2,608 research outputs found
Variation of Milk Yield and Milk Composition of Pivska Pramenka Sheep Breed Through Lactation
The aim of this paper is to present the research results on the milk traits and variation of milk composition during lactation of Pivska pramenka breed, as one of the most important autochthonous sheep breeds in Montenegro. Investigation was conducted on the family sheep farm located in the municipality of Žabljak, a typical rearing area of Pivska pramenka breed.
The following milk traits were studied: length of lactation, milk yield (daily milk yield – DMY and total milk yield - TMY) and milk composition (Fat, Protein, Lactose, Solid non-fat - SNF and Somatic cells count - SCC).
Based on the data of 68 completed lactations, average length of lactation was 178.5 days and average milk yield 94.1 kg. On the basis of 289 milk samples analysed in 5 consecutive milk recordings, average daily milk yield was 0.549 litres, with 5.71% of fat, 5.75% of protein, 4.47% of lactose, 11.04 % of solid non-fat and 600x103 SCC on average.
Differences in averages for milk composition among test days (days of milk recording) during lactation were significant (P0.01). The largest variation was for milk fat, from 2.95% in the first control to 9.42% in the fifth control, while variation of protein was between 4.5% in the first and 7.4 in the fifth control. The content of lactose exposed decreasing trend during lactation (from 4.7% in first to 3.1% in fifth control)
QCSP on reflexive tournaments
We give a complexity dichotomy for the Quantified Constraint Satisfaction Problem QCSP(H) when H is a reflexive tournament. It is well known that reflexive tournaments can be split into a sequence of strongly connected components H1,…,Hn so that there exists an edge from every vertex of Hi to every vertex of Hj if and only if
Vertex routing models
A class of models describing the flow of information within networks via
routing processes is proposed and investigated, concentrating on the effects of
memory traces on the global properties. The long-term flow of information is
governed by cyclic attractors, allowing to define a measure for the information
centrality of a vertex given by the number of attractors passing through this
vertex. We find the number of vertices having a non-zero information centrality
to be extensive/sub-extensive for models with/without a memory trace in the
thermodynamic limit. We evaluate the distribution of the number of cycles, of
the cycle length and of the maximal basins of attraction, finding a complete
scaling collapse in the thermodynamic limit for the latter. Possible
implications of our results on the information flow in social networks are
discussed.Comment: 12 pages, 6 figure
The corticotrophin-releasing factor/urocortin system regulates white fat browning in mice through paracrine mechanisms
Objectives:
The corticotrophin-releasing factor (CRF)/urocortin system is expressed in the adipose tissue of mammals, but its functional role in this tissue remains unknown.
Methods:
Pharmacological manipulation of the activity of CRF receptors, CRF1 and CRF2, was performed in 3T3L1 white pre-adipocytes and T37i brown pre-adipocytes during in vitro differentiation. The expression of genes of the CRF/urocortin system and of markers of white and brown adipocytes was evaluated along with mitochondrial biogenesis and cellular oxygen consumption. Metabolic evaluation of corticosterone-deficient or supplemented Crhr1-null (Crhr1−/−) mice and their wild-type controls was performed along with gene expression analysis carried out in white (WAT) and brown (BAT) adipose tissues.
Results:
Peptides of the CRF/urocortin system and their cognate receptors were expressed in both pre-adipocyte cell lines. In vitro pharmacological studies showed an inhibition of the expression of the CRF2 pathway by the constitutive activity of the CRF1 pathway. Pharmacological activation of CRF2 and, to a lesser extent, inhibition of CRF1 signaling induced molecular and functional changes indicating transdifferentiation of white pre-adipocytes and differentiation of brown pre-adipocytes. Crhr1−/− mice showed increased expression of CRF2 and its agonist Urocortin 2 in adipocytes that was associated to brown conversion of WAT and activation of BAT. Crhr1−/− mice were resistant to diet-induced obesity and glucose intolerance. Restoring physiological circulating corticosterone levels abrogated molecular changes in adipocytes and the favorable phenotype of Crhr1−/− mice.
Conclusions:
Our findings suggest the importance of the CRF2 pathway in the control of adipocyte plasticity. Increased CRF2 activity in adipocytes induces browning of WAT, differentiation of BAT and is associated with a favorable metabolic phenotype in mice lacking CRF1. Circulating corticosterone represses CRF2 activity in adipocytes and may thus regulate adipocyte physiology through the modulation of the local CRF/urocortin system. Targeting CRF receptor signaling specifically in the adipose tissue may represent a novel approach to tackle obesity
The Effect of Addition of Lucerne Biomass and NPN Substances on Quality of Grape Pomace Silage
Grape pomace (GP) of white varieties without stalks was ensiled by the method of single factor trial in the two treatments: in the first treatment, with the addition of lucerne biomass (L) of the last cut, which was harvested at the stage of forming pods with equal shares in the weight ratio and in the second with the addition of Benural S (B) in the amount of 1%. Chemical analyses were conducted on GP and L to determine the suitability of biomass for silage and to determine the chemical composition and nutritional value and the process of lactic acid fermentation. It has been found that the biomass of GP had 2 times higher concentration of water-soluble carbohydrates (WSC 140.5:69.4 gkg-1DM) relative to L, and a lower buffer capacity (BC) what makes it 10 times more favourable for ensiling (ratio WSC/BC 13.1 : 1.3). GP, as compared to L, had lower contents of CP, CF, and a lower nutritional value expressed in NEL and NEM units and a higher content of crude fat. Silage with the equal share of GP + L compared to silage with GP + B had a slightly lower CF and significantly less crude fat and ash, especially Ca. More favourable ratio Ca : P (2.93 : 1) was established in silage GP + L compared to 10.1:1 silage GP + B. Silages GP + L in the fermentation process were scored/rated one class higher according to the DLG and Zelter assessment methods, compared to the silages GP + B.
The aim of the study was to investigate the possibility of ensiling grape pomace with equal proportion of biomass of lucerne and added NPN substances and to determine the detailed chemical composition, nutritive value and silage quality on the basis of the process of lactic acid fermentation
Surface Transformations and Water Uptake on Liquid and Solid Butanol near the Melting Temperature
Water interactions with organic surfaces are of central importance in
biological systems and many Earth system processes. Here we describe
experimental studies of water collisions and uptake kinetics on liquid and
solid butanol from 160 to 200 K. Hyperthermal D2O molecules (0.32 eV) undergo
efficient trapping on both solid and liquid butanol, and only a minor fraction
scatters inelastically after an 80% loss of kinetic energy to surface modes.
Trapped molecules either desorb within a few ms, or are taken up by the butanol
phase during longer times. The water uptake and surface residence time increase
with temperature above 180 K indicating melting of the butanol surface 4.5 K
below the bulk melting temperature. Water uptake changes gradually across the
melting point and trapped molecules are rapidly lost by diffusion into the
liquid above 190 K. This indicates that liquid butanol maintains a surface
phase with limited water permeability up to 5.5 K above the melting point.
These surface observations are indicative of an incremental change from solid
to liquid butanol over a range of 10 K straddling the bulk melting temperature,
in contrast to the behavior of bulk butanol and previously studied materials.Comment: 28 pages, 4 figures + introduction figur
The Energy Value and Energy Yields of Alfalfa Forage Depending on the Cutting Time in Forage-Seed Production System
Economic importance of alfalfa (Medicago sativa L.) is reflected in the production of high-quality forage, however, the seeds of alfalfa are valuable commodity in the domestic and international markets. In Serbia, the seed is produced in forage-seed mode of exploitation where the second or third growth is used for seed production, and the remaining growths are used for fodder. The aim of this work was to determine the influence of cuttings and time of cutting on total energy value of hay in a model of forage and seed production. The second and third cuts were used as seed cut. In the variant where the second cut was used as seed cut, the first cut was harvested at different times (A1-early, A2-medium early, A3-late and A4- very late). In the model where the third cut was used for seed, two pre-cuts were used for forage production (A5). In all the following variants, seed cut was followed by one more cutting (final cut), used for the production of fodder. The highest average total production (from pre-cut and final cut) of NEL (34606 MJha-1) and NEM (33811 MJha-1) was realized in the system of cutting with two pre-cuts. In the variant with single pre-cut, the highest yield was formed in the early system. Later cutting of the first cut causes decline of NEL production and it was the lowest in the system of very late cutting or 15.1 % less than in the early system and 38% lower than in the system of cutting with two pre-cuts. Delaying of utilization of alfalfa to the later stages of exploitation has contributed to the lower yield of NEM and in the medium early system and late system and especially in the very late cutting system, where by 22.2 % less was realized than in the early production system. Studies have shown that late cutting of first cut resulted in the reduction of nutritional value expressed in the amount of net energy per unit area
A post-IR IRSL chronology and dustmass accumulation rates of the Nosak loess-palaeosol sequence in northeastern Serbia
In the Middle Danube Basin, Quaternary deposits are widely distributed in the Vojvodina region where they cover
about 95% of the area.Major research during the last two decades has been focused on loess deposits in the Vojvodina
region. During this period, loess in the Vojvodina region has become one of the most important Pleistocene European
continental climatic and environmental records.Herewe present the dating results of 15 samples taken from theNosak
loess-palaeosol sequence in northeastern Serbia in order to establish a chronology over the last three glacial–
interglacial cycles. We use the pIRIR290 signal of the 4–11 lm polymineral grains. The calculated ages are within the
error limits partially consistent with the proposed multi-millennial chronostratigraphy for Serbian loess. The average
mass accumulation rate for the last three glacial–interglacial cycles is 265 g m�2 a�1
, which is in agreement with the
values of most sites in the Carpathian Basin. Our results indicate a highly variable deposition rate of loess, especially
during the MIS 3 and MIS 6 stages, which is contrary to most studies conducted in Serbia where linear sedimentation
rates were assume
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