Genetic parameter estimates of pre-weaning growth traits in Kermani sheep

Rashidi, Amir; Mokhtari, M.S.; Jahanshahi, A.; Abadi, M R Mohammad

doi:10.1016/j.smallrumres.2007.06.004

Cited by 133 publications

(109 citation statements)

References 19 publications

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“…Differences in body weights between sexes may be due to differences in the sexual hormones. This result was in agreement with those reported by Eftekhari-Shahroudi et al (2002) and Rashidi et al (2008). Single-born lambs were heavier than twin-and triplet-born lambs at all ages.…”

Section: Environmental Effectssupporting

confidence: 93%

“…However, El Fadili et al (2000), Abegaz et al (2002), Safari et al (2005), and Savar-Sofla et al (2011) obtained higher estimates (0.10Á0.24) than the present study. Further, our estimate of the proportion of variance associated with permanent environmental maternal effects for weaning weight (c 2 00.15) was similar to the reported estimates of Rashidi et al (2008) in Kermani sheep (0.13), Tosh and Kemp (1994) in Romanov sheep (0.12), and Mandal et al (2008) in Muzaffarnagari sheep (0.10). Lower estimates were reported by Abegaz et al (2005) in Horro sheep (0.06), Ozcan et al (2005) in Merino sheep (0.08), and Matika et al (2003) in Sabi sheep (0.07) as compared to the present findings.…”

Section: Weaning Weightsupporting

confidence: 85%

“…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%

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Genetic parameter estimates for growth traits in Iran-Black sheep

Kamjoo

Baneh

Yousefi

et al. 2013

Journal of Applied Animal Research

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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.

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Section: Environmental Effectssupporting

confidence: 93%

Section: Weaning Weightsupporting

confidence: 85%

Section: Environmental Effectsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Genetic parameter estimates for growth traits in Iran-Black sheep

Kamjoo

Baneh

Yousefi

et al. 2013

Journal of Applied Animal Research

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“…Several authors found influence of the type of birth on lamb performance, in which the ones born from single birth presented greater performance than the ones born from twin birth (Rashidi et al, 2008;Rocha et al, 2009;Mohammadi et al, 2010). The explanation for this fact is the nonexistence of intrauterine competition or competition for food (maternal milk) in single-birth lambs (Barros et al, 2005).…”

Section: Resultsmentioning

confidence: 99%

Effect of environmental factors on performance of purebred and crossbred Santa Inês lambs from birth to 154 days of age

Koritiaki¹,

Ribeiro²,

Mizubuti³

et al. 2013

R. Bras. Zootec.

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-The objectives of this study were to evaluate the environmental effects (age of dam at lambing, type of birth and sex of lamb) and genetic groups (Santa Inês and ½ Santa Inês) on weight and morphometric measurements (heart girth, body length and height) of lambs; to test linear and allometric regressions to predict the weight through the measurements; and to describe the type of growth of the measurements from weight. Weight and morphometric measurements were sampled from birth to 154 days of age, at every 14 days. For the evaluation of the environmental factors and to predict the regressions the data of birth, weaning and 154 days of age were used; and to determine the type of growth all the data collected were used. The lambs derived from younger (two-tooth) ewes recorded lower averages than the ones from eighttooth ewes for weight, heart girth and body length at birth and length at weaning. The animals born from single births presented higher average weight from birth to weaning, as well as of all the measurements from birth to 154 days of age than those from twin births. There was no difference between the genetic groups Santa Inês and ½ Santa Inês. The correlations between the weight and measurements were significant, and it was possible to predict the weight from the morphometric measurements through regressions. The type of weight gain with heart girth was isometric, while with length it was positive allometric, and with height it was negative allometric. Thereby, in the absence of a scale it is possible to predict the weight from the morphometric measurements, and the type of birth is the most important factor that affects the development of lambs from birth to weaning.

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Association between growth hormone gene polymorphism and some growth traits in Akkaraman and Anatolian Merino sheep

Tanış,

Keskin

2024

Mol Biol Rep

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Genetic parameter estimates of pre-weaning growth traits in Kermani sheep

Cited by 133 publications

References 19 publications

Genetic parameter estimates for growth traits in Iran-Black sheep

Genetic parameter estimates for growth traits in Iran-Black sheep

Effect of environmental factors on performance of purebred and crossbred Santa Inês lambs from birth to 154 days of age

Association between growth hormone gene polymorphism and some growth traits in Akkaraman and Anatolian Merino sheep

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