Showing 30 results for Production
Mohammad Reza Vahhabi, Mehdi Bassiri, Jamaleddin Khajeddin,
Volume 1, Issue 1 (4-1997)
Abstract
Short-term changes (5 years) in canopy cover, species composition and forage production were studied under protection from grazing and grazed condition in 19 range sites in Fereydan region, Isfahan province. In this study, density, canopy cover and forage production data were obtained from quadrates inside and outside exclosures in the spring of 1983. These parameters were studied again in 1988 and compared with the previous data. Results indicated that species diversity in these range sites was relatively high up to 212 plant species were identified. Sixteen, 8.5 and 75.5 percent of these species were classified into I, II and III palatability classes respectively. After five years, comparison of inside and outside exclosures indicated an increase in the density of species of I, II and III palatability classes by 138.8, 120.8 and 51.5 percent inside exclosures, respectively. Density of all species had increased by 62 percent as a result of 5-year protection from grazing. Species composition data as canopy cover were used to construct 3 dendrograms to investigate the similarity among range Sites. Assuming 32% similarity as the threshold level, 19 range sites were classified into 10 vegetation types in 1983. After 5 years, these vegetation types decreased to 8 and increased to 11 under protection from grazing and grazed conditions, respectively. The average forage production inside exclosures was almost twice as much as in grazed sites (600 Vs. 315 kg/h). Three groups of range sites were recognized according to the time requirement for rehabilitation by grazing protection. The first group was improved considerably by the end of the 5-year protection Period. The second group improved relatively within five years of grazing exclusion. The third group did not improve by 5-year grazing protection and needed much longer protection period or some other range rehabilitation practices.
Javad Pour-Reza, Mehdi Mehrshad,
Volume 1, Issue 2 (10-1997)
Abstract
Two experiments were designed and conducted to evaluate the effect of tallow and the nutritional value of millet and the effect of substituting millet for corn on the performance of laying hens. In the first experiment, the nitrogen corrected true metabolizable energy (TMEn) of tallow and millet was determined. Also the digestibility of dry matter (DM), protein, fat and crude fiber of millet was determined using the Sibbald's method. In the second experiment, with a completely randomized design and in a factorial arrangement, the effect of different levels of substitution of corn (0.0, 25, 50 and 75%), introduction of tallow at various amounts of 0, 3 and 6 percent, and also the effect of processing millet (ground and unground) on the diet of HY-Line layers from 26 to 38 weeks of age were studied. The criteria used were egg production rate, egg weight, egg output, feed intake, and feed conversion ratio. The results from the first experiment showed that screening millet increased its true metabolizable energy. Furthermore, crude fiber digestibility increased as a result of introducing fat into the diet (p<0.05). The results from the second experiment revealed that grinding millet had no significant effect on the performance of laying hens, but feed conversion ratio tended to improve in diets containing ground millet. Substitution of any amount of millet for corn significantly improved egg weight, egg output, and feed intake (P<0.05). Introduction of tallow by 6% significantly increased feed intake (P<0.05) too.
ٍsayed Mohammad Hashemi, Javad Pourreza,
Volume 2, Issue 3 (10-1998)
Abstract
This experiment was carried out to study the effects of different levels of vitamin C (0, 150, 300 and 450 ppm) and cage density (3, 4 and 5 birds) on performance and egg shell quality of laying hens under high environmental temperature. In a completely randomized design with 3 × 4 factorial arrangement, one hundred and ninety two (192) 25 week white leghorn hens were divided into 48 replicates four hens per replicate. The experimental period lasted 90 days. The criteria measured were: percentage production, egg weight, egg output, feed conversion ratio, shell thickness, shell weight, shell calcium and albumin height. Daily egg production and biweekly egg weight, shell thickness, shell weight and albumin height were recorded. Shell c1acium was measured at the end of the experiment's period. The results indicate that, 150 ppm vitamin C significantly (P < 0.05) increased egg weight and shell calcium. Albumin height was significantly (P < 0.05) increased at 300 ppm vitamin C supplementation. Cage density had no effects on shell weight, thickness and calcium, and albumin height. Egg weight, egg production and egg output were reduced significantly (P < 0.05) due to increased cage density. Feed conversion ratio was also increased significantly (P < 0.05) as cage density was increased. Interactions between vitamin C and cage density on shell and egg weight were significant (P < 0.05).
Mohammad Ali Edriss, Javad Pourreza, Saeid Ansari,
Volume 3, Issue 1 (4-1999)
Abstract
This experiment was conducted to study egg production traits in a flock of native fowl from Isfahan region and their crosses with three improved exotic breeds. Sexual maturity (SM), weight of the first egg (WFE), number of eggs (EP), egg weight (EW), feed intake (FI), and feed conversion ratio (FCR) were recorded individually during laying period up to 52 weeks of age. There were no significant differences (P < 0.05) in WFE between the four groups, but the difference between the four genetic groups was highly significant (P < 0.01) for SM, EP, EW, FI and FCR. During laying period, pooled coefficients of heritability (sire component) for SM, WFE, EP, EW, FI and FCR were estimated to be 0.24 ± 0.10, 0.03 ± 0.08, 0.41 ± 0.12, 0.48 ± 0.12, 0.13 ± 0.09 and 0.18 ± 0.09, respectively. In combined analysis, part record egg production (SM to 34 weeks of age) was positively correlated (genetically and phenotypically) with EP up to 52 weeks of age (rg = 0.74 ± 0.11, rp = 0.71). The values suggested that there is a relatively appropriate relationship in the combined groups analysis. In addition, EP up to 34 weeks of age was negatively correlated with FCR during the same period (rg = -0.92 ± 0.53, rp = -0.81).The estimated genetic and phenotypic correlation in this study suggested that selection based on part record egg production can not only be used successfully to improve EP during full record, but may also cause a better laying performance during laying period.
A. Abdeshahi, G. Soltani,
Volume 4, Issue 1 (4-2000)
Abstract
Successful implementation of socio-economic projects depends on the degree of planners’ awareness of farmers’ risk coefficient. Because agriculture is a risky activity, knowledge about the farmers’ attitudes toward risk in each area is essential. This research investigated the farmers’ risk behavior in Homayjan district in Sepidan township. Cross-section and time series data were collected from a random sample of farmers and from Agricultural Department of Fars Province, respectively. In this study, the Safety First Rule (SFR), Generalized Stochastic Production Function (GSPF) and Target Motad models were used.
The results indicated that in this area, farmers are risk averse in crop production, but they have a low risk coefficient in the use of modern inputs. Signs of GSPF revealed that the use of modern resource input reduces risk. Target Motad risk programming model confirmed that farmers are risk averse because with increasing risk, crops like wheat that have relatively stable prices and yield enter the model, while crops like onion that have high instability in price and yield are omitted from the model.
M. Ahmadpour Borazjani, G.r. Soltani,
Volume 4, Issue 2 (7-2000)
Abstract
Marine products are currently important in Iran due to the following reasons: 1) aquatics are recognized as safe and healthy food by food scientists 2) because of low dependence of fishing technology on foreign resources, they are more reliable sources for protein and food security. Therefore, it is important to increase labor productivity using advanced fishing technology under a sustainable fishery management policy. In general, the prevailing methods of fishing in the southern coasts of Iran can be classified into three groups based on the level of technology and the length of journey made: traditional, semi-industrial, and industrial. In this study, labor productivity in the traditional and semi-industrial groups were compared using data obtained from a sample of 35 fishermen in Bushehr Province. To determine the marginal and average labor productivities, transcendental production functions were estimated for fish and shrimp, separately. The findings indicated that the marginal and average productivities of labor in semi-industrial fishing were significantly higher than in traditional fishing.
L. Mosharraf Boroujeni, J. Keramat,
Volume 4, Issue 4 (1-2001)
Abstract
Recent restrictions on the use of artificial food colours have prompted extensive research on natural pigments as suitable substitutes. The red beet Beta vulgaris L. has been found as a suitable source of natural red pigment since beet powder and concentrates can conveniently be used in food products. In this research, hot and cold extractions of randomly selected red beets were used after preparation and blanching. The extracts were filtered and passed through a column of Amberlite XAD-7 resins after adjusting the pH to 2.5. The adsorbed colour compounds were extracted from the resins by eluting the column with acidified alcohol. The solvent was removed by vacuum rotary evaporator and solid colour was obtained, using a freeze dryer.
Physicochemical properties of the solid colour were determined by measuring ash and sugar contents of the solid colour. Also, its purity and stability were investigated under different conditions.
The amount of ash and sugar were negligible. The highest stability was observed at a pH value of 5 under cold and dark storage conditions. The purity of the solid colour was determined by scanning in the range of visible wavelengths and preparative TLC. The result showed that purity of the colour as a hundred percent betacyanins. The yield of production was calculated as 2.7 g powder per kilogram of beet. The colour was used in producing ice cream and frozen sherbets, which showed to be a suitable replacement for artificial colour carmoisine. Also the production cost of the colour was as low as less than 0.1 percent of that of ice cream or frozen sherbets.
S. M. B. Nabavi, A. Savari, Gh. H. Vosoughi, A. R. Nikouy,
Volume 5, Issue 4 (1-2002)
Abstract
To estimate the biomass and secondary production of macrobenthos in Khore-e-Mousa creeks, 216 sediment samples were taken. The sampling period started in 1996 and terminated in 1997. A bimonthly sampling strategy was adopted. The samples were taken by Van-Veen grab (0.1 m2) from the beginning, middle and end of each creek (Khor). To estimate the biomass of the macrobenthos, the Crisp method (1984) was employed. The standing crop was expressed as dry weight and ash free dry weight. For the measurement of secondary production, a dominant crustacean species Apseudes sp. was used.
The results indicated a low biomass per unit area in Khore-e-Mousa creeks. Maximum and minimum amounts of the standing crop were found to be in June (33.5 g DW/m2) and December (2.19 g DW/m2), respectively. Amongst all creeks, Douragh creek displayed the highest (24.93 g DW/m2) and Beehad the lowest (2.24 g DW/m2) standing crops. During the study period, 1483 individuals of Apseudes sp. were collected and grouped into 5 age classes according to Bhattacharya (Sparre, 1989) method. The secondary production was estimated to be 0.08 g/m2 ash free dry weight (AFDW). The production/biomass ratio (P/B), therefore, is calculated as 0.08÷0.18=0.44. Considering the ecological efficiency, (transfer efficiency) of different trophic levels which is about 10%, the fish production is estimated to be 2430 tons in Khore-e-Mousa area.
G.a. G. A. Sharzei, M.a. M. A. Ghetmiri, M. M. Rastifard,
Volume 6, Issue 1 (4-2002)
Abstract
This paper studies the structure of cost and production of rice using cross section data from rice farming in Guilan in 1997. A translog cost function is specified for this purpose and estimated, using Iterative Seemingly Unrelated Regressions for both the short and the long run where all factors are taken to be variables. The results of the study are as follows:
1. Neither in the short-run nor in the long-run is the possibility of technical substitution among the factors of production strong.
2. Own and cross price elasticity of demand for inputs are positive but less than one, hence limited substitutability among inputs is possible as the result of a change in input prices.
3. As the structure of production of rice in Guilan exhibits increasing returns to scale, increased allocation of land to the production of rice could result in a lower price of the product.
4. Inputs are not homogeneous, therefore, not all producers are faced with the same price for the same input. Nevertheless, the cost of production has been lower for those farmers who have paid a higher price for an input. Therefore, the higher price for inputs is more than that compensated by the quality of each input in the production process.
5. Due to the inelasticity of the demand for rice with respect to prices, a large price increase is required to stimulate farmers to allocate more resources to the production of rice.
6. Since the possibility of substitution among inputs is limited, a large increase in relative prices is required in order to change the structure of rice production.
J. Torkamani,
Volume 6, Issue 3 (10-2002)
Abstract
The main objective of the present study is to investigate the production and marketing of fresh figs in Garmsar Region. Semnan Province has the largest area under fresh figs in Iran. About 84 percent of this area is in Garmsar region, hence, it was selected as the study area. Data were collected by random sampling method through interviews with a sample of 70 fresh fig producers in Garmsar region in summer 1999. The production functions of fresh figs were estimated using translog form for the study region. Technical efficiencies for fresh fig producers were estimated using translog stochastic frontier production function.
Results of the current study revealed that farmers are not using some of the inputs optimally. Study of technical efficiency of fresh fig producers did not show the possibility of increasing production by increasing farmers’ technical efficiencies. The average of retail, wholesale and marketing margins of one kilogram of fresh figs were estimated to be 900, 550 and 1450 Rials, respectively. Also, marketing efficiency was calculated as 151%.
S. Dehghanian, M. Ghorbani,
Volume 7, Issue 3 (10-2003)
Abstract
In this study, efficiency of apple producers in Khorasan Province was determined by a cross sectional data of 212 apple producers.
Mean technical, allocative, and economic efficiencies were estimated to be around 31, 28, and 9 percent, respectively. A high potential was also detected for increasing these efficiencies. Apple producers’ age and education had positive effects and risk aversion had a negative effect on technical efficiency. Waste reduction, optimal use of inputs, introduction of technical-extension services, and apple insurance are suggested to increase efficiencies.
M. M. Nakhjavani Moghaddam, B. Ghahraman,
Volume 9, Issue 3 (10-2005)
Abstract
In order to determine the water production functions for winter wheat (Variety, C73,5), an experiment was conducted in through of a complete randomized block design with 9 treatments and 3 replications in Mashhad region. While the first treatment (as a control treatment) was selected on the basis of irrigation in all growth stages of growing season, six treatments were selected on the basis of an irrigation cut in the six stages of growth season and two remaining treatments were also selected on the basis of a constant reduction of irrigation to the amount of 20 and 60 percent. In general the water stress was caused that the amounts of depth percolation were calculated negatively which was an indication of the water uptake from below the root zone. According to results, models of the yield in per unit of area had a higher correlation coefficient of determination in relation to the models of the yield in per unit of water. The derived sensitivity coefficients indicated that the winter grain formation and flowering stages were respectively the most sensitive stages of the growth season stages to the water deficit. There are some differences between these computed sensitivity coefficients and the amounts reported by the other researchers. Probably the variety, degree of stress, the climatic conditions and some unknown factors may explain these differences.
J. Torkamani, Sh. Shajari,
Volume 10, Issue 4 (1-2007)
Abstract
This paper investigates the effects of wheat production risk and other socio-economic factors on the probability of adopting new seed technologies. Also, the effects of production inputs and production conditions are examined on wheat production yield and risk. Moreover, the relative risk of new seed varieties will be examined under different scenarios. To carry out the study, farm-level data was collected from a sample of 187 wheat farms located in Fars province, and selected by multi stage random sampling method during the years 2001 and 2002. A generalized stochastic production function by a three-stage estimation procedure was used to determine the influential factors on the production yield and risk. The results showed that yield uncertainty could not be sufficiently explained by the level of input use in the cultivation of both wheat varieties. The comparison of two wheat varieties cultivation indicated that in the absence of suitable production conditions, on the average, the cultivation of new wheat varieties ensures greater yield than traditional wheat varieties, but involves greater risk, as measured by yield variance. Accordingly, the farmers’ risk aversion attitude could be a major factor inhibiting speedy diffusion of new wheat varieties, which besides having greater average yield than traditional wheat varieties, it has less production risk. The results indicated that the risk associated with seed has negative effect on the adoption of new seed technologies.
H. Farhangfar, H. Naeemipour Younesi,
Volume 11, Issue 1 (4-2007)
Abstract
A total of 25,471 Iranian Holstein heifers distributed in 523 herds of 20 provinces were used to estimate heritability, genetic and phenotypic associations between a number of traits related to the production and reproduction performance. The Animal Breeding Centre of Iran collected the records studied in this research between 1991 and 2001. The traits associated with production were 305-day, 2x adjusted milk, fat yields and fat percentage and the traits associated with reproduction were age at first calving, number of services per conception, gestation period, calving interval as well as dry days as a separate trait. The heritability estimates were 0.31, 0.23, 0.31, 0.14, 0.03, 0.05, 0.10 and 0.01 for 305-day, 2x milk, fat yields, fat percentage, age at first calving, dry days, calving interval, gestation period and the number of services per conception, respectively. Milk yield was genetically correlated with age at the first calving (-0.14), dry days
(-0.31), calving interval (0.54), gestation period (0.01) and the number of insemination per conception (0.38). Fat yield had negative genetic correlations with age at first calving (-0.16), dry days (-0.23) while it was positively correlated with calving interval (0.44), gestation period (0.11) and the number of insemination per conception (0.20). Age at the first calving, dry days and gestation period had a positive genetic correlation with fat percenateg (0.03, 0.15 and 0.09 respectively) while calving interval and the number of insemination per conception were negatively correlated with fat percentage (-0.21 and -0.25 respectively).
R. Nikdokht, E. Karami, M. Ahmadvand,
Volume 11, Issue 41 (10-2007)
Abstract
Sustainability of livestock production systems (LPSs) is of prime importance to the needs of human beings. From a sustainability point of view, an LPS is sustainable when it is environmentally nondestructive, economically viable and socially provides appropriate quality of life for producer and the whole community. Iran LPS is primarily based on traditional production systems. Therefore, an important issue for animal production in this country is the question of sustainability of traditional LPSs.The aim of this paper was to investigate and compare the sustainability of traditional LPSs in Firouzabad County. Three dimensions of sustainability were considered. Survey research was used to reach this purpose. Therefore, 300 livestock producers in “Nomadic”, “Semi-nomadic” and “Village- based” system were interviewed. Respondents were selected by a multi-stage cluster random sampling method. Face validity was confirmed by experts and the questionnaires were subjected to reliability testing using data collected in the pilot study. Findings showed that all three LPSs were unsustainable with regard to social, economical, and technico-environmental dimensions. Comparison of LPSs showed that Village-based LPS was from social dimension relatively sustainable and technically and environmentally unsustainable. While nomadic LPS was from social dimension relatively unsustainable and technically and environmentally sustainable.
S.s. Hosseini, M. Ghorbani, M. Khaledi, E. Hassanpour,
Volume 12, Issue 43 (4-2008)
Abstract
This paper analyzed the effect of transaction costs on supply response of rice producers in Iran. Some of these producers participate in market as sellers or buyers and others remain self-sufficient. Farmers have different responses based on fixed and proportional transaction costs. The data used in this research consisted of information about 260 rice producers in Mazandaran province in 2004. The results indicated that lowering transactions costs would increase output by both increasing market participation and increasing production for market participants. Given that transaction costs affect market participation, aggregate supply will respond to changes in the transaction cost structure through its effect on market participation. It is recommended that policies reducing transaction costs be applied as a complementary policy to price policies to affect supply response.
M. Zibaei, M. Jafari Sani,
Volume 12, Issue 43 (4-2008)
Abstract
While technical efficiencies of firms that are estimated with respect to a given frontier are comparable, this is not normally valid the case among firms that operate under different technologies. Such problem arises when comparisons of firms from different regions of country are involved. This study uses the concept of the metafrontier function to investigate regional differences in milk production technologies of Iran. Metafrontier function was estimated using non-parametric data envelopment analysis (DEA) and required data are collected from 726 questionnaires. Results of estimating regional frontier production function indicated that, gap between the best producer and other producers in Yazd is minimum and it is maximum in Esfahan. Also estimation of metafrontier production function and technical gap ratio showed that Tehran and Yazd have higher technical operation in comparison with other studied provinces.
M. Khodagholi, Z. Eskandari, M. Saeidfar, S. Chavoshi,
Volume 12, Issue 44 (7-2008)
Abstract
The effect of nitrogen and phosphorous fertilization on range species production was studied using factor combination method as factorial with 3 blocks and 12 treatments. Nitrogen in 4 levels of 0،25،50 and 75 kg N/ha and phosphorus in 3 rates of 0،30 and 60 kg N/ha were used. Results indicated no significant difference between nitrogen rates in different growth forms of grass, bush and Eurotia ceratoides. Nitrogen in 75 kg/ha rates caused an increase of 40 and 106% in grass and Eurotia production, respectively. The maximum rate of production was seen in N50 with 100 percent increase compared to N0. Moreover, no significant difference in phosphor rates of leguminous and grass was observed. P 60 kg caused 500 and 56 % increase in leguminous and grass production, respectively.
B. Najafi, A. Shirvanian, T. Haghshenas,
Volume 12, Issue 45 (10-2008)
Abstract
In the process of agricultural development, sustainability of pasture utilization to ensure sustained production of meat and dairy products has become increasingly important. This article aims to study factors affecting pasture and meat production imbalances in Fars province. For this purpose, the transcendental production function was used. Data was collected by using two stage cluster random sampling from 71 producers. The results revealed that present method of pasture utilization is not compatible with increasing live animal meat production objective. To optimize pasture utilization, the pasture users should be advised to stop overgrazing. In addition, the results indicated that increasing livestock and pasture mismanagement causes damage to pastures and consequently would decrease meat production in the long-run.
M Valipour, M Karimian Eghbal, M.j Malakouti, A Khosh Goftamanesh,
Volume 12, Issue 46 (1-2009)
Abstract
Salinization and alkalization are considered spatiotemporal dynamic soil degradation processes. In order to investigate the effects of agricultural activities on land degradation and soil salinity, Shamsabad area in Qom province was selected. Aerial photos (1955) and satellite images (1990-2002) were used to examine the changes in land use. Soil samples were collected from 25 locations in the study area from 0-50 cm and 51-100 cm depth at each location. For comparative purposes, sampling locations in this study were similar to locations used for salinity study in 1983. For each sample, pH, electrical conductivity (ECe), base saturation percentage, exchangeable sodium, lime and texture were measured. Land use and salinity maps were created by using geographic information system (GIS) softwares. Results revealed an increase of 9.5 times in cultivated lands in 47 years. Increase in agricultural activities in the study area has also intensified the pressure on water resource in the area, lowering ground water tables and degrading water quality. In the 0-50 cm soil depth, the average soil ECe was 6.5 dS/m in 1983, which increased to 10.7 dS/m in 2005. If soil salinity trend and pressure on water resources continue, large part of Shamsabad area is expected to change to desert in near future years.
