Frequencies of β-casein variants and their influence on genetic merit for production traits in Holstein cows
Context: Traits considered for selection are influenced by social, consumer, and breeder demands. In the past decades, there has been increasing global interest in producing milk free from the β-casein (CSN2) A1 allele because of the health benefits it may have. This has encouraged many breeders to...
| Autores principales: | , , , |
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| Formato: | Artículo |
| Lenguaje: | Inglés |
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CSIRO Publishing
2025
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| Acceso en línea: | http://hdl.handle.net/20.500.12123/22078 https://www.publish.csiro.au/AN/AN24146 https://doi.org/10.1071/AN24146 |
| _version_ | 1855486871258267648 |
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| author | Caffaro, María Eugenia Raschia, Maria Agustina Maizon, Daniel Omar Poli, Mario Andres |
| author_browse | Caffaro, María Eugenia Maizon, Daniel Omar Poli, Mario Andres Raschia, Maria Agustina |
| author_facet | Caffaro, María Eugenia Raschia, Maria Agustina Maizon, Daniel Omar Poli, Mario Andres |
| author_sort | Caffaro, María Eugenia |
| collection | INTA Digital |
| description | Context: Traits considered for selection are influenced by social, consumer, and breeder demands. In the past decades, there has been increasing global interest in producing milk free from the β-casein (CSN2) A1 allele because of the health benefits it may have. This has encouraged many breeders to select A2A2 cows in their dairy cattle herds.
Aims: This study aimed to evaluate the genetic variation in the bovine CSN2 gene regarding A1-like and A2-like variants and to assess the potential association between these variants and production traits in Holstein cows.
Methods: In total, 2600 Holstein cows from three commercial dairy farms with different breeding objectives and phenotypic records taken over different seasons, periods, and lactations were genotyped for single-nucleotide polymorphism rs43703011, which distinguishes A1-like from A2-like β-casein variants. Allele and genotype frequencies were determined and their breeding values for milk, fat, and protein yields, and fat and protein percentages were estimated. The influence of CSN2 genotypes on these breeding values was studied through a one-way ANOVA. For the significant CSN2 genotype–breeding value associations, allele substitution effects were estimated.
Key results: We found allele frequencies for A1-like and A2-like alleles in the ranges 0.262–0.366 and 0.634–0.738 respectively, and genotype frequencies in the ranges of 0.043–0.125, 0.43–0.537, and 0.393–0.523 for A1A1, A1A2 and A2A2 genotypes respectively. We demonstrated that the A2-like CSN2 variant correlates with higher estimated breeding values (EBVs) for milk, protein, and fat yields, and lower EBVs for fat and protein percentages.
Conclusions: These results are valuable to visualize the trends in CSN2 allele and genotype frequency changes over the years and to analyze the effect of the different variants of β-casein on production performance.
Implications: Our findings contribute to evaluating the consequences on dairy performance of selection for the A2-like variant. |
| format | Artículo |
| id | INTA22078 |
| institution | Instituto Nacional de Tecnología Agropecuaria (INTA -Argentina) |
| language | Inglés |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | CSIRO Publishing |
| publisherStr | CSIRO Publishing |
| record_format | dspace |
| spelling | INTA220782025-04-28T13:05:56Z Frequencies of β-casein variants and their influence on genetic merit for production traits in Holstein cows Caffaro, María Eugenia Raschia, Maria Agustina Maizon, Daniel Omar Poli, Mario Andres Beta-casein Dairy Cattle Dairy Cows Milk Production Genotypes Alleles Breeding Value Genetic Variation Beta-caseína Ganado de Leche Vaca Lechera Producción Lechera Genotipos Alelos Valor Genético Variación Genética Raza Holstein Context: Traits considered for selection are influenced by social, consumer, and breeder demands. In the past decades, there has been increasing global interest in producing milk free from the β-casein (CSN2) A1 allele because of the health benefits it may have. This has encouraged many breeders to select A2A2 cows in their dairy cattle herds. Aims: This study aimed to evaluate the genetic variation in the bovine CSN2 gene regarding A1-like and A2-like variants and to assess the potential association between these variants and production traits in Holstein cows. Methods: In total, 2600 Holstein cows from three commercial dairy farms with different breeding objectives and phenotypic records taken over different seasons, periods, and lactations were genotyped for single-nucleotide polymorphism rs43703011, which distinguishes A1-like from A2-like β-casein variants. Allele and genotype frequencies were determined and their breeding values for milk, fat, and protein yields, and fat and protein percentages were estimated. The influence of CSN2 genotypes on these breeding values was studied through a one-way ANOVA. For the significant CSN2 genotype–breeding value associations, allele substitution effects were estimated. Key results: We found allele frequencies for A1-like and A2-like alleles in the ranges 0.262–0.366 and 0.634–0.738 respectively, and genotype frequencies in the ranges of 0.043–0.125, 0.43–0.537, and 0.393–0.523 for A1A1, A1A2 and A2A2 genotypes respectively. We demonstrated that the A2-like CSN2 variant correlates with higher estimated breeding values (EBVs) for milk, protein, and fat yields, and lower EBVs for fat and protein percentages. Conclusions: These results are valuable to visualize the trends in CSN2 allele and genotype frequency changes over the years and to analyze the effect of the different variants of β-casein on production performance. Implications: Our findings contribute to evaluating the consequences on dairy performance of selection for the A2-like variant. Instituto de Genética Fil: Caffaro, María Eugenia. Instituto Nacional de Tecnología Agropecuaria, (INTA). Instituto de Genética; Argentina Fil: Raschia, Maria Agustina. Instituto Nacional de Tecnología Agropecuaria, (INTA). Instituto de Genética; Argentina Fil: Maizon, Daniel Omar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Anguil; Argentina Fil: Maizon, Daniel Omar. Universidad Nacional de La Pampa. Facultad de Agronomía; Argentina Fil: Poli, Mario Andres. Instituto Nacional de Tecnología Agropecuaria, (INTA). Instituto de Genética; Argentina Fil: Poli, Mario Andres. Universidad del Salvador, Facultad de Ciencias Agrarias y Veterinaria; Argentina 2025-04-28T12:56:10Z 2025-04-28T12:56:10Z 2024-12 info:ar-repo/semantics/artículo info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/20.500.12123/22078 https://www.publish.csiro.au/AN/AN24146 1836-5787 https://doi.org/10.1071/AN24146 eng info:eu-repograntAgreement/INTA/2023-PD-L01-I108, Mejora genética animal en la era de la genómica y la ganadería inteligente: adaptación y resiliencia info:eu-repograntAgreement/INTA/2023-PD-L01-I087, Caracterización de la diversidad genética de plantas, animales y microorganismos mediante herramientas de genómica aplicada. info:eu-repograntAgreement/INTA/2023-PD-L01-I112, Biotecnologías reproductivas y plataforma de edición génica para animales de interés zootécnico. info:eu-repo/semantics/reference/hdl/20.500.12123/17558 info:eu-repo/semantics/restrictedAccess http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) application/pdf CSIRO Publishing Animal Production Science 64 (18) : AN24146 (December 2024) |
| spellingShingle | Beta-casein Dairy Cattle Dairy Cows Milk Production Genotypes Alleles Breeding Value Genetic Variation Beta-caseína Ganado de Leche Vaca Lechera Producción Lechera Genotipos Alelos Valor Genético Variación Genética Raza Holstein Caffaro, María Eugenia Raschia, Maria Agustina Maizon, Daniel Omar Poli, Mario Andres Frequencies of β-casein variants and their influence on genetic merit for production traits in Holstein cows |
| title | Frequencies of β-casein variants and their influence on genetic merit for production traits in Holstein cows |
| title_full | Frequencies of β-casein variants and their influence on genetic merit for production traits in Holstein cows |
| title_fullStr | Frequencies of β-casein variants and their influence on genetic merit for production traits in Holstein cows |
| title_full_unstemmed | Frequencies of β-casein variants and their influence on genetic merit for production traits in Holstein cows |
| title_short | Frequencies of β-casein variants and their influence on genetic merit for production traits in Holstein cows |
| title_sort | frequencies of β casein variants and their influence on genetic merit for production traits in holstein cows |
| topic | Beta-casein Dairy Cattle Dairy Cows Milk Production Genotypes Alleles Breeding Value Genetic Variation Beta-caseína Ganado de Leche Vaca Lechera Producción Lechera Genotipos Alelos Valor Genético Variación Genética Raza Holstein |
| url | http://hdl.handle.net/20.500.12123/22078 https://www.publish.csiro.au/AN/AN24146 https://doi.org/10.1071/AN24146 |
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