Accurate mathematical models to describe the lactation curve of Lacaune dairy sheep under intensive management
Although the intensive production system of Lacaune dairy sheep is the only profitable method for producers outside of the French Roquefort area, little is known about this type of systems. This study evaluated yield records of 3677 Lacaune sheep under intensive management between 2005 and 2010 in o...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2013-01-01
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| Series: | Animal |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S175173111200239X |
| _version_ | 1819100545479081984 |
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| author | L. Elvira F. Hernandez P. Cuesta S. Cano J.-V. Gonzalez-Martin S. Astiz |
| author_facet | L. Elvira F. Hernandez P. Cuesta S. Cano J.-V. Gonzalez-Martin S. Astiz |
| author_sort | L. Elvira |
| collection | DOAJ |
| description | Although the intensive production system of Lacaune dairy sheep is the only profitable method for producers outside of the French Roquefort area, little is known about this type of systems. This study evaluated yield records of 3677 Lacaune sheep under intensive management between 2005 and 2010 in order to describe the lactation curve of this breed and to investigate the suitability of different mathematical functions for modeling this curve. A total of 7873 complete lactations during a 40-week lactation period corresponding to 201 281 pieces of weekly yield data were used. First, five mathematical functions were evaluated on the basis of the residual mean square, determination coefficient, Durbin Watson and Runs Test values. The two better models were found to be Pollott Additive and fractional polynomial (FP). In the second part of the study, the milk yield, peak of milk yield, day of peak and persistency of the lactations were calculated with Pollot Additive and FP models and compared with the real data. The results indicate that both models gave an extremely accurate fit to Lacaune lactation curves in order to predict milk yields (P = 0.871), with the FP model being the best choice to provide a good fit to an extensive amount of real data and applicable on farm without specific statistical software. On the other hand, the interpretation of the parameters of the Pollott Additive function helps to understand the biology of the udder of the Lacaune sheep. The characteristics of the Lacaune lactation curve and milk yield are affected by lactation number and length. The lactation curves obtained in the present study allow the early identification of ewes with low milk yield potential, which will help to optimize farm profitability. |
| first_indexed | 2024-12-22T01:04:29Z |
| format | Article |
| id | doaj.art-6c741c72b7ec47508a688b1b76ff0f86 |
| institution | Directory Open Access Journal |
| issn | 1751-7311 |
| language | English |
| last_indexed | 2024-12-22T01:04:29Z |
| publishDate | 2013-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Animal |
| spelling | doaj.art-6c741c72b7ec47508a688b1b76ff0f862022-12-21T18:44:07ZengElsevierAnimal1751-73112013-01-017610441052Accurate mathematical models to describe the lactation curve of Lacaune dairy sheep under intensive managementL. Elvira0F. Hernandez1P. Cuesta2S. Cano3J.-V. Gonzalez-Martin4S. Astiz5TRIALVET S.L., C/ Encina, 22, 28721 Cabanillas de la Sierra, Madrid, SpainGranja Cerromonte S.L., San Juan de la Encinilla, 05358 Ávila, SpainInformatics Department for Research Support, Complutense University of Madrid, Avda de la Complutense s/n, 28040 Madrid, SpainInformatics Department for Research Support, Complutense University of Madrid, Avda de la Complutense s/n, 28040 Madrid, SpainTRIALVET S.L., C/ Encina, 22, 28721 Cabanillas de la Sierra, Madrid, Spain; Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Complutense University of Madrid (UCM), Avda Pta. de Hierro s/n, 28040 Madrid, SpainDepartment of Animal Reproduction, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Avda Pta. de Hierro s/n, 28040 Madrid, SpainAlthough the intensive production system of Lacaune dairy sheep is the only profitable method for producers outside of the French Roquefort area, little is known about this type of systems. This study evaluated yield records of 3677 Lacaune sheep under intensive management between 2005 and 2010 in order to describe the lactation curve of this breed and to investigate the suitability of different mathematical functions for modeling this curve. A total of 7873 complete lactations during a 40-week lactation period corresponding to 201 281 pieces of weekly yield data were used. First, five mathematical functions were evaluated on the basis of the residual mean square, determination coefficient, Durbin Watson and Runs Test values. The two better models were found to be Pollott Additive and fractional polynomial (FP). In the second part of the study, the milk yield, peak of milk yield, day of peak and persistency of the lactations were calculated with Pollot Additive and FP models and compared with the real data. The results indicate that both models gave an extremely accurate fit to Lacaune lactation curves in order to predict milk yields (P = 0.871), with the FP model being the best choice to provide a good fit to an extensive amount of real data and applicable on farm without specific statistical software. On the other hand, the interpretation of the parameters of the Pollott Additive function helps to understand the biology of the udder of the Lacaune sheep. The characteristics of the Lacaune lactation curve and milk yield are affected by lactation number and length. The lactation curves obtained in the present study allow the early identification of ewes with low milk yield potential, which will help to optimize farm profitability.http://www.sciencedirect.com/science/article/pii/S175173111200239XLacaunedairy sheeplactation curvecurve fittingfractional polynomial |
| spellingShingle | L. Elvira F. Hernandez P. Cuesta S. Cano J.-V. Gonzalez-Martin S. Astiz Accurate mathematical models to describe the lactation curve of Lacaune dairy sheep under intensive management Animal Lacaune dairy sheep lactation curve curve fitting fractional polynomial |
| title | Accurate mathematical models to describe the lactation curve of Lacaune dairy sheep under intensive management |
| title_full | Accurate mathematical models to describe the lactation curve of Lacaune dairy sheep under intensive management |
| title_fullStr | Accurate mathematical models to describe the lactation curve of Lacaune dairy sheep under intensive management |
| title_full_unstemmed | Accurate mathematical models to describe the lactation curve of Lacaune dairy sheep under intensive management |
| title_short | Accurate mathematical models to describe the lactation curve of Lacaune dairy sheep under intensive management |
| title_sort | accurate mathematical models to describe the lactation curve of lacaune dairy sheep under intensive management |
| topic | Lacaune dairy sheep lactation curve curve fitting fractional polynomial |
| url | http://www.sciencedirect.com/science/article/pii/S175173111200239X |
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