نوید قوی حسین زاده

Phylogeny as a science that study the evolutionary relationships between species and populations of organisms, as well as their evolutionary history, diversity and patterns of population changes, by integrating genomic data, has become a strong approach in the study of the systematic of species named phylogenomics. The aim of the present study were divergence study an percent genetic similarity along with phylogenetic analysis of the seven existence species of the Equidae family based on mitochondrial genome sequences.

In order to investigate genetic divergence and similarity, the most up-to-date complete sequences of the mitochondrial genome along with the separate sequences of 13 protein coding genes per each genome from seven main Equidae species including E. africanus, E. ferus, E. grevyi, E. hemionus, E. kiang, E. quagga and E. zebra were extracted from NCBI database site and compared to each other.

The results of sequence distance analysis based on the complete mitochondrial genome showed that the highest genetic similarity (99.9%) was observed between Asian wild donkey (E. hemionus) and Tibetan donkey (E. kiang) and the lowest genetic similarity (92.3%) was observed between Asian wild donkey (E. hemionus) and Przewalski's horse (E. przewalskii). In terms of phylogenetic analysis, E. przewalskii species was placed in a separate cluster, and E. africanus, E. grevyi, E. hemionus, E. kiang, E. quagga and E. zebra were placed in a another cluster. The analysis of the nucleotide sequences of 13 protein encoding genes per each genome showed that in all these genes E.kiang and E.hemionus species had the most genetic similarity to each other and also the least genetic similarity was observed between E.przewalskii and E.asinus species. In terms of phylogenetic analysis, E.przewalskii species had the highest distance from other species and was not included in the main cluster, which results were similar to the analysis of complete mitochondrial genome sequences. Also, the results of the analysis for the amino acid sequences of 13 protein-coding genes showed that unlike the nucleotide sequences, the highest and least genetic similarity may be different in the species. Although, E. kiang and E. hemionus species had the most genetic similarities, and the lowest genetic similarity of the species was related to E. przewalskii and E. zebra species, and in terms of phylogenetic analysis, E. przewalskii had the highest distance from other species and was not included in the main cluster.

This research showed that the examination of mitochondrial genomes and sequences of Equidae species can help to determine the evolution and biological processes in the past of these species, as well as to determine the distribution and relationship between different species of the Equus genus and the possibility of correct clustering of the species exists based on the mitochondrial genome.

In recent years, consideration has been given to changing the sex of a female bird to male because it has the functional characteristics of the male phenotype, and the technique of in ovo injection is used to achieve this. For this purpose, the production process of some sex hormones in broiler chickens is changed by injecting a substance containing anti-aromatase. The aromatase enzyme (Arom P450) is considered a key enzyme in estrogen synthesis. The administration of aromatase inhibitors leads to the inhibition of estrogen synthesis (a hormone responsible for ovarian structure and secondary sexual characteristics) in females and the production of males with female genotypes. Therefore, if aromatase enzyme expression is inhibited in some way, it can be expected that the percentage of male chicken production will increase. Aromatase inhibitors can be divided into two main groups in terms of production source, including synthesized and herbal compounds. Among the herbal extracts containing anti-aromatase are nettle root, button mushroom, garlic, green tea, and tomato. On the other hand, the results of some studies have shown that the performance indicators of male and female poultry during the breeding period, such as daily feed intake (DFI), daily weight gain (DWG), feed conversion ratio (FCR), as well as the activity of the digestive system, especially the small intestine, are different and the ability to use nutrients, growth rate and FCR are better in males than females. According to male poultry characteristics, if the number of males in the flock increases, more profitability can be achieved in the production process. Therefore, the objectives of the current study were to determine the effects of in ovo injection of nettle extract, mushroom extract, and their mixture on hatched chickens, performance, and intestinal indicators of Ross 308 broiler chickens. This study was conducted to investigate the in ovo injection effects of nettle and mushroom extracts, and their mixture on hatchability, the percentage of male chickens produced, and some intestinal parameters in broilers. 500 fertilized eggs were divided into five treatments and four replicates (25 eggs per replicate). Experimental treatments included: 1. Nettle hydroalcoholic extract (containing 300 micrograms of dry matter per 0.1 cc of injectable substance), 2. Mushroom hydroalcoholic extract (containing 500 micrograms of dry matter per 0.1 cc of injectable substance), 3. Mushroom and nettle extracts mixture (containing 400 micrograms of dry matter per 0.1 cc of injectable substance), 4. Positive control (distilled water), and 5. Negative control (eggs without any injection). The experimental design was a completely randomized block design. Samples were divided into five treatment groups, with each treatment group having four replications based on the gender segregation of the chicks into male and female. The experimental diet was used based on the requirements of the Ross strain during three periods, including starter, grower, and finisher. After the chickens were hatched, performance and intestinal indices were measured. The results showed that the number of hatched chicks was affected by experimental treatments. Therefore, the lowest hatch percentage was related to URE treatment chicks. The number of normally hatched male chickens, performance indices, and intestinal parameters were not affected by the experimental treatments (P>0.05). The lack of significant difference in the number of male chickens in the experimental treatments may be due to the incorrect selection of the concentration of the experimental extract. Furthermore, villi height, crypt width, and villi surface absorption area were not affected by experimental treatment (herbal extracts). In comparison, DWG and FCR significantly improved by the sex effect (P<0.05). Regarding the difference in the performance of male and female broiler chickens, it has been reported that these two sexes have a significant difference in DFI and FCR. It has also been reported that the increase in BWG and the weight of different parts of the carcass in males was higher than in females, which is consistent with the findings of the current research regarding all three indicators of DFI, DWG, and FCR. Although there was no significant increase in the number of hatched male chickens in this study, it is recommended to optimize the preparation and production conditions of plant extracts containing anti-aromatase by focusing on extracting the pure active ingredient to achieve a higher percentage of male chickens in the flock. This study was conducted to investigate the in-ovo injection effects of nettle and mushroom extracts and their mixture on hatchability, the percentage of male chickens produced and some intestinal parameters in broilers. 500 fertilized eggs were divided into 5 treatments and 4 replications (25 eggs per replication) in a completely randomized design. Experimental treatments consisted: 500 fertilized eggs were divided into 5 treatments and 4 replicates (25 eggs per replicate) in a completely randomized design. Experimental treatments consisted: 1- nettle hydroalcoholic extract (containing 300 micrograms of dry matter per 0.1 cc of Injectable substance), 2- mushroom hydroalcoholic extract (containing 500 micrograms of dry matter per 0.1 cc of Injectable substance), 3- mushroom and nettle extracts mixture (containing 400 micrograms of dry matter per 0.1 cc of Injectable substance), 4- positive control (distilled water) and 5- negative control (eggs without any injection). The experimental diet was used based on the requirements of the Ross strain during three periods, including starter, grower and finisher. After the chicken were hatched, performance and intestinal indices were measured. The results showed that the number of hatched chicks were affected by experimental treatment. So that, the lowest hatch percentage was related to URE treatment chicks. The number of normal hatched male chicken, periodic performance indices and intestinal parameters were not affected by the experimental treatments (P>0.05). The lack of significant difference in the number of male chicken in the experimental treatments may be due to the incorrect selection of the concentration of the experimental extract. Furthermore, villi heigh, crypt width and villi surface absorption area(VSA) were not affected by experimental treatment (herbal extracts). In comparison, DWG and FCR significantly improved by the sex effect (P<0.05). Regarding the difference in the performance of male and female broiler chicken, it has been reported that these two sexes have a significant difference in DFI and FCR. It has also been reported that the increase in BWG and the weight of different parts of the carcass in males was higher than females, which is consistent with the findings of the current research regarding all three indicators of DFI and DWG as well as the FCR. Although there was no significant increase in the number of hatched male chickens in this study, it is recommended to optimize the preparation and production conditions of plant extracts containing anti-aromatase by focusing on extracting the pure active ingredient to achieve a higher percentage of male chickens in the flock.Key words: nettle and mushroom extract, ant i-aromatase, broiler chicken, plant extract, in-ovo injection

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.

Mitochondrial DNA (mitogenome) is a small and extra-chromosomal DNA, located in the cytoplasm and presents an ideal model to study evolution and genetic similarity. Classical phylogenetics is based on the morphological characteristics of the organisms, while in modern approaches, the phylogenetic distance and its related comparative methods are estimated based on observed genetic diversity in the studied genetic sequences. The aim of the present study was to investigate the divergence and percentage of genetic similarity along with the phylogenetic analysis of the seven main known species of wild and domestic sheep based on the complete sequence of the mitochondrial genome and the separate sequences of 13 protein-coding genes for each genome.
In the present study, complete mitochondrial genome sequences along with separate sequences of 13 protein-coding genes (including NADH ubiquinone oxidoreductase (ND1, ND2, ND3, ND4, ND5, and ND6), cytochrome c oxidase (COX1, COX2, and COX3), ATP synthase (ATP6 and ATP8), NADH dehydrogenase 4 L (ND4L), and cytochrome b (CYTB))  per each genome from six wild species of sheep including Asian Mouflon (Ovis orientalis), Bighorn (Ovis canadensis), Argali (Ovis ammon), Urial (Ovis vignei), Snow (Ovis nivicola), Dall (Ovis dalli), and domesticated species of sheep (Ovis aries) were retrieved from NCBI database and compared to each other. Mitochondrial genomes and genes’ alignment were accomplished by the MegAlign module of DNASTAR software and compared by the Clustal W method. The Sequence Distances sub-section of the MegAlign module of DNASTAR also was used for the analysis of complete genome and gene sequences divergence and similarity percentage. For phylogenetic analysis, complete mitochondrial genomes and protein-coding genes’ sequences were aligned using MEGA7 software. Based on the alignment, phylogenetic tree was constructed using the maximum likelihood method. The percentage of replicate trees of 1000 replicates of bootstrap test was used to represent the evolutionary history for the studied sheep species.
The results obtained from sequence distance analysis showed high genetic similarity (99.8 %) between Ovis orientalis and Ovis aries. Also, the lowest similarity (95 %) was observed between Ovis aries and Ovis dalli. In phylogenetic analysis, two main clusters, each with different sub-clusters were identified. Domesticated species of sheep (Ovis aries) along with Ovis orientalis, Ovis vignei, and Ovis ammon wild species of sheep formed distinct cluster, and Ovis nivicola, Ovis dalli, and Ovis Canadensis fell in a same cluster. In terms of all 13 protein-coding genes (including NADH ubiquinone oxidoreductase (ND1, ND2, ND3, ND4, ND5, and ND6), cytochrome c oxidase (COX1, COX2, and COX3), ATP synthase (ATP6 and ATP8), NADH dehydrogenase 4 L (ND4L) and cytochrome b (CYTB)), the results obtained from sequence distance similarity analysis and phylogenetic trees were similar to the sequences of the complete mitochondrial genomes. More than 99% of the genetic similarity for ND1, ND2, ND5, ND6, COX1, COX2, COX3, and ATP6 genes and 100% of the genetic similarity for ND3, ND4, ND4L, ATP8, and CYTB genes between domestic sheep (Ovis aries) and Mouflon (Ovis orientalis) sheep species were found. Also, similar to the results obtained from the comparison of the complete mitochondrial genome, the domestic sheep species (Ovis aries) showed the least genetic similarity with the Dall (Ovis dalli) and Bighorn (Ovis canadensis) wild sheep species in all 13 protein-coding genes. Similar to the results of phylogenetic analysis of complete mitochondrial genomes, domestic sheep species (Ovis aries) together with Ovies orientalis wild sheep were placed in the same sub-cluster and Ovis vignei and Ovis ammon species were placed in other distinct sub-clusters. In addition, the Ovis nivicola, Ovis dalli, and Ovis canadensis wild species fell in another main cluster, and in this cluster, Ovis dalli and Ovis canadensis were placed in a similar sub-cluster and Ovis nivicola in another distinct sub-cluster.
In previous studies, small parts of the mitochondrial genome (such as a part of the control region or cytochrome b gene) have been considered to show the genetic differences and phylogenetic relationships between different species and breeds of sheep. In the present study, the complete sequences of the mitochondrial genome along with the complete sequences of 13 protein-encoding genes per each genome in seven main species of wild and domestic sheep have been considered for examining genetic similarity and divergence and phylogenetic analysis for the first time. Based on the results obtained from the present study, mitochondrial genome sequences could be used for accurate phylogenetic analysis and clustering of different species of sheep.

The aim of the present study was to investigate the performance of the hybrids obtained by crosses of the six Japanese silkworm lines named IRA1, IRA3, IRA5, IRA7, IRA9, and IRA11 and six Chinese silkworm lines named IRA2, IRA4, IRA6, IRA8, IRA10, and IRA12. The new hybrids derived from these lines along with available commercial hybrids (as control groups) for six traits including cocoon weight, cocoon shell weight, cocoon shell percentage, best cocoon weight, pupation rate and best cocoon pupation rate were measured and recorded in spring 2020. The IRA7×IRA6 and IRA7×IRA12 hybrids had more performance in comparison with commercial hybrids in terms of productive traits including cocoon weight and cocoon shell weight (P < 0.01), but, when productive and viability traits (pupation rate and best cocoon pupation rate) were considered together in an evaluation index, they were not among the selected hybrids. Commercial 31×32 hybrid in terms of cocoon shell weight and cocoon shell percentage had more performance in comparison with the other hybrids (new and commercial) (p<0.01). Hybrids had a significant difference for pupation rate and best cocoon pupation rate (P < 0.01), and the IRA5×RA12, IRA1×IRA10 and IRA11×IRA6 hybrids showed the lowest mean for both traits in comparison to other hybrids (P < 0.01). The results obtained from the present study indicated that seven hybrids including IRA9×IRA2, IRA11×IRA2, IRA3×IRA6, IRA3×IRA2, IRA7×IRA4, IRA7×IRA10 and IRA7×IRA8 were greater than the minimum set for every six traits. Therefore, they can be used to supply the country's required silkworm eggs.

 Introducing new commercial lines is one of the goals of silkworm breeding centers in the world. Iran has the potential to introduce new lines for hybrid silkworm production due to its silkworm genetic resources and silkworm egg production technology. The performance of productive, reproductive and viability traits in the parental silkworms, including Japanese-shaped and Chinese-shaped lines, changes after several years for various reasons, including inbreeding. Therefore, after a few years, it is necessary to introduce new silkworm strains. Most silkworm breeding schemes in most of the countries are based on the introduction of the Chinese and Japanese-shaped lines to make commercial silkworm hybrid.

 Five Japanese - shape lines of silkworms named 31, 103, 151, 153, and 1524 were selected from silkworm germplasm of Iran Silk Research Center in the spring of 2012. All genetic combinations obtained by using the diallel method of mating system (20 crosses) were reared in autumn 2012 and spring 2013. After two generations of mass rearing in each genetic combination, the reciprocal crosses in the diallel design were mixed to establish the basic generation of this breeding scheme. The selection program was based on independent culling levels (I.C.L.) method applied from 2014 to 2019 in the selected group. At the same time, all parental lines were reared as control by using a random mating system. Of the 10 genetic compounds, six combinations were retained and the rest were rejected. In this breeding program, due to the necessity of eliminating weak families, family selection, and individual selection were both used simultaneously. In the present study, the productive traits of cocoon weight, cocoon shell percentage, good cocoon percentage, number of cocoons per liter, and cocoon weight per liter were compared simultaneously in the genetic combinations and control lines. Two-factor analysis of variance (including 6 genotypes and 5 years) was performed in a completely randomized design with six replications; then the results were analyzed using SAS statistical software.

In general, the effects of genotype, year and interaction effect of genotype and year were significant for all studied traits. Based on the average performance of each trait during selection program from 2016 to 2019 years (average performance of G2, G3, G4 and G5 generations), the cocoon weight in the combinations of IRA1, IRA11 and IRA7 was more than the parental lines. This advantage was also seen in the trait of cocoon weight per liter. For the cocoon shell percentage, none of the genetic combinations in all the studied years were completely superior to parents. The response to selection for cocoon weight based on deviation from the maternal control line in IRA5 and IRA1 was positive and significant. The two genetic compounds, IRA1 and IRA3, whose parent was 103, had the highest genetic progression for cocoon shell percentage. Due to the superiority of the good cocoons percentage in IRA1, this genetic combination performed well in terms of cocoon economic traits. IRA9, whose cocoon weight gain was lower than the others, not only did not show any improvement in cocoon shell weight compared to the parent during these years, but also showed the lowest amount compared to other genetic combinations.

 The six new genetic compounds in this breeding program had the minimum requirements for the economically important traits of the silkworm. In other words, cocoon-related characteristics such as cocoon weight, good cocoon percentage of each family, and cocoon size are superior to all parental lines, then they could introduce to the silkworm gene bank. IRA1 was superior to parents in most of the studied traits. This genetic combination showed the best performance compared to the parent for both cocoon weight and cocoon shell percentage. Therefore it can be considered more in subsequent evaluations. IRA3 also responded relatively well. Other new genetic combinations did not have a significant advantage over their parents in terms of cocoon shell percentage. However, lower performance in some traits is not a reason for the new strain to be undesirable. Because the selection of the best paternal and maternal lines (Chinese-shaped and Japanese-shaped lines) will be determined after that the hybridization program was carried out to produce all hybrids and then the best hybrids were selected based on  estimation of specific combining ability for all important traits.

This study aimed to investigate the interaction effects between marker effect estimation methods, population structure, and genetic architecture of the trait on the accuracy of genomic evaluations. A reference population with two different effective population sizes (100 and 500) was simulated using the QMSim software. 500 markers and two different numbers of quantitative trait loci or QTLs (50 and 200) were distributed randomly through the genome including a 100 cM chromosome. In this study, three traits with different heritabilities (0.1, 0.3, and 0.5) were simulated. The genomic breeding values were predicted using Bayesian ridge regression, Bayes A, Bayes B, Bayes C, Bayesian LASSO, Reproducing kernel Hilbert space, and neural networks methods. Through the three heritabilities, as the effective population size increased, the accuracy of genomic evaluation decreased with different trends. As the number of QTLs increased, the accuracy of low heritability trait increased, but the accuracy of medium and high heritability traits decreased. Similarly, as the number of QTLs increased, the accuracy of the trait with normal distributed QTLs increased, but the accuracy of traits with gamma and univariate distributed QTLs decreased. For all types of QTL distributions, the increment of effective population size decreased the accuracy of genomic evaluations. The results of this study clearly showed the interaction effects between markers effect estimation methods, population structure, and genetic architecture of the trait on the accuracy of genomic evaluations.

Introducing new lines to produce high-quality silkworm hybrids is one of the ongoing tasks of the silkworm breeding centers. Five lines of Y, 124, 154, 104, and 32 with Chinese-shaped cocoons were selected from the gene bank. Based on the diallel cross, 20 genetic compounds were reared massively over three generations. After establishing the basic generation with 14 genetic combinations, the multi-trait selection was performed for five generations by the independent culling levels method. To compare the performance of parental lines and their combinations, data on the four traits of cocoon weight, cocoon shell percentage, good cocoons percentage, and cocoon number/liter (cocoon size) statistically analyzed in each year and the overall five years. The mean of cocoon weight and cocoon shell percentage of all genetic combinations were higher than the parental lines (p < /em><0.05). The average response to selection for cocoon shell percentage was more than one percent in the three genetic combinations compared to the maternal parent. For the good cocoons percentage, the best combinations had no significant difference with the best lines (104 and Y). While cocoon size in one genotype (IRA14) was very large (94 cocoons/ liter), other genotypes of large cocoons did not show significant differences with those lines with large cocoons (154 and 124). Genetic improvement of cocoon weight was positive for 12 out of 14 genetic combinations, but only one of them increased more than 0.1 g. The best lines will select finally after doing the crossbreeding program of Chinese with Japanese lines.

This study aimed to investigate the  effect  of  the method of estimating the effects of markers , QTLs distribution, number of QTLs, effective population size and trait heritability on the accuracy of genomic predictions. Two effective population sizes, 100 and 500 individuals, were simulated by QMSim software. A 100 cM genome including one chromosome was simulated where 500 SNPs and two different  numbers of QTLs (50 and 200) were distributed on it randomly. In this study three levels of heritability (0.1, 0.3 and 0.5) were considered. Genomic breeding values were predicted using Bayesian ridge regression, BayesA, BayesB, BayesC, Bayesian LASSO, Reproducing kernel Hilbert space and neural networks. In this research, the accuracy of genomic breeding values were affected by trait heritability, effective population size, markers effect estimation methods, QTLs distribution and number of QTLs. The Bayes A and B had the highest accuracy while accuracy of neural networks method was the lowest. The accuracy of genomic breeding values were increased as the heritability of trait and number of QTLs increased while the accuracy was decreased as the effective population decreased. Considering the QTLs distribution, the highest accuracy was achieved when the QTLs distributed normally.

This study was conducted to investigate the effects of two types of omega-3 calcium fat powders with animal and vegetable origin on productive performance, reproductive and egg quality of broiler breeder hens by using 60 hens and 20 roosters (65 weeks), in a completely randomized design with five treatments and four replicates for two months. Experimental treatments were: 1- control (without fat powder); 2- 1.5% animal omega-3 calcium fat powder based on fish oil; 3- 3% animal omega-3 calcium fat powder based on fish oil; 4- 1.5% vegetable omega-3 calcium fat powder based on flaxseed oil; 5- 3% vegetable omega-3 calcium fat powder based on flaxseed oil. Egg production percentage and economic benefit of hens fed with diets containing 1.5% animal and vegetable fat powders were greater than hens that received 3% of them (p<0.05). The highest concentration of yolk docosahexaenoic acid and docosahepanthanoic acid were in eggs of hens fed with diet containing 3% animal and vegetable fat powder and thelowest concentration of linolenic acid was in the yolk of eggs obtained from control hens or hens fed with diet containing 1.5% animal fat powder (P<0.05). The lowest percentage of hatchability and the highest omega-6: omega-3 ratio were related to hens received control diet (P<0.05). Based on current results, adding animal or vegetable omega-3 calcium fat powder at the level of 1.5% in old broiler breeder hen’s diet, without negative effect on performance, improve hatchability and yolk fatty acid composition and is economically more affordable.

This study was conducted to determine the effect of different levels of omega-3 and omega-6 calcium fat powders on performance, hatchability, serum lipids, abdominal fat, and ovarian follicle count in Ross-308 broiler breeder hens (65 week-old). The experiment was performed in a repeated measurement design with 84 hens and 28 roosters with seven treatments (four replicates) during three months. The experimental groups included control group (no fat powder), 1.5 and 3% of animal omega-3 calcium fat powder of fish oil origin (ω3F), plant omega-3 calcium fat powder of linseed oil origin (ω3L), and omega-6 calcium fat powder of soybean oil origin (ω6S). The results showed that the highest average of HDEP was belonged to the experimental groups containing 1.5% ω3F (61.98), and ω3L (60.25) without significant difference with together (P> 0.05). However, among experimental groups, the highest egg mass (44.78 g/h/d) was obtained from consumption of 1.5% ω3F (P<0.05). The highest concentrations of triglycerides (1806.8 mg/dL), cholesterol (206.25 mg/dL), and low density lipoprotein (244/25 mg/dL) of serum were belonged to control group that was significantly different from other experimental groups (P<0.05). The percentage of hatchability of fertile eggs was improved by consuming diets containing fat powder, except 3% ω6S, when compared to control (P<0.05). Overall, considering the production performance, hatchability and economic explanation of diets, it seems that addition of omega-3 calcium fat powder at the level of 1.5% (ω3F and ω3L) is affordable and can have a positive effect on old broiler breeder hens.

Genomic information offers new possibilities to control the level of progeny inbreeding. Traditionally, mating plans constrain the inbreeding of predicted progeny by using a matrix of relationships among individuals. In this study aims to improve genetic gain and restrict the inbreeding level of progeny, a founder population, with effective population size 1000 and 1000 generations, was simulated using the QMSim program to generate linkage disequilibrium. Thereafter, 500 males and 500 females were used to generate a secondary 10-generation population, with 1000 individuals per generation and its corresponding phenotype and genotype in SNP terms. Five hundred sires and 500 dams from generation 1010 were randomly selected to create generation G0 and a trait with heritability of 0.3 was simulated. The eight strategies consisting of two mating designs: minimum_inbreeding (minf) and random (rnd) and four relationship matrices as matrices of A, GRM, IBS and Weighted were used to estimate breeding value for ten generations. Comparison of strategies showed that type of mating designs and different relationship matrices had significant effect on amount of genetic gain, homozygosity and inbreeding (p < 0.05). The type of relationship matrix affected the accuracy of predictions. In strategies with weighted matrix (Gweighted), average of genetic gain during 10 generations was less than strategies using A, GRM and IBS matrices. In strategies with random mating, inbreeding rate had increasing trend. Accuracy of selection (0.63) in strategies with A matrix was lower than other strategies. In general,

The present study was aimed to assess the role of genotype× environment interaction (G×E) and generation interval on the genetic gain caused by importing the genetic materials of dairy cattle in a country without advanced breeding program. Changing allele substitution effects of quantitative trait loci (QTLs) underlying the trait was used to simulate G×E. To this end, three levels of 100 (control), 75 and 50% overlapping of QTL effects in imported sires at the heritability levels of 0.1, 0.3, and 0.5, as well as three scenarios of continuous replacing and discontinuous replacing with one and two generations of foreign genetic materials were considered. Moreover, the effect of decreasing the accuracy of genomic prediction in traits with the low level of heritability was investigated. Based on the performance of daughters of sires in the local population of control scenario, import-based strategies were better than on the strategies of local population. The genetic correlation created in 75% and 50% overlapping of QTL effects were as 0.7 and 0.5, respectively. Although the trend of genetic response increased by decreasing genetic correlation over the time, it was not equal to origin population. Maximum genetic gain (2.56) was observed with a heritability of 0.5 in continuous replacing and absence of G×E. A decrease in the accuracy of prediction resulted in exacerbation of G×E. In general, more genetic improvement is transmitted from origin population to local population only by importing the genetic materials related to populations with higher genetic mean and also by considering G×E in different traits.

The genetic difference in micro-environmental sensitivities are measurable through the heterogeneity of the residual variance between animals and it can be seemed that these differences could be inherited. The objective of current study was to estimate the genetic variance components and heritability of micro-environmental sensitivities for milk yield and somatic cell score (SCS) traits in the first lactation of Iranian Holstein cows. Data included the 1,466,498 and 875,416 test day records for milk yield and somatic cell score, respectively, that were collected by the Animal Breeding Center and Promotion of Animal Products of Iran from 1987 to 2015. The GLM procedure of SAS software was used to determine the fixed effects which were fitted in the statistical model of analysis. Estimation of variance components and genetic parameters of micro-environmental sensitivity was performed using ASReml software, applying the double hierarchical generalized linear model (DHGLM). Heritability of micro-environmental sensitivity for milk yield (0.00201±0.00014) and somatic cell score (0.00188±0.00018) was lower compared with the heritability of milk yield (0.16±0.08) and somatic cell score (0.034±0.007). However, the genetic coefficient variation (GCV) for residual variance of the mentioned traits was estimated to be 0.18 and 0.16, respectively, which indicating a substantial potential for selection responses in both traits. The results of this study indicate that heterogeneity of residual variation in milk yield and somatic cell score of Iranian Holstein cows was partly under genetic control and therefore uniformity of these traits could be improved by selection for residual variance.

One major component in designing breeding programs is accurate assessment of breeding values. In most countries, selection decisions in animal breeding are usually based on predicted genetic values obtained using best linear unbiased predictors (BLUP). The first applications of BLUP and mixed linear models are associated with assuming homogeneous variance components. However, numerous studies have showed that there exists heterogeneity variance for milk yield and genetic and residual variances are not constant between herd and different production level. The level of herd production, management and nutritional practices and breeding strategies are heterogeneous variance factors. The problem of heterogeneous variances in genetic evaluation of dairy cows is that above average animals in the more variable herds may be over evaluated and larger proportion of animals is selected from these herds than when variance is homogeneous. When heterogeneity is not properly taken into account, differences in variance components can result in biased estimates of breeding values, in-correct ranking of sire and dams elite and reduced genetic progress. In evaluation of dairy cows, a simple method to reduce heterogeneous phenotypic variance, is pre-adjustment of records prior to fitting the animal model. The objectives of this study were to investigate the heterogeneity variance components for milk test-day records as well as the impact of data pre-adjustment method on on genetic parameters, breeding values and re-ranking of the top sires and dams in the Iranian Holstein cows.

In this research, heterogeneity of variance components for milk production trait was investigated by using 1843985 test-day records of first parity of Iranian Holstein cows. Collected records were including 199353 cows in 983 herds that were collected by the Animal Breeding Center and Promotion of Animal Products of Iran. According to the average of herd-year production three groups (high, medium and low) were identified. The heterogeneity of variances was studied using the Bartlett’s test. A pre-correction method was used to correct heterogeneity of variance. Variance components, genetic correlations, heritabilities as well as animals’ breeding values (BVs) were estimated by ASreml program, using animal model. Spearman's rank correlations and re-ranking of top sire and dam before and after data pre-correction were estimated. The number of best sires and cows removed from top animal list after adjustment the heterogeneity of variance was obtained in order to investigate the benefit of this adjustment.

The results of Leven’s test for milk test-day records before data pre-correction were significant (P<0.001) which indicated the heterogenous of variances. Data correction did not result in homogeneity of variance across the herd-year classes but the heterogeneity of variance was decreased by 25%. Applying of the pre-correction method resulted in slightly higher heritabilities so that estimates of total heritabilities were 0.319±0.007 and 0.351 ±0.009 before and after adjustment for heterogeneity of variance, respectively. Additive genetic correlations for milk test-day records were estimated in the range of 0.345 to 0.985 before and 0.403 to 0.996 after pre-correction, respectively. Adjustment of data had a considerable effects on the top 1% of animals and caused that 14% and 20% of top sires and dams, respectively, to be excluded from selection when compared to the homogenous variance scenario. Substantially different in re-ranking of top animals occurred and the best of sire and dam cows had rank 8 and 23 after adjustment of heterogeneity of variance

The results showed that variance components of test-day records based on different production levels in Holstein cow population are not homogeneous and heterogeneity of variance may influence the ranking and genetic evaluation of top animals.

 In commercial production, there is often concern about the quantity and/or quality of feathering in both broilers and layers. For broilers, the concern is adequacy of protective feather cover, while in layers usually the necessary degree of feathering needed to optimize feed efficiency. Feather development is under the control of hormones such as thyroxine and estrogen and indirectly by testosterone. Therefore, environmental or nutritional status affecting the hormonal output of the birds will indirectly influence their feathering. Nutrition influences rate of feathering as well as feather structure, color and molting. In spite of the fact that minerals constitute a little proportion of body weight (2 to 5%) in vertebrates, their significance is high for growth, enzyme activation, immune system, regulation of the osmotic pressure, egg production and feathering. Urine and blood serum or plasma are the most commonly used bio fluids for metabolomics-based studies for the simple reasons that they both contain hundreds to thousands of detectable metabolites. In blood, the minerals undergo homeostatic controls, thus the ranges of concentrations are narrow, but the concentration of minerals in hair and feather is broad and can reflect long term metabolic changes. Blood tests can vary significantly depending upon animal’s diet, activity level, the time of day and many other factors. Contrary to the blood, the concentration of minerals in hair and feather is broad and can reflect long term metabolic changes. Hair or feather can be considered as a metabolically inactive tissue, and its composition indicates the levels of trace elements that store in its structure through nutritive blood flow. Feather chemistry has been investigated as a means of identifying the geographic origins of migrating and wintering populations of birds, and as an indicator of environmental pollution. Since the minerals are crucial to the functioning of enzymes, hormones and other biochemical systems, it is possible to read the hair or feather test and see where metabolic patterns are deviating from the norm. The present study was amid to examine the potential applicability of serum or feather samples as a biological indicator to evaluate the broiler responses to (un)sufficient diets with regards to the trace mineral supplementation at 0, 25, 50, 75 and 100% of the recommended requirements.

 A total of 200 one-day-old Ross 308 strain of broiler chicks (male and female) were used in a completely randomized design with 4 replicates of 10 chicks each. A large batch of corn and soybean meal basal diet was prepared for each age period (0-14, 14-35 and 35-42 days) and aliquots used for mixing the experimental diets. The experimental diets were prepared by mixing mineral premix at 100, 70, 50, 25, and 0% of normal inclusion rates, resulting in five experimental diets. At the end of the experiment, two male chicks close to average weight of each experimental unit were selected for bone quality assessment and feathering scores for wing and tail using scores of 1 to 5 for feather coverage with 1 representing minimal coverage, i.e. <25% coverage; 2 for 25-50% coverage; 3 for 50-75% coverage; 4 for >75% coverage and 5 for complete coverage. The wing and tail were further evaluated on a scale of 0 to 2 for the occurrence and severity of poor feathering with 0 indicating no defect; 1 for lesion and torn feathers, and 2 indicating blisters had developed on the shaft, near failure of feather to emerge from the follicle, broken feathers and retarded feathering. Tibia bone morphometric parameters, i.e. weight, diameter, length, density, volume and ash, were determined. The serum mineral concentration was measured in the fasting state at the end of the experiment. At this time, a total of 3mL of the blood samples was accumulated in plain vacutainer tubes from the veins under the wing. After collecting, the blood samples were left undisturbed for at least 1 hour to reach the room temperature. The serums were centrifuging at 3,000 rpm for 15 minutes. The obtained sera were kept in 1.5mL micro tubes at -80°C until they were analyzed for mineral concentration. The method of American Society for Testing and Materials, D4638–03 standard, was used for preparing the serum and feather samples.

 The results showed that treatments supplemented with mineral premix caused increase in average daily gain and feed intake compared to the control group (P<0.05), but the difference among mineral premix-supplemented groups was not significant (P>0.05). Feed conversion ratio in the starter period was not affected by the experimental treatments; nevertheless, in the growing and finishing periods a significant difference was indicated compared to the control. Bone parameters including weight, diameter, length and volume showed significant differences to the control group; but the difference for density and ash were not significant. Effects of dietary trace mineral supplementation on the feathering scores of broilers were described.. The results showed that the effect of trace mineral supplementation was significant for feather coverage and defect feather in both wing and tail regions (P<0.05). Feathering score was increased and the amount of damaged feathers was reduced in concordance with the increase in mineral supplementation. Serum concentration of Ca increased in response to trace mineral supplementation. Feather K (p<0.01) and Zn (p<0.05) concentrations were affected by the dietary treatments. Serum concentration of Zn increased linearly in proportion to the dose of Zn supplementation when 10, 25 or 40 mg/kg Zn were added to the basal diet. The diagnostic usefulness of feather analysis is confirmed by authors who have proven the correlation between the concentration of basic elements in feather and their concentrations in the body both in the physiological and pathological states. With regard to the use of feather as a nondestructive monitoring tool, it is noticeable that it presented inter-tissue correlation with the serum in most occasions.

Feather could be considered as an appropriate criterion to diagnose the mineral status in the body.

In this research, the artificial neural networks (ANNs) and multi-layered non-fuzzy inductive inference system (ANFIS) were used to model the output energy in dairy and beef cattle farms. For this purpose, according to Cochran's relation, 105 beef and dairy farms were randomly selected from five townships which were the main producers of this sector in Mazandaran province from 2016-2017. Using the energy balance of inputs and outputs, the input and output energy averages in beef production farms were calculated to be 16994.76 and 3449.85 MJcow-1 and for dairy production farms were equal to 100100 and 58277 MJcow-1, respectively. Also, ER (Energy Ratio), EP (Energy Productivity), SE (Special Energy) and NE (Net Energy) indices for dairy production farms were 0.58, 0.08 KgMJ-1, 12.5 MJKg-1 and -41825.93 MJcow-1, respectively and for beef production farms were calculated as 0.2, 0.02 KgMJ-1, 50 MJKg-1and 13544.91 MJcow-1, respectively. Using the results of statistical analysis of the data, modeling of the output energy for each unit of input energy was performed by two above methods (ANNs and ANFIS). The results showed that the model of nervous- fuzzy inference comparative multi-layered system with the correlation coefficient of 0.9899 for steer farms and 0.9933 for dairy farms, had better performance and accuracy than that of the artificial neural network with the correlation coefficient of 0.8118 and the structure of 6-16-1 for beef farms and correlation coefficient of 0.9837 and the structure of 5-12-1 for dairy farms.

In order to investigate the effects of Galbanum essential oil (GEO) and xylanase on performance and intestinal microflora of broiler chicks, a total of 160 one-day old chicks (Ross 308 strain) were used to four dietary treatments based on a completely randomized design in a factorial arrangement. The factors included were xylanase (0 and 0.2 gr/kg of diet) and GEO (0 and 0.1 gr/kg of diet). During the experimental periods (0-10 d, 11-24 d and 25-42 d), body weight gain (BWG), feed intake and feed conversion ratio (FCR) were measured. At days 21 and 42 of age two chicks from each replicate were slaughtered to determine carcass characteristic and ileal microbial populations of E. coli and Lactobacillus. Adding enzymes to the diet increased BWG in growing period and improved FCR in the growing and in the entire period of the experiment. At 21 day of age, GEO supplementation alone or GEO and xylanase as mixed significantly (P

As the resources are limited, improving efficiency of sheep farming is of high importance in Iran. In the present study, the technical efficiency of Moghani sheep flocks was investigated using the method of data envelopment analysis, considering constant (CRS) or variable (VRS) returns to scale. Data of year 2015 on inputs for the amount of concentrate, forage and labor as well as outputs including the amount of meat, milk, wool and fertilizer were collected from 214 Moghani sheep flocks through interviews and questionnaires. Data analysis was performed using Deap 2.1 software. The average technical efficiencies with CRS and VRS were 0.978 and 0.977, respectively, showing high efficiency in studied flocks. With CRS and VRS, there were 14 and 25 flocks being technically efficient, respectively, and could be introduced as reference flocks to inefficient ones. The results showed that with VRS, some reduction in flock size, labor, forage, concentrate, rangelands roughages and health costs as 2.99, 2.99, 2.63, 2.79, 2.73 and 6.41 percent, respectively, would let inefficient flocks to become efficient, while maintaining the same level of previous production. The estimates of return to scale showed that most of Moghani sheep flocks had an increasing return to scale, and are able to benefit from scale-based savings and lowered cost per output unit.

The objective of this study was to select the best model among five non-linear growth functions, i.e., Brody, Gompertz, Logistic, Von Bertalanffy and Negative exponential for describing the growth curve in Markhoz goat. The data included 5557 body weight records of goats from birth to yearling which were collected during 2006 to 2013 at Sanandaj Research Station. Growth curve parameters (A, B, K) were estimated by the NLIN procedure of SAS program and in order to compare different models for selecting the best model, statistics of coefficient of determination (R2adj), Akaike´s Information Criterion (AIC), Bayesian Information Criterion (BIC), Root Mean Squares Error (RMSE) and Durbin-Watson were calculated. For all animals, Logistic model was the best model as provided the greatest R2adj and the lowest values of RMSE, AIC and BIC than other models and this model could indicate the best prediction of growth in Markhoz goat. The best selected models for predicting growth of males and females were Brody and Gompertz models, respectively; and Logistic model was selected as the best model for both singles and twins. The negative exponential model provided the worst fit of growth curve for all animals, males, females, singles and twins. Logistic model can provide the best prediction of growth pattern of Markhoz goat over a definite time period.

The Japanese quails are blessed with many desirable characteristics, viz, faster growth, early sexual maturity, high rate of egg production (300 egg/annum), short generation interval (3-4 generations a year), small floor space, less feed requirements (20-25 g/adult bird/day), short incubation period of hatching eggs, less feed cost, and less susceptibility to common chicken diseases (Ernst, 2000). In consequence and due to shortage of available data on nutrient requirements of quails, prediction of biological responses of this type of poultry to nutrients using growth functions seems to be beneficial. Growth modeling are also critical for the understanding and formulation of breeding plans because they shift in response to selection (Marks et al. 1988, Mignon-Grasteau et al. 1999, Aggrey 2003 and Beiki et al. 2011). The representation of biological concepts through the simulation of growth dynamics enables us to better adapt management and nutrition to the requirements of the animals, while taking into account the interaction between genotype, nutrition and environmental conditions [Torres and Ferket 2012]. Eleroğlu et al. (2014) pointed out that the application of mathematical functions to describe the growth of birds was useful in estimating production termination deadline and formulation of appropriate feed mixtures (Michalczuk et al. 2016). Ersoy et al. (2006) claimed the Gompertz and Richards models to be the most appropriate for the characteristics of the growth of chickens, ostriches, turkeys and emus. Conflicting concluding by various authors upon the use of the same functions may result from the use of different genetic groups of birds in experiments. The objective of the present study was 1) to determine the best predictive growth function in describing data from Japanese quails and 2) to investigate the effect of dietary nutrients density on the growth curve parameters estimated by the growth models.
Material and One thousand and fifty one-day-old Japanese quails were randomly divided into 4 dietary treatment groups with 3 replicates of 86 quails in each in order to compare four growth functions (Gompertz, Richards, von Bertalanffy and Lopez) for their predicable abilities in describing growth of Japanese quails. The treatment groups were: 1) group with low dietary nutrient density [95% of nutrients recommended by NRC (1994), -5% NRC], 2) group with medium dietary nutrient density [100% of nutrients recommended by NRC (1994)], 3) group with high dietary nutrient density [105% of nutrients recommended by NRC (1994), % NRC] and 4) group with very high dietary nutrient density [110% of nutrients recommended by NRC (1994), % NRC]. Body weights of the birds were measured weekly over the 56 day of the experimental period. Evaluation on the goodness of fit for the models were made by R2, AIC, BIC, and RMSE criteria.
Evaluation on the goodness of fit for the models using R2, RMSE, AIC, BIC criteria showed advantage for the Richards in describing the growth data of Japanese quails which can be related to the variable point of inflexion in the Richards model and therefore its flexibility. According to the four growth functions considered, estimated final body weights were higher in the high density than the low density diets. The age at point of inflection were earlier in high versus low density diets. As early as 1945, Brody suggested that it was possible to select on the shape of the growth curve. A phenotypic modification of the growth curve was also observed in previous studies. Marks et al. 1988, Mignon-Grasteau et al. (1999), Aggrey 2003 and Beiki et al. (2011) showed that growth curve parameters were heritable. However, data shortage of the nutritional requirement necessary for quail breeding makes the mathematic simulation methods very useful in estimating the biological answer to the food nutrients contribution. The method of mathematic simulation of growth using growth functions can also provide the response of the growth parameters to nutrition (Daren and Marks 1988; Marks 1991; Gebhardt-Henrich and Marks 1993) which has the potential benefits when used for selection.
In summary, it was concluded that data regarding the growth parameters of quails would be best interpreted with the use of the Richards model. Meanwhile, since almost all the growth parameters estimated by the models were affected by the dietary nutrients density, therefore special attention needed will be given to the nutrition when selecting the quails as parental for the next generation through parameters estimated by mathematical simulation using growth functions.

Longevity records of 26991 Mehraban lambs born from 405 sires and 8114 dams which collected by the Agricultural Organization of Hamedan Province during 1981 to 2011 were used in this study. To determine the fixed effects fitted in statistical model (birth year, birth month, type of birth, age of dam, flock, lamb sex and lamb birth weight and their interactions), the GLM procedure of SAS software was used. Interaction between birth year-lamb sex and all fixed effects except for birth type, dam age and linear covariate variable of lamb birth weight was significant on longevity (P

This study was carried out to investigate different data transformation methods on homogeneity and heterogeneity of variance components. Data included 305-day lactation records for protein yield from the first three lactations of Iranian Holstein cows collected from 1983 to 2014 by the Animal Breeding Center and Promotion of Animal Products of Iran. Data included 141670 records for 1st lactation, 115395 records for 2nd lactation and 82529 records for 3rd lactation. Records were categorized to 3 classes according to the average of herd-year production. For testing the heterogeneity of variance components Bartlet test was used and it was significant among all three lactations. A pre-correction method and two different data transformation methods including Box-Cox and Square root were used to correct for heterogeneity of variance. Genetic parameter and heritability estimates were estimated by VCE program, under an animal model. Spearman correlations and proportion of animals selected before and after data transformation were also estimated. Application of the Visscher adjustment method resulted in slightly higher heritabilities, which may be due to the more accurate estimation of additive genetic effects when heterogeneity is considered. Heterogeneity of variance had a significant effect on re-ranking and selection of 5% top sires and 1% of top dams. Pre-correction, Box-Cox and Square root method caused a proportion of 4%, 19% and 10% of top sires and 10%, 21% and 7% of top dams, respectively, to be excluded from selection when compared to the homogenous variance scenario. The results of this research indicate that the variance between different levels of herd-year production is not homogeneous and may influence the ranking and genetic evaluation of top cows.

The objective of the present study was to evaluate the effects of inbreeding on growth traits in Guilan province sheep. Traits included average daily gain from birth to 3 months (ADG1), average daily gain from birth to 6 months (ADG2), average daily gain from 3 months to 6 months (ADG3) and corresponding Kleiber ratios (KR1, KR2 and KR3, respectively). Data and pedigree information used in this study were collected during 1994 to 2011 by the Agriculture Organization of Guilan Province. The effects of inbreeding rate on the traits investigated (for a change of 1% in inbreeding) were analyzed using the Reg procedure of SAS for type of birth, lamb’s sex and all lambs. The effects of inbreeding on all traits except ADG1 were positive. The regression coefficients of ADG1, ADG2 and KR2 were estimated to be -0.138, 0.101 and 0.0053 g, respectively (P

The aim of this study was to estimate genetic parameters associated with longevity and body weights and analysis of longevity in the Guilan province native sheep. The data set included full information of pedigree, sex, year, month and day of culling, dam age, year, month and day of birth, type of birth, and birth weight, 3 and 6-month weight. In order to study genetic relationship between longevity and body weights at different ages, bivariate linear-linear models and AIREML algorithm of WOMBAT software were used. The models included the fixed effects of year and month of birth, sex, type of birth, dam age and linear effect of birth weight as covariate. Direct heritability of longevity was low and equal to 0.03. Althogh direct heritability of birth weight 3 and 6-month weight were equal to 0.13, 0.022 and 0.097 respectively. Also, direct genetic correlation between longevity-birth weight, longevity-three month weight and longevity-six month weight were estimated to be -0.081, 0.91 and -0.90, respectively. Negative correlations indicated that lambs with high birth weight and lambs with high weight in 6 month due to culling from flock don’t have high longevity. Because of the low heritability of longevity, for improving the longevity of lambs from birth to yearling age, environmental and management conditions should be improved and indirect selection should be conducted using the correlated traits to increase the survival rate of Guilan province native lambs.