Iran Agricultural Research
Year:2003 | Volume:22 | Issue:2|Papers Count:8

A complete diallele crosses derived from eight oilseed rape (Brassica napus L.) genotypes was used to estimate the genetic parameters for seed yield, 2-propenyl (allyl), 3-butenyl, total glucosinolate, oil and protein contents. Analysis of variance based on Griffing's Method one with Mixed- B Model revealed the presence of significant mean squares for general and specific combining abilities and reciprocal effects, indicating additive, non-additive and maternal effects, contributed to genetic control of the studied characters. High narrow-sense heritability estimates for the three types of glucosinolates indicated the prime importance of additive genetic effects. However, the degree of dominance greater than one for seed yield, oil and protein contents showed the importance of non-additive genetic effects for these traits. Significant heterosis over better parent was detected for allyl, 3-butenyl and total glucosinolate contents, seed yield, oil and protein percentages. Non-significant correlation between studied traits and seed yield suggested the possibility of improving these traits without any considerable changes in the seed yield. In general, PF7045/9 I and BL I (breeding lines) were good combiner parental lines for seed yield and low glucosinolates. The crosses PF7045/91 x Shiralee and BL1 x PF7045/9 I had the highest positive and negative heterosis for seed yield and glucosinolates, respectively.

This study was conducted to determine the additive effects of microbial phytase, organic acids (citric, ascorbic), vitamin 03 and Ca on broiler performance and nutrient digestibility in a corn-soybean meal-based diet from 1 to 21 d of age. Broilers were fed the following basal diets at either 0.79 or 0.9 % of dietary Ca: 1) a negative control corn-based diet (NC), 0.315% available P; 2) NC + 500 phytase units (FYT) kg-1 diet; 3) phytase + 2%citric acid; 4) phytase + citric acid + 200 mg kg-1 diet ascorbic acid; 5) phytase + citric acid + ascorbic acid +200mg kg-1 diet vitamin D3; 6) NC plus 0.135% available P. The 12 experimental diets were fed to four pen replicates of 20 birds each. Increasing dietary Ca from 0.79 to 0.9% negatively influenced feed conversion ratio but improved feed intake and protein digestibility. Added phytase improved body weight, feed conversion ratio, tibia ash and P and protein digestibility. Subsequent addition of citric acid and ascorbic acid to feed along with phytase increased J0, 8 and 57% body weight, feed efficiency and P retention, respectively, above levels attained with negative control diet. The body weight of chicks fed the pcsitive control diet was similar to those that received the phytase and organic acids supplemented low-P diet. The tibia ash content and P digestibility of broilers fed the diet containing phytase, organic acids and vitamin D3 was 28.9 and 57% more than the negative control diet, respectively. Data presented clearly indicated that supplementation of com-soybeari low-P meal based diet with appropriate concentrations of phytase, citric acid, ascorbic acid and vitamin D3, leads to substantial increases in broiler performance and nutrient digestibility and would have an environmental benefit of reducing P and N concentrations of broiler manure.

An experiment was conducted to investigate the effect of supplemental citric acid and microbial phytase on the growth performance and body composition of common carp (Cyprinus carpio). In a completely randomized design with 3x3 factorial arrangement, the effects of three levels (0, 1.5 and 3%) of citric acid and three levels (0, 500 and 1000 FYT kg-1 diet) of microbial phytase were tested. Two hundred and sixteen fish, averaging 207 g, were divided into 27 pens, 8 fish per pen. Nine experimental diets were given to three replicates of 8 fish for a period of 8 weeks (plus two weeks for adaptation). Supplemental citric acid had no significant effect on plasma cholesterol, triglyceride, phosphorus, liver fat, carcass dry matter and protein, feed conversion ratio, protein efficiency ratio, carcass index, specific growth rate and apparent digestibility of phosphorus. Addition of 3% citric acid significantly (P<0.05) increased body ash (3.13%) and phosphorus (0.41 %). Body fat was reduced significantly (P<0.05) due to supplemental citric acid, although, there were no further significant effects associated with the amount of citric acid given. Feed conversion ratio (2.25, FCR), protein efficiency ratio (1.29), specific growth rate (0.77), percent age of body weight growth (54.3%) and phosphoru-s digestibility (53.7%) were improved significantly (P<0.05) due to supplemental phytase. Phosphorus digestibility was not significantly affected by the amount of phytase fed. The highest body ash and P, protein efficiency ratio and specific growth rate were obtained numerically with 1000 FYT kg-I and 3% citric acid in the diet (3.4, 0.44, 1.3 and 0.8%, respectively). The lowest percent body fat and FCR, 6.1 % and 2.21, respectively, were also observed with this diet. These results indicated that addition of 3% citric acid to the diet of common carp improved carcass composition and provided better digestive tract conditions for microbial phytase without any positive effect on growth.

The inhibitory effects of various concentrations of natural vanillin on the growth of Aspergillus niger, A. flavus, Pencillium expansum and P. italicum in potato dextrose agar (PDA) and apple puree-based agar at pH of 3.5 and water activity (aw) of 0.98 were studied. The most resistant mould was A. niger, followed by A. flavus, P. italicum and P. expansum. For each mould the increase in vanillin concentration affected radial growth rate. The vanillininhibitory concentrations were in general lower than 1500 mg-1.

To evaluate government intervention effects on growth of rice, wheat and cotton production in Iran, nominal protection rates (NPR) were calculated and separate Nerlovian supply models were applied to time series data for 1983-1998. Tf1e results showed that, for most years, producers had not been supported and as a result, there were not been sufficient incentives for exporters. Therefore, redirecting the rice, wheat and cotton markets is recommended in order to improve economic efficiency for these products. In this context, diminishing the share of the government in markets and strengthening the private sector may be listed at the top of a list that could be regarded as a plan for making staple agricultural production profitable.

Factor analysis is a general method for analyzing data and is used to investigate relationships among variables without distinguishing some as independent and others as dependent ones. Phenotypic and genetic factor analyses of 13 traits were carried out for eight genotypes of spring safflower (Carthamus tinctorius L.) under stress and non-stress irrigation regimes. Each experiment was conducted as a randomized complete block design with three replications. Genetic correlation matrix was used to obtain a genetic factor matrix to recognize seed yield-related characters and their associations with seed yield to determine the best criterion for identification of high-yielding genotypes under stress and nonstress irrigation regimes. Results indicated that selection based on biological yield, 1000-seedweight and plant capitula weight, may be desirable for high-yielding genotypes under stress conditions, whereas, selection based on biological yield, number of capitula/plant, plant capitula weight, capitula harvest index and harvest index, may be more efficient for identifying high-yield genotypes under non-stress conditions. Furthermore, biological yield and plant capitula weight may be suitable for screening of high yield genotypes under both irrigation regimes.

An experiment was conducted to investigate the effects of naphthalene acetic acid (NAA), naphthaleneacetamide (NAD) and 2, 4-dichlorophenoxyacetic acid (2,4-D) on quantity and quality of 'Shahani' date. Twenty four l5-year-old 'Shahani' date palms were selected for the experiment in a commercial orchard in Jahrom, Fars province. Fruit bunches on the selected trees were treated with NAA (0, 40, 60 mg 1-1), NAD (0, 80, 120 mg 1-1) and 2,4-D (0, 10, 20 mg 1-1). NAD at 80, 120 mg 1-1 significantly increased weight, length, diameter and pulp weight of fruit during khalal and tamer stages NAA at 40 and 60 mg 1-1 and 2,4-D at 10 and 20 mg r' also increased length and diameter of fruits at khalal and tamer stages, but NAA was more effective than 2,4-D in improving fruit characteristics. In general, NAA, NAD and 2,4-D delayed fruit ripening up to 17 d and reduced total soluble solids (TSS) particularly at higher concentrations

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.