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Survival analysis of sow longevity and lifetime reproductive performance – Review
75-80Views:319Sow longevity plays an important role in economically efficient piglet production. Improving sow longevity results increase in the productivity and profitability of a sow herd. Longevity is a complex trait with many factors that can contribute to a sow having a long and productive life. Not only the sow’s genetics, but also nutrition, environment and the management policies are important. In addition, the removal of non-productive sows along with the introduction of replacement gilts is an essential part of maintaining herd productivity at a constantly high level. The objective of this paper was to summarize the current knowledge about the sow longevity and lifetime performance values, as well as, discusses the survival analysis methods for sow longevity traits. This method can estimate the hazard rate indicating proportional risk of sows being culled at any given time, in addition, it is able to investigate the effects of different factors on longevity. Identifying factors that influence the longevity could assist many commercial pig producers in becoming more efficient.
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Examination of the interval between litters (IBL) of different genotype HLW sows using survival analysis
13-17Views:243In this study our aim was to find out if there is a difference between the genotypes determined for the previously identified mutations of seven genes of the Hungarian Large White in terms of the time spent in production. We identified the previously determined alleles of the seven genes (BF, EGF, ESR, FSHβ, H2AFZ, LEP, PRLR) related to proliferation that were and performed the survival analysis between breeds indicating the risk of culling and the time spent in production on the given farm. Based on the results of survival analysis by Log-rank test, Breslow (Generalized Wilcoxon) and Tarone-Ware test we concluded that they indicated a significant difference in case of the genes BF (Breslow and Tarone-Ware tests) the EGF (Log-rank and Tarone-Ware tests) and ESR (Log rank test) based on which the curves of the survival of the certain genes varied form one another significantly.
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Survival Analysis of Hungarian Large White, Duroc and Pietrain Sows
31-36Views:273The aim of the present study was to perform lifetime performance analysis in three pig breeds; Hungarian Large White (n=295), Duroc (n=76) and Pietrain (n=91) on a commercial farm using analysis of survival sows. We took into consideration the age of sows at the time of their inclusion into breeding, their age at the time of culling, time spent in production, number of mating and parities, parity percentage, intervals between litters, number and mean of piglets born alive and born dead, number of raised piglet litters, number and mean of 21 days old piglets, the weight and mean of raised litter and raise percentage.
We carried out the analysis by SPSS 22.0. Single factor analysis of variants, Kaplan-Meier analysis and Cox PH model were used. The determination of the significance of risk rates differences was done by Wald chi square test.
Our results showed that the average culling age were 1056 (±33.52) days for the Hungarian Large White, 735 (±73.56) days for Duroc and 818 (±71.98) days for the Pietrain.
The log rank test of the survival analysis indicated a significant difference between the three tested genotypes (χ2=16.981, P<0.001), which means that the survival percentage of the individual breeds varied significantly from one another. In comparison with the Hungarian Large White genotype the Duroc genotype has a 1.6 times higher (P<0.001) culling risk while that of the genotype Pietrain was 1.36 times higher (P<0.001).
Our results can be used to compare the breeds kept under the same conditions and to compare the life span of one genotype under different farming conditions. Factors that increase survival and improve the profitability of pig farming can be determined by this method.
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Brief overview of the polymorphism analysis of genes affecting pig prolificacy (LEP, PRLP, ESR BF, EGF, FSH-β, H2A.Z)
5-10Views:187Researches are being performed around the world to increase swine prolificacy by using marker-assisted selection (MAS). The present study processes researches of polymorphism examinations on 7 genes. The result of the experiments showed that the leptin gene (LEP) prolactin receptor gene (PRLP), estrogen receptor gene (ESR), properdin B (BF) epidermal growth factor (EGF), follicle-stimulating beta gene (FSH-ß) and Z member of the H2A histon family gene (H2A.Z) and their alleles have a positive effect on reproductive characteristics of different swine breeds. In addition to this, leptin gene (LEP) influences the build, meat production and growth of body fat. Further studies are concerned with the polymorphism of an increasing number of genes, which enables a faster genetic development of swine breeding.
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The analysing of value measuring features of Hungarian speckled hen
17-23Views:53Our College has been dealing with the crossbreeding of two Hungarian speckled hen breeds, the bare-neck and the featheredneck, to maintain the breeds since 1977. Apart from the gene preservation, we endeavour to find the best way for the production-purpose utilisation of the speckled hen stock. On the basis of our experiments the laying hens can be used in small-scale egg production. As for meat production, these pure-breds cannot compete with the various types of the colour-feathered hybrid constructions available in Hungary. On the basis of the results of the cross-breeding with cock-lines of various hybrid types for direct production purposes we can conclude that the Hungarian speckled hen is suitable as a mother line to produce meat-type chickens in alternative breeding systems.