Investigating the population structure and genetic differentiation of livestock guard dog breeds.

Livestock guarding dogs are a valuable adjunct to the pastoral community. Having been traditionally selected for their working ability, they fulfil their function with minimal interaction or command from their human owners. In this study, the population structure and the genetic differentiation of three Italian livestock guardian breeds (Sila's Dog, Maremma and Abruzzese Sheepdog and Mannara's Dog) and three functionally and physically similar breeds (Cane Corso, Central Asian Shepherd Dog and Caucasian Shepherd Dog), totalling 179 dogs unrelated at the second generation, were investigated with 18 autosomal microsatellite markers. Values for the number of alleles per locus, observed and expected heterozygosity, Hardy-Weinberg Equilibrium, F stats, Nei's and Reynold's genetic distances, clustering and sub-population formation abilities and individual genetic structures were calculated. Our results show clear breed differentiation, whereby all the considered breeds show reasonable genetic variability despite small population sizes and variable selection schemes. These results provide meaningful data to stakeholders in specific breed and environmental conservation programmes.

Genetic characterization of four native Italian shepherd dog breeds and analysis of their relationship to cosmopolitan dog breeds using microsatellite markers.

Very little research into genetic diversity of Italian native dog breeds has been carried out so far. In this study we aimed to estimate and compare the genetic diversity of four native Italian shepherd dog breeds: the Maremma, Bergamasco, Lupino del Gigante and Oropa shepherds. Therefore, some cosmopolitan dog breeds, which have been widely raised in Italy for a long time past, have also been considered to check possible influence of these dog populations on the Italian autochthonous breeds considered here. A total of 212 individuals, belonging to 10 different dog breeds, were sampled and genotyped using 18 autosomal microsatellite loci. We analyzed the genetic diversity of these breeds, within breed diversity, breed relationship and population structure. The 10 breeds considered in this study were clearly genetically differentiated from each other, regardless of current population sizes and the onset of separate breeding history. The level of genetic diversity explained 20% of the total genetic variation. The level of H E found here is in agreement with that found by other studies. The native Italian breeds showed generally higher genetic diversity compared with the long established, well-defined cosmopolitan dog breeds. As the Border Collie seems closer to the Italian breeds than the other cosmopolitan shepherd dogs considered here, a possible utilization of this breed to improve working performance in Italian traditional working shepherd dogs cannot be ignored. The data and information found here can be utilized in the organization of conservation programs planned to reduce inbreeding and to minimize loss of genetic variability.

Effect of lycopene on semen quality, fertility and native immunity of broiler breeder.

1. The effect of drinking water supplementation with lycopene on the semen quality, fertility and immunity of broiler breeders was evaluated. 2. Broiler breeder males were individually caged from 25 to 42 weeks old and divided into two group: L group, treated birds (lycopene 0.5 g/l) and C group, control birds. Laying hens were divided into two groups and artificially inseminated. 3. Semen variables were evaluated and daily fertility recorded. Serum bactericidal activity was tested. 4. Semen production and viability were affected by lycopene supplementation. Serum bactericidal activity was better in L than in C group. The fertility rate curve of the L group displayed a positive trend.

Gene expression of hepatic glucocorticoid receptor NR3C1 and correlation with plasmatic corticosterone in Italian chickens.

This study examined breed-specific stress-related hormonal and gene expression profiles in three Italian chicken breeds (Valdarnese Bianca, Bionda Piemontese, Robusta Maculata) reared in controlled conditions. Glucocorticoids work through the glucocorticoid receptor (GR), which modulates target genes transcription. We investigated breed-specific changes in corticosterone (ELISA) and GR expression. GR mRNA levels were analyzed using one-tube, two-temperature real-time PCR for absolute quantification of the gene expression by the standard curve method. Our results show high expression of GR in hepatic tissue. Significant effect of the breed was recorded for plasma corticosterone concentration: Valdarnese Bianca 3.35 ng/mL, Bionda Piemontese 1.73 ng/mL, Robusta Maculata 2.02 ng/mL. Breed specific gene expression has been recorded with a GR ranging from 1.12E+04 (Robusta Maculata) to 1.00E+05 (Bionda Piemontese) mRNA copy number/100 ng total RNA. Negative correlation was found between gene expression and blood corticosterone level.