British Poultry Science

Kaewtapee, C.; Thepparak, S.; Rakangthong, C.; Bunchasak, C.; Supratak, A.

doi: 10.1080/00071668.2021.2013439pmid: 34870524

1. Footpad dermatitis (FPD) can be used as an important indicator of animal welfare and for economic evaluation; however, human scoring is subjective, biased and labour intensive. This paper proposes a novel deep learning approach that can automatically determine the severity of FPD based on images of chicken’s feet. 2. This approach first determined the areas of the FPD lesion, normal parts of each foot and the background, using a deep segmentation model. The proportion of the FPD for the chicken’s two feet was calculated by dividing the number of FPD pixels by the number of feet pixels. The proportion was then categorised using a five-point score for FPD. The approach was evaluated from 244 images of the left and right footpads using five-fold cross-validation. These images were collected at a commercial slaughter plant and scored by trained observers. 3. The result showed that this approach achieved an overall accuracy and a macro F1-score of 0.82. The per-class F1-scores from all FPD scores (scores 0 to 4) were similar (0.85, 0.80, 0,80, 0,80, and 0.87, respectively), which demonstrated that this approach performed equally well for all classes of scores. 4. The results suggested that image segmentation and a deep learning approach can be used to automate the process of scoring FPD based on chicken foot images, which can help to minimise the subjective bias inherent in manual scoring.

Krautwald-Junghanns, M.-E.; Sirovnik, Janja

doi: 10.1080/00071668.2022.2050673pmid: 35275024

1. This paper reviews literature on the effects of stocking density on behaviour, health, and production in intensively housed fattening turkeys. 2. Worldwide, there are various regulations and recommendations on the maximum stocking density. While stocking density can be determined based on the space covered by the body, a more appropriate method considers space requirements for natural behaviour. Turkeys are less likely disturbed at low stocking density as seen by increased sitting, lying, and preening behaviours compared to animals housed at high stocking density. Furthermore, lower stocking density together with smaller group size, species-appropriate light conditions and suitable structuring of barn housing are repeatedly mentioned as good strategies to prevent injurious pecking. 3. Increased stocking density – in terms of weight and animal number per floor area – is related to increased litter moisture, which can have negative impact on animal health. High stocking density can also lead to poor body mass gain and increased mortality, which are not only indicators of impaired welfare but also of economic interest. 4. Based on the available scientific literature and economic aspects with regard to the above criteria, a maximum stocking density for turkeys appears to be 36-a maximum of 40 kg live weight per m2 of usable floor space. However, the number of animals per square space should also be limited to avoid increased litter moisture and reduced health.

Liu, D.; Liu, X.; Ma, X.; Li, C.; Li, J.; Li, Q.; Zhang, N.; Cao, Y.; Li, Z.; Kang, X.; Tian, Y.; Li, W.

doi: 10.1080/00071668.2021.2014400pmid: 34923879

1. The objectives of the present study were to elucidate the relationship between novel variations of the SIRT1 gene and chicken growth traits. In total, 1,429 chickens, including six breeds and a Gushi ×Anka F2 resource population, were genotyped using PCR-RFLP. 2. Two novel InDels (c.-1552_-1553insCG and c.-450_-451delCG) in the promoter of the chicken SIRT1 gene were identified. An association study showed that c.-1552_-1553insCG was significantly correlated with growth traits and serum lipid indicators. 3. The insertion genotype was most highly associated with body weight at day old, two- and four-week-old chickens, and with shank circumference at four and eight weeks of age. The wild type genotype at this site was most highly associated with serum lipid indicators. 4. In contrast, c.-450_-451delCG was significantly correlated with muscle fibre diameter. The SIRT1 gene expression in chickens with different InDel genotypes was analysed and was significantly higher with heterozygous genotypes at both sites in muscle and fat tissue, relative to expression in chickens with the corresponding homozygous genotypes. 5. The effects of different haplotypes on SIRT1 promoter activity showed that promoter activity depends on haplotype, with haplotype HapII exhibiting the highest activity. 6. It was concluded that the SIRT1 gene is associated with chicken growth traits and that the two InDels influence SIRT1 promoter activity in chickens.

Liao, C.-M.; Tan, G.-H.; You, M.-F.; Li, J.-Z.; Wu, L.; Qin, Yuan-Yu; Zhang, Yi-Yu

doi: 10.1080/00071668.2021.2019678pmid: 34923880

1. The objective of this study was to investigate the evolution of SCNN1B and AHCYL1 proteins among 10 domestic avian and mammalian animal species, to uncover the expression patterns of SCNN1B and AHCYL1 genes in ducks, identify the genetic variants of the SCNN1B and AHCYL1 genes and analyse their effects on eggshell quality. 2. Expression profiles of the SCNN1B and AHCYL1 genes in Sansui female ducks were determined using real-time fluorescence quantitative PCR to identify SNPs. The duck SCNN1B and AHCYL1 genes were amplified to identify SNPs. A total of 502 Sansui female ducks were genotyped by sequencing, and the associations between the mRNA expression/SNP genotypes and 6 eggshell quality indices were analysed using PASW Statistics 18.0. 3. The results showed that the SCNN1B and AHCYL1 proteins are highly conserved in different mammalian or domestic animals, especially the AHCYL1 protein. The SCNN1B and AHCYL1 genes were widely expressed in different tissues of male and female ducks, and expression level in the uterus was greater than in other tissues. The expression of SCNN1B and AHCYL1 during the oviposition cycle indicated that expression levels were related to the eggshell mineralisation stage. 4. The mRNA expression levels of the uterine SCNN1B and AHCYL1 genes were positively correlated with eggshell strength (ESS), percentage (ESP) and weight (ESW) (P < 0.05), respectively. Ten novel SNPs in SCNN1B and AHCYL1 genes from Chinese domestic laying ducks were identified through PCR amplicon sequencing. 5. Genetic association analysis indicated g.797509 C > T, g.797573 C > T and g.797834 C > T in SCNN1B gene and g.169244 T > A, g.169265 T > C and g.175311 T > C in AHCYL1 gene had a significant effect on eggshell quality. Correlation analysis between the SNP genotype and SCNN1B and AHCYL1 genes expression in the uterus showed that the genotypes of g.797509 C > T, g.797573 C > T, g.797834 C > T, g.169244 T > A and g.175311 T > C sites affected the expression of SCNN1B and AHCYL1 genes in utero (P < 0.05). 6. The study indicated SCNN1B and AHCYL1 as candidate genes to improve eggshell traits in ducks.

Lin, R.; Li, J.; Zhao, F.; Zhou, M.; Wang, J.; Xiao, T.

doi: 10.1080/00071668.2022.2035676pmid: 35094630

1. Plumage colour is an important recognisable characteristic of duck (Anas platyrhynchos), but the colouration mechanisms remain largely unknown. To elucidate the molecular mechanisms underlying the formation of black and white plumage, the following study applied RNA sequencing (RNA-Seq) to catalogue the global gene expression profiles in the duck feather bulbs of black and white colours. 2. Black feather bulbs were collected from Putian Black ducks (B-PTB) and black Longsheng Jade-green ducks (B-LS), while white feather bulbs were collected from Putian White ducks (W-PTW), Putian Black ducks (W-PTB) and Longsheng Jade-green ducks (W-LS). Sixteen cDNA libraries were constructed and sequenced for transcriptional analysis. Three comparison groups were employed to analyse differentially expressed genes (DEGs), including W-PTB versus B-PTB, W-PTW versus B-PTB and W-LS versus B-LS. 3. The results showed 180 DEGs between W-PTB and B-PTB, 303 DEGs between W-PTW and B-PTB, and 108 DEGs between W-LS and B-LS. Further analysis showed that 18 DEGs were directly involved in the pigmentation process and melanogenesis signalling pathway. Additionally, the distribution of DEGs varied amongst groups whereby ASIP appeared only in the W-LS versus B-LS group, GNAI1 and ZEB2 appeared only in the W-PTW versus B-PTB group, and KITLG, EDN3 and FZD4 appeared only in W-PTB versus B-PTB. 4. The findings suggested that the mechanism of feather albinism may differ between duck breeds. This study provided new information for discovering genes that are important for feather pigmentation and helps elucidate molecular mechanisms involved in black and white plumage in ducks.

Li, Y.; Yuan, P.; Fan, S.; Zhai, B.; Li, S.; Li, H.; Zhang, Y.; Li, W.; Sun, G.; Han, R.; Tian, Y.; Liu, X.; Jiang, R.; Li, G.; Kang, X.

doi: 10.1080/00071668.2022.2050674

Al-Rasheed, M.; Ball, C.; Manswr, B.; Leeming, G.; Ganapathy, K.

doi: 10.1080/00071668.2022.2035675pmid: 35179081

1. The role of the Harderian gland (HG), choanal cleft (CC) and turbinate in terms of IBV M41 viral load compared to the trachea, and immune (innate, cellular and mucosal) responses were studied in 21-day-old commercial broiler chickens. 2. After virulent IBV M41 challenge, the antigen concentration detected either by quantitative RT-PCR or immunohistochemistry peaked at 2–3 days post challenge (dpc) in all tissues. Significant increases of lachrymal IBV-specific IgA and IgY levels were found at 4–5 dpc. 3. Gene transcription showed a significant up-regulation of TLR3, MDA5, IL-6, IFN-α and IFN-β, where patterns and magnitude fold-change of mRNA transcription were dependent on the gene and tissue type. 4. The results demonstrated active IBV M41 replication in the HG, CC and turbinate, comparable to levels of replication found in the trachea. Data on immune-related genes in head-associated tissues provide further understanding on the immunobiology of IBV and offer opportunities to identify their use as quantitative biomarkers in pathogenicity and vaccination-challenge studies.

Sartini, I.; Łebkowska-Wieruszewska, B.; Fadel, C.; Lisowski, A.; Poapolathep, A.; Giorgi, M.

doi: 10.1080/00071668.2022.2036699pmid: 35118922

1. Although amoxicillin has broad-spectrum antibiotic activity and is extensively used in poultry, its use has never been investigated in geese. This study aimed to evaluate the pharmacokinetics of amoxicillin after a single and multiple oral doses in geese. 2. A total of 20 geese were enrolled in this study and randomly pooled in two groups (n = 10). In group I, animals were treated with a single oral 20 mg/kg dose of amoxicillin, while geese in group II were administered multiple doses (20 mg/kg/day for 4 d). Concentrations of amoxicillin in plasma were analysed using a validated HPLC-UV method and drug plasma concentrations were modelled for each subject using a non-compartmental approach. 3. amoxicillin showed rapid absorption after a single-dose treatment, with an elimination half-life of approximately 1 h. Cmax, Tmax and AUC values differed statistically between groups I and II (after the first dose administered). A large variability was observed in the pharmacokinetic profiles and drug accumulation may occur after the multiple administration. 4. No accumulation in plasma was predicted from an in-silico simulation performed using the same multiple dosage schedule. The in-silico simulation does not seem to accurately predict in-field conditions.

Naghizadeh, M.; Dalgaard, T. S.; Klaver, L.; Engberg, R. M.

doi: 10.1080/00071668.2022.2042483pmid: 35170392

1. The objectives of this study were to i) compare the effects of a commercial product providing encapsulated butyrate (EB) in combination with salinomycin in diets of broilers with impaired intestinal integrity and ii) to identify easy-to-measure biomarkers to evaluate intestinal integrity and health. 2. In total, 672 one-day-old male broilers (Ross 308) were randomly assigned to three experimental groups (eight replicates/group): no dietary supplement (control); EB (500 mg/kg, UltraGuard™-DUO, Devenish, Ireland); salinomycin (69 mg/kg feed, Sacox® 120). Impaired gut integrity was induced by a 10 times overdose of a commercially attenuated live vaccine against coccidiosis (Hipracox®, Hipra) on d 17 combined with a grower feed providing rye (50 g/kg diet). 3. Improved intestinal integrity and functionality were reflected by reduced fluorescein isothiocyanate-dextran (FITC-D) plasma levels, reduced bacterial translocation to the liver (on d 21) and increased plasma colouration level on d 21 after dietary supplementation of salinomycin, compared to a non-supplemented control diet. Both EB and salinomycin reduced plasma levels of D-lactate (P < 0.05). 4. An anti-inflammatory effect of salinomycin was indicated as the transient increase in circulating monocytes observed in the EB and control group from 20 to 28 d of age was slightly but not significantly reduced, in the salinomycin-fed group. Interestingly, greater expression of tumour necrosis factor α (TNF-α) and mucin 2 (MUC2) genes (P = 0.039 and P = 0.067, respectively) were detected in the group receiving salinomycin. 5. These effects may have collectively contributed to the significantly improved performance of broilers supplemented with salinomycin. The results indicated that EB at 500 mg/kg in feed, in contrast to salinomycin, neither supported gut health nor modulated intestinal integrity in broilers.

Han, X.; Song, Z.; Wang, W.; Tang, H.

doi: 10.1080/00071668.2022.2042484pmid: 35164622

1. The Wnt signalling pathway is centred on the fact that catenin beta-1(CTNNB1) participates in the regulation of ovarian follicle development. The aim of the following study was to identify polymorphisms in the 5ʹ regulatory region of the chicken CTNNB1 gene and evaluate the association between SNPs and egg production traits. 2. The study demonstrated that the 5ʹ regulatory region of the CTNNB1 gene has 10 SNPs in the investigated Jining Bairi chickens. After Bonferroni correction for multiple testing, five SNPs (rs315692306, 2:g43385123, rs735854102, 2:g43385457 and rs737907370) were significantly correlated with egg laying traits. 3. An association study of the haplotypes with egg laying traits revealed that both haplotypes in block 1 (consisting of rs735052881, rs740662190, rs315692306, and 2:43385123) and block 2 (consisting of rs735854102 and 2:g43385457) were associated with point of lay age and the number of eggs laid at 18–23 weeks. Prediction of transcription factor-binding sites showed that transcription factors changed after mutation in block 2. The luciferase assay revealed that the priming activity of the CA haplotype in block 2 was the highest. 4. Taken together, the rs315692306, 2:g43385123, rs735854102, 2:g43385457 and rs737907370 in the 5ʹ regulatory region of the CTNNB1 gene have significant impacts on egg production.