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Regulation of metabolic changes in shredded cabbage by modified atmosphere packaging
Andrej Plestenjak, Tomaž Požrl, Janez Hribar, Tatjana Unuk, Rajko Vidrih, 2008, izvirni znanstveni članek

Opis: The influence of different storage conditions on the storability of packaged shredded cabbage has been studied. The cabbage cultivar Fieldrocket was cut and packaged in glass jars and in polyethylene (PE) or polypropylene (PP) film. Several initial atmospheres were established within the packaged cut cabbage: 100 % N2, 5 % O2/95 % N2, 10 % O2/90 % N2, normal atmosphere (NA), 70 % O2/30 % N2 and 100 % O2. Samples were stored at two different temperatures of 0 and 10 °C for 7 days. Variation in CO2 and O2 concentrations was higher at 10 °C compared to 0 °C and the highest at the atmosphere consisting of 70 % O2/30 % N2. A decrease of O2 below 3–5 % and an increase of CO2 above 2–5 % in the packed product resulted in the appearance of anaerobic metabolism. An initial atmosphere consisting of 100 % O2, and a storage temperature of 0 °C resulted in delayed anaerobic metabolism compared to other atmospheric conditions and storage temperature of 10 °C. Rinsing of fresh cut cabbage also resulted in lower accumulation of acetaldehyde and ethanol. A higher variation in CO2 and O2 concentrations, and consequent accumulation of anaerobic metabolites had a negative influence on the sensorial properties of the cut cabbage. The higher permeability of PE film compared to PP and glass enabled faster exchange of CO2 and O2, which resulted in lower accumulation of anaerobic metabolites. However, a higher O2 concentration had a negative influence on the colour of fresh-cut cabbage. The best results were achieved by packing the fresh-cut cabbage in PE film with an initial atmosphere of 100 % O2 and stored at 0 °C.
Ključne besede: cabbage, modified atmosphere, packaging, polyethylene, polypropylene, respiration, anaerobic metabolism
Objavljeno: 24.07.2017; Ogledov: 14; Prenosov: 0
.pdf Polno besedilo (156,50 KB)

Prediction of standard lactation curves for primiparous Holstein cows by using corrected regression models
Janez Jeretina, Drago Babnik, Dejan Škorjanc, 2015, izvirni znanstveni članek

Opis: Prediction of the expected milk yield is important for the management of the primiparous cows (PPC) with a few or no data on their own milk productivity. We developed a system of regression equations for predicting milk yields in standard lactation. The models include the systematic effects of the calving season, the five-year rolling herd average of milk yield of PPC, the breeding values of the parents for milk production, and daily milk recordings. A total of 21,901 lactations of Holstein PPC were collected during the regular monthly milk recordings of cows in the Republic of Slovenia. By including daily milk recordings in the model, the coefficients of determination of regression models for the prediction of milk yield increase: without known recordings (M0) R 2 =0.80; with one recording (M1) R 2 =0.82; with two first consecutive recordings (M2) R 2 =0.86; and with three recordings (M3) R 2 =0.89. Deviations of milk yield up to 500 kg in a standard lactation (<1.6 kg/day) were as follows: with the model M0, they occurred in 53.4% of PPC; with M1, they occurred in 56.3% of PPC; with M2, they occurred in 64.5% of PPC; and with M3, they occurred in 70.9% of PPC. We concluded that the developed system of regression models is an appropriate method for milk yield prediction of PPC.
Ključne besede: primiparous cows, milk yield, prediction, lactation curves, regression equations
Objavljeno: 24.07.2017; Ogledov: 8; Prenosov: 1
.pdf Polno besedilo (497,85 KB)

An attempt to predict conformation and fatness in bulls by means of artificial neural networks using weight, age and breed composition information
Maja Prevolnik, Marjana Novič, Marjeta Čandek-Potokar, Martin Škrlep, Maria Font-I-Furnols, 2015, izvirni znanstveni članek

Opis: The present study aimed to predict conformation and fatness grades in bulls based on data available at slaughter (carcass weight, age and breed proportions) by means of counter-propagation artificial neural networks (ANN). For chemometric analysis, 5893 bull carcasses (n=2948 and n=2945 for calibration and testing of models, respectively) were randomly selected from the initial data set (n≈27000; one abattoir, one classifier, three years period). Different ANN models were developed for conformation and fatness by varying the net size and the number of epochs. Tested net parameters did not have a notable effect on models’ quality. Respecting the tolerance of ±1 subclass between the actual and predicted value (as allowed by European Union legislation for on-spot checks), the matching between the classifier and ANN grading was 73.6 and 64.9% for conformation and fatness, respectively. Success rate of prediction was positively related to the frequency of carcasses in the class.
Ključne besede: govedo, goveje meso, mastnost mesa, struktura mesa, klavna teža, ANN modeli, modeli za napovedovanje
Objavljeno: 24.07.2017; Ogledov: 8; Prenosov: 0
.pdf Polno besedilo (1,12 MB)

Effect of birth weight and sex on pre-weaning growth rate of piglets
Dejan Škorjanc, Maksimiljan Brus, Marjeta Čandek-Potokar, izvirni znanstveni članek

Opis: A study was conducted to find out the effect of birth weight and sex on growth rate of piglets in pre-weaning period. A total of 466 piglets from 48 litters of multiparous sows (Landrace) were involved in the experiment. Using a clustering approach piglets were assigned into three birth weight groups (Heavy (H), Intermediate (I), Light (L)). For the analysis of growth performance, pigs were weighed every 7 days until weaning at 28 days of age and average daily gain (ADG) was calculated. During lactation, body weight of L piglets was 5.5-fold increased, whereas the increase in I and H piglets were only 4.7-fold and 3.4-fold, respectively. Piglets of L group were significantly lighter at all studied ages compared to piglets of I and H group. The highest ADG was noted in the second week for all three groups; thereafter it decreased in H and L piglets (24% and 17%, respectively). The average birth weight of piglets was positively and significantly correlated with body weight at days 7, 14, 21 and 28. Sex did not affect significantly the ADG of the investigated animals during the four weeks of lactation. The present results indicate that neither milk production after the second week of lactation nor consumption of creep feed are sufficient enough to cover nutrition needs of fast growing piglets. There’s still a lack of optimization of nutrition in pre-weaning period especially for heavier piglets with their higher growth potential.
Ključne besede: piglets, barrow, gilts, birth weight, pre-weaning growth rate
Objavljeno: 20.07.2017; Ogledov: 40; Prenosov: 1
.pdf Polno besedilo (90,34 KB)

Effect of backfat loss during lactation on weaning-to-oestrus interval of sows at gonadotropin application
Dejan Škorjanc, Marko Hohler, Maksimiljan Brus, 2008, izvirni znanstveni članek

Opis: A total of 984 primiparous and multiparous crossbred sows (Swedish Landrace × Large White) housed on a commercial pig farm were used to study the effect of the decrease in backfat thickness during lactation and the level of backfat at weaning on weaning-to-oestrus interval and conception rate of sows. Primiparous sows (n=213) received a single injection of 400 IU eCG + 200 IU hCG (PG600®, Intervet) at weaning and approximately 30 % of sows did not respond to the first treatment. First-farrowing sows produced significantly fewer live-born piglets, had markedly thinner backfat in late gestation, showed significant loss of backfat thickness during lactation and showed thinner backfat at weaning than sows with a greater number of parities. Primiparous sows with backfat thinner than 18 mm at weaning lost an average of 21 % of backfat during lactation and had a significantly longer weaning-to-oestrus interval (31.75 ± 2.22 days), even after a second treatment with PG600®, than both primiparous sows which responded to the first treatment (5.95 ± 0.16 days) and multiparous sows which were not treated (5.19 ± 0.12 days). The primiparous and multiparous sows with thicker backfat at farrowing also had thicker backfat at weaning (r=0.874 and r=0.938 for primiparous and multiparous sows, respectively). Sows with thicker backfat at weaning showed a shorter weaning-to-oestrus interval and this correlation was higher for primiparous than for multiparous sows (r=-0.192 and r=-0.100, respectively). Thicker backfat of the sows at weaning was moderately but significantly correlated with lower loss of backfat during lactation (r=-0.179 and r=-0.273 for primiparous and multiparous sows, respectively). The present study showed that monitoring of backfat thickness and loss of backfat during lactation represents a useful tool to decrease non-productive days and improve the efficiency of high-producing pig herds.
Ključne besede: sow, gilts, backfat thickness, backfat loss, weaning to oestrus interval, conception rate, PG600
Objavljeno: 20.07.2017; Ogledov: 35; Prenosov: 0
.pdf Polno besedilo (185,14 KB)

A note on precise tracking of suckling position by piglets
Janko Skok, Dejan Škorjanc, 2014, izvirni znanstveni članek

Opis: Piglets establish a relatively stable teat order after the first week of lactation, when each piglet chooses a preferred teat or teat pair where they tend to suckle permanently. The mechanism underlying the choice that leads each piglet to the same suckling position is still not clarified. In the present case study, piglets with different preferred suckling positions (anterior, posterior) were transferred to a foster sow after completion of the regular 4 weeks of lactation by their biological mother. For both sows, which were identical based on parity, litter size and farrowing date, we examined the suckling positions of the experimental piglets. Piglets occupied exactly the same suckling positions on both sows. Thus, piglets precisely track positions on the mammary complex of a sows udder even when previously learned discriminable stimuli have been changed, such as odours, tastes, morphologies (of sows udder or the sow itself), vocalizations, and neighbouring littermates. Our observation indicates that the spatial configuration of the mammary complex, which is determined by two parallel rows of teats arranged in pairs, can hypothetically be proposed as an important cue for piglet suckling orientation. Therefore, additional attention should be given to the exact spatial position of piglets (and vacant positions) on the mammary complex of biological and foster mothers in order to reduce stress from cross-fostering, which is standard practice in contemporary piglet production.
Ključne besede: piglets, teat order, suckling orientation, mammary complex, spatial configuration
Objavljeno: 20.07.2017; Ogledov: 35; Prenosov: 0
.pdf Polno besedilo (1,78 MB)

The effect of dietary fibre content on skatole and indole production in faeces of immunocatrsted male pigs
Maja Prevolnik, Urška Tomažin, Marjeta Čandek-Potokar, Martin Škrlep, Nina Batorek, Etienne Labussiere, 2015, objavljeni znanstveni prispevek na konferenci

Opis: The effect of dietary fibre content on intestinal production of indolic compounds was studied in immunocastrated pigs (IC). In addition, entire males (EM) and IC were compared on control diet (with low fibre content). For the study 32 crossbred pigs were assigned, within a litter to 4 treatment groups; 24 pigs were immunocastrated (at the age of 77 and 112 days) and 8 pigs were kept as entire males (EM). IC were split into three groups (IC_H, IC_M and IC_L) fed three diets differing in crude fibre (34, 60 and 80 g/kg dry matter, respectively) and net energy (NE) (10.0, 9.3, 8.5 MJ NE/kg/DM, respectively). EM were fed high NE i.e. low fibre diet. The experiment started when pigs were 84 days old and finished at the age of 172 days, when pigs were sent to slaughter. Skatole and indole concentrations were determined in the samples of intestinal content taken from caecum (CE), ascending (AC) and descending colon (DC). The concentration of indole was the highest in CE and proximal part of the colon, while skatole concentration increased in the distal parts of the large intestine. Concentrations of indolic compounds did not differ between EM and IC that were fed the same diet. Lowering dietary NE by inclusion of high fibre ingredients reduced the production of indole in the intestinal content of IC pigs, whereas the production of skatole was not affected.
Ključne besede: indole, skatole, dietary fibres, pig, entire males, immunocastrates, pig nutrition, immunocastration
Objavljeno: 20.07.2017; Ogledov: 17; Prenosov: 0
.pdf Polno besedilo (561,86 KB)

Poultry meat in the production of meat products
Ciril Varga, Vladimir Strelec, Marko Volk, 2000, objavljeni strokovni prispevek na konferenci

Opis: The authors had studied the possibility of the use of various types of poultrymeat, factors which could have and adverse impact upon the microbiological quality of the raw material, which technology of meat products production and quality of products.
Ključne besede: poultry meat, quality, technology, quality of products
Objavljeno: 20.07.2017; Ogledov: 20; Prenosov: 0

Influence of added fat on the quality of poultry meat
Vladimir Strelec, Marko Volk, Ciril Varga, 2000, objavljeni znanstveni prispevek na konferenci

Opis: In testing conditions six groups of broiler chickens were tested for the effect of feed addition Bergafat and standardised fats added in the feed in the quantity of 3,9% in starter, 8,5% in grower, 8,6% in finisher, and 9,3% in endfinisher. Among testing groups no differences in the achieved productionresults were stated. The organoleptic evaluation of meat however showed considerable differences in the intensity of aroma, smell and taste.
Ključne besede: meat, chickens meat, organoleptic evaluation of meat, poultry fat, added fat
Objavljeno: 20.07.2017; Ogledov: 17; Prenosov: 0
.pdf Polno besedilo (305,20 KB)

Decision making under conditions of uncertainty in agriculture
Karmen Pažek, Črtomir Rozman, 2009, pregledni znanstveni članek

Opis: In decision under uncertainty individual decision makers (farmers) have to choose one of a set number of alternatives with complete information about their outcomes but in the absence of any information or data about the probabilities of the various state of nature. This paper examines a decision making under uncertainty in agriculture. The classical approaches of Wald’s, Hurwicz’s, Maximax, Savage’s and Laplace’s are discussed and compared in case study of oil pumpkin production and selling of pumpkin oil. The computational complexity and usefulness of the criterion are further presented. The article is concluded with aggregate the results of all observed criteria and business alternatives in the conditions of uncertainty, where the business alternative 1 is suggested.
Ključne besede: uncertainty, Wald’s, Hurwicz’s, Maximax, Savage’s and Laplace’s criterion, decision support system, agriculture, oil crops
Objavljeno: 20.07.2017; Ogledov: 19; Prenosov: 0
.pdf Polno besedilo (174,59 KB)

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