Uticaj paragenetskih faktora na reproduktivne osobine krava simentalske rase

The examination was made on the effect of systematic factors (parturition group, calving season, birth type, calf gender, and birth type-calf gender interaction) and age at first conception on the expression of reproductive traits (gestation length, service period, fertility intensity and calf birth weight) in 143 Simmental cows. The overall mean (μ) for gestation length, service period, intercalving period and calf birth weight was 284.14 days, 153.82 days, 416.92 days and 35.40 kg, respectively. The parturition group effect on all fertility traits was highly significant (P lt 0.01). The calving season statistically significantly (P lt 0.05) affected the intercalving period and calf birth weight. Birth type induced very significantly longer gestation (P lt 0.01) and higher calf birth weight in singles (P lt 0.01) and significantly longer service period in twins (P lt 0.05). Calf gender had a very significant effect (P lt 0.01) only on calf birth weight, and the interaction between birth type and calf gender significantly affected gestation duration only (P lt 0.05). The regression effect of age at first conception on all fertility traits was not significant (P>0.05).Na ispoljenost reproduktivnih osobina (dužina bremenitosti, servis period, intenzitet plodnosti i masa teladi pri rođenju) kod 143 krave simentalske rase, ispitivan je uticaj sistematskih faktora (grupe partusa, sezone telenja, tip rođenja, pol teladi i interakcija tipa rođenja i pola teladi) i uzrasta pri prvoj oplodnji. Opšti prosek (μ) za dužinu bremenitosti iznosio je 284.14 dana, servis period 153.82 dana, međutelidbeni interval 416.92 i masu teladi pri rođenju 35.40 kg. Uticaj grupe partusa na sve osobine plodnosti bio je visoko značajan (P lt 0.01). Sezona telenja statistički značajno (P lt 0.05) je uticala na međutelidbeni interval i masu teladi pri rođenju. Tip rođenja uslovio je vrlo značajno dužu bremenitost (P lt 0.01) i veću masu teladi pri rođenju kod jedinaca (P lt 0.01) i značajno duži servis period kod blizanaca (P lt 0.05). Pol teladi vrlo značajno je uticao (P lt 0.01) samo na masu teladi pri rođenju, dok je interakcija tipa rođenja i pola teladi značajno uticala samo na trajanje bremenitosti (P lt 0.05). Regresijski uticaj uzrasta pri prvoj oplodnji na sve osobine plodnosti nije bio signifikantan (P>0.05)

Uticaj sistematskih faktora na mlečnost krava Simentalske rase u celim laktacijama

The effect of systematic factors on production traits over complete lactations was investigated in 2,805 Simmental cows born in 1982 and onwards. The cows were housed at three farms in different areas: at the Zlatiborski Suvati dairy farm, Zlatibor, at the Dobricevo Agricultural Farm, Cuprija and at private farms in the region of Kotraze. The systematic factors (farm, calving season, lactation groups, group (year x season of birth), farm x calving season and farm x lactation group interactions) and age at first conception had statistically highly significant (P (lt) 0.001) effects on all complete lactation traits, with the exception of the effect of calving season on complete lactation duration (P (lt) 0.05) and milk-fat content (P>0.05). No statistically significant effect was produced by age at first conception on complete lactation duration and milk-fat content (P>0.05). Determination coefficients ranged from 0.100 in complete lactation duration to 0.361 in milk-fat content.Ispitivanje uticaja sistematskih faktora na ispoljenost proizvodnih osobina celih laktacija obavljeno je kod 2805 krava simentalske rase rođenih od 1982. godine pa na dalje. Krave su smeštene na tri farme, odnosno područja: farmi muznih krava 'Zlatiborski suvati' na Zlatiboru, Poljoprivrednom dobru Dobričevo u Ćupriji i području Kotraže na individualnim gazdinstvima. Sistematski faktori (farma, sezona telenja, grupe laktacija, grupa (godina x sezona rođenja), interakcije farma x sezona telenja i farma x grupe laktacija) i uzrast pri prvoj oplodnji statistički su vrlo visoko značajano (P (lt) 0.001) uticali na sve osobine punih laktacija, izuzimajući uticaj sezone telenja na trajanje punih laktacija (P (lt) 0.05) i sadržaj mlečne masti (P>0.05). Uzrast pri prvoj oplodnji nije statistički značajno uticao na trajanje celih laktacija i sadržaj mlečne masti u njima (P>0.05). Koeficijenti determinacije kretali su se od 0.100 kod trajanja celih laktacija do 0.361 kod sadržaja mlečne masti

Korelaciona analiza povezanosti proizvodnih osobina kroz tri generacije krava simentalske rase

The relationship between milk production traits over whole lactations was evaluated across three generations of Simmental cows, i.e. between daughters, dams and grand dams, by a phenotypic regression analysis with whole lactation traits in the daughter generation being used as the dependent variables (x1), and those in the dam and grand dam generations being used as the independent variables (x2 and x3). The results were obtained from a sample of 1170 daughters and as many dams and grand dams. The significance of the partial regression coefficients b2 and b3 was separately evaluated by a t-test. An analysis of variance was used to estimate the significance of the simultaneous effect of the production traits of dams and grand dams on the milk production achieved in the daughter generation. The calculated value of the partial regression coefficients for the whole lactation production traits across three generations (grand dams, dams and daughters) and their statistical significances determined by the t and F tests, as well as the regression equations used, suggested that the effect of the grand dam generation on the milk production traits in granddaughters was substantially lower than the effect of dams. The calculated partial regression coefficients (b2 and b3) were positive and statistically very significant (P lt 0.01), excepting the regression coefficients b3 for lactation length and b2 for milk fat content that were not statistically significant (P>0.05). A very significant change (P lt 0.01) was observed in all production traits in the daughter generation as simultaneously affected by the traits in the dam and grand dam generations.Povezanost osobina mlečnosti u punim laktacijama analizirana je između tri generacije krava simentalske rase, odnosno između kćerki, majki i baba, fenotipskom regresionom analizom u uslovima kada su osobine punih laktacija u generaciji kćerki posmatrane kao zavisno (x1), a osobine punih laktacija u generaciji majki i baba kao nezavisno promenljive (x2 i x3). Rezultati su dobijeni na uzorku od po 1170 kćerki, majki i baba. Pojedinačno ispitivanje značajnosti delimičnih regresionih koeficijenata b2 i b3 izvršeno je t-testom, a analizom značajnosti istovremenog uticaja proizvodnih osobina majki i baba na ostvarenu proizvodnju kod kćerki izvršena je metodom analize varijanse. Na osnovu izračunate vrednosti delimičnih regresionih koeficijenata za proizvodne osobine celih laktacija kroz tri generacije (babe, majke i kćerke) i njihove statističke značajnosti određene t i F testom, kao i jednačina regresije konstatovano je da je uticaj generacije baba na proizvodnju unuka znatno manji u odnosu na uticaj kojeg imaju majke. Svi izračunati delimični koeficijenti regresije (b2 i b3) bili su pozitivni i statistički vrlo značajni (P lt 0.01), izuzimajući koeficijent regresije b3 kod trajanja laktacije i b2 kod sadržaja mlečne masti koji nisu bili statistički značajni (P>0.05). Značajnost promena svih posmatranih proizvodnih osobina u generaciji kćerki pri istovremenom uticaju tih osobina iz generacije majki i baba bila je vrlo visoka (P lt 0.01)

Efekat interakcije sistematskih faktora na mlečnost krava simentalske rase u standardnim laktacijama

The effect of interaction between the farm and calving season, as well as the farm and group of lactations on milk performance traits (milk yield, yield of milk fat, 4% fat corrected milk and milk fat content) was analyzed on sample of 2805 Simmental cows with total 9718 standard lactations, housed on dairy farm 'Zlatiborski suvati' on Zlatibor (578 cows and 1968 lactations), dairy farm of the Agricultural holding Dobričevo in Ćuprija (964 cows and 3237 lactations) and dairy animals housed on family farms/households in the region of Kotraža (1263 cows and 4513 lactations). The significance of the effect of interaction between the farm and calving season, as well as interaction between the farm and group of lactations on all milk performance traits was very high (P (lt) 0.001), which justified their inclusion into models for assessment of the breeding value of dairy cows. The share of variance of interactions in total variance of milk performance traits in standard lactations was low (below and around 4%), which clearly indicated even more systematic factors and their interactions which influence the total variability of observed traits of milk performance of cows in standard lactations.Uticaj interakcije farme i sezone telenja kao i farme i grupe laktacija na osobine mlečnosti (proizvodnja mleka, mlečne masti, 4% mast-korigovanog mleka i sadržaj mlečne masti) analizirano je kod 2805 krava simentalske rase sa ukupno 9718 standardnih laktacija koje su bile smeštene na farmi muznih krava 'Zlatiborski suvati' na Zlatiboru (578 krava i 1968 laktacija), farmi muznih krava na Poljoprivrednom dobru Dobričevo u Ćupriji (964 krava i 3237 laktacija) i području Kotraže na individualnim gazdinstvima (1263 krava i 4513 laktacija). Značajnost uticaja interakcija farme i sezone telenja, kao i interakcije farme i grupe laktacija na sve osobine mlečnosti standardnih laktacija bila je vrlo visoka (P (lt) 0.001), što opravdava njihovo uključivanje u modele za ocenu priplodne vrednosti muznih krava. Udeo varijanse interakcija u ukupnoj varijansi osobina mlečnosti standardnih laktacija bio je nizak (ispod i oko 4%), što jasno ukazuje na još veliki broj sistematskih faktora i njihovih interakcija koji utiču na ukupnu varijabilnost posmatranih osobina mlečnosti krava u standardnim laktacijama

Uticaj uzrasta pri prvoj oplodnji na reproduktivne, proizvodne i funkcionalne osobine krava simentalske rase

The effect of cow age at first insemination on productive and reproductive traits, as well as on longevity and lifetime production ones was examined in the Simmental cows housed at the 'Zlatiborski Suvati' (Mt. Zlatibor Pastures) Farm. The general linear model was used to calculate linear regression coefficients for the effect of age at first insemination on productive, reproductive traits, longevity traits and lifetime production traits The calculated linear regression coefficients suggested that the age at first insemination had a statistically significant effect (P lt 0.05) on milk, milk fat and 4% fat milk production in whole lactations (bxy=1.508, bxy=0.056 and bxy=1.464), a very high significant effect (P lt 0.001) on the age at culling and cow utilisation index ((bxy=1.386 and bxy=-0.020), and no significant effect (P>0.05) on other longevity traits. The age of cows at first insemination did not significantly affect (P>0.05) fertility and lifetime milk and milk-fat production traits. The presented results suggest that cow age at first insemination should be included in the models used in estimating breeding values of dairy cows.Uticaj uzrasta krava pri prvoj oplodnji na proizvodne i reproduktivne osobine i osobine dugovečnosti i životne proizvodnje ispitivan je kod krava simentalske rase smeštenih na farmi 'Zlatiborski suvati'. Opštim linearnim modelom izračunati su koeficijenti linearne regresije uticaja uzrasta pri prvoj oplodnji na proizvodne i reproduktivne osobine, kao i osobine dugovečnosti i životne proizvodnje Na osnovu izračunatih koeficijenata linearne regresije uzrast pri prvoj oplodnji statistički je značajno uticao (P lt 0.05) na proizvodnju mleka, mlečne mast i 4% masnog mleka u celim laktacijama (bxy=1.508, bxy=0.056 i bxy=1.464), vrlo visoko značajno (P lt 0.001) na uzrast pri izlučenju i indeks iskorišćavanja krava (bxy=1.386 i bxy=-0.020), dok na ostale osobine dugovečnosti nije imao signifikantan uticaj (P>0.05). Uzrast krava pri prvoj oplodnji nije imao značajnog uticaja (P>0.05) na osobine plodnosti i životne proizvodnje mleka i mlečne masti. Na osnovu prikazanih rezultata uzrast krava pri prvoj oplodnji trebalo bi uvrstiti u modele za procenu odgajivačke vrednosti mlečnih krava

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

Parallel Active Power Filter with Predictive Structure for Reference Current Determination – Experimental System

U svrhu eksperimentalne provjere rezultata simulacije trofaznog aktivnog filtra s prediktivnim određivanjem referentne struje izrađena je njegova laboratorijska maketa. U radu je prikazan funkcionalan opis laboratorijske makete trofaznog aktivnog filtra. Energetski krug aktivnog filtra sastoji se od tri jednofazne prigušnice, trofaznog izmjenjivača s IGBT-ovima i dva simetrična kondenzatora na istosmjernoj strani. Regulacija struje realizirana je pomoću tri neovisna histerezna regulatora. Razrađen je algoritam filtarskog sustava s prediktivnom strukturom za određivanje referentne struje i implementiran na DSP. Prikazani su eksperimentalni rezultati ostvarenog trofaznog aktivnog filtra u stacionarnom i dinamičkom režimu rada. Dobiveni eksperimentalni rezultati potvrđuju učinkovitost aktivnog energetskog filtra pri slabljenju viših harmonika struje u mreži.For the purpose of simulation results testing, a laboratory prototype of three-phase active power filter with predictive structure for reference current determination has been developed. A functional description of the laboratory prototype is presented. Power stage of the proposed active filter has been realized using three serial inductance, three-phase IGBT based current control voltage inverter with two symmetrical capacitors on dc bus. Three independent hysteresis controllers on the base of reference currents were used to generate switching signals for inverter transistors. The algorithm for current reference determination as a combination of digital predictive filter and low pass filter was developed and implemented on DSP controller. The experimental results of three-phase active power filter for stationary and dynamic regimes are presented. Experimental results show that the active power filter gives satisfactory performance in power system harmonic attenuation

Parallel Active Power Filter with Predictive Structure for Reference Current Determination – Experimental System

U svrhu eksperimentalne provjere rezultata simulacije trofaznog aktivnog filtra s prediktivnim određivanjem referentne struje izrađena je njegova laboratorijska maketa. U radu je prikazan funkcionalan opis laboratorijske makete trofaznog aktivnog filtra. Energetski krug aktivnog filtra sastoji se od tri jednofazne prigušnice, trofaznog izmjenjivača s IGBT-ovima i dva simetrična kondenzatora na istosmjernoj strani. Regulacija struje realizirana je pomoću tri neovisna histerezna regulatora. Razrađen je algoritam filtarskog sustava s prediktivnom strukturom za određivanje referentne struje i implementiran na DSP. Prikazani su eksperimentalni rezultati ostvarenog trofaznog aktivnog filtra u stacionarnom i dinamičkom režimu rada. Dobiveni eksperimentalni rezultati potvrđuju učinkovitost aktivnog energetskog filtra pri slabljenju viših harmonika struje u mreži.For the purpose of simulation results testing, a laboratory prototype of three-phase active power filter with predictive structure for reference current determination has been developed. A functional description of the laboratory prototype is presented. Power stage of the proposed active filter has been realized using three serial inductance, three-phase IGBT based current control voltage inverter with two symmetrical capacitors on dc bus. Three independent hysteresis controllers on the base of reference currents were used to generate switching signals for inverter transistors. The algorithm for current reference determination as a combination of digital predictive filter and low pass filter was developed and implemented on DSP controller. The experimental results of three-phase active power filter for stationary and dynamic regimes are presented. Experimental results show that the active power filter gives satisfactory performance in power system harmonic attenuation

Uticaj sistematskih faktora na dužinu bremenitosti kod krava Simentalske rase

The effect of systematic environmental factors on gestation length in Simmental cows was evaluated by calculating the least squares mean (LSM) and its error (SELSM), by analysis of variance and by calculating the coefficient of determination (R2). The study involved Simmental cows reared at three locations, including the Zlatiborski Suvati farm (n=578), the Dobričevo farm (n=964) and individual private farms at the Voćar Farming Cooperative in Kotraža (n=1263). The analysis included gestation length in Simmental cows as affected by continuous systematic factors (age at first conception) and discontinuous factors such as farm, calving season, birth season, parity group, calf sex, type of birth and the interaction of these factors. The effect of age at first conception was statistically significant (P lt 0.05). The discontinuous factors had a very high significant (P lt 0.001) effect on gestation length. The coefficient of determination was as low as 0.086 (8.6%), undoubtedly suggesting the small effect of the non-genetic factors on gestation length, given the fact that the trait is biologically determined and that it shows low variability.Uticaj sistematskih faktora okoline na dužinu bremenitosti analiziran je izračunavanjem sredine najmanjih kvadrata (LSM) i njegove greške (SELSM), analizom varijanse po primenjenom modelu i izračunavanjem koeficijenta determinacije (R2). Istraživanjem su obuhvaćene krave simentalske rase raspoređene na tri lokaliteta i to farmi Zlatiborski suvati (n=578), farmi Dobričevo (n=964) i individualna gazdinstva na području Zemljoradničke zadruge 'Voćar' iz Kotraže (n=1263). Na dužinu bremenitosti ispitivan je uticaj kontinuelnih sistematskih faktora (uzrast pri prvoj oplodnji) i dikontinuelnih faktora kao što su farma, sezona telenja i rođenja, grupe partusa, pola teladi, tipa rođenja i interakcija pomenutih faktora. Uticaj uzrasta pri prvoj oplodnji bio je statistički značajan (P lt 0.05), dok uticaj svih diskontinuelnih uticaja na trajanje bremenitosti bio je vrlo visoko značajan (P lt 0.001). Koeficijent determinacije iznosio je svega 0.086 (8.6%), što nedvosmisleno ukazuje na mali uticaj paragenetskih faktora na ispoljenost dužine bremenitosti obzirom da je ona biološki data i da se odlikuje niskom varijabilnošću

Uticaj starosti mladih bikova simentalske rase na randman

Considering the Serbia's potential and tradition in production of quality beef meat as food for human consumption and raw material in the food industry and the demand of the EU market, shows the need to intensify the production of this foodstuff. Aim of this paper was to analyze the effect of age of young Simmental bulls on dressing percentage in slaughterhouse, according to the standard applied in the EU (Council Regulation (EC) No 1234/2007, Commission Regulation (EC) No 1249/2008; Commission European, Directorate-General for Agriculture and Rural Development). Regulations that define more precisely the quality of meat are only partially implemented in Serbia (Official Gazette of the SFRY 34/74, 26/75, 13/78). The accuracy of the slaughter processing of carcasses is assessed as adequate in the facility in which the analysis was conducted. The study was conducted on 116 young bulls carcasses, from redemption. Two groups of young bulls (cattle) were formed, first group the age of 269-350 days and second group the age of 351-450 days. The results show that due to the wider age intervals in the second group (351-450 days) the difference in mass of animals before slaughter and carcass weight after primary processing is statistically significant (P lt 0.05), while the yield difference between the two groups is statistically insignificant (P> 0.05). The obtained results indicate that it is necessary to undertake concrete measures in the primary sector to achieve better yield and meat quality.Posmatrajući potencijal i tradiciju naše zemlje u proizvodnji kvalitetnog goveđeg mesa kao namirnice za ishranu ljudi i sirovine za preradu u prehrambenoj industriji s jedne strane, i potreba tržista EU sa druge strane, neophodno je intenzivirati proizvodnju ove vrste namirnice animalnog porekla. Cilj rada je bio da se analizira uticaj starosti junadi (mladih bikova) simentalske rase na randman, u klanici, prema standardu koji se primenjuje u zemljama Evropske Unije (Council Regulation (EC) No 1234/2007, Commission Regulation (EC) No 1249/2008; Commission European, Directorate-General for Agriculture and Rural Development). U Republici Srbiji se samo delimično primenjuju propisi koji bliže definišu kvalitet mesa (Pravilnik Sl. list SFRJ 34/74, 26/75, 13/78). Ispravnost klanične obrade trupa je ocenjena kao adekvatna u objektu u kome je sprovedena analiza. Ispitivanje je sprovedeno na 116 trupova junadi (mladih bikova) iz otkupa. Formirane su dve grupe junadi (mladih bikova), prva starosti 269-350 dana i druga 351-450 dana. Rezultati pokazuju da su usled širih starosnih intervala u drugoj grupi (351-450 dana) razlike u masi životinja pre klanja i masi trupova nakon primarne obrade statistički značajne (P lt 0.05), dok su razlike između randmana dve posmatrane grupe statistički nesignifikantne (P>0.05). Dobijeni rezultati ukazuju da je neophodno preduzeti konkretne mere u primarnom sektoru radi postizanja boljeg prinosa i kvaliteta mesa