Dragomir Lukač

Heritability and repeatability estimates of reproduction traits in purebred pigs

Research was performed on four farms, on 2434 highly fertile females Landrace and Yorkshire, and 28 boars of Danish origin, or 7684 consecutive parities, in period 2009 - 2012. Study of genetic parameters of conventional breeds Landrace and Yorkshire were conducted on 3964 females who mated with 49 males or 15764 litters in the same period. Estimates of genetic parameters for litter size show the same tendency as the legality of the purebred sows that produce 11-14 weaned piglets less per sow per year. Environmental factors, HYS, food technology and management expressed no significant effect on traits. Heritability and repeatability of live and still born piglets, litter size and the live at day 5 after birth and the number of piglets weaned in category of low hereditary traits whose values vary within the limits of 0.07 to 0.12 for the heritability and from 0.15 to 0.19 for the repeatability. There was tendency of lower values of genetic parameters in the conventional compared to highly fertile sows, which is considered to be the effect of selection on gene frequency for the observed traits.

Growth intensity of the fertile breed gilts in the nucleus pig farm

Production in the farm directly depends on the quality of gilts. For this reason it would be necessary to replace non-productive sows. By monitoring and control of the growth intensity in the performance test make possibility to provide selection effect and get gilts adequate age and weight at insemination. The present paper analyses of growth traits from birth until the end of the performance test. The investigations included 205 gilts, of which 104 Landrace and 101 Yorkshire, which were obtained from 7 sires (4 of Landrace and 3 of Yorkshire breed). The gilts that had a smaller weight at birth, showed a smaller daily gain and body weight realized at the end of the test. Lactation duration of 32 days, weight at weaning was not less than 7 kg. During the test of 85 days, the realized average weight was 76 kg, with a gain of 0.90 kg for Landrace gilts, while Yorkshire had smaller one (71 kg) and so smaller daily gain (0.84 kg). With an average age of gilts of 160 days, Landrace gilts reached weight 108 kg, with an average life gain of 0.67 kg, while the Yorkshire gilts reached weight of 101 kg, with an average life gain of 0.62 kg. Tests of significance showed that the sire, breed and weight at birth have a highly significant impact on most of the observed traits and represent a significant source of phenotypic variability in growth traits of tested gilts.

Neki parametri nutritivnog kvaliteta mesa svinja rase mangulica i landras

The aim of this study was to provide a comparative analysis of chemical and fatty acid composition, as well as of the connective tissue proteins in pigs of different genotypes, Mangalitsa and Landrace. Both pig genotypes were fed with the same feed of standard composition and quality. At the end of the fattening period, in total 24 pigs of both genotypes were slaughtered. Based on the analysis of the chemical composition we came to the conclusion that the protein content in both genotypes was similar. Moisture and ash content in the Landrace pig genotype differed significantly (P<0.01) compared with genotype of pigs Mangalitsa breed. Statistically significant differences (P<0.01) were established in the fat content, which was 7.95 g/100g, in pigs of Mangalitsa breed and 1.59 g/100g in the Landrace pigs breed. Content of hydroxyproline, non-proteinogenic amino acids, in meat of Landrace was significantly higher (P<0.01) compared to the content in the Mangalitsa breed. The same tendency was observed with regard to the connective tissue protein content as well as with the relative connective tissue protein content. The fatty acid composition of the meat indicated that the most common saturated fatty acid (SFA) in both tested breeds was palmitic fatty acid (C16), whose content was significantly higher in Landrace (P<0.01) compared with its content in Mangalitsa breed. In addition, the share of stearic acid (C18) was significantly higher (P<0.01) in Landrace compared to Mangalitsa pig breed, what significantly contributed to the increase of the SFA share in Landrace compared to Mangalitsa breed. The most common monounsaturated fatty acid in both pig breeds was the oleic fatty acid (C18:1), whose share was significantly higher in Mangalitsa compared to the Landrace breed (P<0.01). Out of the polyunsaturated fatty acids (PUFA), linoleic fatty acid (C18:2) was the most predominant in both pig breeds, with no statistically significant differences (P>0.05). The content of PUFA was not statistically significantly different between the tested breeds, as well as the content of n-3 and n-6 fatty acids, which caused no statistically significant differences in the n-6/n-3 PUFA ratio. Ratio of the unsaturated fatty acids, i.e., of the sum of MUFA and PUFA, and of the saturated fatty acids was significantly higher in Mangalitsa compared to Landrace breed (1.86 versus 1.4), and the same was observed when it comes to the relationship MUFA/SFA (1.51 in Mangalitsa versus 1.08 in Landrace breed) and MUFA/PUFA (4.35 versus 3.38).

Chicken genome modelling for the benefit of science

In the early 21st century, genetic modification of chicken primordial germ cells (PGCs) had not been possible before their transfer and recovery through germ line. Chicken PGCs resist deliberate genetic modification, probably by silencing the transgenes in the genome. The use of mobile genetic elements (transposons) in genetic modification and germ-line transmission of PGCs has recently overcome this problem, so that PGCs can be used for further chicken genome modelling in order to study developmental biology, non-coding RNA (ncRNA) functions, viral DNA-RNA hybridisation, silencing of transgene expression, together with epigenetic modification, and gene function. Application of the transposons, viral integrase, zinc-finger nuclease and site-specific recombinase in whole genome elucidation is not sufficient. The chicken PGCs can be used as a model of choice to establish a new generation of methodology for genome modelling. For this purpose the livesome vectors are proposed.

Estimation of genetic parameters and breeding values for litter size in the first three parity of landrace sows

The aim of this study was to estimate the genetic parameters and breeding values for reproduction traits of Landrace sows in the first three parities by Animal model. Records of 2238 first parity; 2125 second parity and 1872 third parity Landrace sows farrowing between 2007 and 2012 were included in the analysis. The traits included in the analyses were total pigs born (TB), number of pigs born alive (NBA), number of pigs weaned (NW) and litter weaning weight (LW) in the parities. The genetic parameters were estimated using a multivariate analyses Animal model using REML procedure. Estimates of heritability for TB were 0.03, 0.05 and 0.18, for NBA were 0.04, 0.02 and 0.17, for NW were 0.08, 0.08 and 0.01 and for LW were 0.09, 0.11 and 0.03 for parities 1 to 3. Genetic and phenotypic variance were increased from the first to the third parity. Between the majorities of studied reproductive traits were the recorded positive genetic and phenotypic correlations, except between LW and other analyzed properties where they recorded a high correlation negative in third parity. Means of estimated breeding values of reproductive traits from first parity to third parity was indecreased.

Basic chemical composition of meat and carcass quality of fattening hybrids with different slaughter weight

Meat is a very rich and universal source of nutrients. The primary importance of meat is based especially on protein content. Optimum slaughter weight has influence on the basic chemical composition of meat. Fattening pigs were classified by their weight into three groups before the slaughter day. The highest content of proteins and water was found in the part of ham and shoulder in the group of animals at 100–110 and 111–120 kg of live weight, respectively, while the lowest content was found in the part of neck in animals at 121–130 kg of live weight. The highest content of intramuscular fat and mineral substances was in animals at 121–130 kg (neck and loin), while the lowest content was in animals at 100–110 kg live weight (ham). The pH values were within the optimum limits (5.33–5.77). Differences between the groups for the values of proteins content, mineral substance and pH values were statistically highly significant (p 0.05) between the groups.

The effect of parental genotype and parity number on pigs litter size

The aim of this study was to investigate the effect of parental genotype and parity number on the litter size properties of sows (number of live born, stillborn and weaned piglets). The investigation was conducted on a farm in Vojvodina. The analysis included 65535 litters that originated from five genotypes of dams (sows with unknown origin, n = 20980; Yorkshire, n = 3189; Landrace, n = 22426; F1(YxL), n = 14251; F1(LxY), n = 4689) and five genotypes of sires (Yorkshire, n = 21641; Landrace, n = 26623; Pietrain, n = 485; Duroc, n = 13463; Hampshire, n = 3323). Based on the obtained results it can be concluded that the genotypes of the dams had statistically significant (p<0.01) influence on the observed litters properties. Landrace sows achieved the highest average number of born alive piglets (10.12) with a statistically significant difference (p<0.01) compared with sows of other genotypes. The observed effect of sire genotype on litter size properties was statistically significant (p<0.01), where the terminal genotypes were superior when it comes to the number of live born and weaned piglets. Regression analysis of dependence between parity and litter size recorded positive regression coefficients: number of live born (b = 0.007), stillborn (b = 0.09) and weaned piglets (b = 0.07). Influence of parity on the observed traits of litter size was highly statistically significant (p<0.01). [TR 31032]

Selection criteria in relation to pork carcasses quality.

The paper presents the effect of various selection criteria (Landrace, Yorkshire - productive dairy breed and Hampshire - terminal) on the carcasses quality, as well as differences between sex in regard to distribution of meat, fat and bones. The study included 210 randomly selected pig carcasses at commercial farms, classified by breed and sex. Carcass dissection was carried out according to the model of EU 1992. The percentage of meat in fertile breeds carcasses was 2.04% lower (55.02%), compared to the terminal breed (57.06%). Comparing the proportion of muscle tissue in carcasses of male and female animals, there was determined a statistically significant difference (P<0.05). Within the breeds there was no statistically significant difference (P>0.05) in percentage of meat between two fertile breeds (Landrace and Yorkshire). A statistically significant difference (P<0.05) between fertile and terminal Hampshire breeds was determined. Sex and breed had highly significant impact on the amount of meat in the carcasses. Also, sex had a significantly influenced the amount of fat, while breed significantly influenced the amount of bone in carcasses. The largest and most important part of the carcass is a leg with a share of 29.17% in male and 29.17% in female animals. Data collection on the slaughter line as well as knowledge of slaughterhouses properties are basic conditions for work on genetic improvement of pig carcass quality. Quality rating of pigs on the slaughter line and price formation is a prerequisite for establishing trust between farmers and slaughterhouses. Mutual interest lies also in profit, so farmers will earn more carrying out meatiness selection while slaughterhouses will buy cattle with more meat of optimal quality.