Showing 7 results for Fertility
M. Babashahi, Gh. Ghorbani, H. R. Rahmani,
Volume 8, Issue 3 (10-2004)
Abstract
The purpose of this study was to evaluate nutritional status in Isfahan dairy herds and the relationship between milk urea nitrogen (MUN) and fertility in the first postpartum insemination. Blood and milk samples were collected from 170 and 290 Holstein cows from 9 dairy herds, respectively. Feed samples were also collected to quantify the relationship between MUN and protein and energy content of the ration. When simple linear regression was used, a close relationship was found to exist between blood and milk urea nitrogen. Regression equations indicated crude protein percentage and protein to energy ratio in the diet only explained 7 and 10 percent of milk urea nitrogen variations, respectively. The low correlation coefficient is probably due to incorrect nutritional management and variation in diet composition in different feeding days. Logistic regression was used to determine the relationship between MUN and fertility. A negative curvilinear relationship existed between MUN and rate of pregnancy at first insemination. Since cows with MUN concentrations of 16.5 to 19 mg/dl had a better chance for pregnancy than those having either below or above these values, it seems likely that pregnancy chances for those cows having this range of MUN concentration are 1.94 and 1.63 times more than cows with less than 14 mg/dl and between 14 - 16 mg/dl, respectively.
The results of this study indicated that although MUN is a useful tool for nutritional management of dairy cows, it is not suitable for monitoring reproductive performance.
M. Khalili Mahani, H. Seyedoleslami, B. Hatami,
Volume 8, Issue 3 (10-2004)
Abstract
Elm leaf beetle, Xanthogaleruca luteola (Müller), life and fertility tables were investigated under laboratory conditions (25±2°C, 70±5%R.H. and 16L: 8D), on Ulmus carpinifolia, U.c.var.umbraculifera, U. glabra var. pendula and Celtis caucasica, in spring and summer. Since the experiments were conducted under controlled conditions, feeding on hosts with different nutritional qualities was considered to be the only cause of mortality. The aim of this study was to determine the susceptible hosts to the pest. The initial population for each life table was 100 first larval instar on 20 cm foliage which continued to the end of adult longevity. For larval and adult feeding, the foliage was replaced regularly. Larval and adult mortality and eggs number per female were recorded on a daily basis. Results showed that the net reproductive rate (R0) and intrinsic rate of increase (rm) were higher on U. carpinifolia than the other hosts in both seasons. The net reproductive rate was less than one on Celtis caucasica in spring and on U. c. var. umbraculifera in summer, which represented the negative population growth on these hosts. Therefore, U. carpinifolia was the most susceptible host to Elm leaf beetle, the other susceptible hosts being U. glabra var. pendula and U. c. var. umbraculifera, in a descending order and Celtis caucasica was the least susceptible one. .
A. Mazaheri, B. Hatami, J. Khajehali, S. E. Sadeghi,
Volume 11, Issue 41 (10-2007)
Abstract
Sarta longhorned beetle, Aeolesthes sarta, is one of the most destructive wood borer pests of fruit and shade trees in Iran. In this research, the reproductive parameters were studied under laboratory conditions. Fifteen pairs of newly developed adults (1-2 days after emergence from overwintering sites) were caged separately on 15 logs of Ulmus carpinifolia and fertility table was made using this data. The results showed that 3.9±0.2 days after emergence, females began to oviposit for 16.6±0.6 days, as oviposition period. Mean number of laid eggs was 122.6±17.5 per female. The mean longevity of male and female was 26±0.6 and 29.4±0.4 days, respectively. Females had no mortality during oviposition period, so gross reproductive rate (GRR) and net reproductive rate (R0) (famale/female/generation) were equal (61.6±8.7). Intrinsic rate of increase (rm), mean generation time (T) and doubling time of the population (t) were 0.0067±0.24-5 famale/female/day, 612.5±0.4 and 102.7±3.6 days, respectively. The finite rate of increase (λ) (female/female/day) was 1.006±0.24-5. Intrinsic rate of increase (rm) was very low (0.00672), because of longer lifetime of females (mean 602 days), low longevity during reproductive period (maximum 22 days) and long mean generation time (612.5 days).
R Rajabi-Kanafgourabi, R Ebadi, M Fazilati, S.z Mirhoseini,
Volume 13, Issue 47 (4-2009)
Abstract
The effect of mulberry leaves enrichment with riboflavin in 7, 37, 77 and 127ppm concentrations on larval growth and cocoon characteristics of Bombyx mori L., hybrid 103×104 was studied. Silkworm larvae were fed on fresh mulberry leaves of shin inche nevise enriched with riboflavin once a day. All biological and economical parameters were determined by using standard techniques in sericulture. The results showed that larval weight was greater in 77ppm among treatments on the 7th day of the fifth instar which had 47% increase compared to control. Maximum amount of female cocoon weight and female pupal weight were recorded 1.622g and 1.169g, respectively, in 127ppm while male cocoon weight and pupal weight were greater in 37ppm and recorded to be 1.169g and 0.895g, respectively. Maximum amount of cocoon shell weight and cocoon shell ratio were recorded in 77ppm for male (0.311g and 26.06%) and female (0.318g and 21.46%). Maximum weight of 50 eggs (0.027g) was recorded in 127ppm while high fertility and hatchability was recorded in 77ppm concentration. Effective rate of rearing was maximum in control treatment (72%) with no significant difference compared with other treatments. The overall results showed that riboflavin can be used at 77ppm concentration for the significant increase of cocoon weight, cocoon shell ratio and egg production of silkworm, Bombyx mori L.
K. Kamali, M. Mahdian2, M. Arabkhedri1, A. Charkhabi1, N. Ghiasi1 and A. M. Mahdian, M. Arabkhedri, A. Charkhabi, N. Ghiasi, A. Sarreshtehdari,
Volume 15, Issue 57 (10-2011)
Abstract
Floodwater Spreading (FS) plays an effective role in improving soil fertility, ground water recharge, vegetation cover, and desertification control. The soil fertility might increase as a result of a suitable suspended sediment material transferred to the downstream by flood events. To define a relevant FS method which increases the efficiency of the FS projects, it is necessary to study the quality and quantity of transported sediment material, spatially and temporarily. In this research, this subject was investigated by taking soil samples throughout 13 FS stations for physical and chemical analysis over 5 years. Within each of the 13 selected stations in the three first flooded dikes, soil sampling was carried out using random-systematic method. The total Nitrogen, absorbed Phosphorous and Potassium, and Organic Carbon of each sample were analyzed. Because of the abnormality of data, nonparametric test was adopted to compare means. All stations were classified into three groups using cluster analysis method. Based on the results, the variations of fertility factors are irregular between the dikes and amongst years. This could have been affected by several factors such as the quality and quantity of diverted flood, the characteristic of FS sites, and irregularity of sediment material deposited on the sites. Despite the low quality of soil fertility prior to the construction of these stations, in general, FS has a considerable role in improving the soil fertility. However, desirable objectives may be achieved in long term through occurrence of diverse flood events and suitable maintenance of the stations.
V. Sarvi, H. R. Matinfar,
Volume 23, Issue 1 (6-2019)
Abstract
In the face of rapid growth of the population and the need for food production sectors, one of the ways to achieve this is to increase the production per unit area. In modern agriculture, the preparation of soil fertility map seems to be necessary to plan for appropriate use of fertilizers for crops. This study was conducted to prepare a distinct map for evaluating the soil fertility according to soil chemical properties in 191 soil samples of Ardabil Plain in Ardabil Province. To achieve this goal, the available N and P, K, EC, Fe, Zn, Mn and the organic matter of soil were mapped using geostatistical Kriging estimator into the Geographic Information System (GIS) by the ArcGIS software. The Analytical Hierarchy Process (AHP) was used for weighting the soil fertility factors as the input data. Then, a membership functions was defined for each factor by factorial scoring and the map of soil fertility was prepared and classified by using the AHP technique into the GIS program. The results showed that most of nitrogen and phosphorus with the weight of 0.293, 0.202 had the mostly infraction on the soil fertility and production. Survey map of the distribution showed that most of the factors were studied in the northern region with the low nutrients. The results also showed that 23.7 percent of cultivated land fertility maps had a poor fertility status, 28.3 percent of the land had a moderate fertility status, 25.4 percent of the land was good and the fertile land with 22.6 percent had a very good fertility status.
R. Rezaeinejad, H. Khademi, Sh. Ayoubi, H. Jahanbazy Goujani,
Volume 24, Issue 2 (7-2020)
Abstract
In arid and semi-arid ecosystems, isolated trees significantly influence the soil properties and can have a great impact on the soil fertility as well as the conservation and improvement of soil quality. This investigation was conducted to examine the influence of wild almond (Amygdalus arabica Olive.) trees having different ages on the physical and chemical soil properties. Soil samples were taken from the depths of 0-20, 40-60, 80-100 and 120-140 cm at two distances from the tree crown including the basal area (referred to as the rhizosphere) and the canopy edge in 3 replications for the 30, 50, and 130 year-old stands and also, in a control site, all in the Anjarak area, southeast of Baft city, Kerman Province. Soil properties including pH, EC, organic matter, calcium carbonate equivalent, available and non-exchangeable potassium and soil texture were measured in all samples. The results indicated that the measured soil properties in different depths in the study area had been influenced by the age and the canopy size of the wild almond trees. The highest and the lowest amount of pH were found in the control soil and the soils covered by 130 year-old trees, respectively. Besides, the electrical conductivity of the soil under the tree crown was more than that of the soil in the canopy edge. The accumulation of C, N, and other nutrients under the tree canopies resulted in the creation of fertility islands surrounding the trees. Furthermore, the soil physical and chemical properties were greatly improved with the increase in the tree age of Amygdalus arabica Olive. As the conclusion, wild almond trees could have very positive effects on soil properties. Therefore, it is essential to protect the trees. Otherwise, the risk of soil quality reduction would be increased and soils might become more susceptible to soil erosion.
