Berzal Herranz, Beatriz

Calvo Lacosta, Jorge Hugo

Joy Torrens, Margalida

Sarto Aured, María Pilar

Serrano, Mª Magdalena

citaREA Repositorio Electrónico Agroalimentario

EAAP – 62nd Annual Meeting, Stavanger 2011 185Genetic parameters of test day milk yield in Brazilian Girolando cattle using an autoregressive multiple lactation animal modelCosta, C.N.1, Freitas, A.1, Barbosa, M.V.1, Paiva, L.2, Thompson, G.3,4 and Carvalheira, J.3,4, 1Embrapa Gado de Leite, Juiz de Fora, MG, 36038-330, Brazil, 2Girolando Breeders Association, Uberaba, MG, 38040-280, Brazil, 3ICBAS, Universidade do Porto, Porto, 4099-003, Portugal, 4ICETA/CIBIO, Universidade do Porto, Vairão, 4485-661, Portugal; cnc1@mail.icav.up.ptThe Girolando is a dairy cattle formed by crossing the Holstein and the Gir breeds. It is the most predominant cattle in dairy farming in Brazil. In the late nineties the Girolando Breeders Association (GBA) started running an AI progeny test of crossbred young sires. Genetic evaluation is currently based on fitting a lactation model. This study was aimed to estimate variance components and genetic parameters for test day milk yield of Girolando cattle, using an autoregressive test day multiple lactations (AR) animal model. Data consisted of test day (TD) records produced by Girolando cows under milk recording supervised by the GBA. After editing, 108,218 TD records from the first three lactations of 9,119 cows, sired by 1,285 bulls and calving from 1992 to 2008 in 214 herds were used to fit the AR model that included the fixed effects of herd, year-season of calving, days in milk within lactation order, regressions on age at calving (linear and quadratic), additive direct, dominance and recombination effects. The random effects were animal, short and long term environmental effects (fitted with autoregressive covariance structures) and the residuals (accounting for heterogeneity of variance by parity number). Medium heritability estimates, ranging from 0.17 to 0.27 of milk TD yield indicate opportunities for genetic gain by selection. Results from this study confirm the potential of using TD yields to replace the lactation model to estimate breeding values of Girolando sires and cows in Brazil. Further studies are needed to compare the resulting predictions of breeding values from these two models and the impact on selection decisions made by dairy farmers and on the expected genetic gain in milk yield of the Girolando cattle.Characterization of the ovine αs1-casein (CSN1S1) gene and association studies with milk protein content in Manchega sheep breedCalvo, J.H.1, Serrano, M.2, Sarto, P.1, Berzal, B.1 and Joy, M.1, 1CITA, Tecnología en Producción animal, Avda. Montañana 930, 50059- Zaragoza, Spain, 2INIA, Mejora Genética Animal, Ctra. La Coruña km 7,5, 28040- Madrid, Spain; jhcalvo@aragon.esThere are evidences showing that polymorphism of the αs1-casein (CSN1S1) gene have been associated with an effect on milk protein, casein and fat content as well as on cheese yield in ruminants. This work focuses on the characterization and evaluation of the ovine αs1-casein (CSN1S1) as a candidate gene related to protein content. Primers were designed from ovine cDNA, bovine sequences and the Sheep Genome Assembly vs 1.0. Genomic DNA from animals with extreme values for protein content (n=8, Manchega and Assaf sheep breeds) was used to search polymorphisms. BLAST software was used to confirm gene identities. Subsequently, we used ClustalW software to align and identify polymorphisms. Studies of putative regulatory elements within the promoter and potential target sites for miRNA within the 3’ UTR regions were performed using TF Search and microinspector soft wares. The CSN1S1 complete genomic DNA sequence was determined (18,427-bp), including promoter and UTRs regions. Exons were identified by comparison with ovine and bovine sequences. Sequencing studies revealed 61 polymorphisms: 5 polyT, 1 poly A, 1 GT microsatellite, 2 indels and 52 SNPs. Two polymorphisms detected in the 5’ flanking region were located within possible trans-acting factor binding sites, modifying a putative CdxA and GATA-1 consensus sites. The 2 SNPs located in coding regions were synonymous substitutions (exon 14 and 17). Finally, a SNP located in exon18 modify a putative target site for a miRNA (bta-miR-631). This SNP was genotyped using RFLP-PCR. No associations were found between polymorphism in exon 18 and EBVs for protein content in a daughter design comprising 13 sire families in Manchega sheep breed. Further studies are being carried out in order to test the effect of CSN1S1 promoter polymorphisms in protein content.Session 30 Poster 25Session 30 Poster 24

Characterization of the ovine as1-casein (CSN1S1) gene and association studies with milk protein content in Manchega sheep breed

http://citarea.cita-aragon.es/citarea/bitstream/10532/1693/1/2011_305.pdf

Characterization of the ovine as1-casein (CSN1S1) gene and association studies with milk protein content in Manchega sheep breed

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