Ganho genético monetário para resistência ao carrapato com diferentes acurácias.

SIEPE

Delineamento de esquemas de seleção genômica para resistência ao carrapato bovino.

CONGREGA

Linkage disequilibrium, persistence of phase and effective population size estimates in Hereford and Braford cattle.

The objective of this study was to estimate LD levels, persistence of phase and effective population size in Hereford and Braford cattle populations sampled in Brazil.Article 32

Estimation of linkage disequilibrium, persistence of phase and effective population size of Brazilian Hereford and Braford breeds.

A set of 41,241 SNP genotypes from 2,435 Hereford (HH) and Braford (BO) bovines were analyzed to estimate linkage disequilibrium (LD) levels, persistence of phase and effective population size of these populations. LD levels were estimated using the squared correlation of alleles at two loci (r2) at varying distances. Average r2 between adjacent SNP was 0.21 for HH and 0.16 for BO. Average inter-marker distance was 61 kb in both breeds. Useful LD values (r2>0.2) were observed at 0-60 kb bins in HH and 0-20 kb bins in BO. Breeds demonstrated moderate to strong persistence of phase at all distances (range=0.53- 0.97). The greatest phase correlations (r>0.9) were found in 0-50 kb bins. LD estimates decreased rapidly with increasing distances between SNPs, however, useful LD was observed in genomic regions spanning up to ~50 kb

Estimation of linkage disequilibrium, persistence of phase and effective population size of Brazilian Hereford and Braford breeds.

A set of 41,241 SNP genotypes from 2,435 Hereford (HH) and Braford (BO) bovines were analyzed to estimate linkage disequilibrium (LD) levels, persistence of phase and effective population size of these populations. LD levels were estimated using the squared correlation of alleles at two loci (r2) at varying distances. Average r2 between adjacent SNP was 0.21 for HH and 0.16 for BO. Average inter-marker distance was 61 kb in both breeds. Useful LD values (r2>0.2) were observed at 0-60 kb bins in HH and 0-20 kb bins in BO. Breeds demonstrated moderate to strong persistence of phase at all distances (range=0.53-0.97). The greatest phase correlations (r>0.9) were found in 0-50 kb bins. LD estimates decreased rapidly with increasing distances between SNPs, however, useful LD was observed in genomic regions spanning up to ~50 kb

Distribuição de rhipicephalus (boophilus) microplus em diferentes regiões corporais de bovinos resistentes e suscetíveis ao carrapato.

Objetivou-se investigar diferenças na distribuição de carrapatos sobre regiões corporais de bovinos geneticamente resistentes ou sensíveis ao parasito. Participaram das avaliações 40 fêmeas da raça Braford previamente classificadas quanto à resistência e expostas a quatro infestações artificiais. Os dois grupos foram eficientes em limitar a frequência de larvas na região mediana, concentrando a quantidade de carrapatos na região posterior. Animais resistentes foram mais eficientes que os sensíveis em limitar a frequência dos carrapatos na região anterior e apresentaram maior frequência de carrapatos na região posterior que os hospedeiros suscetíveis