Mogućnosti upotrebe selekcijskog indeksa u proceni priplodne vrednosti krava Holštajn rase u Srbiji

The conducted research was aimed at constructing equations of selection index that would be used in the selection of the Holstein-Friesian breed animals in Serbia. The construction of the selection index includes the most important milk traits observed in standard lactation: milk yield (MY305), milk fat content (% MF305) and protein content (% MP305). The variance and covariance necessary for the construction of selection index are calculated using the mixed model by the method of least squares. The economic value of traits is expressed as a ratio of relative changes in costs per unit of traits included in the selection index. Livestock included in the research produced, in the first standard lactation, an average of 7681 kg of milk with 3.58% milk fat and 3.28% protein. The equation of the selection index presented in the paper is selected from the group of equations of selection index, as an equation with the highest correlation between the equation and the aggregate genotype, which amounted to 0.2156.Sprovedeno istraživanje imalo je za cilj konstruisanje jednačine selekcijskog indeksa koja bi se koristila u odabiru grla holštajn-frizijske rase u Srbiji. U konstrukciju selekcijskog indeksa uključene su najvažnije osobine mlečnosti posmatrane u standardnoj laktaciji: prinos mleka (PM305), sadržaj mlečne masti (%MM305) i sadržaj proteina (%MP305). Varijanse i kovarijanse neophodne za konstrukciju selekcijskog indeksa izračunate su primenom mešovitog modela metodom najmanjih kvadrata. Ekonomska vrednost osobina je izražena kao odnos relativne promene troškova po jedinici osobina uključenih u selekcijski indeks. Grla obuhvaćena istraživanjem prosečno su proizvela u prvoj standardnoj laktaciji 7681 kg mleka sa 3,58 % mlečne masti i 3,28% proteina. Jednačina selekcijskog indeksa prikazana u radu odabrana je iz grupe jednačina selekcijskog indeksa, kao jednačina sa najvećom korelacijom između jednačine i agregatnog genotipa, koja je iznosila 0,2156.

Internal Sources of Financing Companies on the Basis of Static and Dynamic Indicators: Comparative Analysis

AbstractThe Republic of Serbia is characterized by an unsatisfactory macroeconomic environment (high degree of illiquidity, high inflation rate, rising unemployment, decline in the level of capacity utilization, followed by the process of globalization, deregulation and liberalization of the market with all its negative connotations to the growth and development of our country). Under such conditions where there is a shortage of liquid assets, the financial capital has moved from the real to the financial sector, which led companies to over-indebtedness and shutdown of their own capacities. Therefore, capital investments largely depend on internal sources of financing and the ability of companies to internally generate funds for investments. In this regard emphasis is placed on the difference in the assessment of the investment ability of companies based on internal sources of financing measured using static and dynamic indicators in order to prove the necessity of applying dynamic coefficients which unfortunately are not present in our domestic practice

Selecting hardfacing technologies for ventilation mill suction plates and extending its working life

This paper presents results of the suction plate surface modification by hardfacing, of the ventilation mill in the Kostolac B power plant. Before applying hardfaced suction plates to exploitation conditions, it is necessary to study model hardfaced samples for determining the optimal tech-nology and filler material for revitalization. Experimental tests of revitalized mill suction plates in real exploitation conditions show that the proposed modification, hardfacing technologies and filler materials give good results. The relative weight loss of the suction plates after 1440 h period of exploitation in real conditions is 1-3%. The application of this approach can reduce the number of possible repairs and extends the period between them, resulting in significant economic effects

Odgajivačka strategija u malim i zatvorenim populacijama domaćih životinja

This paper reviews the main characteristics of small and/or closed livestock populations. Although the emphasis during the realization of the genetic improvement in animal breeding is put on commercial breeding programmes, autochthonous breeds, races, strains, even herds of domestic animas, at the same time represent a potentially important segment for achieving the maintenance of the overall livestock production. These programmes are particularly important for the improvement of populations of animal genetic resources, as well as for the improvement of production in rural marginal areas. One of the main parameters for determining the size, and also the potential danger of a population is a so called effective size of the population (Ne). This parameter is determined according to the available number of male and female head of breeding stock in the population or in the herd and it varies under the influence of the sexes, changes in the size of the families, changes in the size of the population during time, as well as overlapping of the generations. Apart from the improvement of the economically important traits, the breeding programmes in small populations first of all must provide the increase of the effective size of the population aiming to limit or decrease the inbreeding, as well as the decrease of the variance in the size of the family. This is mainly achieved with so called "circular breeding plans" the sires being replaced by sons in the reproduction, and dams by daughters. The shortage of the generation interval by the change of the presence of some age categories i.e. larger number of young animals and animals that are at the peak of production comparing to a small number of older animals, can additionally influence on the genetic improvement of the traits.U radu su prikazane osnovne karakteristike malih i/ili zatvorenih populacija domaćih i gajenih životinja. Iako se akcenat prilikom realizacije genetskog unapređenja u stočarstvu stavlja na komercijalne odgajivačke programe, autohtone vrste, rase, sojevi, pa i zapati domaćih životinja, takođe predstavljaju potencijalno važan segment za dostizanje održivosti celokupne stočarske proizvodnje. Ovi programi su naročito značajni za unapređenje populacija animalnih genetskih resursa, kao i za unapređenje proizvodnje u ruralnim marginalnim oblastima. Jedan od osnovnih parametara za određivanje veličine, pa samim tim i potencijalne ugroženosti jedne populacije jeste tzv. efektivna veličina populacije (Ne). Ovaj parametar se određuje na osnovu raspoloživog broja priplodnjaka i plotkinja u populaciji ili zapatu i varira pod uticajem odnosa polova, promena u veličini familija, promena u veličini populacije tokom vremena, kao i preklapanja generacija. Pored unapređenja ekonomski važnih osobina, odgajivački programi u malim populacijama na prvom mestu moraju obezbediti povećanje efektivne veličine populacije sa ciljem ograničavanja ili smanjivanja inbreeding-a, kao i smanjivanja varijanse u veličini familije. To se uglavnom postiže tzv. "cirkularnim odgajivačkim planovima" u kojima očeve u reprodukciji zamenjuju sinovi, a majke kćeri. Skraćenje generacijskog intervala promenom zastupljenosti pojedinih starosnih kategorija u smislu veće zastupljenosti mladih grla i grla koja su u vrhu proizvodnje, a na račun starijih grla, može dodatno uticati na genetsko unapređenje osobina

Selecting hardfacing technologies for ventilation mill suction plates and extending its working life

This paper presents results of the suction plate surface modification by hardfacing, of the ventilation mill in the Kostolac B power plant. Before applying hardfaced suction plates to exploitation conditions, it is necessary to study model hardfaced samples for determining the optimal tech-nology and filler material for revitalization. Experimental tests of revitalized mill suction plates in real exploitation conditions show that the proposed modification, hardfacing technologies and filler materials give good results. The relative weight loss of the suction plates after 1440 h period of exploitation in real conditions is 1-3%. The application of this approach can reduce the number of possible repairs and extends the period between them, resulting in significant economic effects

Ocena oplemenjivačke vrednosti bikova za broj somatskih ćelija u mleku

The incidence of subclinical and clinical mastitis in the mammary gland produces variety of defensive factors were nuclear leukocytes, lymphocytes and macrophages play an important role and they are marked as somatic cells. Somatic cell count depends on the type of pathogen and stage of infection. Increased number of somatic cells in milk occurs as a result of lesions in the mammary gland. Studies have shown that the somatic cells count is genetically predisposed. Although the heritability of this trait is low, using modern methods and the proper selection of work it is possible to achieve some progress. Therefore it is necessary to the selection of bulls for somatic cells, on the basis of somatic cells in milk of daughters. Data on milk yield and somatic cell count in milk of 247 cows Holstein Friesian and Simmental breed from Vojvodina province, were used to analyze the evaluation of breeding values for somatic cells in milk Average values and variability of somatic cells, milk yield, milk fat yield and protein and content of milk fat and protein were determined. The average number of somatic cells was 317 000 per ml of milk, with high variability. Average milk yield of 7 634kg with an average content and yield of milk fat from 3.74% to 285.69 kg and the average protein content and yield of 3.15% and 237.15 kg were determined. Assessment of breeding values was calculated using BLUP model of father, high variability in the assessment of bulls was found. Getting more accurate breeding values is possible using the Animal Model.Kod pojave subkliničkog i kliničkog mastitisa mlečna žlezda produkuje mnoštvo odbrambenih faktora od kojih značajnu ulogu imaju polimorfo nuklearni leukociti, limfociti i makrofage koje označavamo kao somatske ćelije. Broj somatskih ćelija zavisi od vrste uzročnika i stadijuma infekcije. Povećan broj somatskih ćelija u mleku javlja se kao posledica lezija na mlečnoj žlezdi. Istraživanja su pokazala da je broj somatskih ćelija genetski predisponiran. Iako je heritabilnost za ovu osobinu niska, uz pomoć savremenih metoda i pravilnog selekcijskog rada moguće je postići određeni genetski napredak. Zbog toga je potrebno vršiti selekciju bikova za broj somatskih ćelija i to na osnovu broja somatskih ćelija u mleku ćerki. Podaci o mlečnosti i broju somatskih ćelija u mleku kod 247 krava holštajn-frizijske i simentalske rase sa teritorije Vojvodine, korišćeni su za analizu ocene oplemenjivačke vrednosti za broj somatskih ćelija u mleku krava. Izračunate su prosečne vrednosti i varijabilnost broja somatskih ćelija, prinosa mleka, prinosa mlečne masti i proteina i sadržaja mlečne masti i proteina. Prosečan broj somatskih ćelija u ml iznosio je 317 000, sa velikom varijabilnošću. Utvrđen je prosečan prinos mleka od 7634 kg uz prosečan sadržaj i prinos mlečne masti od 3,74% i 285,69kg i prosečan sadržaj i prinos proteina od 3,15% i 237,15 kg. Ocena oplemenjivačke vrednosti je izračunata primenom BLUP modela oca, utvrđena je velika varijabilnost u oceni priplodnjaka. Dobijanje preciznije oplemenjivačke vrednosti moguće je primenom Animal Modela

Uticaj nivoa mlečnosti na osobine plodnosti krava crno bele rase

In this study a relationship between the milk yield and following reproduction traits: number of inseminations per conception [AIS], service period [SP], age at calving [AC], calving interval [CI] and birth weight [BW] is studied. The research involved dairy cows of European type of Black and White cattle which are being intensively improved by the genes of Holstein - Friesian breed. Mean values of general average for number of inseminations per conception, service period, age at calving, calving interval and birth weight are: 2.00; 98.78; 1088.08; 376.70 and 36.40, respectively. In general, the estimated phenotypic correlations (rp) between the milk yield over standard lactations and fertility traits were positive and unfavorable, and ranged from 0.24 for the relationship between milk yield and birth weight to 0.70 for relationship between milk yield and age at calving.U radu je ispitivan odnos između prinosa mleka i sledećih osobina plodnosti: indeks osemenjavanja [IO], servis period [SP], uzrast pri teljenju [UT], međutelidbeni interval [MI] i masa teladi pri rođenju [MTR]. Ispitivanja su se odnosila na mlečne krave evropskog tipa crno-belih goveda koje se intenzivno oplemenjuju genima holštajn-frizijske rase. Za analizu je korišćen Metod najmanjih kvadrata - LSMLMW (HARVEY, 1990), fiksni model. Srednje vrednosti opšteg proseka za indeks osemenjavanja, servis period, uzrast pri teljenju, međutelidbeni interval i masu teladi pri rođenju su: 2,00; 98,78; 1088,08 ; 376,70 i 36,40, respektivno. Procenjene fenotipske korelacije (rp) između prinosa mleka i osobina plodnosti generalno su bile pozitivne i nepovoljne, i imale su vrednosti od 0,24 za odnos između prinosa mleka i masu teladi pri rođenju do 0,70 za odnos između prinosa mleka i uzrasta pri teljenju

Possibilities of Application of the Index Concentration of Linda in Small Economy: Example of Serbian Food Industries

The aim of this paper is to show the possibility and importance of using the index of concentration of Linda in the analysis of market structure in small economies, and thus, to examine the possibility of its involvement in the practice of anti-monopoly state authorities in those countries. Results of application of the mentioned (system) index are proved in comparison with the results of previously conducted cluster analysis in the food industry, one of the most competitive branch in the economy of Serbia. The study showed the solidity and excellent opportunities of using the index of Lindа even in relatively small economy, in which predominate oligopolistic and other imperfectly-competitive structures