Reza Faraji; Ardeshir Nejati Javaremi; Mostafa Sadeghi; Reza Miraei Ashtiani; Hamid Reza Mozhgani
Abstract
Nowadays one of the major challenges facing herders, dog owners, or working dog training centers is canine parvovirus (CPV-2). The virus has split into several types over the years since it discovered and resulted to genetic and amino acid changes that threaten a wide range of carnivorous around the ...
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Nowadays one of the major challenges facing herders, dog owners, or working dog training centers is canine parvovirus (CPV-2). The virus has split into several types over the years since it discovered and resulted to genetic and amino acid changes that threaten a wide range of carnivorous around the world. The best way to avoiding the consequences of this disease is vaccination. This study were designed, due to the lack of sufficient studies on the distribution and prevalence of different types of this virus, which may be a prominent cause of vaccine errors, also because of high involvement of Iranian dogs with CPV. Molecular study and phylogenetic comparison of Iranian types compared to other types through the world showed that the dominant type of CPV-2 existed in Iran is CPV-2a with a prevalence of 24% and genetic differences in several points of VP2 gene with other types. We are probably facing to a new version of this virus in our country. In addition, based on the drawn phylogenetic tree, it was found that Iranian isolates on the other side have a relatively high topological difference compared to the origin types and conventional vaccines strain, which supports the initial hypothesis of this study.
Mohammad Reza Mansourian; Seyed Reza Miraei Ashtiani; Ardeshir Nejati Javaremi; Mahdi Sargolzaei
Abstract
Accurate genomic evaluation depend on large reference population with reliable performance information such as predicted breeding value (PBVs). The aim of this study was to identify the most appropriate reference population to predict the genomic breeding value for Iran Holstein dairy breeding programs. ...
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Accurate genomic evaluation depend on large reference population with reliable performance information such as predicted breeding value (PBVs). The aim of this study was to identify the most appropriate reference population to predict the genomic breeding value for Iran Holstein dairy breeding programs. Phenotypes and genotypes were simulated based on the dairy cattle Iran population program (open breeding nucleus with gene flows between the nucleus and the commercial population). Medium (0.3) and low (0.05) heritability levels were considered independently. All simulations were performed with 10 replications and the results were evaluated. In the first study, female cows were selected for genotyping in four scenarios: random selection, individuals with upper and lower extremities of phenotypic value, highest phenotypic value and highest breeding value with maximum accuracy; and these females are added to the reference population. Single Step BLUP (SSBLUP) was used to predict the genomic breeding value for individuals in the population. The accuracy and unbiased coefficient of predicted breeding value were investigated. The results showed that when female animals with the highest and lowest phenotypic values were selected (the second scenario of determining females), the highest accuracy of prediction of breeding value was observed compared to other scenarios. Determination of substances with high phenotypic value (third scenario of female selection) showed the least bias. The use of imported males with genotype and their use alone as a reference population showed the least accuracy and the most bias. The combination of males and females showed an increase in accuracy and a decrease in bias compared to the scenarios for males or females alone. However, in relation to the size of the population similar to females, no improvement in the prediction of the breeding value was observed. Therefore, in terms of economic conditions (genotyping costs), the use of only female cows in the reference population (2000 females genotyped), according to the second scenario of female selection, is the best strategy to form a reference population and genomic evaluation at the lowest cost, in Iran.
Rostam Pahlavan; Mohammad Moradi Shahre Babak; Ardeshir Nejati Javaremi; Rostam Abdollahi Arpanahi
Abstract
The main objective of dairy farmers is to maximize their profit. Increased incidence of mastitis in farms is one of the health problems, causing in serious economic losses as a consequence of treatment costs and reduction of production and longevity. The objective of this study was to evaluate the genetic ...
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The main objective of dairy farmers is to maximize their profit. Increased incidence of mastitis in farms is one of the health problems, causing in serious economic losses as a consequence of treatment costs and reduction of production and longevity. The objective of this study was to evaluate the genetic architecture and associated genomic regions with milk production and somatic cell score (SCS) as an indirect measure of mastitis and the quality of raw milk. Thus, an SNP data set from 1938 Holstein bulls were used in a single-step genome-wide association study. The proportion of additive genetic variance (agv) for each of 1.5-Mb genomic window (adjacent SNPs) was used to identify informative genomic regions, accounting for more than 1% of the agv. A total of 11 significant windows over 9 bovine autosomes were found for the SCS. A peak on BTA14 explained the largest proportion of variance (3.85%). These regions together, explained 20% of agv and harbored 94 candidate genes. For milk yield, we identified 6 informative windows across 6 chromosomes, and a peak on BTA10 explained 2.08% of agv. These regions, explained 8.8% of the agv and sheltered 89 candidate genes. For the fat yield, 9 significant windows were identified on 7 chromosomes and explained 15.6% of agv, and 9 windows contained 87 candidate genes on 8 bovine autosomes were associated with milk protein yield (10.6% of agv). Four genomic regions had a pleiotropic effect. These findings can be an important source of information in genomic evaluation of dairy cattle.
Ali Jalil Sarghale; Mohammad Moradi Shahre Babak; Hossein Moradi Shahrbabak; Ardeshir Nejati Javaremi; Mahdi Saatchi
Abstract
The methane production from ruminant production system was estimated to reach 250-500 L per animal per day which has been reported to contribute up to 8-10 % of global warming during the next 50-100 years. The aim of this study was to investigate the correlation among methane emission (predicted by volatile ...
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The methane production from ruminant production system was estimated to reach 250-500 L per animal per day which has been reported to contribute up to 8-10 % of global warming during the next 50-100 years. The aim of this study was to investigate the correlation among methane emission (predicted by volatile fatty acids) with milk production traits, its components and breeding values (BV) of these traits in Iranian Holstein cattle. The rumen digesta was obtained from 150 cattle through stomach tubing and this population divided into 2 groups with 75 cattle in each (the groups have different milk production BV). Data were analyzed by R.3.3.0. The results showed that methane emission per unit of milk and fat were different in the two groups (P<0.0001). Also, the BVs of milk production, fat and protein traits and daily production of milk, fat and protein had weak to moderate negative correlation with methane emission per unit(P<0.05). The highest correlation was observed between daily production of fat with methane emission per unit of fat (-0.79) as well as daily milk production with methane emission per unit of milk (-0.62). These results showed that methane emission may be reduced by indirect selection per generation for the traits had a high correlation with the gas (daily production of milk and fat).
Morteza Sattaei Mokhtari; Mohammad Moradi Shahrebabak; Ardeshir Nejati Javaremi; Guilherme J. M. Rosa
Abstract
In this research the causal structure among calving traits of 29950 first-parity Holstein cattles of Iran including calving difficulty (CD), birth weight of calves (BW) and gestation length (GL) was revealed applying data collected by Iranian Animal Breeding in 131 herds from 1995 to 2004 by Inductive ...
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In this research the causal structure among calving traits of 29950 first-parity Holstein cattles of Iran including calving difficulty (CD), birth weight of calves (BW) and gestation length (GL) was revealed applying data collected by Iranian Animal Breeding in 131 herds from 1995 to 2004 by Inductive Causation (IC) searching algorithm. Significant structural coefficients were found for causal effects of BW on CD (0.060±0.002) and of GL on CD (0.007±0.002). Furthermore, the causal effect of GL on BW was significant (0.219±0.005). Considering the revealed causal structure, standard and recursive multivariate models were compared applying deviance Information criterion (DIC) and predictive ability of models in terms of two measures including mean square of error and correlation between observed and predicted values. The obtained results revealed the causal effect of BW and GL on CD and the plausibility of recursive multivariate model over standard multivariate one. Therefore, considering the causal structure among calving traits is of crucial importance.
Nahid Parna; Ardeshir Nejati Javaremi; Mostafa Sadeghi; Rostam Abdollahi Arpanahi
Abstract
Using SNP markers information and genomic evaluation approach, predicting the genetic merit of individuals without phenotypic records is now possible. However, using high-density panels for genomic evaluation of all individuals is not economically feasible. To achieve high genomic prediction accuracy ...
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Using SNP markers information and genomic evaluation approach, predicting the genetic merit of individuals without phenotypic records is now possible. However, using high-density panels for genomic evaluation of all individuals is not economically feasible. To achieve high genomic prediction accuracy with reasonable price, it is possible to genotype a proportion of animals with high-density panels and the rest of animals with low-density panels then impute them to high-density genotypes. In this study, the effect of three low-density panels (1k, 2k and 4k), genotype imputation to 10k panel and the relationship between reference and validation populations on the accuracy of genomic predictions and also the correlation between the estimated breeding values using panels with different densities in simulated data were assessed. The low density panels genotypes were actually consisting of 10, 20 and 40 percent of 10k markers selected randomly and FImpute was used for genotype imputation. As a general trend, by increasing the density of markers, the correlation between the estimated breeding values was increased using different panels. So, the accuracy of genomic predictions was similar using 4k and 10k genotypes. Moreover, imputing 4k to 10k genotypes, did not improve the accuracy of genomic prediction. However, the accuracy of estimated breeding values was increased after imputation from 1k or 2k to 10k. The accuracy of imputation was decreased when the reference and validation populations were more distant.
Azade Boustan; Elham Rezvannejad; Ardeshir Nejati Javaremi; Reza Seyedsharifi
Abstract
An important question about genomic evaluation is the effectiveness of using superior animals as reference population, on the accuracy of estimated breeding values of selection candidates. In this research, the accuracy of genomic evaluation is selecting superior animals as reference population (strategy1) ...
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An important question about genomic evaluation is the effectiveness of using superior animals as reference population, on the accuracy of estimated breeding values of selection candidates. In this research, the accuracy of genomic evaluation is selecting superior animals as reference population (strategy1) was compared to situations in which the animals in reference population were a random sample of population (strategy2) and superior and inferior animals (strategy3). Best linear unbiased prediction method was used to estimate marker effects. The results showed that using only superior animals as reference population would decrease the accuracy of genomic evaluation. If the ratio of animals in the reference group is low (for example 10%) the difference between strategy1 and the other strategies would be more than the situation in which this ratio is high (for example 50%). For example in situation that the generation before validation set (generation four) was used as reference population, the accuracy of strategy1 was about 0.34 lower than strategy3 when 10% of animals were used as reference population but this difference was decreased to 0.04 when 50% of animals were used as reference population. These results showed that genotyping and using some of no superior animals in the reference population, beside to superior animals with high accurate traditional estimated breeding values, could lead to increase in the accuracy of genomic evaluation.
Somayeh Barani; Mohammad Moradi-Shahrbabak; Ardeshir Nejati-Javaremi; Mohammad Hosein Moradi; Mohsen Gholizadeh; Majid Khansefid
Abstract
Understanding the pattern of linkage disequilibrium (LD) in different populations provides useful information for genomic selection (GS), genome wide association studies (GWAS) and identification of genetic architecture of traits by estimating the persistence of LD phase between markers and quantitative ...
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Understanding the pattern of linkage disequilibrium (LD) in different populations provides useful information for genomic selection (GS), genome wide association studies (GWAS) and identification of genetic architecture of traits by estimating the persistence of LD phase between markers and quantitative trait loci (QTL). The aim of this research was to estimate of the extent of LD in three Iranian native sheep breeds. Therefore, 186 blood samples were taken from three sheep breeds (96 Baluchi, 45 lori-Bakhtiari and 45 Zel) and genotyped by Illumina ovine 50K SNPChip, then linkage disequilibrium in any breed were measured using r2. The results showed that the highest average values of r2 at inter marker distance of less than 10Kb were 0.392± 0.323, 0.360±0.308 and 0.340±0.306 in Baluchi, Lori-Bakhtiari and Zel, respectively. The highest average values of r2 in autosome chromosomes of each breed were obtained for chromosome 24 and 25 in Baluchi, 9 and 21 in Lori-Bakhtiari and 23 and 24 in Zel. The amount of LD reduced with increasing the distance between markers, the extent of LD was less than 0.1 at inter marker distances greater than 100Kb. The comparison of correlation coefficients LD between different breeds showed a strong persistence of LD phase between Zel and Lori-Bakhtiari breeds which is probably due to recent common ancestors between these two breeds. Generally, with increase amount of LD means that lower marker density in association studies will be required. The results of this study showed to achieve genomic prediction accuracy of 85% (assuming there is no other accuracy limiting factor) and robust GWAS results, the density of markers must be higher than 50K SNPChip.
Mohammad Hossein Moradi; Amir Hossein Farahani; Ardeshir Nejati-Javaremi
Abstract
The aim of the present study was to estimate the effective population size (Ne) in some Iranian sheep breeds using genome wide SNP data. A total of 217 animal samples consisting of 45, 37, 34, 35, 45 and 11 samples from Zel, Afshari, Moghani, Qezel, Lori-Bakhtiari and a wild-type of Iranian sheep breeds, ...
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The aim of the present study was to estimate the effective population size (Ne) in some Iranian sheep breeds using genome wide SNP data. A total of 217 animal samples consisting of 45, 37, 34, 35, 45 and 11 samples from Zel, Afshari, Moghani, Qezel, Lori-Bakhtiari and a wild-type of Iranian sheep breeds, genotyped by Illumina OvineSNP50K Beadchip assay were used in this study respectively. This study has been performed in collaboration with the Ovine HapMap project. The Ne was estimated using linkage disequilibrium across 4 up to 3500 generations ago. The result of principal component analysis (PCA) indicated that all breeds will be separated from each other in the first two principal components. Average expected and observed heterozygosity for different breeds ranged 0.36-0.37 and 0.37-0.43 respectively. The Ne results showed a decreasing trend over the last 3500 generations for all breeds, with an increasingly slope since about last 550 generations. The Ne in Iranian sheep breeds for 4 generations ago were ranged from 9 up to 89. The highest historically effective population size was found for Zel breed (89 heads) and the lowest for Afshari (44 heads) and wild_type (9 heads) sheep breeds. Generally, the results indicated that although a considerable genetic variation exists in these populations, however Ne has been decreased strongly in Iranian sheep breeds especially in Afshari and wild-type sheep breeds during recent years and designing of appropriate programs is necessary to conserve remaining purebred animals of these indigenous sheep breeds.
Azadeh BOOSTAN; Ardeshir NEJATI-JAVAREMI; Mahammad MORADI SHAHRBABAK; Mehdi SAATCHI
Abstract
Throughout the present study the effect of using markers close to genes affecting a trait, ascompared with the use of all the markers of a genome, and also the effect of on increase in thenumber of reference groups, on the accuracy of a genetic evaluation, was investigated. Genomicevaluation was done ...
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Throughout the present study the effect of using markers close to genes affecting a trait, ascompared with the use of all the markers of a genome, and also the effect of on increase in thenumber of reference groups, on the accuracy of a genetic evaluation, was investigated. Genomicevaluation was done using BLUP method. The results indicated that use of markers close to genesaffecting a trait and on increase in the number of reference groups would enhance the accuracy inan evaluation of the Estimated Breeding Values (EBVs). Use of phenotypic records (incomparison with breeding values of reference group) would result in an increase in the accuracy ofestimating the breeding values by use of markers close to the effective genes on the trait ascompared with the use of all the markers of a genome. Increase in number of generations betweenreference and validation groups would result in a decrease of the accuracy of EBVs.
M. BAGHERI; R MIRAIE- ASHTIANI; M MORADI-SHAHRBABAK; A PAKDEL; A NEJATI-JAVAREMI
Abstract
The Toll-like Receptor 4 (TLR4) is an innate immune protein on cell surfaces that identifies Lipopolysaccharide (LPS) of gram-negative bacteria. Genetic markers associated with innate responses during mastitis could help in selection of cattle to improve disease resistance. The objective of this study ...
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The Toll-like Receptor 4 (TLR4) is an innate immune protein on cell surfaces that identifies Lipopolysaccharide (LPS) of gram-negative bacteria. Genetic markers associated with innate responses during mastitis could help in selection of cattle to improve disease resistance. The objective of this study was to determine the association between TLR4 gene and clinical mastitis, using selective genotyping method. A total of 270 cows of two extreme groups namely: top clinical mastitis resistant vs. top susceptible ones were selected. For genotyping, the 2 methods of: PCR-RFLP and PCR-SSCP were made use of. Identified polymorphisms induced A-G in exon 2, and C-T in exon 3. Following sequencing, polymorphism effects on clinical mastitis were analyzed using logistic regression. The results indicated that TLR4 gene was significantly associated with clinical mastitis resistance.
ali sadeghi; mohamad moradi shahre babak; ardashir nejati javaremi; seyed reza mirayi ashtiani; piter arimer; temti jan bern; mahdi taghi nejad
Abstract
The aim followed in the present study was to investigate the economic aspects of , and to derive Economic Weights (EWs) for Mature Body Weight (MBW) as well as for age at First Calving (AFC) in Holstein dairy cattle of Iran. Economic values (EVs) for traits were estimated using trait-by-trait bio-economic ...
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The aim followed in the present study was to investigate the economic aspects of , and to derive Economic Weights (EWs) for Mature Body Weight (MBW) as well as for age at First Calving (AFC) in Holstein dairy cattle of Iran. Economic values (EVs) for traits were estimated using trait-by-trait bio-economic models. Absolute EVs were RLs -16400 and -17900 per cow per year for MBW and AFC, respectively. Because of the negative effects of these traits on profitability, EWs of -7540 for MBW and -3760 for AFC are suggested for a national selection index. A one day increase in AFC increased production costs by Rls 39600 per cow per year. Sensitivity analysis revealed that the EV for MBW was more sensitive to changes in live weight price than to feed costs. Results obtained in this study can be used in the development of breeding objectives and in the cost- benefit analysis of management programs which aim at changing the attitudes of farmers and of their consultants towards decreasing costs and therefore increasing profitability.
hossein mehrabn; ardashiri nejati; seyed reza mirayi ashtiani; hasan mehrbani yegane; venolia ibanz
Abstract
The objective of this study was to investigate the effect of principal components (PC) of the regression coefficients (co)variance matrix on the lactation curve, and on the formation of selection index to modify the curve, based on these PC’s, and as well to estimate additive genetic and phenotypic ...
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The objective of this study was to investigate the effect of principal components (PC) of the regression coefficients (co)variance matrix on the lactation curve, and on the formation of selection index to modify the curve, based on these PC’s, and as well to estimate additive genetic and phenotypic variances and heritability of the constructed selection index. Lactation period of 301 d (5-305) was partitioned into 10 equal stages, such that the values of weighted coefficients (unrestricted selection index) were considered the same value as of the lactation stage. In contrast, the value of weighted coefficients (restricted selection index) which were calculated based on the genetic gain in each stage of lactation. The results showed that the first PC had an impact on milk production and the second PC was associated with persistency. The third PC increased (decreased) milk production in early and late (middle) lactation and the fourth PC decreased (increased) milk production in early (late) as well as middle of second (first) part of lactation curve. Because of more emphasis on persistency and decreasing genetic gain in early lactation in compared with , the value of weighted coefficients first (third) and second (fourth) PC were decreased (increased). Because of decreasing the variance of additive genetic in due to negative genetic covariance between the stages of lactation, the heritability of (0.08) decreased in comparison with (0.33) which lead to decline genetic gain.
Ali Sadeghi-Sefidmazgi; Mohammad Moradi Shahrbabak; Ardeshir Nejati Javaremi; Seyed Reza Miraei Ashtiyani; P. R. Eymer
Volume 42, Issue 4 , March 2012, , Pages 345-353
Abstract
The financial losses, absolute and net economic values (EVs) for direct (DCD) and Maternal Calving Difficulty (MCD) were estimated using a bioeconomic model and taking into account the categorical nature of the trait. The effects of dystocia on other traits were estimated. But because of low reliability ...
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The financial losses, absolute and net economic values (EVs) for direct (DCD) and Maternal Calving Difficulty (MCD) were estimated using a bioeconomic model and taking into account the categorical nature of the trait. The effects of dystocia on other traits were estimated. But because of low reliability they were not considered for calculations in the base situation. In the base situation, the average costs of dystocia incidence were estimated to be Rls 518,700 per calving. Absolute EVs (per calving per cow) and net EVs (per cow per year) for DCD were Rls -27,800 and -14,200 respectively, and for MCD the two of them were stimated as Rls-2800. Most important economic consequences of calving difficulty were milk losses, probability of dead cow and stillbirth. Sensitivity analysis showed that frequency of dystocia incidence was the factor with the largest impact on the costs and economic values for difficult calving. According to population, production and economic parameters valid in 2009, total dystocia costs to Holstein dairy cattle industry were estimated to be Rls 49.1 billions. Results obtained in this study can be helpful to change the attitudes of farmers and their consultants to pay more attention to calving performance and use management and genetic strategies to reduce dystocia incidence.
m. khaldari; a. pakdel; h. mehrbani yeganeh; ardeshir nejati
Abstract
The current study was conducted to investigate the effect of short-term selection in Japanese quail for its 4-week body and breast weights. Two selected lines, one for selection of body weight based upon in. breeding values (line 1) and another for breast weight based on between family selections (line ...
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The current study was conducted to investigate the effect of short-term selection in Japanese quail for its 4-week body and breast weights. Two selected lines, one for selection of body weight based upon in. breeding values (line 1) and another for breast weight based on between family selections (line 2) were randomly selected from a base population. In each generation, 39 sire and 78 dam-birds were taken as parents in each line and for the next generation. The number of selected replacements in line 2 was less due to decreasing population size. Data were collected over 2 consecutive hatches for 4 generations and selections responses determined for 3 generations. The levels of improvement of 4-week body weights in line 1 were recorded 14.4, 12.6 and 8.1 grams respectively for the 3 generations. Correlated response to breast weight in line 1 was 4.1, 3.6, and 3.2 grams in generations 2, 3, and 4, respectively. Directed selection from 4-week breast weight in line 2 led to improvements of: 4.0, 3.5 and 2.7 grams in generations 2, 3 and 4, respectively. Also, correlated responses for body weight in this line were recorded as: 14.5, 13.0 and 7.4 grams in generations 2, 3 and 4, respectively. There were significant differences in body weight and carcass traits between sexes and also in generations 2 and upward (P<0.01) but not for percentage components of carcass. Higher figures were obtained for femals than for males. Selection for 4-week body weights in line 1 and 4-week breast weights in line 2 improved Feed Conversion Ratios (FCR) for about 0.16 and 0.19 units over the selected periods, respectively. Genetic and phenotypic correlations between body and breast weights in line 1 were 0.90±0.12 and 0.73±0.06 and for line 2 they were: 0.85±0.06 and 0.82±0.02, respectively. Results obtained from this study do not support the in-between family selection as a tool to increase breast weight selection as based on body weight, due to its high genetic correlation with body weight (0.85-0.90), can be employed as a proper selection criterion for improving carcass traits, including breast weight.
Mohammad Razmkabir; Mohammad Moradi Shahrbabak; Abbas Pakdel; Ardeshir Nejati Javaremi
Volume 42, Issue 2 , October 2011, , Pages 171-178
Abstract
Test day records of first lactation Holstein cows from 1996 to 2008 were obtained from Animal Breeding Center of Iran and used in this research. Data consisted of 872125 test-day milk records of 95816 cows from 59 herds. (Co)Variance components and genetic parameters were estimated using random regression ...
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Test day records of first lactation Holstein cows from 1996 to 2008 were obtained from Animal Breeding Center of Iran and used in this research. Data consisted of 872125 test-day milk records of 95816 cows from 59 herds. (Co)Variance components and genetic parameters were estimated using random regression model via Gibbs sampling method. Two order Legendre polynomials and third coefficient of Wilmink function were used to describe the lactation curve in genetic and permanent environment levels. The heterogeneity of the residual variance in days 5 to 365 of lactation was modeled using a number of thirty six 10-day intervals. Residual variance was high at the beginning but it was steady and decreased slowly to the end of the lactation. Permanent environmental variance was high at the extremes. The total variance and heritability were affected by the pattern of PE variance. The lowest and highest genetic variances occurred at the beginning and at the end of lactation, respectively. Heritability estimates for daily yields were low in the early lactation and generally ranged from 0.077 to 0.252 for days 5 and 305, respectively. High residual and permanent variances and lower genetic variance were lead to low heritability at the first part of lactation. Genetic correlations were positive and higher than phenotypic ones for all the days in lactation. The lowest genetic correlation was 0.35, between the extremes. Genetic correlations between daily yields decreased with increase in interval between tests. The estimated parameters in this study can be used to predict breeding values for Holstein dairy cattle of Iran.
Heydar Ghiasi; Ardeshir Nejati javaremi; Abbas Pakdel; Hassan Mehrbani yeganeh
Volume 42, Issue 1 , July 2011, , Pages 57-64
Abstract
Economic data and performance records from 10 Iranian Holstein dairy cattle herds, as well as milk production and fertility records from Iranian Center of Animal Breeding and Animal Production Improvment were used to estimate the effect of calving difficulty on milk production, fertility and as well ...
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Economic data and performance records from 10 Iranian Holstein dairy cattle herds, as well as milk production and fertility records from Iranian Center of Animal Breeding and Animal Production Improvment were used to estimate the effect of calving difficulty on milk production, fertility and as well on the economic aspects of maternal and direct calving difficulty. Calving difficulty could be divided into 3 classes. Class 1: normal calving; Class 2: calving that needed help by one man worker, and Class 3: calving with serious damage to calf and mother. Milk production decreased about 46 kg and 323 kg in classes 2, and 3 of the calving difficulty incidences, respectively. Calving difficulty caused decreases in fertility performance by 0.22 more inseminations to be performed in class 2 and 0.35 more ones in class 3. Stillbirth was not affected as by class 2 but was intensified in class 3 by 5 percent. Total economic loss attributed to classes 2 and 3 of calving difficulties were $57.76 and $243.83, respectively. Estimated economic value for maternal and direct effect were $37 per unit change in liability per cow/year. Following a correction of the economic values by cumulative discounted expressions, the economic values for maternal and direct effects amounted to $22.79 for direct, and $8.54 for maternal difficulties.
Homa Arabi; Mohammad Moradi Shahrbabak; Ardeshir Nejati Javaromi
Volume 41, Issue 4 , March 2011, , Pages 373-380
Abstract
In the present research, divergent selection for Japanese quail body weight at four and five weeks of age was performed in five generations to estimate the response to selection and realized heritability. The average body weight was significantly (p
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In the present research, divergent selection for Japanese quail body weight at four and five weeks of age was performed in five generations to estimate the response to selection and realized heritability. The average body weight was significantly (p
Ali Sadeghi Sefidmazgi; Ardeshir Nejati-Javaremi; Mohammad Moradi-Shahrbabak; Seyed Reza Miraei Ashtiani; Peter R AYMER
Volume 42, Issue 3 , January 2011, , Pages 189-197
Abstract
The objective of this study was to assess the Discounted Genetic Expressions (DGEs) for different categories of animal traits as regards Holstein cattle of Iran. Using discounted gene-flow principles, DGEs per calf born were estimated for self replacing females and also for their sires. In the situation ...
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The objective of this study was to assess the Discounted Genetic Expressions (DGEs) for different categories of animal traits as regards Holstein cattle of Iran. Using discounted gene-flow principles, DGEs per calf born were estimated for self replacing females and also for their sires. In the situation for sires of self replacing females, relative GDEs per cow per year for annual cow traits, traits of the calf at birth and slaughter, traits of heifer and traits of cow at culling were estimated as 1, 0.96, 0.4, 0.44 and 0.43, respectively. The respective values for self replacing females were 1, 0.5, 0.21, 0.44 and 0.43, respectively. The effects of different factors on DGEs were quantified using sensitivity analysis. Results obtained in this study provide important information for properly weighting the traits in national selection indexes and as well in conducting cost- benefit analyses of breeding strategies.
MohammadAli Talebi; Seyed Reza Miraei Ashtiani; Mohammad Moradi Shahrbabak; Ardeshir Nejati Javaromi
Volume 41, Issue 3 , December 2010, , Pages 203-210
Abstract
In this study, production, reproduction, managerial, and economic parameters obtained from data recorded for Lori-Bakhtiari flock of sheep (500 heads of breeding ewe) stationed at the sheep's Breeding Station, were employed to determine the relative economic values of and breeding objectives for an annual ...
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In this study, production, reproduction, managerial, and economic parameters obtained from data recorded for Lori-Bakhtiari flock of sheep (500 heads of breeding ewe) stationed at the sheep's Breeding Station, were employed to determine the relative economic values of and breeding objectives for an annual cycle of production, in village system in this breed of sheep. Economic value for a trait was estimated as the level of change in the profit of system as its mean increased by one unit, while the means of other traits being kept constant. The economic values were investigated in three approaches including a included to maximization profit to maximize economic efficiency and to minimize cost. The results show, live weight of (carcass weight) accounted for 94.51% while wool and manure for the remaining 5.49% of the revenue, respectivly. Feeding and management costs represented about 72.28 and 25.94% of total costs, respectively. Relative economic values for conception rate, litter size, mature ewe live weight, weight of wool, lamb survival at 6 months of age, 6-month live weight, carcass lean weight and carcass fat weight at 6 months of age were 60.52, 48.00, -0.05, 1, 56.55, 1.01, 4.61 and -0.92, respectivly for maximization of profit approach. Relative economic values from the three approaches were approximately the same. Litter size, conception rate and ewe live weight were the most important traits in the breeding objectives for ewe in the village system. Lamb survival at 6 months of age, carcass lean and fat weights were the most important traits in the breeding objectives for the lamb in the village system. Estimates of sensitivity analysis of relative economic values to changes in prices of input and output by ?20% indicated that the relative economic values of traits, relative to change in cost of input (feed and management), were of low sensitivity, while relative to change in output (carcass and carcass lean weight) indicated a relatively higher sensitivity.
Abbas Pakdel; Marziyeh Heydari Tabar; Ardeshir Nejati Javaromi
Volume 41, Issue 2 , September 2010
Abstract
The main objective of the present study was to explore the feasibility of nonlinear mixed models to describe the Somatic Cell Score (SCS) lactation curves and to compare the fit of four nonlinear vs. two linear models when applied to SCS lactation records in Iranian Holstein cows. The Animal Breeding ...
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The main objective of the present study was to explore the feasibility of nonlinear mixed models to describe the Somatic Cell Score (SCS) lactation curves and to compare the fit of four nonlinear vs. two linear models when applied to SCS lactation records in Iranian Holstein cows. The Animal Breeding Center of Iran provided the SCC data. The data consisted of 445077 test-day observations from 69124 first to fourth lactation Iranian Holstein cows recorded during the years 2002 to 2007. Six different mathematical functions including Incompelete gama function (Wood), Morant and Gnanasakthy, Ali and Schaeffer function, Wilmink, Rook as well as Nelder functions were fitted to data. The functions were compared based on adjusted R-square and Mean Standard Error (MSE). The results indicated that in the first as well as in the second lactations, Ali and Schaeffer functions described the SCS lactation curve more appropriately than other functions. However in the third and forth lactation, Morant function was better filted than the other five functional forms. Therefore, it can be concluded that the best function is a relative term and depends on the lactation period.
Azadeh Boustan; Mohamad Moradi ShahrBabak; Ardeshir Nejati Javaromi
Volume 41, Issue 1 , May 2010
Abstract
Test day milk records of a Holstein dairy farm collected during years 2004 to 2006 on 142 cows in the 1st lactation vs. 140 cows in the 2nd lactation were used in this research. There were real milk yields of cows available in each part of lactation in this farm making it possible to compare functions ...
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Test day milk records of a Holstein dairy farm collected during years 2004 to 2006 on 142 cows in the 1st lactation vs. 140 cows in the 2nd lactation were used in this research. There were real milk yields of cows available in each part of lactation in this farm making it possible to compare functions based on the new criteria (squared error of estimation). Five functions were compared to estimate production records during each month of lactation, using test day records. These functions were incompelete gama, polynomial regression, inverse polynomial, Wilmink and mixed log function. These functions were compared with third order legender polynomial function for an estimation of total lactation milk yield (305 day milk yield). The criterion for comparing these six functions was the squared error of estimation. Functions were ranked through Quad test on squared error. The first rank in the 1st lactation belonged to incomplete gama function in the 1st, 2nd, 4th, 5th, 8th, and 9th month, polynomial regression function in the 3rd, and 6th month, mixed log function in the 7th month while Wilmink function in the 10th month of lactation. The first rank in the 2nd lactation belonged to incomplete gama function in the 1st, 4th, 5th, 6th, and 9th month, mixed log function in the 7th, and 8th month, while Wilmink function in the the 3rd, and 10th month and polynomial regression function in the 2nd month of lactation. Incomplete gama function won the first rank for estimation of total milk yield (305 day milk yield) in the 1st, 2nd lactation. In the 1st lactation, difference between Incomplete gama function and polynomial regression, third order legender polynomial function and in the 2nd lactation the difference between incomplete gama function and polynomial regression functions were significant.
mehdi eftekhari; kamran rezayazdi; ali nikkhah; ardeshir nejati javaremi
Volume 40, Issue 2 , September 2009
Abstract
Twenty-four Holstein male calves (BW=217±57kg) were employed to evaluate the effects of rapeseed oil supplementation on growth, carcass as well as on meat quality and fatty acid content of longissimus thoracis muscle in a completely randomized design. The calves were divided into three groups and allocated ...
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Twenty-four Holstein male calves (BW=217±57kg) were employed to evaluate the effects of rapeseed oil supplementation on growth, carcass as well as on meat quality and fatty acid content of longissimus thoracis muscle in a completely randomized design. The calves were divided into three groups and allocated to three diets of: a corn/barley-based diet (C); a diet containing 2% (DM basis) rapeseed oil (LC); and one containing 4% (DM basis) rapeseed oil (HC). Feed offered was recorded daily, the calves were weighed monthly and slaughtered after 4 months of trial. The obtained data indicated that dry matter intake was greater for steers fed C diet than for those fed LC and HC (P0.05) in carcass readings except for back fat in which calves fed the HC diet had more back fat as compared to those fed the C diet. There were significant differences observed in meat quality of longissimus thoracis muscle, i. e. the ether extract was significantly increased (P0.05). Fatty acid composition was affected by treatments, Feeding LC and HC diets increased (P
bakhtiyar amini; mohammad moradi shahr babak; ardeshir nejati javaremi; mohammad bagher sayad nejad
Volume 40, Issue 2 , September 2009
Abstract
Adjusted milk yield for 305 days and two milking times along with actual first lactation records of 187138 Holstein cows were used to find out the effect of record adjustment on variance components estimation and on genetic evaluation. Records had been gathered by the Animal Breeding Center of Iran during ...
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Adjusted milk yield for 305 days and two milking times along with actual first lactation records of 187138 Holstein cows were used to find out the effect of record adjustment on variance components estimation and on genetic evaluation. Records had been gathered by the Animal Breeding Center of Iran during years 1991 to 2006. The pedigree file included 288032 animals. A single animal model with Average Information Restricted Maximum Likelihood (AIREML) was employed for data analysis. Milk yield heritability was estimated as 0.24 and 0.23 for adjusted and actual records, respectively. The rank correlations of 0.977, 0.975, and 0.987 were estimated for all, female, and male animals respectively based on the estimated breeding values of adjusted and non-adjusted records. The rank correlations among the 100, 200, 1000, and 2000 top animals were 0.500, 0.377, 0.491, and 0.529 respectively. In general, it could be concluded that adjustment of records tends to incline the breeding value of animals toward the population mean, leading to selection of animals of average breeding value.
heshmat-o-lah bahrami yekdangi; kamran rezayazdi; mehdi dehghan banadaki; ardeshir nejati javaremi
Volume 40, Issue 2 , September 2009
Abstract
The effects of Monesin and propylene glycol on feed intake, milk production, and composition as well as some blood metabolites of 16 primiparous and multiparous Holstein lactating cows (60±30 Days In Milk (DIM), milk production of 33±3 Kg/day) were evaluated. Cows were experimentally in a arranged ...
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The effects of Monesin and propylene glycol on feed intake, milk production, and composition as well as some blood metabolites of 16 primiparous and multiparous Holstein lactating cows (60±30 Days In Milk (DIM), milk production of 33±3 Kg/day) were evaluated. Cows were experimentally in a arranged in a randomized complete block design of: 4 feeding treatments, and 2 blocks of either primiparous or multiparous. They were fed a balanced total mixed ration of 60% concentrate and 40% forages (with or without additives). Cows in group I were fed Total Ixed Ration (TMR) with no additives (control). Cows in group ? were fed TMR with 335 mg/head/day Monensin. Cows in group ? were fed TMR with 400 ml/head/day of propylene glycol, and finally cows in group IV were fed TMR with 335 mg/head/day of monensin and 400 ml/head/day of propylene glycol. Daily milk yield, milk composition and some blood metabolites were recorded. Data were analyzed using mixed models for repeated measurements. The experimental treatments did not affect either feed intake or milk composition, but propylene glycol caused significant increase in cows' milk yield (P
