Hasan Baneh

Bio: Hasan Baneh is an academic researcher from Islamic Azad University. The author has contributed to research in topics: Heritability & Genetic correlation. The author has an hindex of 11, co-authored 25 publications receiving 275 citations.

Genetic analysis of growth rate and Kleiber ratio in Zandi sheep

Abstract: Genetic parameters for average daily gain from birth to weaning (ADGa), birth to 6 months (ADGb), weaning to 6 months (ADGc), weaning to yearling age (ADGd), and corresponding Kleiber ratios (KRa, KRb, KRc, and KRd) were estimated by using records of 3,533 Zandi lambs, descendent of 163 sires and 1265 dams, born between 1991 and 2005 at the Zandi Sheep Breeding Station at Khojir National Park, Tehran, Iran. A derivative-free algorithm combined with a series of six single-trait linear animal models was used to estimate phenotypic variance and its direct, maternal, and residual components. In addition, bivariate analyses were done to estimate (co)variance components between traits. Estimates of direct heritability (h 2 ) were 0.11, 0.15, 0.09, 0.10, 0.10, 0.10, 0.06, and 0.07 for ADGa, ADGb, ADGc, ADGd, KRa, KRb, KRc, and KRd, respectively, thereby indicating the presence of low additive genetic variation for growth rate and Kleiber ratio in this population of Zandi sheep. Maternal genetic component was found to be significant on ADGa and KRa and contributed 3% and 5%, respectively, in total phenotypic variance of ADGa and KRa. A widespread range of genetic correlations among traits studied was observed. Except for negative genetic correlations between ADGa and KRc, ADGa and KRd, and between KRa and KRc, in other cases, genetic correlations were positive and moderate to very high. Phenotypic correlations ranged from −0.49 (ADGa/KRd) to 0.94 (ADGc/KRc). These results indicate that selecting for improved growth rate or Kleiber ratio in Zandi sheep would generate a relatively slow genetic progress.

Effects of environmental factors on growth traits in Ghezel sheep

Abstract: The present study was carried out to study the effects of environmental factors on growth traits in Ghezel sheep breed. Growth related data (birth weight, weaning weight, month 6 weight, average daily gain from birth to weaning and weaning to month 6) were collected from lambs that have been born during 1994 - 2006 at Ghezel sheep breeding station in west Azerbaijan and data was analyzed using SAS software. The birth year and herd had a significant effect on all traits (P < 0.01) while the effect of birth type significantly (P < 0.01) affected all traits except birth weight and daily gain from birth to weaning periods. The lamb's sex had a significant effect on all traits except daily gain from weaning to month 6 weight periods. The effect of dam’s age had a significant effect only on daily gain from weaning to month 6 weight periods. The interactions between birth year and lamb’s sex, birth year and birth type, birth year and herd, lamb's sex and herd and also dam's age and herd were significantly affected on all traits (P < 0.01). The interactions between lamb’s sex and dam's age and birth type and dam's age significantly affected weight of birth, daily gain from birth to weaning period and month 6 ages, respectively (P < 0.05). In all ages, the male and single lambs were heavier than female and twin lambs. Results showed that environmental factors have an important role in expressing of genetic potential in the lambs.

Estimation of genetic parameters for body weight at different ages in Mehraban sheep

Abstract: The objective of the present study is to estimate genetic parameters of birth weight (BW, n = 3005), weaning weight (WW, n = 2800), 6 months weight (6 MW, n = 2600), 9 months weight (9 MW, n = 1990) and yearling weight (YW, n = 1450) of Mehraban sheep, collected during 1995 - 2007 at Mehraban sheep Breeding Station in Hamedan province, Iran. (Co)variance components and genetic parameters were estimated with univariate and multivariate animal model using restricted maximum likelihood (REML) procedure. Effect of herd, lamb's sex, and year of birth were significant on all traits (P < 0.05). The estimates of direct heritability for BW, WW, 6MW, 9MW and YW were 0.30±0.05, 0.30±0.04, 0.35±0.05, 0.37±0.04 and 0.43±0.04 respectively. Maternal heritability estimates for mentioned traits were 0.17±0.03, 0.18±0.03, 0.14±0.03, 0.12±0.03 and 0.10±0.02, respectively. The estimates of the direct genetic correlation between BW-WW, BW-6MW, BW-9MW, BW-YW, WW-6MW, WW-9MW, WW-YW, 6MW-9MW, 6MW-YW and 9MW-YW were 0.287±0.09, 0.305±0.09, 0.249±0.03, 0.136±0.07, 0.825±0.34, 0.713±0.05, 0.845±0.52, 0.862±0.06, 0.596±0.09 and 0.712±0.02 respectively. The estimates of the phenotypic correlation between traits were positive and ranged from 0.152 for BW-9MW to 0.835 for 9MW-YW. Key words : Mehraban sheep, heritability, genetic correlation, body weight traits.

Estimation of Genetic Parameters of Body Weight Traits in Ghezel Sheep

Abstract: The present study was carried out to estimate genetic parameters for body weight traits in Ghezel sheep. The data set used was records of 9,221 lambs from 180 sires and 5,060 dams for birth weight (BW), 7,206 lambs from 167 sires and 4,497 dams for weaning weight (WW) and 6,112 lambs from 157 sires and 3,841 dams for 6-months weight (6 MW), which were collected from 1999 to 2007 (9-years) at Ghezel sheep Breeding Station in west Azarbaijan. Variance components and corresponding genetic parameters were obtained with univariate analyses fitting animal models using restricted maximum likelihood (REML) methods. The most suitable model for each trait was determined based on log likelihood ratio tests. Birth year, lamb gender, type of birth, age of dam and herd were significant sources of variation on BW, WW and 6 MW (p<0.01). Direct estimate of heritability for BW, WW and 6 MW was 0.24, 0.29 and 0.37, respectively. The estimate of maternal permanent environmental variance as a proportion of phenotypic variance was 0.09 and 0.05 for BW and WW, respectively. The results of this study showed that genetic progress for growth traits is possible by selection.

How Depressing Is Inbreeding? A Meta-Analysis of 30 Years of Research on the Effects of Inbreeding in Livestock

Abstract: Inbreeding depression has been widely documented for livestock and other animal and plant populations. Inbreeding is generally expected to have a stronger unfavorable effect on fitness traits than on other traits. Traditionally, the degree of inbreeding depression in livestock has been estimated as the slope of the linear regression of phenotypic values on pedigree-based inbreeding coefficients. With the increasing availability of SNP-data, pedigree inbreeding can now be replaced by SNP-based measures. We performed a meta-analysis of 154 studies, published from 1990 to 2020 on seven livestock species, and compared the degree of inbreeding depression (1) across different trait groups, and (2) across different pedigree-based and SNP-based measures of inbreeding. Across all studies and traits, a 1% increase in pedigree inbreeding was associated with a median decrease in phenotypic value of 0.13% of a trait’s mean, or 0.59% of a trait’s standard deviation. Inbreeding had an unfavorable effect on all sorts of traits and there was no evidence for a stronger effect on primary fitness traits (e.g., reproduction/survival traits) than on other traits (e.g., production traits or morphological traits). p-values of inbreeding depression estimates were smaller for SNP-based inbreeding measures than for pedigree inbreeding, suggesting more power for SNP-based measures. There were no consistent differences in p-values for percentage of homozygous SNPs, inbreeding based on runs of homozygosity (ROH) or inbreeding based on a genomic relationship matrix. The number of studies that directly compares these different measures, however, is limited and comparisons are furthermore complicated by differences in scale and arbitrary definitions of particularly ROH-based inbreeding. To facilitate comparisons across studies in future, we provide the dataset with inbreeding depression estimates of 154 studies and stress the importance of always reporting detailed information (on traits, inbreeding coefficients, and models used) along with inbreeding depression estimates.

Estimation of genetic parameters for body weight at different ages in Mehraban sheep

Abstract: The objective of the present study is to estimate genetic parameters of birth weight (BW, n = 3005), weaning weight (WW, n = 2800), 6 months weight (6 MW, n = 2600), 9 months weight (9 MW, n = 1990) and yearling weight (YW, n = 1450) of Mehraban sheep, collected during 1995 - 2007 at Mehraban sheep Breeding Station in Hamedan province, Iran. (Co)variance components and genetic parameters were estimated with univariate and multivariate animal model using restricted maximum likelihood (REML) procedure. Effect of herd, lamb's sex, and year of birth were significant on all traits (P < 0.05). The estimates of direct heritability for BW, WW, 6MW, 9MW and YW were 0.30±0.05, 0.30±0.04, 0.35±0.05, 0.37±0.04 and 0.43±0.04 respectively. Maternal heritability estimates for mentioned traits were 0.17±0.03, 0.18±0.03, 0.14±0.03, 0.12±0.03 and 0.10±0.02, respectively. The estimates of the direct genetic correlation between BW-WW, BW-6MW, BW-9MW, BW-YW, WW-6MW, WW-9MW, WW-YW, 6MW-9MW, 6MW-YW and 9MW-YW were 0.287±0.09, 0.305±0.09, 0.249±0.03, 0.136±0.07, 0.825±0.34, 0.713±0.05, 0.845±0.52, 0.862±0.06, 0.596±0.09 and 0.712±0.02 respectively. The estimates of the phenotypic correlation between traits were positive and ranged from 0.152 for BW-9MW to 0.835 for 9MW-YW. Key words : Mehraban sheep, heritability, genetic correlation, body weight traits.

Genetic Analysis of Pre-weaning and Post-weaning Growth Traits of Mecheri Sheep under Dry Land Farming Conditions

Abstract: Data on 2,365 Mecheri sheep (1,201 males and 1,164 females), maintained at the Mecheri Sheep Research Station, Pottaneri, India, and recorded between 1979 and 2006, were analysed to study the growth related traits and their genetic control. The body weights at different ages (i.e. at birth, weaning (3 months), 6, 9 and 12 months) were recorded and collected from the birth and growth registers maintained in the farm. The average weights of Mecheri sheep at birth, and at 12 months of age were 2.24±0 .01 and 16.81±0.15 kg respectively. The pre- and post-weaning average daily weight gains were 63.84±0.75 and 29.52±0.43 g respectively. Study revealed a significant difference with the period of lambing on body weight, weight gain and efficiency in weight gain at different stages of growth. Males were heavier and had a higher weight gain than females at almost all stages of growth and the differences tended to increase with age. The direct heritability estimates increased from birth to six months of age and then decreased. The direct heritabilities of all body weights at different stages of growth were low to moderate in magnitude and the values at birth, weaning, six, nine and 12 months of age were 0.08, 0.17, 0.21, 0.13 and 0.10 respectively. For the estimation of heritability at birth and three months body weights, the direct additive genetic and maternal additive genetic effects have to be taken into account and for the estimation of six months weight, the direct additive genetic and maternal permanent environmental effects have to be included in the model. The estimates of heritability, phenotypic and genetic correlations among the different body weights indicated that the selection for improving the body weights at different traits should be done on the basis of three or six months weight because of higher heritability estimates and