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M. R. Bahreini Behzadi, F. Eftekhari Shahroudi, L. D. van Vleck,
Volume 9, Issue 1 (spring 2005)
Abstract

Data from the birth weight (BW), the average daily gain from birth to weaning (ADG) and the weaning weight (WW) of 1182, 1099 and 1099 lambs were respectively collected and applied to estimate the maternal effects on heritabilities as well as on the determination of the environmental factors. The data were collected from Shahrbabak Sheep Breeding Research Station within five year, from 1993 to 1998. The effects of the year of birth, the age of the dam and its sex on all the traits were significant. The type of birth had no effect on BW but it was significant for the other two traits. Estimates of (co)variance components and genetic parameters were obtained by restricted maximum likelihood, using single and two-trait animal models. Based on the most appropriate fitted model, direct heritability of BW, ADG and WW were estimated at 0.10± 0.06, 0.21 ±0.08 and 0.22± 0.09, respectively. The maternal heritability for the three traits was also estimated at 0.27± 0.04, 0.15 ±0.05 and 0.19 ±0.05, respectively. Direct genetic and phenotypic correlations between BW and ADG BW and WW ADG and WW were estimated at 0.85 and 0.41 0.82 and 0.48 and 0.99 and 0.99, respectively. Ignoring maternal effects in animal model caused overestimation of direct heritability. Thus maternal effects are significant sources of variation for early growth traits and their ignorance in the animal model causes inaccurate genetic evaluation of the lambs.
M. Hagian Shahri, J. Zad, A. Sharifi Tehrani, S. M. Okhovat, A. Safarnejad,
Volume 9, Issue 1 (spring 2005)
Abstract

A 2-year vineyard survey failed to the provide evidence that Uncinula necator (Schw.) Burr. survived winter as mycelium in dormant infected buds in Khorassan province. Ascospores of U. necator, were collected by a volumetric spore trap operating constantly in a vineyard for 55 days after the bud burst. The first powdery mildew colonies were consistently found on the leaves of the shoots (7.30 cm long) growing on the vine. Cleistothecia were found on all plant parts infected during the previous growing season. More than 35-45 % of the cleistothecia borne on the leaves and stems died during winter. Most of the ascospore discharge occurred between the bud burst and the blooming time. Ascospores were periodically released from cleistothecia on the leaves kept in vineyard from October to May, while the ascospores germinating on the glass slides germinated from October to January and then germination slowed down to zero in early March and the water content potential of ascospore cytoplasm decreased constantly during this period as well. The mass required to fracture the ascocarp wall during maturation was measured to be approximately 5g in autumn, 3g in winter and 2.5 g in early spring. The most rapid decrease in the strength of the ascocarp wall occurred during a 4-week period before dehiscence in the field. The effect of the pathogenic property ascospores on healthy leaves demonstrated their role as a primary inoculum source. Cleistothecia appear to be the principal means of overwintering of U. necator in Khorassan province vineyards.
A. Shooshtarian, M. Bakhshoodeh,
Volume 9, Issue 2 (summer 2005)
Abstract

This paper attempts to introduce two indices for measuring the level of Intra-industry Trade (IIT) between Iran and the members of the European Economic Community (EEC) according to five agricultural product groups. For this purpose, the indices suggested by Grubel-Lioyd and Aquino, were employed and explained how these indices obtained. The required data and information were collected from the year books and the internet site of “Iran Trade Point”. In general, the measured indices indicated a low level of trade between Iran and the members of EEC. In three groups, export value was higher than import value. On the contrary, for the two another groups of cereals and flowers, the import values were higher in most years. But in general, there wasn't seen any certain trend in indices values. In addition, many uses of these two indices also explained. Because Intra-Industry Trade is a new subject, further study and research seems to contribute to the economic communities specially in Iran.
H. Emami, G. Savaghebi, M. Shorafa,
Volume 9, Issue 2 (summer 2005)
Abstract

Increasing soil contamination by chemicals has become an issue of increasing environmental concern. Leaching of chemicals into and through the vadose zone creats serious problems due to the contamination of the soil matrix, soil solution and groundwater. Therefore, in order to study the effect of the preferential flow, macropores and organic matter on mobility and leaching of the metals such as cadmium lead, and zinc, an experiment was conducted as a factorial-split plot based on the completely randomized design with three replications. Three treatments of the undisturbed soil (U), the disturbed soil (D) and the disturbed soil containing 3 percent organic matter (O) were leached by the solutions with the concentration of 20 mg.L-1 of Cd, Pb, and Zn for a month. Then the concentrations of Cd, Pb and Zn in the leachate were measured at different time intervals. The ANOVA results indicated that the metals had a significant difference in the leachate at 1% and the order of their mobility was: Zn>Pb>Cd. Also, there was a significant difference between different soil treatments at 1% and the concentration of the three metals in U and O treatments was more than their concentrations in D treatment. Furthermore, a significant difference between the time intervals of leaching (pore volumes) was observed at 1%. So that, Cd in leachate of U, O and D treatments indicated a significant difference after leaching for 3, 3 and 5 days, respectively (1%). But, Pb in the leachate of the three soil treatments after leaching for 11 days had a significant difference. Zn concentration only in O treatment had a clear trend at different time intervals of leaching and a significant difference was observed after leaching for 8 days.
Gh. Elyasi, Dj. Shodja, M.r. Nassiry, A. Tahmasebi, O. Pirahary,
Volume 9, Issue 2 (summer 2005)
Abstract

In modern programmes of animal breeding, the polymorphisms of the milk proteins can be used as marker systems. Beta-Lactoglobulin is the major milk whey protein in the ruminants. The BLG coding gene located on ovine chromosome 3. This protein, synthesis in the mammary glands during pregnancy and the lactation stages. Studies have indicated that this protein is polymorphic in the many breeds of sheep. This is the result of a single base pair substitution in the Beta-Lactoglobulin gene that also rises to the RsaI restriction fragment length polymorphism (RFLP). The aim of this work was to analyze the genotype distribution of Beta-Lactoglobulin in sheep. Blood samples were supplied from 142 sheep of the 5 breeds (Ghezel, Afshari, Moghani, Makoii and Arkharmerino). Genomic DNA was extracted from the 200ul blood sample according to Boom et al. (1989) method modified by Shaikhayev (1995). The Gel monitoring and the spectrophotometeric methods were used for determination of the DNA quality and quantity. the Primers BLG5 and BLG3 amplified a 452 bp fragment from the exon II of the ovine Beta-Lactoglobulin gene. the Products of the amplification were recognized by the electrophoresis on the 1% agarose gel stained with ethidium bromide. The RsaI enzyme was used for restriction of the PCR products. The digested products were separated by the electrophoresis on the 8% nondenaturant polyacrylamide gel and visualized after staining with the ethidium bromide on UV transillumination. The popGen32 software (ver.1.31) was used to estimate the allele and the genotype frequencies, the Hardy-Weinberg equilibrium and dendrogram of the genetic distance. The frequency of A-allele in Ghezel, Afshari, Moghani, Makoii and Arkharmerino breeds was 56%, 34%, 36%, 53% and 48% respectively. The populations were in Hardy-Weinberg equilibrium except to Afshari breed. The lowest genetic distance was observed between Moghani and Afshari breeds and the highest genetic distance between Ghezel and Afshari breeds. The results of this study indicated that PCR-RFLP is an appropriate tool for evaluating genetic variability in sheep.
M. R. Safari Motlagh, F. Padasht, Gh. Hedjaroude,
Volume 9, Issue 2 (summer 2005)
Abstract

The brown spot disease is one of the seed-borne diseases of rice, found in the all stages of its growth from nursery to farm. It causes qualitative and quantitative damage on rice. Therefore, some studies carried out on the different aspects of this disease and the reaction of some cultivars of rice against the pathogenic fungous agent of the diseases. To do so, 120 isolates, isolated from plant samples were collected from the 91 paddy fields in Guilan. To isolate the pathogenic fungous agent of the disease, the collected samples were cultured on PDA and filter paper. According to the results, the present isolation related to Bipolaris with the 3 species : Bipolaris oryzae (Ito & Kurib.) Drechsler ex Dastur Bipolaris victoriae Nelson Bipolaris sp. The total isolataes were consisted of 15% Bipolaris oryzae, 75% Bipolaris -victoriae and 10% Bipolaris sp. The study of pathogenicity of isolation in these three species was applied to Khazar rice in desicator. The symptoms created by these three species were different from necrotic spots to leaf death. The results indicated that not only the symptoms but also the virulence in these three species were different. The virulence in B. oryzae was more than B. sp and this was more than B. victoriae. To study the reaction of some cultivars of rices to the pathogenic fungous agent, 8 cultivars of rice: “ Bejar, Khazar, Sepeedroud, Domsephid, Hassan saraee, Binam, Neda, Nemat” respectively were used in the two stages of the plant growth, to leaf in the seedling stage and heading. The results indicated that in seedling stage there was no significant difference between these cultivars with respect to the amount of infection. And in heading stage, according to “Dunken” test (5%) they divided into the 3 groups: “Neda, Sepeedrud, Khazar and Binam” with the lowest amount of infection were in the first group, “Bejar, Domsephid and Hassan saraee” classified in the second group and “Nemat” was in the third one. But there was no significant difference between them according to the variance analysis table.
Y. Fathipour, A. Hosseini, A. A. Talebi, S. Moharramipour, Sh. Asgari,
Volume 9, Issue 2 (summer 2005)
Abstract

The biological parameters of cabbage aphid, Brevicoryne brassicae (L.) was studied in the laboratory conditions under the three constant temperatures (20, 25 and 30 ºC), RH 60±5% and a photoperiod of 16:8 (L:D) using 40 first instar nymphs. Among nymphs, 40%, 55% and 10% of them completed their nymphal period in 20, 25 and 30 ºC, respectively and developed to adult stage. In 30 ºC, the most biological acitivities of aphid were disrupted and the most individuals (nymphs and adults) were killed. Most developmental periods, longevity and the amount of reproduction in 20 ºC were significantly greater than other temperatures. In temperatures 20, 25 and 30 ºC the last individual of a cohort died in age of 33, 29 and 16 days, respectively. The life expectancy of cabbage aphid in the first day of experiment was 13.93, 10.50 and 7.19, respectively according to the mentioned temperatures. There was a little difference between net reproduction rates in temperatures 20 and 25 ºC (16.74 and 15.92, respectively). Net reproduction rate was reduced extremely in temperature 30 ºC (1.75). The intrinsic rate of the increase in the temperatures 20, 25 and 30 ºC were 0.187, 0.226 and 0.042, respectively. The results indicated that 25 ºC was the optimal temperature for biological activities of B. brassicae and its highest population growth was observed at this temperature.
Z. Banihashemi,
Volume 9, Issue 2 (summer 2005)
Abstract

The dissemination of Phytophthora spp. in the surface irrigation water was studied during 1993-94 in Marvdasht area and certain other parts of Fars province. Monthly the water samples were taken along 100Km of the Kor river 22Km up stream from the Doroudzan Dam to about 80Km down stream to Mardvdasht where Sivand and Kor rivers joined. The other sampling locations includede the Maeen river adjecent to the Dam, and the Sivand river from Dashte-Morghab to Mardasht. Few samples were also obtained from Shapour and Dalaky rivers and also from Yasouj and the Sisakht regions in Khkilueh and Boir Ahmad. The water temperature, pH and EC were measured and samples were assayed on the same day of the collection. The water sample was filtered through the two layers of the cheese cloth and about 1L was placed in a plastic container (30 × 20 Cm) 2-3C deep and 100 fresh citrus leaf disks (6mm dia) were also added and incubated at the room temprature. After 48hr, disks were collected, washed, blotted dry and plated on Phytophthora were collected, washed, blotted dry and plated on Phytophthora selective medium (PARPH). At least 50 disks were used in the 5 plates for each sample. The five to 8 boiled hemp seeds were placed on each growing colony and transferred to the distilled water, after 12hr for sporangium production. The Phytophthora species were idenified by their morphological characteristic and temperature requirement. Phytophthora spp. were present in the most rivers except the Shapour and Dalaky. The predominant species were non-popilate high temperature (above 35C) species mainly P. cryptogea and P. drechsleri. In some cases P. capcisi and the other unidentified species were also detected. Phytophthora spp. were present throughout the year but the lowest population was detected during winter months. The fluctuation of the phytophthora population and the other water microorganisms in the Kor river after shiraz petrochemical complex during the growing season was very high, but sometimes reduced to zero (perhaps due to the water pollution). No Phytophthora colonies were detected in the dam lake or in the most cases in the cement canals.
M. J. Nazemosadat, A. Shirvani,
Volume 9, Issue 3 (fall 2005)
Abstract

Since the fluctuations of the Persian Gulf Sea Surface Temperature (PGSST) have a significant effect on the winter precipitation and water resources and agricultural productions of the south western parts of Iran, the possibility of the Winter SST prediction was evaluated by multiple regression model. The time series of PGSSTs for all seasons, during 1947-1992, were considered as predictors, and the time series of MSSTs during 1948-1993, as the prrdictand. For the purpose of data reduction and principal components extraction, the principal components analysis was applied. Just the scores of the first four PCs (PC1 to PC4) that accounted for the total variance in predictor field were considered as the input file for the regression analysis. For finding the dependency of each principal component to the first time series of the PGSST, the Varimax rotation analysis was applied. The results have indicated that PC1 to PC4 respectively are the indicator of temperature changes during winter, autumn, Spring and Summer. According to the regression model, the components of PC1, PC2 and PC4 were significant at 5% level. But the components of PC3 was insignificant. The results indicated that the significant variables are held accountable for the 33.5% of the total variance in the winter PGSSTs. It became obvious that for the prediction of the winter PGSST, the PGSST during the winter of the last year has a particular importance. At the next stage, autumn and summer temperature have also a role in prediction of winter PGSST.
Z. Pakkish, M. Rahemi,
Volume 9, Issue 3 (fall 2005)
Abstract

Green skin (hull) of pistachio fruits is a barrier against the penetration of fungi and insects into the kernel of pistachio. Splitting of husk facilitates the entry of fungi and infection of pistachio kernels during the harvest. So far no effective way has been reported for controlling this problem. To evaluate the effects of gibberellic acid on hull spliting the present research was conducted in a commercial orchard of pistachio during 2001-2002 in Rafsanjan, Iran. Gibberellic acid (GA3) at 0,25,50 and 100 mg –1 was applied on 25-year-old of “Owhadi” pistachio cultivar. Two branches of each tree was sprayed during two years of study. GA3 at 25,50 and 100 mg –1 significantly reduced hull splitting and penetration by Aspergillus spp. into pistachio fruits. There was a positive correlation between the hull splitting and fungi penetration (r=0.92*). The exocarp, mesocarp and endocarp of pistachio fruits cultured on selective medium of Aspergillus spp. showed no infection of pistachio kernel by Aspergillus spp. The highest concentration of aflatoxin was detected in the kernel of non-treated fruits (6.25 ppb) and the lowest (0.5 ppb) fruits treated by GA3 . GA3 reduced husk slippery of pistachio fruits at harvest. The rate of husk slippery was reduced by increasing the concentration of GA3. Gibberellic acid treatments had no significant effect on dehiscence, weight of 100 fruits, total soluble solids, but significantly increased fat and chlrophyll content of kernel of pistachio fruits. The results of the study is recommended for commerical pistachio production in Iran.
E. Khosravi, Sh. Dokhani, G. H. Kabir,
Volume 9, Issue 3 (fall 2005)
Abstract

The meat productions are the most popular among different food products. On of the serious problems of this kind of products may be the change of the physical and chemical properties. The Restriction of the use of synthetic antioxidants have prompted the extensive research on the effect of the natural antioxidant and replacement of synthetic antioxidant with the natural ones. In this study, the effect of α-tochopherol (vitamin E) and propyl gallate on German sausage was evaluated. Four different German sausages were formulated and prepared in 30 Kg batches as follows: control without antioxidant, sausages plus α- tochopherol (200 or 500 ppm) and sausages plus propyl gallate (200 ppm). Twelve Kg of the samples were filled into cellulosic casings and the other 18 Kg in polyamidic casings. All samples were cooked. One third of the packed samples were stored at (4˚C ± 1) for 10 days and the rest were stored at (– 18 ˚C ± 1) for 6 months. The extent of autoxidation for samples were determind by peroxid and TBA values. During the storage period, autoxidation rates of control samples were more than other treatments. Propyl gallate was more effective in reduction of autoxidation than α- tochopherol treatments. Addition of 500 ppm vitamin E was more effective than 200 ppm. Significant differences were observed among treatments (P< 0.05). The study of the shear strength of the stored susages at the (4 ºC ±1) for the 10 days indicated that the most shear strength is seen in the cellulosic casing samples. The same results obtained for the stored samples at the (-18 ºC ±1) for the 6 months.
A. Sarreshtehdari,
Volume 9, Issue 4 (winter 2006)
Abstract

Of the applications of remote sensing and satellite images in natural resources is distinguishing and detection of changes in land surface. The image classification using Maximum Likelihood (MLC) is one the prevalent method which is used in a study of the application of TM and ETM+ satellite images to detect sediment deposition on an implemented floodwater spreading scheme. In order to implement the research, field sampling and checking were done using transect networking method by selection of 30 sample points in floodwater spreading area as well as another 30 control points in the study area. The results of the study are shown that detection of sediment deposition using MLC method by application of LANDSAT TM and ETM+ can lead to increase the precision of change detection up to 82 percent. Furthermore, the results also show that the trend and changes due to sediment deposition on water spreading area can be precisely detected. Considering the present and potential applicability of the applied method in distinguishing changes due to sediment deposition on land surface which is absorbed on 450 hectares of water spreading area in this research study, it can be pointed out that the use of this method in larger area could be tend to increase the precision of change detection and to decrease the required time.
P. Shekari, M. Baghernejad,
Volume 9, Issue 4 (winter 2006)
Abstract

Chenges in the soil characteristics is rather continuously. A method that takes this continuity into account would present a realistic pattern of soil distribution either in taxonomic or geographical space. The fuzzy set theory provides such an approach. In this study, the robustness of fuzzy clustering in soil pattern recognition was evaluated in a subcatchment of western Iran. The clustering carried out on the basis of minimization of an objective function in assigning membership values to each pedon in each fuzzy class. Fuzziness exponent values from 1.15 to 1.5 were used. The following validation of the resulted clusters (classes), optimal number of classes in whole, morphological and particle-size subsets were determined 8, 4, and 5 respectively. Plots of membership values across the landscape indicated class overlap and considerable contiguity. Considering low differentiation of these young soils and the high similarity among their properties, the method indicated a high capacity in recognizing different soil types over the study area. Furthermore, there was relationships between the soil fuzzy classes and landform. Thus, the method is capable in continuous classification, which could be so important in construction of continuous soil maps at low aggregation levels, e. g., pedon.
B. M. Ashour, A. Arzani, A. Rezaei, S. A. M. Mirmohammady Maibody,
Volume 9, Issue 4 (winter 2006)
Abstract

The Genetic basis of grain yield and related characteristics were studied by a generation mean analysis in five crosses of winter wheat (Triticum aestivum L.). “Roshan”, “Mahdavi”, “Inia”, “Atila” and “Goscoyin” cultivars along with their F1, F2, BC1 and BC2 populations were evaluated by a split-plot design with crosses as the whole plot in a randomized complete block design with two replications and generations were applied as the subplots. Analysis of variance revealed significant differences among generations for studied characteristics including the grain yield per plant, the number of spikelet per plant, the number of spikelet per spike and grain weight per spike. For the majority of traits and crosses, F/DH1/2 was less than one, indicating that the sign and magnitude of gene actions were different. Estimates of broadsense and narrow sense heritabilities were low for the grain yield per plant compared with other traits, rating from 28.5% to 58.6% and 24% to 48,5% for the five crosses, respectively. Genetic components of generation means were calculated by fitting different models and choosing the best model indicated that the impact of additive, dominance and epistasis genetic components in controlling the traits depend on the cross and the trait under study.
Gh. Khajouei Nejad, H. Kazemi, H. Alyari, A. Javanshir, M. J. Arvin,
Volume 9, Issue 4 (winter 2006)
Abstract

This study was conducted to evaluate the effects of four levels of irrigation (irrigation of plants after I1 = 40, I2 =60, I3 = 80 , and I4 = 100mm of evaporation from class A pan) and four plant densities(D1 = 30, D2 = 40, D3 = 50 and D4 = 60 plants/m2) on the seed yield and seed quality in three soybean cultivars(V1=Hobit, V2=Williams and V3=Hill) in a split factorial design, based on the completely randomized blocks, with three replication for two years(2001 and 2002). The Irrigation treatments were assigned to the main plots, and the plant densities and cultivars to the sub plots. Results indicated that soybean seed yield was influenced by the different irrigation and plant density levels in the both years. Irrigation levels I2 produced the highest and I4 the lowest seed yield. It was also revealed that the plant density D3 produced the highest and D1 the lowest seed yields. Among the cultivars under investigation, V2 produced the highest and V3 the lowest seed yield . Seed oil and its protein contents both were affected significantly by the irrigation levels, plant densities and cultivars in both years. The plants receiving I1 treatment had the highest and those having I4, the lowest percentages of seed oil. Changes in the plant densities also affected seed oil and protein content. The plant density of D1 caused the seeds to have the highest oil and lowest protein percentages. However, D4 decreased oil and increased protein percentages. The highest water use efficiency was obtained from I3 and that of the lowest value from I1. The results also indicated that D4 had the highest and D1 the lowest water use efficiencies. Therefore, it could be concluded that the water use efficiency can be increased by increasing the plant density per unit area. The highest efficiency for biological and grain yield belonged to V2 and V1 respectively where as the lowest efficiency for those two mentioned characters belonged to V1 and V3, respectively. However, the treatment I2V2D2 is recommended for higer the seed yield production per unit area.
F A. Frouzandeh Shahraky, M. R. Khajehpour,
Volume 9, Issue 4 (winter 2006)
Abstract

Under irrigation and in double-cropping system, a large amount of plant residue remains after harvest that along with the limited time for residue decomposition and complete seedbed preparation, necessitates reduced tillage and special residue management. In the present study, the effects of various seedbed preparation methods on vegetative growth, yield components and seed and oil yields of sunflower (Euroflor hybrid) were studied in a barley-sunflower cropping system during 2001 at the Agricultural Research Station, Isfahan University of Technology. Three residue management treatments (standing, partly removed and burned) along with five tillage systems (moldboard + disk chisel + disk disk moldboard and furrower as the minimum tillage) were laid out in a split-block design with three replications. Burning residue treatment significantly increased plant dry weight at various developmental stages and also head diameter. Number of seeds per head, 1000 seed weight, harvest index, and oil yield were non-significantly higher in the burned residue treatment. Seed yield was significantly higher in the burned and partly removed residue treatments. Moldboard + disk and chisel + disk treatments significantly produced higher plant dry weight at various developmental stages, head diameter and seed yield. Number of seeds per head, 1000 seed weight, harvest index, and oil yield were non-significantly higher in these treatments. Minimum tillage ranked the lowest for these traits. The results of this experiment indicate that chisel + disk treatment with the partly removed residues might be an appropriate seedbed preparation method in a barley-sunflower double planting under conditions similar to this experiment.
M. Rezaei, H. Nassiri Moghaddam, J. Pourreza, H. Kermanshahi,
Volume 9, Issue 4 (winter 2006)
Abstract

An experiment was conducted with the male Ross broiler chicks from 1 to 42 days of age to test the effects of different dietary protein and lysine levels on performance, carcass characteristics, and N excretion. Treatment diets consisted of three levels of supplemental lysine in starter and grower period (0, 0.15, and 0.30 %) and the two levels of protein (20.84, 17.84 in starter, and 18.12, 16.12% in grower period) with 2900 Kcal ME/kg diet. The results indicated that the Reducing dietary protein decreased significantly the weight gain in starter, grower, and total period up to 6, 4.6, and 5.6%respectively (P<0.05). It also decreased the feed consumption in starter period (P<0.05). Decreasing dietary protein had no significant effect on gain to feed ratio and breast meat yield, but increased abdominal fat percentage significantly (P<0.05). Increasing dietary lysine increased the feed consumption in starter and weight gain, gain to feed ratio in grower and total period of the experiment (P<0.05). Increasing lysine in diet caused a significant increase in breast meat and tight yield, and percentage. Adding supplemental lysine reduced the N excretion in starter period significantly (P<0.059). N excretion reduced significantly by decreasing dietary protein (P <0.05). Dietary treatments had not significant effect on mortality percentage. The results of the present experiment indicated that with providing limiting amino acids and adding supplemental lysine to diet, the crude protein could be reduced up to 3 and 2 percent in starter and grower periods respectively. Reducing the crude protein had not adverse effect on the feed efficiency.
A. Hassanabadi, H. Nassiri Moghaddam, H. Kermanshahi, J. Pourreza, D. Korver,
Volume 9, Issue 4 (winter 2006)
Abstract

In the current experiment seven catheterized broiler breeder hens were used at 60 weeks of age. Retention of 14CO2 in the body of the hens following continuous infusion of NaH14CO3 during each of tow-30-hr continuous infusion studies was determined. Oxidation rate plateau was established within two hours in each experiment. Recovery of 14CO2 at the steady state in the first and second study were 91.09 and 87.55 percent respectively and were not significantly different. Mean breath 14CO2 recovery was 89.32 percent and hence retention was 10.68 percent. Recovery of 14CO2 in breath was not significantly affected by laying of egg or photoperiod. Recovery of 14CO2 during the fed state was significantly lower than the fasted state. The results of this experiment indicated that, using of uncorrected data for the retained isotope into body, lead to 10.68 percent AA requirements underestimation in broiler breeder hens by indicator amino acid oxidation technique.
S. R. Miraei Ashtiani, P. Zamani, A. Nikkhah, M. Moradi Shahrbabak, A. Naserian, F. Akbari,
Volume 9, Issue 4 (winter 2006)
Abstract

Improvement of feed efficiency in dairy farming economically has a great importance. In this study, the genetic parameters of net energy efficiency and its relationships with milk yield, 3.2% fat corrected milk, body weight, gross income and income over feed costs were investigated, by the 2589 monthly records collected from the 723 lactating cows in the 3 herds. The different requirements of energy were estimated, by the National Research Council (NRC) models. A general linear model was employed for determining significant factors affecting each trait. The genetic parameters were estimated by a multivariate analysis with the derivative free approach of restricted maximum likelihood algorithm. The animal models contained the fixed effects of herd-year-season, parity number and stage of lactation, the regression coefficients of each trait on the dietary levels of rumen undegradable protein and metabolizable energy, and the random effects of animal additive genetic, permanent environment and residuals. The heritability of milk yield, 3.2 percent fat corrected milk, body weight, net energy efficiency, gross income and income over feed cost, were estimates 0.31, 0.32, 0.30, 0.34, 0.24 and 0.29 respectively. The results of this study indicated that the direct selection for net energy efficiency might genetically improve the feed efficiency. It also seems that the selection for fat corrected milk may be effective for the indirect improvement of feed efficiency and economic performance of dairy cows.
L. Rozbeh Nasiraei, Sh. Dokhani, M. Shahedi, R. Shokrani,
Volume 9, Issue 4 (winter 2006)
Abstract

The Two cultivars of kiwi fruit, Hayward and Abbot, with the desirable quality were harvested on time from Valiabad, a region in Tonekabon (Mazanddaran Provicnce). Fruits were graded and packed in the wooden boxes, cartons and low density polyethylene (LDPE) films, the fruits were cold stored in a proper and constant conditions (T= ±0.5 & RH=90-95%) for a period of 6 months. Samples were taken in completely randomised design from each package for intervals of 30±3 days and during storage (6 months). Chemical characteristics such as the total soluble solids(TSS), titratable acidity as citric acid, dry matter, vitamin C and the Physical characteristics such as yield point (Y.P.), yield point strength (Y.P.S.), penetration force (P.F.) and penetration stress (P.S.) were measured. Statistical analysis was performed with the factorial experiment in an unequal completely randomized design and the means compaired by Duncan multiple range test. The results indicated that, cv, Abbot has shorter shelf life, 4 months, compared to Hayward with 6 months storage period. Hayward contained more dry matter than Abbot throughout the storage period. Total soluble solids of cultivars increased and titrable acidity as citric acid decreased during storage. Vitamin C of Abbot was more than Hayward throughout the storage. Total factors in relation to texture and physical properties decreased by time such texture Hayward cv.after six month storage and in Abbot after four month storage was softer. As the final conclusion, wooden bins packaging for longer storage and plastic packaging for monotonous rippening of kiwifruit was the best in compared with other packaging.

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