Effect of the FecX(R) polymorphism in the bone morphogenetic protein 15 gene on natural or equine chorionic gonadotropin-induced ovulation rate and litter size in Rasa Aragonesa ewes and implications for on-farm application
Loading...
Date
2011
Authors
Lahoz Crespo, BelénAlabart Alvarez, José Luis
Jurado, J.J.
Calvo Lacosta, Jorge Hugo
Martínez Royo, Alberto
Fantova Puyalto, Enrique
Folch Pera, José
Journal Title
Journal ISSN
Volume Title
Publisher
Typology
Journal ContributionArticle
Abstract
A new mutation in the bone morphogenetic protein 15 (BMP15) gene (FecXR allele) causing increased prolificacy in heterozygous (R+) and sterility in homozygous ewes has been recently described in Rasa Aragonesa, a low-prolificacy Mediterranean breed. The current study determined, first, the effect of this polymorphism on natural and eCG-induced ovulation rate (OR) and the effect of eCG dose on reproductive performance; and second, its effect on prolificacy and its interaction with progestagen + eCG treatment on farms, which have not been reported to date. The FecXR allele increased OR by 0.44 and 0.63 ovulations in young (n = 91) and adult (n = 84) R+ ewes, respectively (both, P < 0.01), increments less than reported in prolific breeds carrying other mutations in BMP15. When the standard dose of eCG used on farms (480 IU) was applied to R+ ewes (n = 36), an extremely high OR (3.95) was recorded, which was accompanied by greater partial failure of multiple ovulations (PFMO). On the contrary, OR using 240 IU in R+ ewes (2.90; n = 35) was similar to 480 IU in wildtype (++) ewes (2.82; n = 48; both P < 0.01 when compared with 480 IU in R+ ewes). No differences were found in the birth weight of the offspring between R+ and ++ eCG-stimulated ewes within the same litter size. To validate the genealogy identification on farms, PCR genotyping was carried out in 1,667 ewes from 4 elite flocks, resulting in a negligible misclassification of R+ ewes, which demonstrated that identification by genealogy is a reliable tool to identify FecXR ewes within the breeding program. In recorded farms, the natural litter size of ++ ewes (1.34, n = 599,160 lambing records) was increased due to the FecXR allele by 0.35 lambs (P < 0.0001, n = 6,593 lambing records). A similar increase (0.30) was observed when comparing ++ and R+ ewes treated with 480 IU of eCG (P < 0.0001, n = 62,055 and n = 866, respectively). When applying 480 IU of eCG to R+ ewes, the increase in prolificacy was only due to increased percentages of triplets (P < 0.001) and quadruplets (P < 0.0001), but not of twin births. In conclusion, the favorable reproductive performance of R+ ewes, with 0.63 extra ovulations and 0.35 extra lambs per lambing ewe, is responsible for the increased interest in the use of this polymorphism. Nevertheless, care must be taken in the application of eCG to R+ ewes, with the current results showing that the standard dose increases prolificacy by only increasing triple and higher-order births.
Description
Keywords
Bibliographic citation
Lahoz, B.; Alabart, J. L.; Jurado, J. J.; Calvo, J. H.; Martinez-Royo, A.; Fantova, E.; Folch, J.. Effect of the FecX(R) polymorphism in the bone morphogenetic protein 15 gene on natural or equine chorionic gonadotropin-induced ovulation rate and litter size in Rasa Aragonesa ewes and implications for on-farm application. Journal Of Animal Science. 2011, 89 (11): 3522-3530
AGROVOC subjects
OvinoOvulación
Reproducción animal
Variedad específica de la zona
Gen
Sponsorship
This work was supported by TRACE PET-2008-0076 project (Spain). B. Lahoz and A. MartínezRoyo were supported by an INIA fellowship. The authors would also like to thank Pilar Sánchez and Elías Echegoyen for technical support and Nancy D´Cruz for manuscript revision. All authors
hold the patent related to the present research, entitled (ES)Procedimiento de mejora de la productividad en Ganado ovino”, number ES2338960 and published on 13/05/2010.