پیله

Considering the importance of comparing the silkworm performances of Iranian and imported commercial hybrids from China production traits, viability index and cocoon dimensions index were investigated in eight Iranian (31×32, 32×31, 103×104, 104×103, 151×154, 154×151, 153×154 and 154×153), and nine imported Chinese commercial hybrids (Suju×Minghu (S×M), Minghu×Suju (M×S), Baiyue×Qiufeng (B×Q), Qiufeng×Baiyue (Q×B), BaiyueB×QiufengA (BB×QA), QiufengA×BaiyueB (QA×BB), 781×7532, Lianggang No2 and Guican No 5) in the present study.
After eggs hatched and according to the standard protocols, the studied hybrids were reared under the same conditions at Iran Silk Research Center (ISRC). Statistical analyses were done in three replications of 200 larvae (totally 600 records per each hybrid) based on completely randomized design. For comparing the means, Tukey's statistical test was used at a significance level of P<0.05. The GLM procedure was used in SAS software version 9.4. Data generated in respect of the studied traits were subjected for further analysis by a multiple trait evaluation index using the following formula: evaluation index (E.I.)= (A-B/C×10) + 50, where A is value of a particular breed for particular trait, B is mean value for a particular trait of all the hybrids, C is standard deviation of a particular trait for all the hybrids, 10 is standard unit and 50 is fixed value. Minimum / average Evaluation Index (E.I) value fixed for selection of a hybrid is >50. Based on the evaluation index (E.I) consisted of production traits and viability, best hybrids were identified.
The result of the research showed the close competition between Iranian and Chinese silkworm hybrids. In the situation that the performance of Iranian 32×31 and 31×32 hybrids for traits related to weight, shell weight and shell percentage of best cocoons was higher than the other hybrids but based on a composite index that was used in this research, 151×154, 154×151, 153×154 and 154×153 hybrids showed superiority. Based on this index, M×S and S×M as well as BB×QA and QA×BB had a higher average than the other hybrids. This result is based on the average of two-way crosses for the hybrids that both pairs were used in the experiment.
Generally, the results of mean comparisons and evaluation index showed that Iranian hybrids had better performance in all traits related to produce cocoons than the Chinese hybrids. Although, Chinese hybrids were significantly different from the Iranian for pupa viability percentage trait as Lianggang No2 hybrid showed the highest value.

Considering the production of new silkworm hybrids by prominent countries in the sericulture industry such as China and the import of these hybrids to the country in recent years, it is necessary to update these evaluations so that correct decisions can be made to choose the most suitable type of hybrid in terms of functional traits. Therefore, such comparisons are done annually and the results are sent to the Iran Sericultural Corporation- Silk Worm Research Center as an executive body for final decision. The present study aimed to investigate the performance of eight Chinese commercial silkworm hybrids, including Suju×Minghu (S×M), Minghu×Suju (M×S), Baiyue×Qiufeng (B×Q), Qiufeng×Baiyue (Q×B), BaiyueB×QiufengA (BB×QA), QiufengA×BaiyueB (QA×BB), 874×873, and 874×873. Hybrids 872×871 and 872×871 also were among the studied hybrids, but due to the decrease in the performance of cocoon-related traits compared to other hybrids that had a big difference in terms of the obtained values, they were removed and excluded from the final analysis. The desired hybrids for 14 traits including best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), weight of cocoons per liter (WCPL), percentage of pupa viability (PPV), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS), and mean of female cocoon shell percentage (MFCSP) were reared in the spring of 2022 after hatching and according to standard methods and under the same conditions in Iran Silk Research Center and their performance was recorded. Each silkworm hybrid was reared in three replications of 200 larvae (total number of observations including 600 records per hybrid for all traits) in a completely randomized design. The analysis of the obtained data was done by SAS software by using the procedure of generalized linear model (GLM), and the average performance of the traits was compared to each other using Tukey's range test at the probability level of P<0.05. The results of the analysis of variance for the studied traits showed that the effect of the hybrid type for most of the studied traits including best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), the weight of cocoons per liter (WCPL), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS) and mean of female cocoon shell percentage (MFCSP) was significant (P<0.05). In the meantime, only traits of the percentage of pupa viability (PPV) as the most important index related to survival and the mean of male cocoon shell percentage (MMCSP) were not affected by the hybrid type (P<0.05). The average performance of the hybrids showed a significant difference (P<0.05) for all the traits except for the percentage of pupa viability (PPV) and the mean of cocoon shell percentage (MCSP). The BB×QA hybrid showed a higher performance than other hybrids for six traits including the best cocoons weight produced per 26,000 larvae (BCW), the total cocoons weight produced per 26,000 larvae (TCW), the weight of cocoons per liter (WCPL), the mean weight of a cocoon (MWC), the mean weight of a male cocoon (MWMC), and the mean weight of a female cocoon (MWFC) (P<0.01). Also, the M×S hybrid showed a higher performance than other hybrids for the five traits of the mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon shell (MWMCS), mean weight of a female cocoon shell (MWFCS), and the mean of female cocoon shell percentage (MFCSP) (P<0.05). In addition, the M×S hybrid showed the lowest value compared to other hybrids for the number of cocoons per liter (NCPL), which the lower values of this trait are preferred (P<0.01).  Based on the results of the present research, the priority of importing and rearing silkworm eggs in 2023 is suggested for BB×QA and M×S hybrids. Although the performance of these two hybrids with other hybrids, except for the 874×873 and 874×873 hybrids, is not significant in most of the examined traits, they can still be considered as next-import priorities. The desired hybrids for 14 traits including: best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), weight of cocoons per liter (WCPL), percentage of pupa viability (PPV), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS) and mean of female cocoon shell percentage (MFCSP) were reared in the spring of 2022 after hatching and according to standard methods and under the same conditions in Iran Silk Research Center and their performance was recorded. Each silkworm hybrid was reared in 3 replications of 200 larvae (total number of observations including 600 records per hybrid for all traits) in a completely randomized design. The analysis of the obtained data was done by SAS software (version 9.4) by using the procedure of generalized linear models (GLM) and the average performance of the traits was compared to each other using Tukey's range test at the probability level of P<0.05. The results of the analysis of variance for the studied traits show that the effect of the hybrid type for most of the studied traits including best cocoons weight produced per 26,000 larvae (BCW), total cocoons weight produced per 26,000 larvae (TCW), number of cocoons per liter (NCPL), the weight of cocoons per liter (WCPL), mean weight of a cocoon (MWC), mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon (MWMC), mean weight of a male cocoon shell (MWMCS), mean of male cocoon shell percentage (MMCSP), mean weight of a female cocoon (MWFC), mean weight of a female cocoon shell (MWFCS) and mean of female cocoon shell percentage (MFCSP) is significant (P<0.05). In the meantime, only traits of the percentage of pupa viability (PPV) as the most important index related to survival and the mean of male cocoon shell percentage (MMCSP) were not affected by the hybrid type (P<0.05). The average performance of the hybrids showed a significant difference (P<0.05) for all the traits except for percentage of pupa viability (PPV) and the mean of cocoon shell percentage (MCSP). The hybrid BB*QA showed a higher performance than other hybrids for six traits including the best cocoons weight produced per 26,000 larvae (BCW), the total cocoons weight produced per 26,000 larvae (TCW), the weight of cocoons per liter (WCPL), the mean weight of a cocoon (MWC), the mean weight of a male cocoon (MWMC) and the mean weight of a female cocoon (MWFC) (P<0.01). Also, the M*S hybrid showed a higher performance than other hybrids for the five traits of mean weight of a cocoon shell (MWCS), mean of cocoon shell percentage (MCSP), mean weight of a male cocoon shell (MWMCS), mean weight of a female cocoon shell (MWFCS), and the mean of female cocoon shell percentage (MFCSP) (P< 0.05). Also, the M*S hybrid showed the lowest value compared to other hybrids for the number of cocoons per liter (NCPL); the lower values of which are preferred (P<0.01). Based on the results of the present research, the priority of importing and rearing silkworm eggs in 2023 is suggested for BB*QA and M*S hybrids. Although the performance of these two hybrids with other hybrids, except for the 874×873 and 874×873 hybrids, is not significant in most of the examined traits, and they can still be considered as next import priorities.

Different types of imported and domesticatedhybrids of silkworm are rearing in different climatic conditions in Iran. The purpose of this study was to compare the performance of silkworm hybrids used in two climatic regions ofIran, namely Shaft in Guilan province and Torbat Heydariyeh in Khorasan Razavi province.For this study, four Iranian hybrids and 14 Chinese imported hybrids were used in a completely randomized block design. For the studied traitsnumber of cocoons per liter, average weight of a cocoon, and weight of cocoon produced from a box, there was a significant difference(P<0.01) between the hybrids as well as the regions. The results of the present study showed that the performance of silkworm hybrids, regardless of their origin, is more affected by the rearing environment and there is a difference between hybrids in the studied climates. Therefore, selecting the most suitable hybrids for different climates of Iran seem to be essential.

City of Torbat Heydarieh in the northeast of Iran is one of the most important region in rearing silkworm in country. In Iran, two types of silkworm are used for rearing, mostly hybrids produced in center of Iran silkworm research, also in some regions some of imported hybrids using for rearing. Understanding the resistance and sensitivity of these hybrids is essential for choosing the best hybrid in each region and for understanding their genetic capabilities to apply future breeding hybrid. In addition, considering the conditions in the traditional and industrial field of silkworm breeding, which is suffering from many contamination and morality reasons, the selection of resistant strains and hybrids is important for preventing a severe drop in production. The goals of many of pervious experiments were to identify the proper hybrid for each region. Results of studies in Iran showed that Iranian hybrids as 103 x 104, 104 x 103, 31 x 32 and 154 x 151 are proper for rearing in some region in Iran. Seven Iranian commercial silkworm hybrids were hatched and reared during the spring 2016 in center of silkworm development of Torbat Heydarieh. Propose of the study was compare of performance for silkworm hybrids.

The field survey was conducted for determination of performance in six Iranian silkworm hybrids namely 154 x 153, 32 x 31, 104 x 103, 151 x 154, 154 x 151, 153 x 154 and one Chines hybrid. Study was carried out by feeding on the mulberry variety Kenmuchi. For the propose one box of disease-free laying of each hybrid was obtained from Iran Sericulture Research Center (ISRC) and the eggs were rearing in the center of sericulture development of Torbat Heydarieh under standard conditions of 25°C with RH of 80 and photoperiod of 16L:8D. After hatching, silkworm larvae fed base on standard rearing conditions. The larvae were fed with the healthy leaves of Kenmuchi mulberry tree. After finishing of rearing stages, the produced cocoons were collected. Some of recorded traits were including: number of live larva, number of live pupa, cocoon weight, cocoon shell weight, cocoon shell percent, color of cocoon shell and duration of larva period. Results according by CRD were analysis using procedure of GLM in SAS 9.2.

While Iranian Hybrids in this study were similar for many of quality trait, Chinese hybrid was different in most of the traits. Chinese hybrid has longer molt period for 3th instar, young larvae and longer nutritional period for 4th instar, 5th instar and adult larvae, also the hybrid has longer larvae period in compare with Iranian hybrids. Results of analysis showed that Chinese hybrid had most number of good cocoons in litter (P<0.05) due to mean good cocoon weight in this hybrid was lowest in compare with hybrids. Results showed that Chinese hybrid had the lowest good cocoon weight and good cocoon mean (P<0.05). Mean weight of a good cocoon with female pupa in 32 x 31 and 151 x 154 hybrids was more than other hybrids, meanwhile Chines hybrid showed lowest weight (P<0.05). Male pupa in different hybrids had similar weight, but female pupa in 151 x 154 hybrid and Chines hybrid showed the most and the least weight, respectively. In other hand, 32 x 31 had a higher performance for these traits. Chines hybrid and 151 x 154 hybrid showed lowest mean of cocoon shell weight meanwhile, for the trait 32 x 31 had most performance. Number of egg laying in 32 x 31 hybrids was higher in compare with other hybrids. For other traits did not observe difference between studied hybrids although, for example 151 x 154 and Chines hybrid had the least number of cocoon production and number of good cocoon. Other studies identified that using directly of imported hybrids for rearing in different region of Iran will not lead to good results.

According to the results, Chinese hybrid had the lowest value for rearing in Torbat Heydarieh region due to the hybrid has the lowest mean of good cocoon and weight of shell cocoon. Although Iranian hybrids in most of traits had similar performance but this study indicates that 32 × 31 is better for cocoon production in Torbat Heydarieh Region

This research was carried out to compare the physical effectiveness of grape pomace(GP) with alfalfa hay in Makui sheep. Four adult male Makui sheep with 40±1.2 Kg livebody weight were selected. In this experiment, three treatments including alfalfa hay asa basal diet (control), white GP (WGP) and red (RGP) were separately substituted at50:50 in a ratio with alfalfa hay as experimental diets. The diets were fed over 10 days. Chewing activity of sheep was determined by direct visual observation over 24 h and physical effectiveness factors was done using Penn state separator sieves method. The result of this study showed that the value for physical effective NDF in basal diet was significantly more than WGP and RGP. The physical effective NDF of basal, RGP and WGP was 0.96, 0.68 and 0.61, %, respectively. The distribution of particle on 19 (P<0.0004), 8 (P<0.0001), 1.18 (P<0.0037) sieves were significantly different. Chewing time for basal ration, RGP and WGP mixes was significantly different. The results of the current experiment showed that substitution of alfalfa hay with GP significantly decreased total chewing activity and rumination time in experimental animals in comparison to those were fed with alfalfa hay.

This experiment was conducted to determine the effect of selection index in four iranian commercial silkworm lines (107, 110, 153, 154) on resistance of their hybrids including 107×110, 110×107, 153×154, 154×153 under stress of nuclear polyhedrosis virus (N.P.V) Infection. Selection index program was performed on 3P commercial lines during 9 generations. Later generation parents of 3P lines were selected in each generation, by forming selection matrix based on heritability parameters, correlation between cocoon weight, cocoon shell weight and cocoon shell percentage and phenotypic mean of traits. In the 10th generation, 2P populations (produced by random cross of 3P) were mated randomly and P (parent) silkworm eggs were produced by random mating of 2P population. P populations in selected and random groups were reared in village conditions (growths silkworm rearing house silkworm). Control P population was produced by crossing 2P population (produced by non-selected 3P lines). F1 hybrids of control group (non-selected) were reared simultaneously. From the obtained results, the hybrids of 110×107 and 154×153 significantly showed the highest performance for individual cocoon traits (P<0.05).The best cocoon percentage, middle cocoon percentage, low cocoon percentage, double cocoon percentage, total cocoon weight, larva survival rate and pupation rate were studied, that showed negative relationship between resistance and production characteristics. The results demonstrated that selection index method have a negative effect on resistance of silkworm hybrids as well as improving production and economic performance of silkworm hybrids. It is recommended that economical coefficients and genetically parameters are estimated for productive, resistance and quantitative cocoon characters together. Then parents would be selected on the basis of those parameters.