Use of Esienia fetida Worms to Produce Peptone for Clostridium perfringens Vaccine Production.

Concurrent with an increase in the human population on the earth, more than ever, the creation of energy and maintenance of health is necessary, and nowadays, various sources of energy supply are being developed. The general global view in this regard is to provide protein and energy from available and cheap sources. Iran is no exception to this general rule, only in the field of ensuring the health of livestock resources every year, about 10 tons of peptone is needed for producing clostridial vaccines. Vermicomposting worms (Esienia fetida) with high protein percentages and rapid reproductions are a suitable source for peptone production. Based on this, the vaccine strain of Clostridium perfringens type D cultivated in two different media contain peptone produced from worms and meat peptone. The growth rate, epsilon toxin (ETX), and alpha toxin (CPA) of Cl. perfringens have been compared in two media. The results showed that the growth rate of bacteria in the worm peptone medium in 48 h was 22% higher than that of the meat peptone. Additionally, the activity of alpha toxin (phospholipase C) was in worm peptone 15% higher than meat peptone during 80 min of measurement. Regarding epsilon toxin lethality, all three mice of the N-worm peptone group died, while all three mice of the meat peptone group survived even 72 h after injection. The average survival time of mice in the N-worm peptone group was 1700 min. Therefore, we suggest the worms' protein is more suitable than industrial meat in peptone production for vicinal propose. To eliminate the need for hydrolyzed protein in the production of vaccines in the future, we suggest an increase in the fields of employment and the development of fertilizer and worm farms in Iran.

Klebsiella pneumoniae infection in canaries (Serinus canaria Domestica): a case report.

Background: Klebsiella pneumoniae can cause high mortality in birds. In recent years, small farming of canaries has been developed in Iran and infectious diseases are the main obstacle in the progress of these occupations which increases the importance of identification of pathogenic bacterial agents. Case description: A flock with 250 one-year-old canaries presented a history of anorexia, lethargy, mild diarrhea, and approximately 30% mortality. Physical examination revealed that the birds were severely debilitated, cachectic, dehydrated with ruffled feathers, and wet discolored stool around the cloaca. Necropsy findings revealed enlarged liver with multiple pale white, irregular foci on the surface of parenchyma, serosal petechial hemorrhages, and enlargement of lungs, liver, and kidneys. The entire intestine was intensely reddened with fibrinonecrotic exudate content. Histopathological findings of the liver elicited multifocal hepatocellular necrosis, hemorrhage, and also basophilic bacterial colonies. The results of biochemical and molecular tests confirmed K. pneumonia as the causative agent. Findings/treatment and outcome: Based on antimicrobial susceptibility test, K. pneumonia isolates were susceptible to gentamycin and ciprofloxacin which were administrated for the considered treatment protocol. Conclusion: K. pneumoniae is one of the most important causes of mortality in canaries with multiple antibiotic resistance, therefore assessments of health conditions can supply suitable information to help decision-making about the sanitary processes, control, prevention, and treatment.

The effect of ascorbic acid and bio fertilizers on basil under drought stress.

Evaluate the effect of ascorbic acid application and coexistence of Mycorrhiza fungus and Azospirillium on basil (Ocimum basilicum L.) under drought stress. This experiment was performed as a split factorial in a randomized complete block design with three replications in the crop year 2017-2018 in Shahriar, Iran. In this experiment, irrigation was the main factor in three levels, including drought stress based on 40-70-100 mm from the evaporation pan of class A. Biofertilizer including growth-promoting bacteria (Azospirillium) and mycorrhiza fungus in four levels, including a(Non-consumption) B (Seeds of growth-promoting bacteria (Azospirillium)) C (Consumption of mycorrhiza fungus as seeds) D (Concomitant use of growth-promoting bacteria Azospirillium with mycorrhiza fungi as seeds) and ascorbic acid in two levels of foliar application, including A (Absence Application of ascorbic acid) and B (Application of ascorbic acid (two days after irrigation treatment)) was considered as a factorial factor. The results showed that the highest biological yield was obtained in drought stress of 40 mm and application of biological fertilizers in the form of mycorrhiza application with an average of 3307.1 kg/ha, which was about 70% more than 100 mm evaporation stress and no application of biological fertilizer. The use of ascorbic acid under drought stress conditions improved by 10%, the essential oil using ascorbic acid evaporated under drought stress conditions of 100 mm. As a general conclusion, the use of ascorbic acid and Mycorrhiza + Azospirillium biological fertilizer improved the quantitative and qualitative characteristics of basil under drought stress.

Variation in volatile organic compounds in Atlantic salmon mucus is associated with resistance to salmon lice infection.

Salmon lice are ectoparasites that threaten wild and farmed salmonids. Artificial selection of salmon for resistance to the infectious copepodid lice stage currently relies on in vivo challenge trials on thousands of salmon a year. We challenged 5750 salmon with salmon lice (Lepeophtheirus salmonis) from two distinct farmed strains of salmon in two separate trials. We found that volatile organic compounds (VOC), 1-penten-3-ol, 1-octen-3-ol and 6-methyl-5-hepten-2-one in the mucus of the salmon host after salmon lice infection, were significantly associated with lice infection numbers across a range of water temperatures (5 °C, 10 °C, 17 °C). Some VOCs (benzene, 1-octen-3-ol and 3,5,5-trimethyl-2-hexene) were significantly different between lines divergently selected for salmon lice resistance. In a combined population assessment, selected VOCs varied between families in the range of 47- 59% indicating a genetic component and were positively correlated to the salmon hosts estimated breeding values 0.59-0.74. Mucosal VOC phenotypes could supplement current breeding practices and have the potential to be a more direct and ethical proxy for salmon lice resistance provided they can be measured prior to lice infestation.

Quantitative trait loci and genes associated with salmonid alphavirus load in Atlantic salmon: implications for pancreas disease resistance and tolerance.

Salmonid alphavirus infection results in pancreas disease causing severe economic losses for Atlantic salmon aquaculture. Knowledge about genes and pathways contributing to resistance is limited. A 54 K SNP panel was used to genotype 10 full-sibling families each consisting of ~ 110 offspring challenged with salmonid alphavirus subtype 3. Relative heart viral load was assessed at 4- and 10-weeks post-infection using quantitative PCR. A moderate genomic heritability of viral load at 4 weeks (0.15-0.21) and a high positive correlation with survival (0.91-0.98) were detected. Positions of QTL detected on chromosome 3 matched those for survival detected by other studies. The SNP of highest significance occurred in the 3' untranslated region of gig1, a fish-specific antiviral effector. Locus B of immunoglobulin heavy chain mapped to an area containing multiple SNPs with genome-wide association. Heart mRNA-seq comparing parr from families with high- versus low-genomic breeding value, and matching sample genotypes for SNPs, identified two eQTL for salmonid alphavirus load. Immune genes associated with trans-eQTL were numerous and spread throughout the genome. QTL regions contained several genes with known or predicted immune functions, some differentially expressed. The putative functional genes and variants identified could help improve marker-based selection for pancreas disease resistance.

Response of the Salmon Heart Transcriptome to Pancreas Disease: Differences Between High- and Low-Ranking Families for Resistance.

Pancreas disease caused by salmonid alphaviruses leads to severe losses in Atlantic salmon aquaculture. The aim of our study was to gain a better understanding of the biological differences between salmon with high and low genomic breeding values (H-gEBV and L-gEBV respectively) for pancreas disease resistance. Fish from H- and L-gEBV families were challenged by intraperitoneal injection of salmonid alphavirus or co-habitation with infected fish. Mortality was higher with co-habitation than injection, and for L- than H-gEBV. Heart for RNA-seq and histopathology was collected before challenge and at four- and ten-weeks post-challenge. Heart damage was less severe in injection-challenged H- than L-gEBV fish at week 4. Viral load was lower in H- than L-gEBV salmon after co-habitant challenge. Gene expression differences between H- and L-gEBV manifested before challenge, peaked at week 4, and moderated by week 10. At week 4, H-gEBV salmon showed lower expression of innate antiviral defence genes, stimulation of B- and T-cell immune function, and weaker stress responses. Retarded resolution of the disease explains the higher expression of immune genes in L-gEBV at week 10. Results suggest earlier mobilization of acquired immunity better protects H-gEBV salmon by accelerating clearance of the virus and resolution of the disease.

Scoring multiple features to predict drug disease associations using information fusion and aggregation.

Prediction of drug-disease associations is one of the current fields in drug repositioning that has turned into a challenging topic in pharmaceutical science. Several available computational methods use network-based and machine learning approaches to reposition old drugs for new indications. However, they often ignore features of drugs and diseases as well as the priority and importance of each feature, relation, or interactions between features and the degree of uncertainty. When predicting unknown drug-disease interactions there are diverse data sources and multiple features available that can provide more accurate and reliable results. This information can be collectively mined using data fusion methods and aggregation operators. Therefore, we can use the feature fusion method to make high-level features. We have proposed a computational method named scored mean kernel fusion (SMKF), which uses a new method to score the average aggregation operator called scored mean. To predict novel drug indications, this method systematically combines multiple features related to drugs or diseases at two levels: the drug-drug level and the drug-disease level. The purpose of this study was to investigate the effect of drug and disease features as well as data fusion to predict drug-disease interactions. The method was validated against a well-established drug-disease gold-standard dataset. When compared with the available methods, our proposed method outperformed them and competed well in performance with area under cover (AUC) of 0.91, F-measure of 84.9% and Matthews correlation coefficient of 70.31%.

Comparison of serum and urine lead levels in opium addicts with healthy control group.

CONTEXT: Lead-contaminated opium is one of the new sources of lead exposure in our region. As far as the literature review is concerned, there are limited comparative studies about comparison of blood lead level (BLL) in addict patients with healthy controls. OBJECTIVE: We aimed to compare BLL and urine lead level (ULL) between opium addicts with the healthy control group. MATERIALS AND METHODS: Forty opium addict subjects (mean age: 43 ± 10 years) as the patient group and 40 healthy subjects (mean age: 41 ± 9 years) as the control group participated. Three milliliter of whole blood and urine was obtained from both groups and lead level was assessed using atomic absorption spectrophotometry. RESULTS: The mean value of BLL in patient group was 7.14 ± 1.41 mcg/dL and that in the healthy control group was 5.42 ± 1.46 mcg/dL. The mean value of ULL was 2.62 ± 0.83 mcg/dL in the patient group and 2.50 ± 0.76 mcg/dL in the healthy control group.BLL was different in the two groups (p < 0.001), but ULL was not (p = 0.5). There was a significant correlation between BLL with duration of opium addiction in the patient group (r = -0.403, p = 0.01). BLL and ULL were significantly correlated in controls (r = 0.436, p = 0.005) and not in patients. DISCUSSION AND CONCLUSION: It was observed that the BLL in opium addicts was significantly higher than that in the healthy control group. This can be due to use of adulterated opium with lead. Therefore, screening of blood lead concentration is helpful for opium-addict patients especially with nonspecific symptoms.

Characterizing Awake and Anesthetized States Using a Dimensionality Reduction Method.

Distinguishing between awake and anesthetized states is one of the important problems in surgery. Vital signals contain valuable information that can be used in prediction of different levels of anesthesia. Some monitors based on electroencephalogram (EEG) such as the Bispectral (BIS) index have been proposed in recent years. This study proposes a new method for characterizing between awake and anesthetized states. We validated our method by obtaining data from 25 patients during the cardiac surgery that requires cardiopulmonary bypass. At first, some linear and non-linear features are extracted from EEG signals. Then a method called "LLE"(Locally Linear Embedding) is used to map high-dimensional features in a three-dimensional output space. Finally, low dimensional data are used as an input to a quadratic discriminant analyzer (QDA). The experimental results indicate that an overall accuracy of 88.4 % can be obtained using this method for classifying the EEG signal into conscious and unconscious states for all patients. Considering the reliability of this method, we can develop a new EEG monitoring system that could assist the anesthesiologists to estimate the depth of anesthesia accurately.

Monitoring depth of anesthesia using combination of EEG measure and hemodynamic variables.

Monitoring depth of anesthesia (DOA) via vital signs is a major ongoing challenge for anesthetists. A number of electroencephalogram (EEG)-based monitors such as the Bispectral (BIS) index have been proposed. However, anesthesia is related to central and autonomic nervous system functions whereas the EEG signal originates only from the central nervous system. This paper proposes an automated DOA detection system which consists of three steps. Initially, we introduce multiscale modified permutation entropy index which is robust in the characterization of the burst suppression pattern and combine multiscale information. This index quantifies the amount of complexity in EEG data and is computationally efficient, conceptually simple and artifact resistant. Then, autonomic nervous system activity is quantified with heart rate and mean arterial pressure which are easily acquired using routine monitoring machine. Finally, the extracted features are used as input to a linear discriminate analyzer (LDA). The method is validated with data obtained from 25 patients during the cardiac surgery requiring cardiopulmonary bypass. The experimental results indicate that an overall accuracy of 89.4 % can be obtained using combination of EEG measure and hemodynamic variables, together with LDA to classify the vital sign into awake, light, surgical and deep anesthetised states. The results demonstrate that the proposed method can estimate DOA more effectively than the commercial BIS index with a stronger artifact-resistance.

Whole genome duplication: challenges and considerations associated with sequence orthology assignment in Salmoninae.

To illustrate some of the challenges and considerations in assigning correct orthology necessary for any comparative genomic investigation among salmonids, sequence data from the non-coding regions of different chromosomes in three members of the subfamily Salmoninae, rainbow trout Oncorhynchus mykiss, Atlantic salmon Salmo salar and Arctic charr Salvelinus alpinus, were compared. By analysing c. 55 distinct loci, corresponding to c. 142 kbp sequence information per species, 18 duplicated patterns representative of the two sequential rounds of teleost-specific whole genome duplications (i.e. 3R and 4R WGD) were identified. Sequence similarities between the 4R paralogues were c. 90%, which was slightly lower than those of the 4R orthologues and c. 60% for the 3R products. Through careful examination of the sequence data, however, only 14 loci could reliably be assigned as true orthologues. Locus-specific trees were constructed through maximum parsimony, maximum likelihood and neighbour-joining methods and were rooted using the information from a close relative, lake whitefish Coregonus clupeaformis. All approaches generated congruent trees supporting the {Coregonus [Salmo (Oncorhynchus, Salvelinus)]} topology. The general phenotypic characteristics of sequences, however, were highly suggestive of the basal position of Oncorhynchus, raising the hypothesis of an accelerated rate of nucleotide evolution in this species.

The genetic architecture of embryonic developmental rate and genetic covariation with age at maturation in rainbow trout Oncorhynchus mykiss.

The genetic architecture underlying variation in embryonic developmental rate (DR) and genetic covariation with age of maturation (MAT) was investigated in rainbow trout Oncorhynchus mykiss. Highly significant additive parental effects and more limited evidence of epistatic effects on progeny hatching time were detected in three diallel sets of families. Genome scans with an average of 142 microsatellite loci from all 29 linkage groups in two families detected significant quantitative trait loci (QTL) for developmental rate on RT-8 and RT-30 with genome-wide and chromosome-wide effects, respectively. The QTL on linkage group RT-8 explained 23·7% of the phenotypic variation and supports results from previous studies. The co-localization of QTL for both DR and MAT to several linkage groups and the observation that alleles associated with faster developmental rate were found significantly more often in early maturing rather than typical and later maturing male ancestors supports the hypothesis of genetic covariation between DR and MAT. The maturation background and schedule of additional sires, however, did not have a consistent association with their progeny hatching times, suggesting that other genetic, environmental and physiological effects contribute to variation in these life-history traits.

Genetic mapping of the ornithine decarboxylase (odc) gene complex in rainbow trout (Oncorhynchus mykiss).

Ornithine decarboxylase (odc) and its associated gene complex, including antizymes of ODC and inhibitors of the antizymes, play a key role in regulating the overall polyamine levels (i.e., putrescine) in cells. Polyamine production levels are intricately coupled to mitotic and cellular turnover rates. Hence, these genes may be important candidates of growth regulation in vertebrates, if their chromosomal locations coincide with known quantitative trait locus (QTL) regions influencing growth traits. Here we report the genetic mapping of multiple duplicated forms of genes within this complex to previously known life-history and growth QTL regions in rainbow trout (Oncorhynchus mykiss). Specifically, duplicated copies of the 2 antizyme genes map to Om-8/9/24, while antizyme inhibitor and odc duplicates map to Om-27/31 and Om-14/25, respectively. All sets of paralogous mapping locations correspond to ancestrally duplicated synteny regions within the genome of rainbow trout (i.e., ancestral A, B, GH/I and M linkage groups).

Genomic organization of the IGF1, IGF2, MYF5, MYF6 and GRF/PACAP genes across Salmoninae genera.

Whole-genome duplication in the ancient ray-finned fish and subsequent tetraploidization in the ancestor to the salmonids have complicated genomic and candidate gene studies in these organisms as many genes with multiple copies are present throughout their genomes. In an attempt to identify genes with a potential influence on growth and development, we investigated the genomic positions of insulin-like growth factors 1 and 2 (IGF1, IGF2), myogenic factors 5 and 6 (MYF5, MYF6) and growth hormone-releasing factor/pituitary adenylate cyclase-activating polypeptide (GRF/PACAP) in three salmonid species: rainbow trout (Oncorhynchus mykiss), Atlantic salmon (Salmo salar) and Arctic charr (Salvelinus alpinus). Our results suggest a tight association between the IGF1, MYF5 and MYF6 genes in all three species. We further localized the duplicated copies of IGF1 to the homeologous linkage groups RT-7/15 in rainbow trout and AC-3/24 in Arctic charr, and the two copies of MYF6 to homeologous linkage groups AS-22/24 in Atlantic salmon. Localization of GRF/PACAP to RT-7, AS-31 and AC-27 and IGF2 to RT-27, AS-2 and AC-4 in rainbow trout, Atlantic salmon and Arctic charr respectively is consistent with previously reported homologies among these chromosomal segments identified using other genetic markers. However, localization of the second copy of GRF/PACAP to RT-19 and AC-14 and the duplicated copy of IGF2 to AC-19 suggest a possible new homology/homeology between these chromosomes. These results might also be an indication of a more ancient polyploidization event that occurred deep in the ray-finned fish lineage.

Genome organization of glutamine synthetase genes in rainbow trout (Oncorhynchus mykiss).

Unlike mammals, bony fish appear to possess multiple genes encoding glutamine synthetase (GS), the nitrogen metabolism enzyme responsible for the conversion of glutamate and ammonia into glutamine at the expense of ATP. This study reports on the development of genetic markers for each of the four isoforms identified thus far in rainbow trout (Oncorhynchus mykiss) and their genome localization by linkage mapping. We found that genes coding for GS01, GS02, GS03, and GS04 map to four different linkage groups in the trout genome, namely RT-24, RT-23, RT-08, and RT-13, respectively. Linkage groups RT-23 and RT-13 appear to represent distinct chromosomes sharing duplicated marker regions, which lends further support to the previous suggestion that GS02 and GS04 may be duplicate gene copies that evolved from a whole-genome duplication in the trout ancestor. In contrast, there is at present no further evidence that RT-24 and RT-08 share ancestrally homologous segments and additional genomic studies will be needed to clarify the evolutionary origin of genes coding for GS01 and GS03.

Heritability of sudden death syndrome and its associated correlations to ascites and body weight in broilers.

(1) Genetic parameters for the sudden death syndrome (SDS) were estimated in meat-type chickens. Data were collected over 11 generations of selection for body weight within two distinct breeds (Cornish and White Rock). (2) The animal model was used exclusively with linear methods (LM) to estimate genetic parameters. Heritability (h2) of SDS on the liability scale was 0.30 +/- 0.002 and 0.25 +/- 0.002 in the Cornish and White Rock breeds, respectively. (3) A positive genetic correlation (r(g)) with ascites (AS) was determined (approximately 0.3 +/- 0.006). However, it was not possible to estimate the rg of SDS with body weight because of the low prevalence of the defect trait studied (1.8% in the Cornish and 1-5% in the White Rock). (4) Heritability of SDS calculated using male records only was 0.45 +/- 0.009 and 0.35 +/- 0.009, and r(g) with body weight was 0.30 +/- 0.010 and 0.27 +/- 0.009, in the Cornish and White Rock breeds, respectively. (5) In conclusion, the heart defect investigated was heritable with a positive genetic correlation with AS and body weight.

Cyclin D1 binding to the androgen receptor (AR) NH2-terminal domain inhibits activation function 2 association and reveals dual roles for AR corepression.

The androgen receptor (AR) is a member of the nuclear receptor superfamily, the activity of which is critical for the development and progression of prostate cancer. We and others have previously demonstrated that cyclin D1 is a potent corepressor of the AR. Although cyclin D1 is suspected to recruit histone deacetylases to the AR complex, previous studies have demonstrated that this activity alone is insufficient for cyclin D1 function. Here, we uncover a novel, secondary means of cyclin D1-mediated repression, through modulation of AR amino-carboxy terminal interactions. We show that cyclin D1 predominantly binds the N-terminal domain of the AR, dependent on the AR 23FxxLF27 motif. Through this motif, cyclin D1 abrogates the ability of the AR N-terminal domain to interact with the C terminus. Secondary amino-terminal domain sites capable of fostering interaction with the C terminus were refractory to cyclin D1 action, indicating that the ability of cyclin D1 to modulate AR amino-carboxy terminal interactions is specific to 23FxxLF27. Deletion of the N-terminal cyclin D1 binding site severely compromised AR activity (due to loss of FxxLF) but unmasked a repressor action through interaction with the AR C terminus. In summary, these data reveal novel, unexpected mechanisms of cyclin D1 activity and demonstrate that this function of cyclin D1 is critical for AR modulation.

A retrospective study of mushroom poisoning in Iran.

The objective of this study was to describe the pattern of mushroom poisoning in adults admitted to the Loghman-Hakim Hospital Poison Center from 1992 to 2002. All patients > or = 12 years of age were included in the study. The frequency of mushroom poisoning with respect to age, sex, season, reason, place of residence, latent phase, clinical and laboratory findings, treatment, and outcome of patients was investigated. Of the 72421 poisoning cases admitted to Loghman-Hakim Hospital Poison Center from 1992 to 2002, only 37 were poisoned by consumption of toxic mushrooms. As some of the patients' files were incomplete, only 25 files were included in the study. Of this number, 68% were male. The patients' age ranged between 12 and 65 years, with a mean of 31 years of age. All cases were accidental and mostly from Tehran (36%) and the northern provinces (rainy woodlands) of Iran (32%). Autumn was the most common season for poisoning with a frequency of 80%. The latent phase of poisonings was between 0.5 and 12 hours. The most frequently reported symptoms were vomiting (84%), nausea (60%), abdominal pain (60%) and diarrhea (40%). Jaundice was observed in 44% of cases, with a 50% rate of hepatic encephalopathy. A total of 66% of patients were discharged and the duration range of hospitalization was 1-12 days. In conclusion, people should be more informed of the dangers posed by wild mushrooms. Training of physicians and nurses in the accurate diagnosis and management of patients poisoned with poisonous mushrooms would improve the rate of survival.

Epididymo-orchitis risk factors in traumatic spinal cord injured patients.

STUDY DESIGN: Retrospective audit and interview-based study of a traumatic spinal cord injured cohort, assessing the incidence and risk of epididymo-orchitis (E-O). OBJECTIVES: Assess the potential risk factors for E-O in this cohort (spinal cord injured patients). SETTING: Janbazan Clinic for Spinal Cord Injuries, Mashad, Iran. METHODS: A retrospective notes audit of 169 male traumatic spinal cord injured (SCI) patients was performed. In addition, interviews were performed to confirm any equivocal data. The following risk factors were assessed: history of recurrent urinary tract infections (UTIs), urethral stricture, urethral diverticuli, urinary fistula, urinary calculi, spinal injury type, neurogenic bladder type, autonomic dysreflexia, vesico-ureteral reflux, sphincterotomy, vasectomy, marriage status, bladder residual and emptying method, ejaculation, spinal injury level, micturation control, and muscular spasm, which included detrusor, external sphincter or lower limb spasm. RESULTS: A total of 65 patients from our group (38.5%) had suffered E-O at least once. E-O presented on average, 3.9 years after the SCI. Patients with a history of muscular spasm appeared less likely to develop E-O (P<0.05). None of the vasectomised patients developed E-O. The relation between all the other factors and E-O were not significant. CONCLUSIONS: Our study has shown that the presence of muscular spasm decreases the risk of E-O, although the mechanism remains unclear. Surprisingly, the other historical risk factors showed no clear relation with E-O occurrence.

Marker-assisted estimation of quantitative genetic parameters in rainbow trout, Oncorhynchus mykiss.

Estimation of quantitative genetic parameters conventionally requires known pedigree structure. However, several methods have recently been developed to circumvent this requirement by inferring relationship structure from molecular marker data. Here, two such marker-assisted methodologies were used and compared in an aquaculture population of rainbow trout (Oncorhynchus mykiss). Firstly a regression-based model employing estimates of pairwise relatedness was applied, and secondly a Markov Chain Monte Carlo (MCMC) procedure was employed to reconstruct full-sibships and hence an explicit pedigree. While both methods were effective in detecting significant components of genetic variance and covariance for size and spawning time traits, the regression model resulted in estimates that were quantitatively unreliable, having both significant bias and low precision. This result can be largely attributed to poor performance of the pairwise relatedness estimator. In contrast, genetic parameters estimated from the reconstructed pedigree showed close agreement with ideal values obtained from the true pedigree. Although not significantly biased, parameters based on the reconstructed pedigree were underestimated relative to ideal values. This was due to the complex structure of the true pedigree in which high numbers of half-sibling relationships resulted in inaccurate partitioning of full-sibships, and additional unrecognized relatedness between families.