmus diameter on d 14 and 21 compared with CON and M350.3. No differences were seen in mucosa for the <i>Lamina propria</i> and the extent of <i>Tunica muscularis</i> of gizzard on d 21 and ileum mucosal depth on d 14 between WM and CON diets. However, WM reduced villus-to-crypt ratio compared with CON on d 21. The M350 reduced (<i>p</i> < 0.05) gizzard digesta particle size compared with CON, M2600 and WM on d 14.4. Both WM and M350 decreased (<i>p</i> < 0.05) nitrogen excretion compared to birds fed CON. Feeding WM increased nitrogen efficiency compared with M350 and M2600 diets, but was similar to birds fed CON. Feeding M350, M2600 or WM decreased (<i>p</i> < 0.05) litter moisture and footpad dermatitis (FPD) scores compared with results from birds fed CON.5. Overall, diluting the protein level in broiler diets with whole maize appeared better than fine or coarse maize in terms of growth performance, digestive tract development, nitrogen excretion and litter parameters. This may lead to economic benefits by reducing grinding costs and dependence on rich protein resources contributing to sustainable meat production and food security.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"615-624"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141086750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"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.","authors":"Y Cufadar, S Golzar Adabi, E T Gül, L Nollet","doi":"10.1080/00071668.2024.2352835","DOIUrl":"10.1080/00071668.2024.2352835","url":null,"abstract":"<p><p>1. This study was conducted to determine the effects of graded levels of phytase on the performance, egg quality and gut health of white laying hens.2. Treatments consisted of a negative control (NC) diet containing 0.14% available phosphorus (avP), positive control (PC) diet containing 0.35% avP provided via dicalcium phosphate (DCP) and DCP replaced in the PC by with three graded levels of phytase derived from <i>Komagataella phaffii</i> at 500 (PC-500), 750 (PC-750) and 1000 (PC-1000) FTU/kg which provided 0.176%, 0.188% and 0.200% of avP, respectively.3. Egg production, feed intake, feed conversion ratio and jejunal morphometry were negatively affected in NC-fed birds (<i>p</i> < 0.05). Considering the whole period, birds fed a diet supplemented with graded levels of phytase shared the same egg production and feed intake levels with PC birds (<i>p</i> < 0.05). Feed conversion ratio was significantly lowered by 4.9%, 1.6% and 7.6% in hens fed on diets PC-500, PC-750 and PC-1000, respectively compared to those fed the PC (<i>p</i> < 0.05).4. Neither of the dietary treatments affected cracked eggs, dirty eggs, eggshell breaking strength and eggshell thickness. Dietary supplementation of phytase significantly increased villus surface area by 15%, 36% and 40% in PC-500, PC-750 and PC-1000 birds, respectively compared to PC (<i>p</i> < 0.05).5. A significant increase in lactobacillus count was observed in line with increasing the level of phytase (<i>p</i> < 0.05). Dietary treatments had no effect on the caecal coliform or aerobic populations. Furthermore, phytase supplementation significantly increased the concentrations of total caecal short-chain fatty acid (SCFA; <i>p</i> < 0.01).6. In conclusion, along with improving performance parameters, the inclusion of phytase in laying hen diets can ameliorate intestinal morphology and stimulate caecal microflora and increase SCFA concentrations.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"595-604"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141589707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of manganese amino acid complexes on growth performance, meat quality, breast muscle and bone development in broilers.","authors":"L Li, M Ma, G Zuo, J Xiao, J Chen, X He, Z Song","doi":"10.1080/00071668.2024.2346640","DOIUrl":"10.1080/00071668.2024.2346640","url":null,"abstract":"<p><p>1. This study was conducted to investigate the effects of dietary supplementation of manganese (Mn) amino acid complexes on growth performance, Mn deposition, meat quality, breast muscle and bone development of broilers.2. A total of 504, one-day-old male Arbor Acres broilers were randomly divided into seven treatments; control diet (CON; basal diet, no extra Mn addition), manganese diet (MnN as Numine®-Mn; CON + 40, 80, 120 or 160 mg Mn/kg), manganese-S group (MnS; CON + 120 mg Mn/kg as MnSO4·H2O), manganese-A diet (MnA as Mn from hydrolysed feather meal; CON + 40 mg Mn/kg as MnA).3. There were no significant differences for average daily gain (ADG) or feed intake (ADFI) among diets during the feed phases (<i>p</i> > 0.05). The FCR in the starter and over the whole period were quadratically affected by dietary MnN dosage and gave the lowest FCR at 80 mg/kg (<i>p</i> < 0.05). The Mn content of thigh muscle, jejunum, heart, pancreas, liver and tibia increased linearly with MnN addition (<i>p</i> < 0.05).4. For meat quality, MnN significantly increased colour (a*), pH_45 min and pH_24 h, reduced shear force, drip loss and pressure loss of breast muscle (<i>p</i> < 0.05).5. Moreover, MnN significantly upregulated <i>MYOD</i> expression at d 21 and <i>SOD</i> expression at d 42, decreased <i>MuRF1</i> and <i>Atrogin-1</i> mRNA level at d 42 in breast muscle. Transcriptome analysis revealed that the regulating effect of MnN on muscle development significantly enriched signalling pathways such as adhesion, ECM-receptor, MAPK, mTOR and AMPK. Furthermore, dietary MnN significantly affected tibia length and growth plate development (<i>p</i> < 0.05) and promoted growth plate chondrocytes by increasing <i>SOX-9</i>, <i>Runx-2</i>, <i>Mef2c</i>, <i>TGF-β</i>, <i>Ihh</i>, <i>Bcl-2</i> and <i>Beclin1</i> and decreasing <i>Bax</i> and <i>Caspase-3</i> (<i>p</i> < 0.05) expression which affect longitudinal tibial development.6. In conclusion, Mn amino acid complexes could improve growth performance, tissue Mn deposition, breast muscle development, meat quality and bone development.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"582-594"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141589705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of embryo injected with ochratoxin A on growth performance, jejunal morphology and barrier of ducklings.","authors":"X Peng, J Liu, C Liu, X Jiang, Y Yang, S Zhai","doi":"10.1080/00071668.2024.2355638","DOIUrl":"10.1080/00071668.2024.2355638","url":null,"abstract":"<p><p>1. This trial investigated the effect on embryo injected with ochratoxin A (OTA) and the growth performance, jejunal morphology and barrier of ducklings to 21 d old.2. Two hundred forty, fertilised eggs were individually weighed and randomly assigned to two groups, a control (CON) and the OTA treatment, according to average egg weight. On d 13 of embryonic development, the treatment group was injected with 8 ng OTA/g egg and the CON group was injected with NaHCO₃ solution as a placebo. All newly hatched ducklings were assigned to the CON or OTA group based on the different treatments. Each treatment consisted of six replicates and each included 10 ducklings and the experiment lasted until 21 d of age.3. The results showed that embryos injected with OTA affected the 21 d body weight (BW) and average daily gain (ADG) of ducklings (<i>p</i> < 0.05). OTA exposure increased the relative weights of the liver, pancreas, gizzard, proventriculus and jejunum (<i>p</i> < 0.05); and decreased the relative length of the jejunum of ducklings (<i>p</i> < 0.05). Moreover, jejunal crypt depth increased (<i>p</i> < 0.05) and the villus height-to-crypt depth ratio (Vh/Cd) decreased in the OTA-injected group (<i>p</i> < 0.05). Compared with those in the CON group, the mRNA expression of <i>Zonula Occludens-1</i>; (<i>ZO-1</i>) (<i>p</i> = 0.0582) and <i>Occludin</i>; (<i>p</i> = 0.0687) in the OTA treatment group was downregulated.4. The findings demonstrated that a single low-dose injection of OTA increased body weight and daily gain in ducklings. Moreover, embryo exposure to OTA had negative effects with increased relative weight of organs and the jejunal crypt depth, decreased relative length of the intestine and mRNA expression of tight junctions (<i>ZO-1</i>, <i>Occludin</i>).</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"574-581"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141589706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interplay of poultry-microbiome interactions - influencing factors and microbes in poultry infections and metabolic disorders.","authors":"C E Aruwa, S Sabiu","doi":"10.1080/00071668.2024.2356666","DOIUrl":"10.1080/00071668.2024.2356666","url":null,"abstract":"<p><p>1. The poultry microbiome and its stability at every point in time, either free range or reared under different farming systems, is affected by several environmental and innate factors. The interaction of the poultry birds with their microbiome, as well as several inherent and extraneous factors contribute to the microbiome dynamics. A poor understanding of this could worsen poultry heath and result in disease/metabolic disorders.2. Many diseased states associated with poultry have been linked to dysbiosis state, where the microbiome experiences some perturbation. Dysbiosis itself is too often downplayed; however, it is considered a disease which could lead to more serious conditions in poultry. The management of interconnected factors by conventional and emerging technologies (sequencing, nanotechnology, robotics, 3D mini-guts) could prove to be indispensable in ensuring poultry health and welfare.3. Findings showed that high-throughput technological advancements enhanced scientific insights into emerging trends surrounding the poultry gut microbiome and ecosystem, the dysbiotic condition, and the dynamic roles of intrinsic and exogenous factors in determining poultry health. Yet, a combination of conventional, -omics based and other techniques further enhance characterisation of key poultry microbiome actors, their mechanisms of action, and roles in maintaining gut homoeostasis and health, in a bid to avert metabolic disorders and infections.4. In conclusion, there is an important interplay of innate, environmental, abiotic and biotic factors impacting on poultry gut microbiome homoeostasis, dysbiosis, and overall health. Associated infections and metabolic disorders can result from the interconnected nature of these factors. Emerging concepts (interkingdom or network signalling and neurotransmitter), and future technologies (mini-gut models, cobots) need to include these interactions to ensure accurate control and outcomes.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"523-537"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141449804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Partial budget analysis of laying hens' transition from cages to production systems of improved welfare: a case study in Greece.","authors":"M Z Kritsa, K Tsiboukas, E N Sossidou, P E Simitzis, M Goliomytis","doi":"10.1080/00071668.2024.2360631","DOIUrl":"10.1080/00071668.2024.2360631","url":null,"abstract":"<p><p>1. In recent years, public concern regarding animal welfare has increased while, at the same time, cage systems for animal production have been greatly criticised by EU citizens. In addition, large food retailers promote food products that are made with eggs produced in cage-free systems.2. The objective of this study was to evaluate the economic viability of the transition of laying hens' to production systems; from conventional to alternative systems with improved welfare. Three independent scenarios were assumed as follows: transition from enriched colony cages to barn (S1), transition from barn to free-range (S2), and transition from free-range to organic (S3). Economic assessments of each transition was applied to a model farm in Greece with 12 000 hens, through partial budget analysis and net benefits and costs were estimated.3. The results showed a positive economic impact in all transitions to a production system of improved animal welfare (€12,044 in S1, €18,957 in S2 and €7,977 in S3) which indicated that they are economically sustainable. In all scenarios, unit cost increased by 19% in S1, 12% in S2, and 85% in S3.4. In conclusion, transitioning towards improved animal welfare production systems in laying hen farms could be an economically viable option for egg producers in compliance with societal demands and market trends.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"503-512"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141305496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular and transcriptomic analysis of the ovary during laying and brooding stages in Zhedong white geese (<i>Anser cygnoides domesticus</i>).","authors":"Y Wang, S Wang, Z Zang, B Li, G Liu, H Huang, X Zhao","doi":"10.1080/00071668.2024.2364351","DOIUrl":"10.1080/00071668.2024.2364351","url":null,"abstract":"<p><p>1. This study investigates the molecular mechanisms affecting brooding in Zhedong white geese by examining differences in reproductive endocrine levels, ovarian histology and transcriptomics.2. Twenty 18-month-old Zhedong white geese were selected to examine their ovaries using histological, biochemical, molecular biological, and high-throughput sequencing techniques during the laying and brooding periods.3. The results showed that the number of atretic follicles and apoptotic cells in the ovaries increased significantly (<i>p</i> < 0.05), the levels of follicle-stimulating hormone, luteinising hormone, gonadotropin-releasing hormone and oestradiol decreased significantly (<i>p</i> < 0.05), and the level of prolactin increased significantly (<i>p</i> < 0.01) during the brooding stage.4. In broody geese, the expression of <i>CASP3, CASP9, P53, BAX</i>, and <i>Cyt-c</i> were considerably higher (<i>p</i> < 0.05), but <i>BCL2</i> expression was significantly lower (<i>p</i> < 0.05).5. In ovarian tissues, 260 differentially expressed lncRNAs, 13 differentially expressed miRNA and 60 differentially expressed mRNA were all discovered using transcriptome sequencing analysis. Functional enrichment analysis revealed that the differentially expressed mRNA and non-coding RNA target genes were primarily involved in ECM-receptor interaction, cell adhesion, cardiac muscle contraction, mTOR signalling, and the calcium signalling pathway.6. In conclusion, follicular atrophy and apoptosis occurred in the ovaries and serum reproductive hormone levels were significantly changed during the brooding period of Zhedong white geese. <i>COL3A1, COL1A2, GRIA1, RNF152</i>, miR-192, and miR-194 may be important candidates for the regulation of brooding behaviour, with the mTOR signalling pathway playing a key role.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"631-644"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141445181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of grinding method and extent of pelleting of broiler diets on performance, feeding behaviour and digestive tract functionality.","authors":"S Dhakal, H Hetland, B Svihus","doi":"10.1080/00071668.2024.2405208","DOIUrl":"10.1080/00071668.2024.2405208","url":null,"abstract":"<p><p>1. An experiment was carried out to examine if a heterogeneous diet consisting of pellets and coarse cereal particles would result in a similar feed intake to pelleted-only diets. It also considered whether coarser particles entering the gizzard would encourage the development of the gizzard and thus improve digestive tract functionality. Maize and wheat were hammer milled through a 3 mm screen after coarse grinding using either one of the two screens with a novel pattern. Three pellet-only diets were produced based on three grinding sizes. Additionally, four diets were produced by separating coarse cereal particles from moderately coarse particles by sieving either once or twice, pelleting the remainder and finally mixing these into a complete heterogeneous diet.2. No difference in performance between birds fed the three pelleted-only diets was observed. However, heterogeneous diets resulted in a lower feed intake (FI) and weight gain (WG) than pelleted-only diets (<i>p</i> < 0.05). The dietary treatments neither affected the feed conversion ratio nor ileal digestibility of starch and protein (<i>p</i> > 0.05). As expected, feeding a heterogeneous diets increased (<i>p</i> < 0.05) the relative weight of the gizzard and its contents. Approximately 50% of the particles in the small intestine were between 0.15 mm and 0.36 mm in diameter, with more fine particles observed when the pelleted-only diets containing coarsely ground cereals were fed, confirming the capacity of the gizzard to finely grind feed.3. Sieving of the diet remaining in the feeder during 4 h of feeding two of the heterogeneous diets showed that the particles > 2.8 mm disappeared first (<i>p</i> < 0.05), showing the birds' preference for larger particles when offered heterogeneous diets. Although the birds were able to handle the coarse microstructure of the diets without any negative effects, the reduced performance in the case of heterogeneous diets might have been related to feed intake issues and particle selection, resulting in an imbalance in nutrient intake.</p>","PeriodicalId":9322,"journal":{"name":"British Poultry Science","volume":" ","pages":"1-11"},"PeriodicalIF":1.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142342017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}