Estimation of Genetic Parameters of Body Weight Traits in Ghezel Sheep

Baneh, Hasan; Hafezian, Seyed Hasan; Rashidi, Amir; Gholizadeh, Mohsen; Rahimi, G

doi:10.5713/ajas.2010.90266

Cited by 33 publications

(31 citation statements)

References 32 publications

(50 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Significant variation in body weights of lambs at all ages were found among different birth years and can be attributed to variation in climatic conditions (weather, temperature, moisture etc. ), farmer accessibility to needed feedstuff, and management conditions (Baneh et al 2010). Male lambs were heavier than their female counterpart by 0.20, 2.10, 2.98, 3.58, and 5.69 kg at birth, 3, 6, 9, and 12 months of age, respectively.…”

Section: Environmental Effectsmentioning

confidence: 98%

“…Significant variation in body weights of lambs due to dam age and birth status might be partially explained by differences in uterine capacity, milk production, and mothering ability of ewes at different ages. In addition, effects of litter size are probably explained by the competition for uterine space and capacity during pregnancy and for milk before weaning among multiple-born lambs Baneh et al 2010). Significant effect of various environmental factors on body weight have been reported in several breeds of sheep (EftekhariShahroudi et al 2002;Ozcan et al 2005;Rashidi et al 2008;Baneh et al 2010).…”

Section: Environmental Effectsmentioning

confidence: 99%

“…Nasholm and Danell (1994) observed that when maternal genetic effects are important, but not considered in the statistical model, heritability estimates are biased upward and the realized efficiency of selection is reduced. A number of studies have demonstrated that maternal effects are substantial for growth-related traits in sheep and the inclusion of maternal effects in animal models has an important effect on the estimates of direct heritability (Maria et al 1993;Ozcan et al 2005;Mandal et al 2006;Rashidi et al 2008;Baneh et al 2010). Genetic and environmental relationships between direct and maternal effects for growth have often varied from moderately positive to highly negative in various sheep breeds (Maria et al 1993;Tosh & Kemp 1994;Snyman et al 1995;Nasholm & Danell 1996;Yazdi et al 1997;Notter 1998).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Genetic parameter estimates for growth traits in Iran-Black sheep

Kamjoo

Baneh

Yousefi

et al. 2013

Journal of Applied Animal Research

Self Cite

View full text Add to dashboard Cite

The present study was conducted to estimate variance components and genetic parameters for growth traits of Iran-Black sheep, maintained at the Abbasabad sheep breeding station, located in northeast of Mashhad, (Razavi Khorasan province of Iran) over a period of 24 years (1981 through 2004). Records of 4607 lambs descended from 155 rams, and 1227 ewes were used in the study. Traits included for the present study were birth weight (BW), weaning weight (WW), weight at 6 months (W6), weight at 9 months (W9), and yearling weight (YW). Analyses were carried out by restricted maximum likelihood (REML) fitting an animal model and ignoring or including maternal genetic or permanent environmental effects. Six different animal models were fitted for all traits. The most appropriate model was chosen after testing the improvement of the log-likelihood values. Heritability estimates for weight at birth; weaning; and 6, 9, and 12 months of age were 0.04, 0.14, 0.16, 0.19, and 0.18, respectively. Maternal heritability of body weight declined from 0.33 at birth to 0.04 at six months of age. The maternal permanent environmental component accounted for 6% to 15% to the total variance for all traits under study. The direct-maternal genetic correlation (r am ) was positive for all traits and ranged from 0.3690.27 for BW to 0.9990.98 for YW, but was never significant. The results showed that modest rates of genetic progress appear possible for all weights. Results also suggest that maternal additive effects were only important in early stages of growth, whereas a permanent environmental maternal effect existed at all ages up to 12 months of age, probably as a carry-over effect of maternal influences present at weaning. Direct genetic correlations (r a1,a2 ) between traits were positive and ranged from 0.82 (BW-WW) to 0.99 (W6-YW). The estimates of correlation between permanent environmental maternal effect among traits were close to those of r a1,a2 . Phenotypic and environmental correlations for all traits were generally lower than direct genetic correlations.

show abstract

Section: Environmental Effectsmentioning

confidence: 98%

Section: Environmental Effectsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Genetic parameter estimates for growth traits in Iran-Black sheep

Kamjoo

Baneh

Yousefi

et al. 2013

Journal of Applied Animal Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…In recent years, some published reports demonstrated that one of the maternal effects such as additive maternal genetic and permanent environmental effects (or both) could significantly affect growth traits (Abegaz, 2005;Rashidi et al, 2008;Vatankhah and Talebi, 2008;Baneh et al, 2010). Information about genetic parameters and variance components for growth trait in Arabi sheep is inadequate, and thus, this study was performed to estimate genetic and phenotypic parameters for body weight traits in the Arabi sheep breed.…”

Section: Introductionmentioning

confidence: 99%

“…In order to obtain an optimum rate of genetic progress using selection, it is necessary to have high efficiency selection indices and a reliable heritability coefficient for each trait and genetic correlations among traits. Also, estimation of genetic parameters is critical to achieve maximum genetic improvement, taking the best animal selection schemes into account (Baneh et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

(Co)variance components and genetic parameters for growth traits in Arabi sheep using different animal models

Shokrollahi¹,

Baneh²

2012

Genet. Mol. Res.

View full text Add to dashboard Cite

ABSTRACT. The objective of the present study was to estimate genetic parameters for body weight at different ages in Arabi sheep using data collected from 1999 to 2009. Investigated traits consisted of birth weight (N = 2776), weaning weight (N = 2002) and weight at six months of age (N = 1885). The data were analyzed using restricted maximum likelihood analysis, by fitting univariate and multivariate animal models. All three weight traits were significantly influenced by birth year, sex and birth type. Age of dam only significantly affected birth weight. Log-likelihood ratio tests were conducted to determine the most suitable model for each growth trait in univariate analyses. Direct and total heritability estimates for birth weight, weaning weight and weight at six months of age (based on the best model) were 0.42 and 0.16 (model 4), 0.38 and 0.13 (model 4) and 0.14 and 0.14 (model 1), respectively. Estimation of maternal heritability for birth weight and weaning weight was 0.22 and 0.18, respectively. Genetic and phenotypic correlations among these traits were positive. Phenotypic correlations among traits were low to moderate. Genetic correlations among traits were positive and higher than the corresponding phenotypic correlations. Weaning weight had a strong and significant correlation with weight at six months of age (0.99). We conclude that selection can be made in animals based on weaning weight instead of the present practice of selection based on weight at six months.

show abstract

Investigation in early growth traits, litter size, and lamb survival in two Iranian fat-tailed sheep breeds

Atashi

Izadifard

Zamiri

et al. 2012

Trop Anim Health Prod

View full text Add to dashboard Cite

In the present study, 1,635 lambing records of Ghezel (n=766) and Mehraban (n=869) breeds were used to evaluate the early growth traits, litter size, and lamb survival in sheep reared in Fars Province, southern Iran, during a 5-year-long period. The least squares means (± SE) of lamb birth weight for Ghezel were 5.27 (± 0.22), 5.02 (± 0.22), and 3.98 (± 0.23) kg for single males, single females, and twin lambs, respectively; whereas, the corresponding values for Mehraban were 4.39 (± 0.18), 4.18 (± 0.18), and 3.50 (± 0.19) kg. The least squares means of pre-weaning lamb growth (gram per day) for Ghezel were 239 (± 15), 218 (± 15), and 181 (± 16) for single males, single females, and twin lambs, respectively, and the corresponding values for Mehraban were 204 (± 12), 187 (± 12), and 156 (± 13). Lambs from 2 year old ewes or younger were on average lighter at birth and at weaning and had a lower average daily gain than those from older ewes (P<0.05). The percentage of twin births increased from 1.1 and 1.3 % for ewes aged ≤ 2 years to 19 and 12 % for those aged ≥ 6 years old in Ghezel and Mehraban, respectively (P<0.05). The mean pre-weaning lamb mortality was 7.1 and 4.1 % for Ghezel and Mehraban, respectively.

show abstract

Estimation of Genetic Parameters of Body Weight Traits in Ghezel Sheep

Cited by 33 publications

References 32 publications

Genetic parameter estimates for growth traits in Iran-Black sheep

Genetic parameter estimates for growth traits in Iran-Black sheep

(Co)variance components and genetic parameters for growth traits in Arabi sheep using different animal models

Investigation in early growth traits, litter size, and lamb survival in two Iranian fat-tailed sheep breeds

Contact Info

Product

Resources

About