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

Effect of Different Levels of Nano-selenium on Performance, Blood Parameters, Immunity and Carcass Characteristics of BroilerChickens

The aim of the present study was to test the hypothesis that nano- seleniuminclusion in broilers’ diets can improve productivity and metabolic functions of broilers.Feed and water were provided ad libitum. A total of 180 one-day old male Ross 308 chicks were randomly assigned to six groups based on a completely randomized design, each with three replicates of 10 birds. One of the groups served as the control (CON) and was given a basal diet without further dietary supplementation, whereas the other five groups were offered the same starterandgrower diets further supplemented with dietary nano-selenium (NS) at 0.1 mg/kg of feed (NS1), 0.2 mg/kg of feed (NS2), 0.3 mg/kg of feed (NS3), 0.4 mg/kg of feed (NS4), and 0.5 mg/kg of feed (NS5). Nano-selenium dietary supplementation significantly improved weight gain and feed conversion ratio in starter (1st-21st day), grower (22nd-42nd day) and whole (1st-42nd) periods of experiment (P0.05). While, albumin levels in blood were decreased and anti-Newcastle disease hemagglutination-inhibition titer was increased after the dietary supplementation with the nano-selenium (P< 0.05). As conclusion, the current study demonstrated that the supplementation of nano-selenium in broiler diets could improve growth performance, carcass components and immune function, without negative effects on internal organs, and other carcass parameters and gastrointestinal parts

Estimation of genetic parameters in three commercial silk-worm lines of Iran

In order to estimate genetic parameters of the cocoon weight (CW), cocoon shell weight (CSW) and cocoon shell percentage (CSP) of three industrial lines of silk-worm (number 31, 103 and 107), data were collected from three successive generations. (Co)variance components were as follows: additive genetic variation (δ2g) and environmental variation (δ2e) of traits and additive genetic covariance (covg1, 2) and environmental covariance (cove1, 2). Heritability of traits was estimated with maximum likelihood procedure (REML) by using algorithms (DFREML) based on a three trait animal model. Data were from half-sibs and the heritability and genetic, phenotypic and environmental correlation were estimated between traits. The highest heritability for CW was estimated in lines 31 and 107 (0.58 and 0.58, respectively) and the lowest heritability for CW was in line number 103 (0.28). The highest and lowest heritability for CSW was in lines 107 and 103 (0.70 and 0.01, respectively). Also, the highest heritability for CWP was in line 31 (0.48) and the lowest value was in line 103 (0.077). The highest δ2g for CSP was estimated in line 103 (0.004) and lowest δ2g was estimated in line 107 (0.001). The highest and lowest δ2g for CW were estimated in lines 103 and 31 (0.0004 and 0.00003, respectively). The δ2g for CW was high inline 31 (0.604) but low in line 103 (0.257). The highest and lowest δ2e for CW were in lines 103 and 107 (0.02 and 0.01, respectively). Furthermore, the highest δ2e for CSW was estimated in line 103 (0.0013) butminimum δ2e was in line 107 (0.0007). Maximum covg1, 2 for CW-CSW was estimated in line 103 (0.00087) and minimum value was estimated in line 31 (0.00012). A high cove1,2 for CW- CSP was estimated in line 103 (0.093) but it was low in line 31 (0.00026). The highest covg1, 2 for CSW-CSP was in line 103 (0.002) but it was low in line 31 (0.00079).Key words: Cocoon, correlation, heritability, genetic (Co) variance

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