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The identification of genes involved in phenotypes related to milk quality is important for both economic and health aspects in livestock production. The aim of this study was to assess the level of gelsolin gene expression in two breeds of dairy sheep - Sarda and Gentile - with pronounced differences in quantitative and qualitative milk traits. Gelsolin, a type of actin-modulating proteins is involved in the processes of actin remodeling during cell growth and apoptosis; therefore a role of this protein in mammary changes during lactation was here hypothesized. Individual milk samples were collected three times during lactation from 26 ewes of the two breeds. The differential gene expression of gelsolin in the two breeds and the three lactation times was estimated by quantitative PCR on RNA extracted from milk somatic cells. Correlations of gelsolin gene expression with milk yield and quality and days of lactation were also estimated. The results showed that gelsolin gene expression was significantly higher in the Sarda compared to the Gentile at each lactation stage, in agreement with the longer lactation duration and the higher daily milk yield of the first breed. Significant correlations of gelsolin gene expression were found with milk fat content in Sarda breed (-0.46, P<0.05). Gelsolin expression analysis confirmed the link between gelsolin gene function and milk fat content of sheep.

Longevity is one of the most important traits determining dairy cow profitability. In the last decades dairy cows suffered a lowering in the age at culling. With the aim to identify the genes involved in longevity, dates of birth, yields, dates of calving during lifespan and culling dates were collected for 946 culled cows which had been genotyped with the Bovine High Density panel. Using the GenABEL package in R, genome-wide association analysis was performed on three potential traits of longevity: (1) 'days in production,' (2) 'days in herd,' (3) number of calvings over lifespan.' Five genome-wide significant single nucleotide polymorphisms (SNPs) associated with all three longevity traits were detected. Several consecutive SNPs identified on chromosomes 16 and 30 indicated the presence of two suggestive quantitative trait loci (QTL). The genes comprised in the QTL regions had biological functions related to fertility, reproductive disorders, heat stress and welfare of cows. These findings might contribute to improving breeding strategies to improve longevity.

This study seeks to verify the feasibility of increasing twinning in a herd of the Italian autochtonous Maremmana breed. The data set included 1260 individuals born from 1963 to 2014, 527 males and 733 females, 402 of them calving at least once from 1983 through 2015. Breeding values for twinning were estimated by a single-trait linear animal model. However, since twinning is a dichotomous trait and the frequency of twins is far smaller than the frequency of single births, breeding values were also estimated by a single-trait animal threshold model. Heritability of twinning was 0.014±0.018 and 0.062±0.093 for the linear and the threshold models, respectively. Repeatability was 0.071±0.004 and 0.286± 0.012, respectively, for the two models. Genotyping with the Illumina BovineSNP54 BeadChip was performed for cows living on farm in 2012 (119 cows) and a genome-wide association analysis was performed on the corrected phenotype of all calving during the lifespan of each cow, using the GenABEL package in R and a three step GRAMMAR-GC approach. Genomic heritability, calculated from the genomic kinship matrix estimated through genomic marker data, was 0.29±0.021. The most significant detected single nucleotide polymorphisms (Hapmap22923-BTA-129564) was located in proximity of two genes, ARHGAP8 and TMEM200C, which might be potential functional candidates for twinning rate in cattle.

The aim was to investigate the effect of the genetic polymorphisms of leptin (LEP) and stearoyl-CoA desaturase (SCD1) genes on the fatty acid (FA) composition of the muscle of 103 Simmental bulls. Ten single nucleotide polymorphisms (SNP) were detected in exons 2 and 3 of the LEP gene, two of them encoding non-synonymous mutations. Allelic substitution effects of all the SNP on 28 single fatty acids, monounsaturated (MUFA) and polyunsaturated (PUFA) and desaturation indexes were estimated. Both the SCD1 SNP, as well as three SNP of the leptin gene, affected, to different extents, the desaturation of FA into MUFA. Because it was previously proposed that leptin's metabolic action involves down-regulation of SCD1, it is possible that, beyond the mere additive effect of SCD1 gene on FA desaturation, the non-synonymous mutations in the leptin gene also contribute to the variability of FA composition in muscle fat., (© 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.)

The aim of this study was to investigate the effect of Montbéliarde (Mb) gene frequency on fatty acid composition and sensory properties of Italian Simmental (IS) steaks (longissimus thoracis m.). Twenty-seven bulls belonging to three strains with different percentages of Mb genes: traditional (ISt), without Mb ascendants (ISt=0% Mb genes), cross-strain (ISmt=37.5-50% Mb genes), Montbéliarde strain (ISm=87.5-100% Mb genes) and balanced for stearoyl Co-A desaturase genotype were considered. ISt has the highest C20:4 n-6 (P<0.01), C22:4 n-6 (P<0.05) and total PUFA n-3 level (P<0.01), while ISt and ISmt have higher C18:3 n-3 (P<0.05) and slightly lower MUFA (P=0.08) than ISm. Sensory tests indicated that the three experimental groups can be differentiated; moreover, ISmt meat is perceived as less hard (P<0.01), less chewable (P<0.01) and less fibrous (P<0.05) than ISt meat.

To set up routine assays for molecular meat traceability along the food chain, the availability of a simple and low cost test for the identification of cattle carcasses is required. For this purpose, we evaluated 13 microsatellites for their ability in the identification of animals belonging to four Italian cattle breeds. Here we propose a criterion for a microsatellite-based test with the best reliability when reducing the number of loci to be analysed. The method is based on the observation that in the same loci breeds can show differences in frequencies and number of fixed alleles. This non-uniform distribution of alleles between breeds results in differences in the informative content of the same loci in different breeds. Taking into account these differences, it is possible to perform tests for the allocation of samples to specific animals utilizing a small number of microsatellites. The proposed approach allows cost reduction and ease in performing the analyses.