Vladimir Margeta

Differentiation of pork longissimus dorsi muscle regarding the variation in water holding capacity and correlated traits

Abstract This study was performed on 87 randomly selected carcasses of castrated pigs, slaughtered at approximately 100 kg live weight in 2 abattoirs from east Croatia. Important meat quality traits were measured on the samples of musculus longissimus dorsi: initial and ultimate pH values (pH45 and pH24), meat colour and drip loss. Samples were further differentiated into 5 groups on the base of meat quality conditions. Results show that 14.66%, 32%, 40%, 10.67% and 2.66% of the longissimus dorsi muscles belonged to PSE, RSE, RFN, PFN and DFD conditions respectively. The highest correlations were observed between ultimate pH value, drip loss and meat colour. Interpolated threshold value for ultimate pH was 5.69. It is suggested to verify the values used for differentiation of meat according to quality on a larger sample.

A simple DNA based method for determination of pure Black Slavonian pigs

Abstract The aim of this work was to determine the MC1R genotype of Black Slavonian pigs and to find an efficient and simple PCR-RFLP method, based on differences in MC1R genotype, to distinguish between purebred Black Slavonian pigs and their crossings with commercial pig breeds and Wild Boars. Sequencing of the MC1R exon was performed to determine the genotype of MC1R in Black Slavonian pig breed, which was shown to be MC1R*2. Digestion reactions of both PCR products representing the majority of MC1R exon revealed presence of the BspHI restriction site at position 121 and absence of the AccII and CrfI restriction site at position 240, which is characteristic for the MC1R*2 genotype. A simple PCR-RFLP method, based on different coat colour MC1R gene genotypes was determined by which it is possible to detect potential crossings of autochthonous Black Slavonian pig with commercial pig breeds and also with Wild Boars.

Influence of housing systems on stillbirth and mortality rate in preweaning pigs farrowed by different gilt breeds

Abstract The aim of this paper was to investigate the influence of housing systems on stillbirth and mortality rate in preweaning pigs farrowed by different gilt breeds. The investigation included first farrowings of 225 Large White (LW) gilts, 297 Swedish Landrace (SL) gilts and 260 crossbreed gilts (LWxSL) in the period of five years. Despite of positive influence of straw through decreased number of stillborn pigs, especially in LW gilts, in further process of production until weaning, less appropriate microclimatic conditions developed in farrowing houses with straw, especially if accompanied with poor ventilation, can result with higher number of perished pigs and lower number of weaned pigs. Most sensible to unsuitable microclimatic conditions in straw bedded farrowing houses, according to the number of perished pigs before weaning, were the pigs from SL gilts, while the pigs from crossbreed gilts LWxSL were the most resistant. These results suggest that adding straw requires special attention on influence of such production on microclimate conditions in pigs’ biozone in order to maintain its initial benefits in the time of farrowing through the whole preweaning period, especially in pure breeds of gilts.

Análise genética de raças suínas autóctones da Croácia através do uso de microssatélites como marcadores

Black Slavonian pig (BS) and Turopolje pig (TP) are two Croatian autochthonous pig breeds. At the beginning of this century attempts were made to preserve and re-establish them, which included also employment of the genetic methods for studying genetic characteristics of both breeds. The number of Black Slavonian breed sows was increased from 237 in 2001 to 1305 last year, while the number of Turopolje breed sows rose from 45 to 132 in the same period. A set of 18 microsatellite markers was used to genotype 20 BS pigs, 20 TP pigs and 20 wild boars. The basic statistical analysis included number of samples, number of alleles for each locus, expected and observed heterozygosity, FIS and their statistical significance FISsign. In observed populations, a relatively high variety of loci was present. Average heterozygosity was between 0.35 and 0.64. The average fixation index (FST) was 0.24. Multilocus FST values indicated that around 24% of the total genetic variation was explained by population differences, with the remaining 78% corresponding to differences among individuals within population. Genetic distances between populations were made with PCA method and it was noticed that studied populations are clearly defined. The analysis of population structure indicates no admixture among analysed breeds. However, some substructuring in the Black Slavonian pig population was observed. Results confirmed usefulness of microsatellites for studying genetic diversity among Croatian autochthonous pig breeds, but for obtaining more accurate results, a study involving larger number of animals and other related breeds would be required.

Genetic diversity of autochthonous pig breeds analyzed by microsatellite markers and mitochondrial DNA D-loop sequence polymorphism

Abstract The evaluation of the genetic structure of autochthonous pig breeds is very important for conservation of local pig breeds and preservation of diversity. In this study, 18 microsatellite loci were used to detect genetic relationship between autochthonous pig breeds [Black Slavonian (BS), Turopolje pig (TP), and Croatian wild boar] and to determine phylogenetic relationship among Croatian autochthonous pig breeds and certain Asian and European pigs using the mitochondrial DNA (mtDNA) D-loop sequence polymorphism. Relatively high degree of genetic variation was found between the observed populations. The analysis of mtDNA showed that haplotypes of the studied pig populations are different from the other European and Chinese haplotypes. BS pigs showed some similarities with Mangalitsa and Duroc breeds. The genetic distances of TP can be explained by high degree of inbreeding during the past century. Despite the European origin of Croatian pig breeds with some impact of Chinese breeds in the past, the results of present study show that genetic diversity is still pronounced within investigated breeds. Furthermore, the genetic diversity is even more pronounced between Croatian breeds and other European and Chinese pig breeds. Thus, conservation of Croatian pig breeds will contribute to overall genetic diversity preservation of pig breeds.

Efficiency of PCR-RFLP and species specific PCR in identification of meat origin in dry sausages

The purpose of the investigation was the identification of chicken, beef and sheep meat in pork sausages using PCR-RFLP and PCR with species specific primers. Six dry fermented pork sausages were produced by adding beef, sheep and chicken meat to each in the amount of 1% and 5%. DNA was extracted from five locations of each sausage and PCR-RFLP together with PCR using species specific primers was performed. PCR-RFLP analysis was successful only for chicken meat, while species specific PCR was effective for identification of chicken, beef and sheep meat in all ratios and at all locations. The results of our study showed that in investigated products discovering of adulteration using PCR-RFLP is suitable only for chicken meat, while for detection of beef and sheep meat use of species specific oligonucleotides is more adequate.

Carcass leanness of pigs in Croatia estimated by EU referent method

Abstract The experiment was performed on 146 swine carcasses slaughtered at several Croatian slaughterhouses, selected according to backfat measures obtained by method for lean percentage prediction approved in Croatia (NN 40/2007). One day after slaughter left sides of the carcasses were dissected according to EU reference method (Commission Regulation No 3127/94, Walstra and Merkus, 1996). The dissected lean percentage was assessed using the formulae prescribed in EU Regulation from 1994 (Commission Regulation (EC) No 3127/94) and 2006 (Commission Regulation (EC) No 1197/2006). There were statistically significant differences between the lean shares estimated by Croatian prediction routine and assessed by both previous and current European regulation (p<0.01). When pig carcasses were classified by SEUROP system based on the lean percentage established by three mentioned methods, the distribution into quality classes was markedly different. It was concluded that because of substantial difference between the procedures for estimation of dissected lean percentage (51.00 vs 56.32%) further investigations on that matter are suggested. Croatian lean meat prediction equation significantly differed from dissected lean expressed by both European assessment methods and needs to be adjusted.