Ivan Pihler

Detecting population admixture in honey bees of Serbia

Summary Honey bee workers were sampled across the Serbian territory during 2009–2010 from mostly non-migratory apiaries to determine the population structure of these bees using morphometric, genetic, and spatial information. A total of 134 bees were sampled, of which 77 were analysed using classical wing morphometrics and 122 bees were successfully analysed using 24 DNA microsatellite markers. A combination of methods including multivariate statistics and assignment tests (frequency-based and Bayesian) revealed the honey bees of this region to resemble the subspecies Apis mellifera macedonica, Apis mellifera carnica or hybrids of these two subspecies. Based on Bayesian assignment (‘Structure’) and spatial PCA, honey bees within the Serbian territory were composed of 56%-58% A. m. carnica and 42%-44% A. m. macedonica. Spatial analysis showed the existence of a north-west to south-east cline in genetic differentiation. The bees in the north-west resemble A. m. carnica,while the bees in the south-east of the country are more similar to A. m. macedonica. Thus, the extent of A. m. macedonica within Serbia was greater than previously estimated. We define a line of hybridisation between A. m. carnica and A. m. macedonica within our study area. The cline of differentiation was still evident using a combination of genetic and spatial information, in spite of beekeeping activities including transhumance and breeding efforts.

Reproductive traits of German fawn goats in Vojvodina.

Reproductive efficiency of goats of German fawn breed was established based on reproduction parameters: age of goats at first mating and first kidding, duration of gestation, kidding interval, number of kids in the litter and mass of kids at birth and weaning. Average age of goats at first mating was 242 days, and first kidding 398,1 days. Duration of gestation was in average 151,6 days, and kidding interval 337 days, which is characteristic for dairy goat breeds. Number of kids in litter varied from 1 to 4, and in average it was 1,96 kids. Average mass of kids at birth was 3,38 and differed significantly depending on the sex, type of birth and order of kidding (parity), whereas the mass of kids at weaning was 18,39 kg and was under the influence of sex and type of birth. Based on presented reproductive indices of German fawn goats in Vojvodina, it can be concluded that this breed has adjusted well to local conditions and that they realize results similar to those obtained in Germany, the country of origin.

Genetic differentiation between the Old and New types of Serbian Tsigai sheep

Two Tsigai sheep populations exist in Serbia: the Old type, called Čokan, and the New type. It is assumed that the New type results from upgrading Tsigai sheep with exotic genetic material. We investigated genetic diversity and differentiation of these types by analysing 23 autosomal microsatellites. Tests for Hardy-Weinberg proportions, linkage equilibrium between genotypes across loci and the calculation of inbreeding coefficients were performed and the deficiency in the number of alleles within the Tsigai types was examined using a Wilcoxon sign-rank test. The New type displayed a higher level of genetic variability than the Čokan in terms of allele numbers, but the New Tsigai showed a pattern of heterozygosity deficiency. The positive f value for the Čokan suggests the occurrence of inbreeding in this type. The proportion of linkage disequilibrium was below that expected by chance. Exclusion of two loci in Hardy-Weinberg disequilibrium did not alter our conclusions based on the entire data set i.e. the two Tsigai types are clearly differentiated and the New Tsigai type has been influenced by crossbreeding. Therefore, the Čokan Tsigai should be considered as a distinct endangered breed in the FAO classification.

Ultimate pH, colour characteristics and proximate and mineral composition of edible organs, glands and kidney fat from Saanen goat male kids

ABSTRACT Ultimate pH value and instrumental colour (CIEL*a*b* values) characteristics, proximate (moisture, protein, total fat and total ash) and mineral composition (K, P, Na, Mg, Ca, Zn, Fe, Cu, Ni and Mn) were determined in 10 (heart, tongue, lungs, spleen, liver, kidney, brain, testicle, thymus and kidney fat) edible by-products of Saanen goat male kids. Many significant or numerical differences were found in the mean values of quality characteristics among the edible by-products. Among edible organs and glands, liver had the lowest surface CIEL* value (darkest colour), and the highest levels of protein, Zn, Cu and Mn. Furthermore, the highest pH24h, total ash, K, P and Mg levels were determined in the thymus. The testicle had the highest moisture, Ca and Ni levels. The spleen had the lowest fresh cut cross-section CIEL* value (darkest colour), and the highest Fe level. The highest total fat content and Na level were determined in the brain and kidney, respectively. Among all the edible by-products, kidney fat had the highest pH24h, surface CIEL* value (lightest colour) and total fat content, and the lowest moisture, protein, total ash, K, P, Na, Mg, Ca, Zn, Fe, Cu, Ni and Mn levels.