Iran Agricultural Research
Year:2004 | Volume:23 | Issue:1|Papers Count:7

The effect of different levels of oats and β-glucanase supplementation in a corn-soya based diet was investigated using a 5x2 factorial arrangement. Oats was included in lieu of corn at levels of 0.0, 10, 20, 30 and 40%. β-glucanase was added at levels of 0.0 and 5600 BGU/kg of diet. Body weight (BW), feed intake (FI), feed conversion ratio (FCR), abdominal fat (AF), ileal digestibility of fat and protein, and plasma cholesterol and triglyceride concentrations were determined. Increasing oat content of the diet significantly (p<0.01) reduced BW, FI, AF, fat and protein digestibility as well as plasma cholesterol and triglyceride levels. Feed conversion ratio was increased significantly (P<0.05). The lowest BW, FI, AF, digestibility of fat and protein, plasma cholesterol and triglyceride levels and highest FCR were observed at 40% oat inclusion. Supplemental β -glucanaseimproved (P<0.05) BW, FI, and digestibility of fat and protein. Enzyme addition increased (P<0.05) plasma cholesterol and triglyceride levels, and AF. Males had higher plasma cholesterol levels than females, whereas AF was higher in females (P<0.05).

A knowledge based system prototype was developed to simulate the decision making process of plant managers in a pistachio processing plant. Plant managers served as the domain experts. From numerous interview sessions, observations, and practical work in the processing plant, a knowledge rule base was created using the integration of a Bayesian strategy with the daily pistachio marketing situation (observation), The results indicate that the knowledge based system decisions agreed in 88% of the cases with those of the domain experts, The 12% of results where differences occurred presented an intriguing insight into the actual decision making process carried out by the human experts.

Sugar beet (Beta vulgaris L.) plants grown in sand culture were gradually exposed to different levels of salinity (0,50,150,250, and 350 mM, NaCl + CaCl2 in 5:1 molar ratio) and photosynthetic rates of individual attached leaves were measured during salinisation period at external CO2 concentrations ranging from approximately 70 to 1500µmol CO2 mol-1 air. Salinity dramatically decreased net photosynthesis (ACO2) and stomatal conductance (gs). Net photosynthesis was plotted against computed leaf internal CO2 concentration (Ci), and the initial slope of this ACO2-Ci curve was used as a measure of photosynthetic ability. Leaves from plants exposed to 50 mM salinity showed little change in photosynthesis, whereas those treated to high levels of salinity had up to 91.5% inhibition, with increase in CO2 compensation point. Leaves appeared healthy and leaf chlorophyll content increased with increasing salinity. Aithough partial stomatal closuer occurred with salinisation but reductions in photosynthesis were partly non-stomatal at high levels of salt treatment. Photosynthetic ability was inversely related to the concentration of either Na+ and cl- in the leaf laminas sampled at the end of experimental period.

Salt tolerance of four Iranian rice cultivars were evaluated in vitro using modified MS medium supplemented with six levels of NaCl (0, 20, 40, 60, 80 and 100 mM). Fresh weight, dry matter, water content, Na+, K+, Ca2+ and cl- ions and proline content of callus as well as plant regeneration percentage were measured. When NaCl content of the medium was increased from 0 to 20 mM fresh weight of callus and plant regeneration increased from 382.6 mg and 59% to 437.8mg and 63%, respectively, and thereafter, rapidly decreased. The callus induction and growth as well as plant regeneration were found to be maximum on MS medium containing 20mM NaCl supplemented with 2.0 mg l-1 2, 4-D (9.04µM) and 0.2 mg l-1 BAP (8.88µM) (for callus induction) and medium with 3 mg l-1 NAA (16.11µM), 2 mg l-1 kinetin (9.3µM), 50 mg l-1 tryptophan, respectively. Also, results showed that proline accumulation in callus was negatively correlated with the fresh weight and water content and was not correlated with Na+ and Cl- ion contents of the callus. Path coefficient analysis based on correlation matrix showed that Ca2+ and K+ions, which remained positively correlated with fresh weight and water content, affected fresh weight via their effects on water content. Proline, Na+ and Cl- ions had negatively influenced the water content of callus. It is concluded that 'Zayandeh Roud' cultivar due to its evaluated callus growth and plant regeneration on NaCl containing medium might be an appropriate candidate to be transformed by genes that enhance the rice salt tolerance.

In this experiment in vitro and in vivo trials were performed to investigate the efficacy of whole cottonseed to limit protozoal population and fermentation parameters. Treatments were I) control (without whole cottonseed) and 2) 20% whole cottonseed (WCS). Dry matter disappearance (DMD) and fermentation characteristics of the treatments were determined in the in vitro incubation studies. In the in vivo trial, all sheep were fed a control diet for 3 wk, prior to the start of the 28-day experimental period, in a completely randomize design. Ruminal fluid was taken by rumenocentesis (3 h after feeding) on days 1,3,5, 7, 9, 11, 14, 21 and 28 from four sheep fed treatment diets. The pH and protozoal counts were determined on each ruminal fluid sample was taken from sheep, while ammonia nitrogen and volatile fatty acids (VFA) were determined in samples taken on days 7, 14, 21 and 28. The in vitro DMD at 72 h incubation was higher (P<0.01) for the control diet. After 72 h of incubation, the total VFA concentration (mM) (P<0.05) and the acetate to propionate ratio (P<0.05) was higher for the control diet than WCS diet. After 24 h of incubation, the molar proportion (%) of acetate, propionate and valerate (P<0.05) were, higher, but the molar proportion of isovalerate was lower (P<0.05) for the control diet than for the WCS diet. In in vivo study, feeding cottonseed decreased (P<0.05) total protozoa population from approximately 450,000 to 240,000 ml-1 Holotrich and cellulolytic protozoa disappeared from the rumen samples of sheep whereas Entodinium sp., remained. This was associated with lower concentrations of ammonia nitrogen in rumen fluid of sheep fed WCS diet (P<0.01). In vivo molar proportion of propionate was higher and the acetate to propionate ratio was lower for control diet than for WCS diet. It was concluded that feeding whole cottonseed reduced rumen fauna, ammonia nitrogen and the molar proportion of propionate and increased the acetate to propionate ratio, but had no effect on ruminal pH and total VFA concentration.

Drought monitoring is difficult, though it is essential for risk management of this destructive natural disaster. A number of indices which play a major role in detection of drought severity, its onset and end for monitoring purposes, have been introduced and applied in this regard. This paper compares the capabilities of three drought indices for the 1997-2000droughts in Tehran province, Iran. A series of maps of the province are used to illustrate how the indices would have been able to detect the onset of the drought, as well as monitor its progress on a monthly timescale. The results show that the DJ (Deciles Index) is very responsive to the rainfall events of this year, but with inconsistent spatial and temporal variations. The SPI (Standard Precipitation Index) shows a slow response to the drought according to the applied timescale. Finally, the EDI (Effective Drought Index), a relatively new drought index, is able 10 detect the onset of drought and its spatial as well as temporal variations very consistently, and seems the most promising as an operational index for local and regional drought watch system in the province. Also, EDI the ability of EDI to detect drought status on a daily basis is another advantage of this index for the management of drought risk.

The present paper reports thirteen species of macropyline oribatid mites that were collected from various localities in Iran. All species are new to the fauna of Iran. A list of the sampling places is given together with a map.