An analysis of the maxillary beak shape variation between 2 pure layer lines and its relationship to the underlying premaxillary bone, feather cover, and mortality
ABSTRACT: Beak shape varies considerably within and between intact-beak laying hens, and aspects of beak shape appear to be heritable. As an alternative to beak treatment (an effective method of reducing damage from severe feather pecking (SFP)), this variation could be used to genetically select he...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-08-01
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| Series: | Poultry Science |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0032579123003735 |
| _version_ | 1797770153949134848 |
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| author | S. Struthers B. Andersson M. Schmutz O. Matika H.A. McCormack P.W. Wilson I.C. Dunn V. Sandilands J.J. Schoenebeck |
| author_facet | S. Struthers B. Andersson M. Schmutz O. Matika H.A. McCormack P.W. Wilson I.C. Dunn V. Sandilands J.J. Schoenebeck |
| author_sort | S. Struthers |
| collection | DOAJ |
| description | ABSTRACT: Beak shape varies considerably within and between intact-beak laying hens, and aspects of beak shape appear to be heritable. As an alternative to beak treatment (an effective method of reducing damage from severe feather pecking (SFP)), this variation could be used to genetically select hens whose beak shapes are less apt to cause damage. To be able to select certain phenotypes, the beak shape variation that exists within laying hen flocks must first be characterized. The objectives of this study were to 1) describe the maxillary beak shape variation in 2 pure White Leghorn layer lines with intact beaks using geometric morphometrics to analyze images, and 2) examine the beak shape's relationship to the premaxillary bone, feather cover, and mortality. A lateral head image was taken of each hen (n = 710), and 20 landmarks were placed along each image's dorsal and ventral margins of the maxillary beak. Landmark coordinates were standardized by Procrustes superimposition, and the covariation was analyzed by principal components analysis and multivariate regression. Feather cover was scored at 3 ages and mortality was monitored throughout the production cycle. Three principal components (PCs) explained 83% of the maxillary beak shape variation and the first PC partially separated the 2 lines. Maxillary beak shapes ranged from long and narrow with pointed tips to short and wide with more curved tips. Moderate correlations were found between the maxillary beak and premaxillary bone shape (rs = 0.44) and size (rs = 0.52). Line A hens had better feather cover than Line B at all ages. Line A hens also had less total and cannibalism-related mortality than Line B (10.7 and 0.4% vs. 16.7 and 2.4%, respectively). Beak shape may be one factor contributing to the observed differences in feather cover and mortality. The results suggest that distinct maxillary beak phenotypes within each line could be selected to help reduce SFP damage and improve bird welfare. |
| first_indexed | 2024-03-12T21:18:14Z |
| format | Article |
| id | doaj.art-cb1e748326fc4e2795740e2f80849739 |
| institution | Directory Open Access Journal |
| issn | 0032-5791 |
| language | English |
| last_indexed | 2024-03-12T21:18:14Z |
| publishDate | 2023-08-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Poultry Science |
| spelling | doaj.art-cb1e748326fc4e2795740e2f808497392023-07-29T04:34:31ZengElsevierPoultry Science0032-57912023-08-011028102854An analysis of the maxillary beak shape variation between 2 pure layer lines and its relationship to the underlying premaxillary bone, feather cover, and mortalityS. Struthers0B. Andersson1M. Schmutz2O. Matika3H.A. McCormack4P.W. Wilson5I.C. Dunn6V. Sandilands7J.J. Schoenebeck8Department of Agriculture, Horticulture, and Engineering Science, Scotland's Rural College, Midlothian EH25 9RG, United Kingdom; The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, United Kingdom; Corresponding author:Lohmann Breeders GmbH, Cuxhaven DE 27472, GermanyLohmann Breeders GmbH, Cuxhaven DE 27472, GermanyThe Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, United KingdomThe Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, United KingdomThe Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, United KingdomThe Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, United KingdomDepartment of Agriculture, Horticulture, and Engineering Science, Scotland's Rural College, Midlothian EH25 9RG, United KingdomThe Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian EH25 9RG, United KingdomABSTRACT: Beak shape varies considerably within and between intact-beak laying hens, and aspects of beak shape appear to be heritable. As an alternative to beak treatment (an effective method of reducing damage from severe feather pecking (SFP)), this variation could be used to genetically select hens whose beak shapes are less apt to cause damage. To be able to select certain phenotypes, the beak shape variation that exists within laying hen flocks must first be characterized. The objectives of this study were to 1) describe the maxillary beak shape variation in 2 pure White Leghorn layer lines with intact beaks using geometric morphometrics to analyze images, and 2) examine the beak shape's relationship to the premaxillary bone, feather cover, and mortality. A lateral head image was taken of each hen (n = 710), and 20 landmarks were placed along each image's dorsal and ventral margins of the maxillary beak. Landmark coordinates were standardized by Procrustes superimposition, and the covariation was analyzed by principal components analysis and multivariate regression. Feather cover was scored at 3 ages and mortality was monitored throughout the production cycle. Three principal components (PCs) explained 83% of the maxillary beak shape variation and the first PC partially separated the 2 lines. Maxillary beak shapes ranged from long and narrow with pointed tips to short and wide with more curved tips. Moderate correlations were found between the maxillary beak and premaxillary bone shape (rs = 0.44) and size (rs = 0.52). Line A hens had better feather cover than Line B at all ages. Line A hens also had less total and cannibalism-related mortality than Line B (10.7 and 0.4% vs. 16.7 and 2.4%, respectively). Beak shape may be one factor contributing to the observed differences in feather cover and mortality. The results suggest that distinct maxillary beak phenotypes within each line could be selected to help reduce SFP damage and improve bird welfare.http://www.sciencedirect.com/science/article/pii/S0032579123003735morphometricsinjurious feather peckingprincipal components analysisradiographylaying hen |
| spellingShingle | S. Struthers B. Andersson M. Schmutz O. Matika H.A. McCormack P.W. Wilson I.C. Dunn V. Sandilands J.J. Schoenebeck An analysis of the maxillary beak shape variation between 2 pure layer lines and its relationship to the underlying premaxillary bone, feather cover, and mortality Poultry Science morphometrics injurious feather pecking principal components analysis radiography laying hen |
| title | An analysis of the maxillary beak shape variation between 2 pure layer lines and its relationship to the underlying premaxillary bone, feather cover, and mortality |
| title_full | An analysis of the maxillary beak shape variation between 2 pure layer lines and its relationship to the underlying premaxillary bone, feather cover, and mortality |
| title_fullStr | An analysis of the maxillary beak shape variation between 2 pure layer lines and its relationship to the underlying premaxillary bone, feather cover, and mortality |
| title_full_unstemmed | An analysis of the maxillary beak shape variation between 2 pure layer lines and its relationship to the underlying premaxillary bone, feather cover, and mortality |
| title_short | An analysis of the maxillary beak shape variation between 2 pure layer lines and its relationship to the underlying premaxillary bone, feather cover, and mortality |
| title_sort | analysis of the maxillary beak shape variation between 2 pure layer lines and its relationship to the underlying premaxillary bone feather cover and mortality |
| topic | morphometrics injurious feather pecking principal components analysis radiography laying hen |
| url | http://www.sciencedirect.com/science/article/pii/S0032579123003735 |
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