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)

The effect of rearing system and length of fattening period on selected parameters of broiler carcass quality

This study involved analysis of some carcass quality parameters in broilers reared under two different non-industrial systems (extensive indoor and free range) at two different lengths of fattening period (56 and 63 days). The quality parameters tested included dressed carcass yield, dressing percentage, proportion of primal cuts (breast, drumstick, thigh, wing, pelvis and back) in dressed carcass, and proportion of major tissues (muscular tissue, bone and skin) in high-value carcass cuts (breast, drumstick and thigh). The objective of the study was to evaluate the effect of broiler rearing system, length of fattening period and gender on the carcass quality traits tested. The male broilers had a higher carcass weight at the slaughtering line at both lengths of fattening period, and the obtained differences were statistically significant. The broilers raised under extensive indoor system had a somewhat higher proportion of breast and a lower proportion of thigh and drumstick. A significant effect of gender was observed on these traits. The proportion of muscular tissue, bone and skin in the high-value primal cuts, including breast, drumsticks and thighs, dependent also on broiler gender and partly on the rearing system and length of fattening period

Techno-economic analysis of heat exchangers with parallel helical tube coils

The paper deals with the investment and exploitation costs for shell and tube heat exchangers with parallel helical tube coils. The most common correlations for estimating prices of shell and tube heat exchangers found in open literature were tested using the market data for a comparison and they have shown significant deviations. A new correlation for calculating prices of heat exchangers with helical tubes (when the shell is made of carbon steel and the helical tube of copper) was determined. In addition, the costs of electricity needed to drive pumps, as well as the costs of chemical cleaning of the apparatuses with inhibited mineral acids were estimated

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

Genetic diversity of a Serbian grapevine germplasm collection based on morphoagronomic characteristics

The objective of this study was to evaluate diversity and relationships among grapevine cultivars from the Serbian gene bank in Sremski Karlovci, and to identify the most useful variables for discrimination. A total of 54 grapevine cultivars have been studied. During the period 2000-2005, twelve quantitative and qualitative characteristics were evaluated using OIV categories to each trait. Characterization was done using multivariate statistical analyses: cluster and principal component analysis (PCA), Based on cluster analysis cultivars divided into three major groups and the clustering pattern was related to the classical eco-geographical grouping: occidentalis, pontica and orientalis. Beside geographic origin clustering position of cultivars throughout the dendrogram was related to main uses. The major part (70.1%) of the total variation presented was explained by four principal components. PC1 is highly correlated with the bunch and berry size and PC2 with the density of prostrate hairs of young shoot tip and the density of prostrate hairs between veins on the lower side of mature leaf. The overall arrangement of cultivars suggests considerable phenotypical (and presumably genetic) variability in studied germplasm collection. Furthermore, obtained results may be useful for further utilization of available genetic resources in gene bank managers, growing and breeding

Effect of non-genetic factors on standard lactation milk performance traits in simmental cows

The effect of systematic and continuous environmental factors on milk performance traits over standard lactations in 2805 Simmental cows was evaluated using the general linear model. The systematic factors included the effect of farm or breeding area, calving season, year of birth, season of birth, lactation group and their interactions. The continuous factor analysed was the effect of age at first conception. The effect of farm, lactation group and calving season on standard lactation milk performance was found to be highly significant (P lt 0.01), excepting the effect of calving season on milk fat percent in standard lactations which showed statistical significance (P lt 0.05). The interactions between year and season of birth, farm and calving season, and farm and lactation group had a highly significant effect (P lt 0.01) on all performance traits studied. Age at first conception, as a continuous factor, had a highly significant effect (P lt 0.01) on milk yield and milk fat percent, and a non-significant effect on milk fat yield. The model used to correct the performance traits over standard lactations for the effect of systematic factors was highly significant (P lt 0.01). The variance of the model accounted for 20.06 and 37.31% of the total variance of milk fat yield and milk fat percent, respectively. The resulting coefficients of determination (R-2) ranged from 0.20 for milk fat yield to 0.37 for milk fat percent

Supplementary data for article: Stanojević, M.; Trifković, J.; Akšić, M. F.; Rakonjac, V.; Nikolić, D.; Šegan, S.; Milojković-Opsenica, D. Sugar Profile of Kernels as a Marker of Origin and Ripening Time of Peach (Prunus Persicae L.). Plant Foods for Human Nutrition 2015, 70 (4), 433–440. https://doi.org/10.1007/s11130-015-0515-4

Supplementary material for: [https://doi.org/10.1007/s11130-015-0515-4]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2001

Reproductive biology traits affecting productivity of sour cherry

The objective of this work was to evaluate variability in reproductive biology traits and the correlation between them in genotypes of 'Oblacinska' sour cherry (Prunus cerasus). High genetic diversity was found in the 41 evaluated genotypes, and significant differences were observed among them for all studied traits: flowering time, pollen germination, number of fruiting branches, production of flower and fruit, number of flowers per bud, fruit set, and limb yield efficiency. The number of fruiting branches significantly influenced the number of flower and fruit, fruit set, and yield efficiency. In addition to number of fruiting branches, yield efficiency was positively correlated with fruit set and production of flower and fruit. Results from principal component analysis suggested a reduction of the reproductive biology factors affecting yield to four main characters: number and structure of fruiting branches, flowering time, and pollen germination. Knowledge of the reproductive biology of the 'Oblacinska' genotypes can be used to select the appropriate ones to be grown or used as parents in breeding programs. In this sense, genotypes II/2, III/9, III/13, and III/14 have very good flower production and satisfactory pollen germination

Techno-economic analysis of heat exchangers with parallel helical tube coils

U radu su prikazani investicijski i eksploatacijski troškovi kod bubnjastih izmjenjivača topline s paralelnim zavojnim cijevima. Provedena je statistička analiza najčešće rabljenih korelacija iz otvorenih literaturnih izvora za određivanje cijena bubnjastih izmjenjivača topline s tržišnim podacima aparata s kojom je utvrđeno da pokazuju značajna odstupanja i da se ne mogu s dovoljnom pouzdanošću koristiti za navedeni tip aparata. Uspostavljena je nova korelacija za procjenu cijena aparata sa zavojnim cijevima (za slučaj kada je omotač aparata izrađen od ugljičnog čelika, a cijevni snop od bakra). Procijenjeni su troškovi električne energije za pogon pumpi kao i troškovi kemijskog čišćenja aparata inhibiranom klorovodičnom i sumpornom kiselinom.The paper deals with the investment and exploitation costs for shell and tube heat exchangers with parallel helical tube coils. The most common correlations for estimating prices of shell and tube heat exchangers found in open literature were tested using the market data for a comparison and they have shown significant deviations. A new correlation for calculating prices of heat exchangers with helical tubes (when the shell is made of carbon steel and the helical tube of copper) was determined. In addition, the costs of electricity needed to drive pumps, as well as the costs of chemical cleaning of the apparatuses with inhibited mineral acids were estimated