Feed evaluation provides essential information’s to animal nutritionists for better feed formulation on the basis of physiological and economical view of point to improve animal performance. There are various feed evaluation method at present time and In Situ technique (nylon bag or in sacco method) is commonly used in this way. In this study, ruminal degradability of dry matter, organic matter, crude protein and ADF was measured. Four different oil seed meals consist of canola meal, cotton seed meal, soybean meal and sunflower meal was studied using in Situ method. Results of this experiment indicated that degradability (a+b) and effective degradation (EP) in soybean meal, canola meal and cotton seed meal produced in Behpak oil plant was (98.5, 98.7 and 56.8%) and (55.8, 62.0 and 48.3%) and for soybean meal, canola meal and sunflower meal produced in kesht-o-sanat oil plant was (81.7, 90.1 and 90.5%) and (47.1, 52.5 and 45.2%) respectively.

This study carried out to determine of chemical compositions and nutritive value of five species of range plants in Sistan including Oshnan (Seidlitzia rosmarinus), Rendouk (Salsola yazdiana Assadi), Siyah Shor (Suaeda fruticosa), Shoran (Salsola vermiculata) and Anabasis (Anabasis setifera) by in vitro and in Situ techniques. Samples were collected by systematic and random sampling procedure in autumn according to standard methods. The samples were dried in shade and after milling, chemical compositions including dry matter (DM), organic matter (OM), ash (ASH), crude protein (CP), crude fat (EE), cell wall (NDF) and cell wall- hemicellulose free (ADF), dry matter degradability (in Situ), cumulative gas production at 2, 4, 6, 12, 24, 48, 72 and 96 h, the organic matter digestibility (OMD) and metabolisable energy (ME) were determined. The results of this experiment showed that, there were significant differece in terms of chemical compositions of these samples (p<0.05). Crude protein, ADF and NDF contents were between 6.05 and 11.95%, 28.02 and 36.54% and 41.14 and 48.94% respectively. There was significant difference (p<0.01) between dry matter degradability, degradability parameters and effective degradability in different incubation times. The maximum potential degradability and effective degradability (k=0.02) was in Oshnan species. Also, the maximum cumulative gas volume at 96 hours was related to Rendouk. But, the gas production parameters (b, OMD, ME) in Oshnan species was higher than other species. The results showed that in these plants, Oshnan species has the highest nutritive value and also, there was a high positive correlation between in Situ and in vitro experiments in these species and can use the gas production technique for assessing of nutritive value of these species.

Rumen degradability was determined for six wheat, three corn and three millet cultivars in six ruminally cannulated sheep. The sheep were fed a ration containing 55% alfalfa and 45% ground barley. All grains were incubated for 2, 4, 8, 12, 24 and 48 h in dacron bags (50-llm pore size). The mean soluble and degradable portions, rate of degradation and effective degradability of dry matter ranged from 3.3 to 8.2%, 80.9 to 92.8%, 5.4 to 27.5% and 44;.8 to 74.2% for wheat, corn and millet, respectively. Corresponding values for crude protein of wheat corn and millet ranged from 5.7 to 9.6%, 4$.7 to 83%, 5.3 to 28.9% and 35.1 to 78.4%, respectively. It was concluded that grains varied widely in their ruminal degradability and this information may aid in synchronizing degradation of protein and starch in the rumen to improve lactation performance.

The present study was conducted to determine some feedstuffs nutritive values through different methods and to make a comparison between the methods. Six canulated steers (Holstein and Sistani) were taken into experiment in a completely randomized design of two observations per each replication. The amount of gas production at 0, 2, 4, 6, 8, 12, 24, 48, 72 and 96 hours and feed degradation through nylon bag method at 0 , 4 , 8 , 16 , 24 , 48 , 72 and 96 hours were measured. The feedstuffs used included: alfalfa hay, wheat straw, corn silage, concentrate and cotton seed, fed at the maintenance level. Dry matter degradabilityat 96 hours for alfalfa hay, wheat straw and corn silage were 71.52, 51.02 and 77.89, and at 48 hours for concentrate and cotton seed were 80.59, and 53.51 percent, respectively. Dry matter effective degradability for the above feedstuffs at the maintenance level was 64.40, 36.70, 66.43, 76.03 and 48.16%, respectively. Dry matter degradability for these respective feedstuffs at 24 hours was 66.93, 33.57, 68.24, 79.83 and 48.71. The amount of gas production at 96 hour of incubation for alfalfa hay, wheat straw and corn silage were 51 , 45 and 75.5 milliliters , respectively, and for concentrate and cotton seed at 48 hour of incubation were 81 and 58.5 milliliters. Correlation coefficient between dry matter degradation and gas production for these feedstuffs were 0.99, 0.99, 0.99, 0.96 and 0.99 respectively and correlation coefficient between crude protein degradation and the amount of gas production were respectively recorded as 0.97, 0.99, 0.99, 0.99 and 0.98. Due to the high correlation coefficient existing between dry matter degradation, crude protein degradation, ADF and NDF degradation, and gas production, regression equations between these parameters and gas production were assessed for an estimation of the amount of these parameters from the amount of gas production without a need for tedious digestion experiments. As an example regression equation between alfalfa dry matter degradation and its gas production was: Y = 35.724+ 0.714x. In line with 51 milliters of gas production for alfalfa at 96 hour, this equation estimated 72.14% of degradation for alfalfa dry matter during this time, which in comparison with the 71.52% from digestion experiments, there is not any significant difference observed between the two recordings.

Monitoring and evaluation of transformers are essential to prevent their insulation failure. In this paper, the use of 2-furan-carboxaldehyde (2-FAL) and methanol (MeOH) concentrations as the main products of paper insulation degradation, and insulation condition markers, has been studied. In order to study the degradation process and production of degradation products, the thermal aging process of the transformer insulation system was implemented in laboratory conditions. The results of laboratory studies show that in the early stages of degradation the amount of MeOH is significant compared to 2-FAL. Also, the estimation of the degree of polymerization (DP) in the early stages of degradation (DP>800) through MeOH concentration and with decreasing DP (DP <800) through 2-FAL concentration is closer to the real value. The results of studies performed on 35 distribution transformers confirm the production of significant amounts of MeOH in the early stages of degradation. Also, the estimated DP values for the studied transformers were obtained through 2-FAL and MeOH concentration. The results show that estimating the amount of DP through MeOH concentration is associated with a probability of error of about 9% compared to estimating DP through 2-FAL concentration.