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.

The concept of modern industrial production of pigs on commercial farms is based, among other things, on the implementation of biosecurity measures as well as solving problems of environmental protection, which greatly burden the production. It is well known that good health is a prerequisite for good pig reproduction, that is, a successful and profi table production. The health status of the herd depends on many factors such as the maintenance technology, nursing, nutrition, organization, level of staff training and systematic implementation of good health care policies. Today, we are witnessing high incidence of bacterial diseases, viral etiology and certain parasites that seriously aff ect the pig production in intensive farming conditions. Keeping such diseases under control is possible only by applying appropriate prophylactic and therapeutic measures, as well as by increased monitoring by professional services.

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The main goal of commercial pig production is to produce as much fattened pigs per sow per year as possible. Artificial insemination serves to enable maximum utilization of animal genetic potential. That is possible to achieve by applying adequate and controlled conditions of housing, care, feeding and health monitoring along with implementation of modern management. Expected production results on healthy farms implies farrowing rate of over 90% with 18 born piglets, 16 weaned piglets per liter, 37 piglets per sow per year and 31 fattened pigs per sow per year. Such results are achieved on modern farms in countries which invest a lot in pig production, but in Serbia are rarities. By analyzing of all factors which may cause reproductive problems on farms, we concluded that reproduction results can be improved by modern solutions from the domain of boar exploitation and technology of semen production. Motility and viability of spermatozoa to a large extent determine the quality parameters of sperm. Spermatozoa should be moved from the place of ejaculation through the reproductive tract of sows to the site of fertilization and to be capable to fertilize the oocytes at the right moment. Percentage of dead and deformed spermatozoa is an important factor which influences fertilization ability of boars. Besides routine macroscopic assessment and microscopic examination of semen, it is recommended to do smears and determine pathological forms of spermatozoa. It allows that bad quality semen can be excluded timely. Implementation of proper hygienic measures with the use of disposable equipment is required. By applying of all this specified measures during 12 months, we achieved improving of sows' conception rate for 7% and the number of weaned piglets per litter increased for 0.6.