scholarly journals Genetic parameters between slaughter pig efficiency and growth rate of different body tissues estimated by computed tomography in live boars of Landrace and Duroc

animal ◽  
2012 ◽  
Vol 6 (1) ◽  
pp. 9-18 ◽  
Author(s):  
E. Gjerlaug-Enger ◽  
J. Kongsro ◽  
J. Ødegård ◽  
L. Aass ◽  
O. Vangen
Keyword(s):  
Computed Tomography ◽  
Growth Rate ◽  
Genetic Parameters ◽  
Body Tissues

scholarly journals (Co)variance components and genetic parameters for growth rate and Kleiber ratio in fat-tailed Mehraban sheep

2013 ◽  
Vol 56 (1) ◽  
pp. 564-572 ◽  
Author(s):  
F. Ghafouri-Kesbi
Keyword(s):  
Growth Rate ◽  
Variance Components ◽  
Genetic Parameters ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Phenotypic Variance ◽  
Genetic Progress ◽  
Kleiber Ratio ◽  
Derivative Free ◽  
Maternal Heritability

Abstract. The aim of the present study was to estimate (co)variance components and genetic parameters for average daily gain from birth to weaning (ADGa), weaning to 6 months (ADGb), weaning to 9 months (ADGc), 6 months to 9 months (ADGd) and corresponding Kleiber ratios (KRa, KRb, KRc and KRd) in Mehraban sheep. A derivative-free algorithm combined with a series of six univariate 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 (h2) were 0.10, 0.11, 0.16, 0.09, 0.13, 0.13, 0.15 and 0.08 for ADGa, ADGb, ADGc, ADGd, KRa, KRb, KRc and KRd, respectively and indicate that in Mehraban sheep genes contribute very little to the variance of the growth rate and Kleiber ratio. Estimates of maternal heritability (m2) were 0.10, 0.08 and 0.05 for ADGa, KRa and KRb, respectively. Direct additive genetic correlations ranged from −0.32 (KRa-KRd) to 0.99 (ADGb-KRb) and phenotypic correlations ranged from −0.53 (ADGa- ADGd) to 0.99 (ADGa-KRa). Estimates of direct heritability and genetic correlations show that genetic improvement in efficiency of feed utilization through selection programmes is possible, though it would generate a relatively slow genetic progress.

Genetic parameters and responses to selection for pre-weaning growth in suffolk and texel sheep

1995 ◽  
Vol 1995 ◽  
pp. 48-48
Author(s):  
I.W. Purvis ◽  
J.P. Hanrahan
Keyword(s):  
Growth Rate ◽  
Genetic Variation ◽  
Genetic Gain ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Present Report ◽  
Growth Data ◽  
Genetic Trend ◽  
Breeding Objective ◽  
Selection For

In order to evaluate genetic gain in populations under selection it is necessary to be able to partition the observed response into genetic and environmental components. This requires estimates of the appropriate genetic and environmental (co)variances unless appropriate genetic controls are available. Growth rate is an important component of the breeding objective for sheep breeds used as terminal sires and, whereas older estimates of the contribution of genetic variation to differences in preweaning growth indicated heritabilities of the order of 0.1, more recent studies have indicated considerably higher values. The present report concerns analyses of preweaning growth data on purebred Suffolk and Texel sheep to estimate genetic parameters for preweaning growth traits and genetic trend in growth rate from birth to weaning.

Genetic parameters and trends for lean growth rate and its components in U.S. Yorkshire, Duroc, Hampshire, and Landrace pigs1

2002 ◽  
Vol 80 (8) ◽  
pp. 2062-2070 ◽  
Author(s):  
P. Chen ◽  
T. J. Baas ◽  
J. W. Mabry ◽  
J. C. M. Dekkers ◽  
K. J. Koehler
Keyword(s):  
Growth Rate ◽  
Genetic Parameters ◽  
Lean Growth

scholarly journals Effect of iodine deficiency on the reproductive performance of female rats and the viability and growth rate of their progeny

1970 ◽  
Vol 42 (2) ◽  
pp. 137-145
Author(s):  
Vappu Kossila ◽  
Ritva Myllymaa
Keyword(s):  
Growth Rate ◽  
Iodine Deficiency ◽  
Growth Period ◽  
Normal Growth ◽  
The Body ◽  
Female Rats ◽  
Deficient Diet ◽  
Adult Rats ◽  
Commercial Diet ◽  
Body Tissues

The experimental period was apparently too short and the number of rats too small to demonstrate a significant effect of iodine deficiency on some indices of reproduction of the females and the growth rate of their progeny. It was found, however, that iodine deficiency: a) delayed significantly the conception of the second generation females (C2) (Table 3) but was quite ineffective in the first generation females (B1, C1) (Tables 2 & 4), b) did not significantly affect the number of pups dropped or their birth weight, c) increased pup mortality during suckling period, d) tended to decrease the weight of the female sex organs of adult rats (Table 5), e) increased the absolute thyroid weight more rapidly in young growing rats than in old fullgrown rats (Tables 3, 4 & 5), and more rapidly in growing males than females, f) decreased significantly and progressively the PBI level in the serum of adult females which had pregnancies and lactations, g) obviously adversely affected the milk secretion of C1 rats during their second lactation on iodine deficient diet (Experiment II) as judged from the growth rate of their pups during 0—15 days after birth, h) did not adversely affect the growth rate of the suckling offspring of the dams during their first lactation on iodine deficient diet (Tables 3 & 4), i) did not significantly affect the rate of gain of the young rats from weaning up to 60-days of age. The rats transferred from iodine deficient to commercial diet at weaning had larger body weights and smaller thyroids at the age of 60 days than their litter mates remaining on an iodine deficient diet (Table 4). There is of course a possibility that the commercial diet was more palatable than the semisynthetic diet. It is also possible that the iodine deficiency activated the thyroid during the preweaning period and that after the transfer to iodine containing commercial diet at weaning, more thyroxine was secreted from preactivated glands compared to thyroids of the controls or thyroids of the rats kept on an iodine deficident diet throughout the growth period. Thyroid hormones are required for normal growth. A hypothyroid condition favours the accumulation of water and fat into the body tissues and may by this way result in an increase of the body weight. ln this study, however, no attempt was made to estimate the fat content of the body of the experimental rats.

scholarly journals Factors influencing infarct growth including collateral status assessed using computed tomography in acute stroke patients with large artery occlusion

2019 ◽  
Vol 14 (6) ◽  
pp. 603-612 ◽  
Author(s):  
Bin Jiang ◽  
Robyn L Ball ◽  
Patrik Michel ◽  
Ying Li ◽  
Guangming Zhu ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Growth Rate ◽  
Growth Rates ◽  
Artery Occlusion ◽  
Conditional Inference ◽  
Imaging Biomarkers ◽  
Large Artery ◽  
Perfusion Computed Tomography ◽  
Computed Tomography Images ◽  
Head Computed Tomography

In major ischemic stroke caused by a large artery occlusion, neuronal loss varies considerably across individuals without revascularization. This study aims to identify which patient characteristics are most highly associated with this variability. Demographic and clinical information were retrospectively collected on a registry of 878 patients. Imaging biomarkers including Alberta Stroke Program Early CT score, noncontrast head computed tomography infarct volume, perfusion computed tomography infarct core and penumbra, occlusion site, collateral score, and recanalization status were evaluated on the baseline and early follow-up computed tomography images. Infarct growth rates were calculated by dividing infarct volumes by the time elapsed between the computed tomography scan and the symptom onset. Collateral score was graded into four levels (0, 1, 2, and 3) in comparison with the normal side. Correlation of perfusion computed tomography and noncontrast head computed tomography infarct volumes and infarct growth rates were estimated with the nonparametric Spearman's rank correlation. Conditional inference trees were used to identify the clinical and imaging biomarkers that were most highly associated with the infarct growth rate and modified Rankin Scale at 90 days. Two hundred and thirty-two patients met the inclusion criteria for this study. The median infarct growth rates for perfusion computed tomography and noncontrast head computed tomography were 11.2 and 6.2 ml/log(min) in logarithmic model, and 18.9 and 10.4 ml/h in linear model, respectively. Noncontrast head computed tomography and perfusion computed tomography infarct volumes and infarct growth rates were significantly correlated (rho=0.53; P < 0.001). Collateral status was the strongest predictor for infarct growth rates. For collateral=0, the perfusion computed tomography and noncontrast head computed tomography infarct growth rate were 31.56 and 16.86 ml/log(min), respectively. Patients who had collateral >0 and penumbra volumes>92 ml had the lowest predicted perfusion computed tomography infarct growth rates (6.61 ml/log(min)). Collateral status was closely related to the diversity of infarct growth rates, poor collaterals were associated with a faster infarct growth rates and vice versa.

Sign in / Sign up

Export Citation Format

Share Document