British Poultry Science最新文献

1. The purpose of this meta-analysis was to evaluate the effect of mannan oligosaccharide (MOS) as an alternative to antibiotic growth promoters (AGP) on feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR) of broilers.2. Data from 75,594 broilers were extracted from 17 articles (19 trials) published between January 2010 and March 2023. The main criteria for the publication selection were as follows, at least three treatments applied (negative control group without MOS or AGP versus MOS or AGP supplementation), presence of performance results, and intra-experimental variation associated with the mean of response (such as standard error). Treatments were classified as control, MOS, or AGP, and adjusted means of treatment were compared. Additionally, the average daily gain (ADG) and average daily feed intake (ADFI) of each type of supplementation were calculated relative (Δ) to the control group (ΔADFI and ΔADG) and expressed as a percentage of the difference.3. Broilers receiving a diet supplemented with MOS had a 3.7% better BWG and 3% better FCR compared to the control diet (P < 0.001), but these variables were similar to the group receiving AGP supplementation. No significant difference was detected in FI among treatments (P > 0.050). The relationship between ΔADG and ΔADFI was linear for the MOS and AGP-supplemented group (P < 0.050). The ΔADG of broilers fed diets supplemented with MOS or AGP was 6.4% and 4.54% when ΔADFI was zero, respectively. The ΔADG of MOS increased by 0.58% for every 1% of increasing observed in ΔADFI. The corresponding value for the increased ΔADG for the AGP group was 0.69%.4. The results of this meta-analysis indicated that MOS supplementation is effective in increasing BWG and reducing FCR, similar to broilers fed a diet supplemented with AGP. Therefore, MOS is a safe and sustainable alternative for AGP-free poultry production.

1. Salmonella Gallinarum strains isolated from a southern Brazil fowl typhoid outbreak were subjected to phenotypic and genotypic analyses to identify genetic elements that could improve prevention and control strategies.2. Whole-genome sequencing revealed the presence of the aac(6')-Iaa gene, conferring aminoglycoside resistance, along with novel chromosomal point mutations, including the first detection of parE p.S451F in Salmonella Gallinarum.3. Additionally, IncFII(S) plasmid replicons, Salmonella pathogenicity islands and 105 virulence genes associated with cell adhesion, invasion and antimicrobial peptide resistance were identified.4. These findings shed light on the molecular mechanisms of fowl typhoid and provide crucial insights into emerging antimicrobial resistance and virulence factors.

1. The objective of this study was to test the effect of microbial phytase and calcium (Ca) levels on the Zn bioavailability depending on the Zn source.2. A total of 144, one-day-old broilers received a diet containing 40 mg Zn/kg for 1 week. They were then assigned to one of the eight experimental treatments during 2 weeks. Diets contained 27 mg native Zn and were formulated according to a 2 × 2 × 2 factorial design with two added Zn sources (23 mg Zn/kg), sulphate (ZnSO₄) or oxide (ZnO); two dietary Ca levels of either 6 (low) or 10 g/kg (moderate); and two microbial phytase levels, of either 0 or 750 phytase unit/kg.3. Moderate Ca plus phytase improved body weight gain (BWG) and low Ca level without microbial phytase decreased tibia weight (Ca × Phy; p = 0.049). Zinc oxide resulted in a higher tibia development (i.e. tibia weight and length; p < 0.05) and BWG (p = 0.009) and lower FCR (p < 0.001) compared to ZnSO₄.4. Phytase improved tibia Zn concentration especially in birds given ZnSO₄ compared to ZnO (Zn × Phy; p = 0.049). Moderate Ca diets improved tibial characteristics and Zn deposition compared to low Ca diets (p < 0.05).5. Soluble Zn in the gizzard increased in the presence of phytase (p = 0.011), while higher dietary Ca reduced this in birds receiving ZnO (p = 0.004). In the jejunum, Zn solubility was higher with phytase (p = 0.008).6. Under the conditions of this study, dietary levels of Ca and microbial phytase affect Zn availability in broilers more than the Zn source.

1. This study calculated descriptive statistics for the production traits of two broiler populations: 1) the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF white broilers), including fat and lean lines; and 2) the Guangxi yellow broilers. Their genetic parameters were estimated, including (co)variance components, heritability (h²) and genetic correlations (r_g), using the REML method.2. Heritability estimates (h²) for NEAUHLF white broilers ranged from 0.07 to 0.61. Traits with high heritability (h² >0.3) included body weight at 3, 5 and 7 weeks of age (BW3, BW5, BW7), carcass weight (CW), metatarsal circumference (MeC), liver weight (LW), gizzard weight (GW), spleen weight (SW) and testis weight (TeW), while in Guangxi yellow broilers, heritability estimates ranged from 0.18 to 0.76, with every trait exhibiting high heritability, except for SW (0.18).3. Positive genetic correlations for NEAUHLF were found (r_g >0.3, ranging from 0.31 to 0.84) between BW7 and metatarsal length (MeL), MeC, body oblique length (BoL), chest angle (ChA), LW, GW, heart weight (HW) and SW. Genetic correlations between abdominal fat weight (AFW) and BW1, BW3, BW5, CW, MeL, keel length (KeL), BoL and LW were positive (r_g >0.3, ranging from 0.31 to 0.58).4. Among the Guangxi population, BW (125 d of age) showed strong positive genetic correlations with all other traits (r_g >0.3, ranging from 0.30 to 0.99), while AFW displayed strong positive genetic correlations with leg muscle weight (LeW), CW, BW and thigh diameter (TD) (r_g >0.3, ranging from 0.44 to 0.51).5. It was concluded that the characteristics of the two populations were different, which means there is a need to use different strategies when performing the breeding work to improve productivity and efficiency in both broiler populations.

1. Monitoring behavioural dynamics in complex animal environments, such as poultry breeding facilities, poses a challenge. Utilising technological approaches, such as accelerometers, offers a solution to assess long-term changes in reproductive activity at an individual bird level. Specifically, these sensors measure acceleration associated with the position and movements of the body over time. However, it is important to assess the most suitable method for attaching accelerometer tags to ensure they do not negatively impact behaviour and yield high-quality data.2. The potential of tri-axial accelerometer tags for assessing reproductive behaviour in Japanese quail was evaluated. Two attachment methods - a backpack (plastic platform with elastic bands near wing bases) and a patch (accelerometer on fabric glued to the synsacrum region) - were compared. Controls were handled similarly but without tags. Eighteen pairs of females were housed in pens and assessed immediately and 24 h after handling. After a week of habituation, a male from the same treatment group was introduced into each pen on d 8. The reproductive behaviour of the males was recorded using accelerometers and video recordings.3. The results showed that birds with patches were able to remove their conspecific's accelerometer and displayed an increased initial immobility response compared to the control and backpack groups. The presence of accelerometer tags did not impact male/female reproductive interactions nor fear responses to a novel object. From accelerometer recordings, male reproductive behaviour was easily identified as high amplitude fluctuations in the three axial components of the acceleration vectors, which was reflected as large values of dynamic body acceleration (VeDBA).4. In conclusion, the use of backpacks with accelerometers is a useful strategy to address highly relevant and difficult to tackle behavioural topics such as the temporal dynamic of male reproductive behaviour within breeding groups.

1. The objective of the present study was to examine the effect of lighting programs and light colour on ocular health variables as welfare indicators in Ross 308 broilers.2. A total of 384, male, one-d-old broiler chickens (Ross 308) were placed in a completely randomised design with a 2 × 2 factorial arrangement of lighting program (continuous or intermittent) and light colour (white and green LED light). Ross 308 broilers under restricted lighting had 18 h of light (18 L:6D), while those under intermittent lighting had cycles of 17 L:3D:1 L:3D throughout the experimental period, which lasted 42 d.3. At the end of the experiment, all eyes of birds (n = 96 birds) underwent a complete ophthalmic examination, which included the Schirmer tear test I, intraocular pressure and eye dimensions. In addition, 32 broilers (eight birds per trial groups) aged 42 d underwent ophthalmic examination to include assessment of ocular ultrasound biometry.4. Light colour had a significant influence on the mean intraocular pressure (p < 0.001). The Ross 308 broilers kept with intermittent lighting had lower eye weights (2.29 g; p < 0.05), palpebral fissure length (14.39 mm; p < 0.01), eye dorsoventral diameter (17.46 mm; p < 0.05), anteroposterior size (13.70 mm; p < 0.01) and corneal dorsoventral diameter (7.81 mm; p < 0.05) compared to those reared under restricted lighting.5. In conclusion, these values for Ross 308 broilers may be applied in poultry ophthalmology to detect early eye disease symptoms and to help the diagnosis of tear disorders that could cause economic losses and welfare issues. Intermittent lighting and green LED light may help reduce eye health problems thus contributing to improved welfare in broilers.

1. This study evaluated the effects and mechanisms of action of the peptide gADP3 on hepatic inflammatory injury induced by lipopolysaccharide (LPS).2. Hepatic inflammatory injury was induced in geese by intraperitoneal injection of LPS and gADP3, and the adiponectin receptor agonist AdipoRon (positive control) was used for potential amelioration. Serum inflammatory factor levels, liver function-related biochemical indicators and oxidative stress-related biochemical parameters in the liver tissues were determined. The expression levels of adiponectin and its receptors, inflammation and oxidative stress-related genes and key signalling molecules involved in adiponectin, inflammation and oxidative stress signalling pathways in liver tissues were detected.3. The peptide gADP3 alleviated inflammatory cell infiltration and hepatic inflammatory changes, reversed the decrease in serum albumin (ALB), total protein (TP), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) content or activity induced by LPS and increased the activity of the antioxidant enzymes CAT (catalase), SOD (superoxide dismutase) and GSH-Px (glutathione peroxidase).4. The peptide gADP3 upregulated the expression of antioxidant enzyme-related genes GCLC, HO-1 and NQO1 in liver tissues, decreased the levels of inflammatory factors like TNF-α, IL-1β, IL-6, IFN-γ and TGF-β and reduced mRNA expression levels of inflammatory-related genes TNF-α, IL-1β, iNOS and TGF-β. Additionally, it increased the mRNA and protein expression levels of adiponectin and its receptors, as well as key molecules in the adiponectin signalling pathway like AMPK and PPARα. In addition, gADP3 reversed the changes in mRNA or protein expression of inflammatory and oxidative stress signalling pathway-related genes P38MAPK, NF-κBP65, TLR4 and Nrf2 in liver tissues caused by LPS treatment.5. In conclusion, goose-derived adiponectin peptide gADP3, similar to the adiponectin receptor agonist AdipoRon, attenuated LPS-induced hepatic inflammatory injury in geese.

1. This study compared two broiler housing models with different technologies (conventional versus fully automated climate control) to verify their performance and carcass characteristics at slaughter, as well as the economics of production.2. A database regarding 20 443 flocks of heavy broilers produced in an integrated operation during the years 2020 and 2021, in eight Brazilian regions was used in the analysis. The dependent variables included feed conversion, average live weight gain, total and partial carcass condemnation and the total mortality. For economic analysis, the production cost of each technology including feed, labour, energy, heating and depreciation was calculated.3. The technology used in the broiler houses had a significant effect on the technical indicators which were positive for fully automated climate control in most geographical regions. One important exception was the effect on total and partial carcass condemnations, with better results seen for conventional housing. The total cost per ton of broiler meat delivered, deducting condemnation losses, was lower in the automated climate controlled housing compared to conventional housing.4. In conclusion, there was a reduction in broiler chicken production costs for birds raised in fully automated climate controlled housing, indicating better economic results for this model in Brazil.

1. As one of the most widespread poultry species in the world, pigeons have been bred primarily for meat production due to their high nutritional value and good taste. Their breast muscle is an important economic product as it determines the yield and quality of meat from pigeons.2. Long non-coding RNA (lncRNA) plays an important role in transcription and post-transcriptional regulation, but research on the molecular mechanisms of this process in pectoral muscle development in pigeon squabs is lacking.3. Herein, RNA sequencing was used to analyse these mechanisms in pigeon squabs at different ages: 3(D3), 14 (D14) and 25 d (D25). A total of 56 169 differentially expressed (DE) lncRNA and 29 939 DE mRNA were identified among the three age groups, of which 483 were differentially co-expressed. A lncRNA-mRNA interaction network was constructed, and cis-trans identification, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed.4. The results showed that lncRNA affected muscle development through the cell cycle, cytoskeleton in muscle cells, motor proteins, extracellular matrix (ECM) receptor interaction, focal adhesion, and other signalling pathways. Five DE lncRNA and mRNA were selected (LTCONS_00073284,LTCONS_00012834, LTCONS_00032767, LTCONS_00041298, LTCONS_00028245;TNNC1, XIRP1, PITX3, COL4A6, and TNNT3). Their expression patterns were validated by reverse transcription-quantitative polymerase chain reaction (RT-QPCR), which were consistent with the high-through sequencing results.

1. E. coli is an opportunist pathogen of animals, including food-producing ones and humans. Chickens may be a notable source of pathogenic and antimicrobial resistant E. coli for transmission to humans.2. This study compared virulence-associated genes (VGs) and antimicrobial resistance (AMR) in avian pathogenic E. coli (APEC) and extraintestinal pathogenic E. coli (ExPEC) isolates from broiler chickens, specifically APEC isolates in liver samples (n = 78) and ExPEC or non-ExPEC isolates in litter samples (n = 34). Virulence was evaluated by PCR for feoB, hlyF, iroN, iss, iutA and ompT genes, while AMR was evaluated by using antimicrobials from seven classes and detecting bla_SHV, bla_TEM, bla_OXA, qnrB, stcM, mrc1, mrc2, sul1 and tetA genes.3. The APEC isolates were found in 100% of livers, while ExPEC and non-ExPEC isolates were found in 44% and 56% of the litter samples. The predominant VG was feoB (100%), followed by ompT (63%), iutA (60%), iss (58%) and hlyF (43%). Surprisingly, iroN, omp T and iutA had higher prevalences in APEC isolates (85%, 96% and 96%, respectively) than in ExPEC isolates (73%, 87% and 73%, respectively) and non-ExPEC isolates (0% for all). The presence of all VG in 33% of isolates indicated high pathogenicity.4. The isolates were phenotypically resistant to ampicillin (93%), ceftazidime (72%) and nalidixic acid (82%). All APEC and ExPEC isolates (100%) were multidrug resistant (MDR), while 63% of non-ExPEC isolates were MDR. Genotypic AMR testing revealed that 53% and 52% of all isolates had stcM and tetA, respectively. No isolate was positive for bla_SHV, bla_OXA, mrc1 or mrc2, which suggested the benefits of colistin for treating carbapenem-resistant enteric pathogens, due to the high resistance detected to meropenem (47%).5. Given the potential pathogenicity of E. coli isolates, improving biosecurity practices in chicken flocks should be prioritised to eliminate transmission to humans through the food chain.