Evaluation of single-nucleotide polymorphisms in CAPN1 for association with meat tenderness in cattle

Micromolar calcium activated neutral protease (CAPN1) was evaluated as a candidate gene for a quantitative trait locus (QTL) on BTA29 affecting meat tenderness by characterization of nucleotide sequence variation in the gene. Single-nucleotide polymorphisms (SNP) were identified by sequencing all 22 exons and 19 of the 21 introns in two sires (Piedmontese X Angus located at the U.S. Meat Animal Research Centre in Clay Centre, NE; Jersey X Limousin located at AgResearch in New Zealand) of independent resource populations previously shown to be segregating meat tenderness QTL on BTA29. The majority of the 38 SNP were found in introns or were synonymous substitutions in the coding regions, with two exceptions. Exons 14 and 9 contained SNP that were predicted to alter the protein sequence by the substitution of isoleucine for valine in Domain III of the protein, and alanine for glycine in Domain II of the protein. The resource populations were genotyped for these two SNP in addition to six intronic polymorphisms and two silent substitutions. Analysis of genotypes and shear force values in both populations revealed a difference between paternal CAPN1 alleles in which the allele encoding isoleucine at position 530 and glycine at position 316 associated with decreased meat tenderness (increased shear force values) relative to the allele encoding valine at position 530 and alanine at position 316 (P < 0.05). The association of maternal alleles with meat tenderness phenotypes is consistent with the hypothesis of CAPN1 as the gene underlying the QTL effect in two independent resource populations and presents the possibility of using these markers for selective breeding to reduce the numbers of animals with unfavourable meat tenderness traits

Freqüência do gene Miostatina (GDF-8) em rebanhos brasileiros da raça Marchigiana Frequency of myostatin gene (GDF-8) in Marchigiana herds in Brazil

Identificou-se e determinou-se a freqüência do gene miostatina (GDF-8) normal e mutante em rebanhos Marchigiana, em 377 bovinos da raça Marchigiana, criados nos estados de São Paulo e Paraná. Identificaram-se 37,9% de animais normais, 55,2% de portadores e 6,9% homozigotos afetados para musculatura dupla. Estes resultados indicam que os criadores têm interesse na característica musculatura dupla, promovendo, ainda que aleatoriamente, selecão a favor da mutação.<br>The frequency of the normal myostatin gene (GDF-8) and the mutant allele in Marchigiana herds was detected. Three hundred and seventy-seven animals of Marchigiana breed raised in São Paulo and Paraná States, Brazil, were tested. The results showed that 37.9% were homozygous normal animals, 55.2% heterozygous and 6.9% homozygous double muscling. The results suggest the interest of the breeders in having interest in the character double muscling, randomly promoting, the selection in favor of the mutation

Energetic efficiency of protein and body fat retention in crossbred Bos indicus and Bos Taurus &#215; Bos indicus raised under tropical conditions Eficiência energética de retenção de proteína e gordura corporal em zebuínos e mestiços Europeu &#215; Zebu mantidos em clima tropical

The efficiency of fat and protein retention by Bos indicus and its cross-breds was estimated from data obtained in the literature to verify possible differences between these animals and Bos taurus. After estimating the efficiencies, a correction factor was used to discount the metabolizable energy fraction that was spent in the maintenance and support metabolism processes. The efficiencies were then estimated again, assuming that all the remaining energy would correspond to the metabolizable energy available for body mass retention. The correction value used was considered satisfactory to discount energetic losses for maintenance and support. The efficiency values of partial body fat and protein retention in Bos indicus and its cross-bred were very similar to values reported by other authors who researched Bos taurus exclusively.<br>A eficiência com que animais zebuínos e seus cruzamentos transformam a energia metabolizável consumida em gordura e proteína corporal foi estimada a partir de informações obtidas na literatura no intuito de verificar se existem diferenças entre esses animais e os de raças europeias. Após a estimativa das eficiências, usou-se uma correção para descontar a porção da energia metabolizável gasta na manutenção da massa corporal e no metabolismo de suporte. Posteriormente à aplicação da correção, as eficiências foram estimadas novamente, partindo-se do pressuposto de que o montante de energia restante corresponderia à energia metabolizável utilizada para acúmulo de massa corporal. O valor de correção utilizado foi considerado suficiente para descontar as perdas energéticas para mantença e suporte. Os valores de eficiência de retenção parcial de gordura e proteína corporal em animais zebuínos e mestiços Europeu &#215; Zebu são muito próximos dos encontrados por outros autores em pesquisas com animais exclusivamente europeus

Report of the first workshop on the genetic map of bovine chromosome 1

A report of the first workshop on the genetic map of bovine chromosome 1 (BTA1) is presented. Five laboratories contributed 31 962 informative meioses from 70 loci. Thirty-two loci which had been typed by at least two laboratories were used to construct a framework genetic map with a likelihood ratio support of at least 1000:1 for locus order. The resulting sex-averaged framework map contained 26 loci and spanned 163.6 CM. The lengths of the female and male maps were 159.5 CM and 165.3 CM, respectively, and there was evidence for an expansion in the telomeric one-third of the male map. Of the four cases where order for closely linked loci differed among the maps produced for each of the contributing laboratories, a consensus order was obtained for three in the framework map. The average genetic distance between framework loci on the sex-averaged map was 6.3 CM