Comparison of response to selection in three peanut cocoon lines of silkworm during spring and autumn seasons

The aim of this experiment was to study the season effect on response to selection in three Iranian silkworm pure lines. In the first year, a parental group was selected, recorded and coded for each 3 lines of 31, 103 and 107, which had further weight average than the population average. These parents were crossed with each other and a selected group was made for these three lines. Also, a parental group was chosen, recorded and coded for each of the three lines which include the weight average equal to population average weight. These parents also were crossed with each other and a coincidental group was made for these three lines in two spring and autumn seasons. The members of each group were grown up and crossed during three successive generations coincidentally with out any re selection. The 27 average records were registered and analyzed in two spring and autumn seasons. The data analysis showed that in spring, among three studied lines for larva vitality, the highest response to selection was shown by line 31 (2.706%) and line 103 (-4.489%),  respectively and the least response belonged to line 107 (-5.064%). The comparison of response average to selection in these three lines also had no significant difference statistically (P > 0.05). In the same season, the highest response to selection for the number of produced cocoons was observed in line 103 (51.19 cocoon) and line 31 (25.56 cocoon), respectively in the base population. Also, the least response to the selection in the base population belonged to line 107 (22.44 cocoon). The comparison of average response to selection in these three lines showed no significant difference statistically (P > 0.05). Among these three studied lines for the best cocoon total weight in spring, the highest response in the base population belonged to line 103 (67.09 g) and line 31 (40.16 g), respectively and the least response to selection in base population belonged to line 107 (19.58 g). The comparison of response to selection in these three lines showed that there was no significant difference statistically (P > 0.050). Among the line for best single cocoon weight in spring, the highest response to selection in the base population belonged to line 31 (0.05888 g) and then line 103 (0.04075 g), respectively and the least response to selection belonged to line 107 (0.03863 g). The comparison of response average to selection among three lines showed that the difference of response to selection in lines was not significantly statistically (P > 0.05). Among lines for cocoon weight resulted from 10000 larva and in spring, the highest response to selection in the base population belonged to line 31 (728.3 g), then line 107 (401.9 g) and the least response was observed in line 103 (289.7 g). The comparison of response average to selection in lines shows that there is no significant difference statistically among these three lines (P > 0.05). Among the lines in autumn, for best single cocoons weight, the highest response to selection in base population belonged to line 107 (0.07700 g) and line 31 (0.05513 g), respectively and the least response to selection in line belonged to line 103 (-0.04657 g) in the base population. The comparison of response average to selection in these three lines has shown that there is a significant difference statistically for response to selection in lines (P < 0.05).Key words: Silkworm, genotype, season, selection, performance

An investigation on the replacement of antibiotics by medicinal plants to control the infection of Escherichia Coli (E. coli) in broiler chickens

This study was done to determine the effects of garlic, mint and onion in feeding of the broiler chickens as a growth natural factor (GNF) instead of antibiotics. First, the antibacterial effects and minimum inhibitory concentration (MIC) of 0.5, 1, 2.5, 5, 10 and 20% concentrations of aqueous extracts of garlic (Allium sativum), mint (Mentha spp.) and onion (Allium cepa) on E. coli were determined in in vitro conditions. Results show that the minimum inhibitory concentration (MIC) of garlic extract was 0.5%. Distilled water, phenol phenicol and Floxacin were used as solvent and control. In the next step, the effects of adding garlic to the diet of broiler chickens were analyzed at farm. 300 day-old broilers (Arbor Acres Plus) were divided into groups of 60 birds each and randomly assigned to the five treatment diets. Each treatment has three replicates. These chickens were kept up to the age of 56 days (8 weeks), all under study and fed with the standard ration. According to the corrections, adding 8% garlic to the diet was equal to the minimum inhibitory concentration (MIC) in the lab. As a result, we used garlic itself instead of its aqueous extract in the diet. The different experimental groups did not receive any antibiotic and growth additives. The different experimental groups were as follows. The 1st group which was considered as the control group received feed without garlic. The 2nd group, one day in week, during breeding period received feed containing 8% garlic. The 3rd group, 2 days in week, during breeding period received feed containing 8% garlic. The 4th group, one day in week and in the 1st, 4th, 5th, 6th, 7th and 8th weeks, received feed containing 8% garlic. The 5th group, 2 days in week and in the 1st, 4th, 6th, 7th, and 8th weeks, received feed containing 8% garlic. During the conduct of the study, the performance of broiler chickens was recorded and then analyzed statistically. In the end, the results show that adding 8% of garlic to the feed of broiler chickens, in the probability level of 5% statistically did not have a significant effect on feed intake, body weight gain, feed conversion ratio, the mean of chicken’s weight, mortality percentage, dressing percentage, offal percentage, abdominal fat weight, weight of liver, spleen, pancreas, cecum, leg and breast and cecum and intestine size and taste (p>0.05), although, there was a little difference in the case of feed intake, weight gain, mortality percentage, intestine size and taste among different experimental groups. As a result, groups that consumed garlic showed a better performance.Key words: Medicinal plants, aqueous extracts, garlic, mint, onion, antibiotic, E. coli, broiler chickens, performance

Investigation of antibacterial effects of garlic (Allium sativum), mint (Menthe spp.) and onion (Allium cepa) herbal extracts on Escherichia coli isolated from broiler chickens

This study was done to determine minimum inhibitory concentration (MIC) of the aqueous extracts of garlic (Allium sativum), mint (Menthe spp.) and onion (Allium cepa) in in vitro conditions against the Escherichia coli isolated from broiler chickens. E. coli was isolated from the infected tissues of the chickens which were suspected of Colibacillus infection. In this study, distilled water, phenol phenicol and floxacin antibiotics were used as control. E. coli was sensitive to antibiotics, but distilled water had no inhibitory effect on the activity of E. coli. In this experiment, each of the aqueous extracts was prepared by using distilled water in 6 concentrations: 0.5, 1, 2.5, 5, 10 and 20%, and was poured into the cavities in nutrient agar medium, and then the plates were kept in incubator at 37°C for 24 h. The results indicated that MIC of the garlic aqueous extract was 5%, but E. coli was resistant to the aqueous extracts of onion and mint.Key words: Herbal extracts, garlic, onion, mint, Escherichia coli, broiler chickens, minimum inhibitory concentration, antibacterial effect

Evaluation of productive performance of 51 different peanut cocoon strains of Iran silkworm Bombyx mori (Lepidoptera: Bombycidae) germplasm

In our study, 51 peanut strains of Iran silkworm germplasm were evaluated for 36 economically important traits and for the feasibility of using these strains for breeding programs. After hatching of eggs, neonates were brushed and reared up separately on fresh leaves of mulberry (Morus alba). Newlyhatched larvae of all strains were reared for experiment. Individual egg laying were prepared for each strain before rearing and each individual egg laying consisted of about 500 eggs taken from one disease free laying and decreased to 250 larvae at the beginning of the 4th instar

Genetic diversity and classification of 51 strains of silkworm Bombyx mori (Lepidoptera: Bombycidae) germplasm based on larval phenotypic data using Ward’s and UPGMA methods

The aim of this experiment was to study and classify all 51 pure lines of Iran silkworm germplasm based on larval traits and identification of pure lines relationships. The average linkage between two groups is considered as the average of distance between all pairs of cases with one number from each group. Hierarchical clustering analysis was carried out by considering all studied parameters together. The grouping methods allowed the study to subdivide the observations into several subgroups in such a way that homogeneity was obtained inside the subgroups and heterogeneity among the subgroups. Various methods generated similar dendograms. On the basis of these dendrograms, analyzed strains were divided into 2 distinct groups. Frequent divisions were also observed in major groups. The first group was divided into two sub groups including three and eight strains, respectively. The second major group was divided into two sub groups which include 4 and 36 strains, respectively.Key words: Silkworm, unweighted pair-group method using arithmetic average (UPGMA), ward, cluster, gene bank, Iran

Study of polymorphism of leptin gene receptor in Mazandaran fowls

In chickens, leptin is expressed mainly in the liver and adipose tissue. In Iran, Mazandaran native fowls are under recording and breeding programs, but according to the action modes and importance of the leptin receptor, its polymorphisms can be related to economical traits such as body weight. In this study, in order to identify allelic polymorphism in leptin gene receptor, a restriction fragment length polymorphism (RFLP) method was used. Blood samples were collected randomly from 100 individuals. The DNA extraction was based on a salting-out method, while an amplified polymerase chain reaction technique was used. The quantity and quality of extracted DNA were examined using spectrophotometric and agarose gel electrophoresis. A strategy, employing polymerase chain reaction, was used to amplify a 374 bp fragment of 9 to 11 exon leptin gene receptor. Digestion of amplicons with HaeIII revealed leptin gene receptor. The obtained results from restriction digestion showed none of the polymorphism in leptin receptor gene, so all samples were monomorph due to the fact that there was no mutation that was related to polymorphism.Key words: Leptin gene receptor, PCR- RFLP, polymorphism, fowl, HaeIII

Investigation on Intera-Specific Biodiversity of 51 Peanut Cocoon Strains of Iran Silkworm (Bombyx mori) Germplasm Based on Reproductive Traits

Abstract: This study was conducted in ordered to analyze of phylogenetic relationships and determination of relationship amounts in all peanut cocoon strains of Islamic Republic of Iran germplasm based on reproductive characteristics. Hierarchical agglomerative clustering was done by using NTSYS-pc, version 2.02e based o