Age of dam and age at measurement adjustments and genetic parameters for scrotal circumference of Canadian Hereford bulls

2003 ◽  
Vol 83 (2) ◽  
pp. 183-188 ◽  
Author(s):  
D. H. Crews Jr. ◽  
D. J. Porteous
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Genetic Parameters ◽  
Heritability Estimate ◽  
Positive Association ◽  
Multiple Trait ◽  
Partial Regression Coefficient ◽  
Scrotal Circumference ◽  
Adjustment Factors ◽  
Quadratic Effects

The objective of the study was to estimate age of dam and age at measurement as adjustment factors for scrotal circumference in Canadian Hereford bulls (n = 9029) and to estimate genetic parameters for scrotal circumference, and birth and yearling weights. Quadratic effects of age at measurement and the interaction of age of dam with age at measurement were not important. Adjustment factors recommended for yearling bulls were 1.02, 0.33, 0.10, and 0.16 cm to adjust scrotal circumference of sons of 2-, 3-, 4-, and ≥ 10-yr-old cows to a mature dam (5 to 9 yr of age) equivalent. The linear partial regression coefficient for age at measurement was 0.036 cm d-1. Genetic parameters were estimated using a multiple trait animal model and REML. The heritability estimate for (age of dam and age at measurement) adjusted scrotal circumference was 0.40 ± 0.03, and heritability estimates were 0.43 ± 0.05, 0.21 ± 0.09, and 0.36 ± 0.03 for direct birth weight, maternal birth weight, and yearling weight, respectively. The genetic correlation of adjusted scrotal circumference with direct birth weight was low (0.15), and was moderate (0.38) with yearling weight, but was near zero (-0.01) with maternal birth weight. Environmental and phenotypic correlations of adjusted scrotal circumference were low with birth weight, and were high with yearling weight. These results indicate that there was a positive association between adjusted scrotal circumference and body weight. Genetic improvement of fertility through the use of adjusted scrotal circumference as an indicator trait would not be expected to be antagonistic to that for body weight. Key words: Beef cattle, fertility, Hereford, scrotal circumference

Estimates of genetic parameters for pre-weaning and post-weaning growth traits of Chios lambs

1980 ◽  
Vol 30 (2) ◽  
pp. 271-276 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Louca ◽  
O. W. Robison
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Correlations ◽  
Heritability Estimate ◽  
Weaning Weight ◽  
Phenotypic Correlations ◽  
Selection For ◽  
Daily Gain

ABSTRACTData on 792 Chios lambs born during the 1972/73 and 1973/74 lambing seasons were used to estimate genetic and phenotypic parameters for birth weight, weaning weight, age at weaning, pre-weaning daily gain, body weight at 5, 10, 15 and 20 weeks of age, and postweaning daily gain. Body weight at 15 weeks of age had the highest heritability estimate (0·73 ± 0·17) and that of post-weaning daily gain was also high (0·56 ± 0·15). Selection for either weight at 15 weeks or post-weaning daily gain would be expected to yield a greater response than selection for pre-weaning daily gain or weaning weight. Genetic correlations among weights and/or gains were positive (approximately 0·20). Phenotypic correlations among weights and gains were generally higher than genetic correlations. However, the correlation between pre— and post-weaning daily gain was small (0·08). Likewise, post-weaning daily gain had low correlations with all weights before 10 weeks. Age at weaning had moderate negative associations with all weights but a very low positive correlation with post-weaning daily gain.

Genetic and phenotypic parameters of body weight and wool production in Iranian Moghani sheep

2005 ◽  
Vol 2005 ◽  
pp. 134-134
Author(s):  
M. Nosrati ◽  
J. Shoja
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Genetic Parameters ◽  
Average Daily Gain ◽  
Random Effect ◽  
Weather Conditions ◽  
Fleece Weight ◽  
Daily Gain ◽  
Meat Type ◽  
Birth Type

In spite of the fact that there are many sheep breeds in Iran, few studies have been established with respect to their economical traits. Moghani sheep is one of the best Iranian meat type breeds with a 5.5 million population. Some specifications of this breed include Resistance to weather conditions, big body size and ability to producing heavy lambs. The aim of this research was to survey the environmental effects and estimates of genetic parameters for birth weight (BW), average daily gain from birth to three mounts of age (ADG1), three months age weight (TRW), average daily gain from three to six months age (ADG2), six months age weight (SIW), nine months age weight (NIW), yearly weight (twelve months age weight or TWW), lamb fleece weight (LFW) and yearly greasy fleece weight in mature sheep (YFW). The effect of birth year, ewe’s gestation period (or age for yearling greasy fleece weight), birth type and sex as fixed effect and sires (nested in years) as random effect on aforesaid traits were studied.

scholarly journals Analysis of environmental and genetic factors in growth characteristics of Balkan goat

2012 ◽  
Vol 28 (2) ◽  
pp. 275-282 ◽  
Author(s):  
V. Caro-Petrovic ◽  
Z. Ilic ◽  
D. Ruzic-Muslic ◽  
M.P. Petrovic ◽  
M.M. Petrovic ◽  
...  
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Environmental Factors ◽  
Genetic Parameters ◽  
Genetic Factors ◽  
Growth Traits ◽  
Growth Characteristics ◽  
The Body ◽  
Goat Breed ◽  
The Impact

Research was conducted on animals of Balkan goat breed. The impact of environmental factors on the weight of kids was analyzed, and also the value of genetic parameters of growth traits of kids to weaning had been examined. The body weight of kids varied depending on the year from 2.27?0.09 kg to 2.43?0.08 kg at birth and 10.81?0.58 kg to 11.13?0.51 kg at weaning. Variations depending on the season, ranged from 2.24?0.09 kg to 2.51?0.05 kg. Sex also had an impact because the male kids had higher weight of 0.12 kg at birth and 0.20 kg at weaning. All differences caused by environmental factors were statistically significant (P<0.01). Single born kids in comparison with twin born kids had higher birth weight by 0.22 kg at birth and 0.37 kg in weaning. The differences were statistically significant (P<0.01). It is a known fact that the increase in litter size influences decrease in body weight of kids. We also found that the weight at birth is associated with body weight at weaning. Heritability for growth traits observed moving in the range of low values from 0.102 ? 0.039 to 0.153 ? 0.041. Repeatability of the observed traits varied from low to medium values in the interval from 0.118 ? 0.030 to 0.528 ? 0025.

Adjusting scrotal circumference of yearling beef bulls in five composites

1996 ◽  
Vol 76 (2) ◽  
pp. 189-191 ◽  
Author(s):  
D. D. Kress ◽  
K. C. Davis ◽  
M. W. Tess
Keyword(s):  
Birth Weight ◽  
Low Birth Weight ◽  
Beef Cattle ◽  
Key Words ◽  
Fixed Effects ◽  
Linear Quadratic ◽  
Scrotal Circumference ◽  
Adjustment Factors ◽  
Significant Regression ◽  
Linear Regressions

Records from five composite strains of beef cattle were used to estimate age of dam and age of bull adjustment factors for scrotal circumference of yearling bulls. Data were obtained from Beefbooster Cattle Alberta Ltd., Calgary, AB. There were 5244 scrotal circumference records on yearling bulls born from 1987 to 1992. M1, M2, and M4 were maternal composites selected primarily for weaning weight, M3 was a terminal composite selected primarily for low birth weight, and TX was a terminal composite selected primarily for feedlot gain. The prominent foundation breeds were Angus for M1, Hereford for M2, various small breeds for M3, Limousin and Gelbvieh for M4, and Charolais for TX. Statistical analyses were performed for each composite separately according to the model that included the fixed effects of herd, year, age of dam and linear (quadratic was not significant) regression on age of bull at measurement. Average age at measurement was 340, 333, 361, 358, and 375 d for M1, M2, M3, M4, and TX, respectively, and range in age was about 100 d for most composites. Age of dam was significant for all composites except M4. Linear regressions on age of bull were 0.0376, 0.0379, 0.0308, 0.0410, and 0.0349 cm d−1 for M1, M2, M3, M4, and TX, respectively. Scrotal circumference of composite bulls should be adjusted additively for age of dam and linearly for age of bull. These adjustments tended to be smaller for age of dam and larger for age of bull than those reported for straighbred or purebred bulls. Key words: Beef cattle, composites, scrotal circumference, adjustment factors

The use of 'bending' in multiple trait selection of Border Leicester - Merino synthetic populations

1986 ◽  
Vol 37 (5) ◽  
pp. 539 ◽  
Author(s):  
B Gunawan ◽  
JW James
Keyword(s):  
Body Weight ◽  
Genetic Parameters ◽  
Genetic Selection ◽  
Positive Definite ◽  
Multiple Trait ◽  
Genetic Covariance ◽  
Synthetic Populations ◽  
Selection Indices ◽  
Genetic Covariances ◽  
Selection Of

The consistency of phenotypic and genetic parameters estimated for various body weight and wool characters in Border Leicester-Merino synthetic populations was investigated by calculating the eigenvalues of matrices of phenotypic covariances (P), genetic covariances (G), and the product of the inverse of the phenotypic with the genetic covariance matrix (P-1G). If these estimates were found to be inconsistent (non-positive definite), the bending technique was applied before genetic selection indices were calculated. In general, the P were positive definite, but the G or P-1G were always non-positive definite. The results suggest that P and G should always be checked carefully before genetic selection indices are calculated. The bending technique was quite effective in giving reasonable results for accuracy of selection.

A genetic analysis of early growth and ultrasonic measurements in hill sheep

1995 ◽  
Vol 61 (1) ◽  
pp. 85-93 ◽  
Author(s):  
J. Conington ◽  
S. C. Bishop ◽  
A. Waterhouse ◽  
G. Simm
Keyword(s):  
Birth Weight ◽  
Genetic Analysis ◽  
Genetic Improvement ◽  
Environmental Effect ◽  
Genetic Parameters ◽  
Heritability Estimate ◽  
Early Growth ◽  
Ultrasonic Measurements ◽  
Lamb Growth ◽  
Improved Pasture

AbstractGenetic parameters were estimated for early lamb growth and ultrasonic measurements taken on Scottish Blackface lambs reared under extensive conditions on two Scottish hill farms. Measurements were taken on approximately 2000 lambs born to unselected ewes, and sired by 32 rams previously selected for divergent predicted carcass lean content. Heritabilities for birth weight, marking iveight (at approx. 6 weeks of age) and weaning weight (at 17 weeks) were 0·07 (s.e. 0·04), 0·02 (s.e. 0·03), and 0·14 (s.e. 0·05), respectively. Heritabilities for ultrasonic muscle and fat depths at weaning were 0·27 (s.e. 0·09) and 0·16 (s.e. 0·06), respectively. There was a strong maternal effect on weight which declined from birth with lamb age and was relatively unimportant for the ultrasonic measurements. The rearing environment of the lambs (hill pasturev.‘improved’ (or ‘inbye’) pasture) was an important environmental effect on the heritability estimate for backfat thickness, with that for lambs reared on improved pasture being twice that of hill-reared lambs. The implications of the results from this work on genetic improvement of sheep in liill environments are discussed.

scholarly journals Comparison of different models for the estimation of genetic parameters of body weight traits in Moghani sheep

2008 ◽  
Vol 19 (3) ◽  
pp. 207 ◽  
Author(s):  
N.G. HOSSEIN-ZADEH ◽  
M. ARDALAN
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Maximum Likelihood ◽  
Animal Models ◽  
Maternal Effects ◽  
Genetic Parameters ◽  
Pedigree Information ◽  
Breeding Station ◽  
Maximum Likelihood Procedure ◽  
Estimation Of Genetic Parameters

Genetic parameters for birth weight (BW), 3-month weight (3MW), 6-month weight (6MW), 9-month weight (9MW) and yearling weight (YW) in Iranian Moghani sheep were estimated using restricted maximum likelihood procedure of MTDFREML program. The data and pedigree information used in this research were collected at the Breeding station of Moghani sheep (Ardebil province, Iran) during 1987–2005. Six different animal models were fitted, differentiated by including or excluding maternal effects, with and without covariance between maternal and direct genetic effects. The estimates for direct heritability ranged from 0.31 to 0.54, 0.21 to 0.34, 0.13 to 0.25, 0.11 to 0.22 and 0.10 to 0.17 for BW, 3MW, 6MW, 9MW and YW, respectively. The estimates were substantially higher when maternal effects, either genetic or environmental, were ignored in the model. The results of this study show that full models with maternal genetic and environmental effects gave the most accurate estimates for body weight traits in Moghani sheep.;

Estimates of genetic parameters of growth rate in sheep with reference to the method of estimation

1968 ◽  
Vol 10 (1) ◽  
pp. 109-112 ◽  
Author(s):  
E. Salah ◽  
E. Galal
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Birth Weight ◽  
Genetic Parameters ◽  
Regression Coefficient ◽  
Research Station ◽  
Phenotypic Correlations ◽  
Genetic And Phenotypic Correlations ◽  
Heritability Estimates ◽  
Desert Research

There were 563 lambs in the study. They were single Barki lambs born during the period 1961–62 to 1965–66 in Ras El-Hekma Desert Research Station (U.A.R.). All lambs were weighed at birth and at weaning. From 1963–64 onward lambs were weighed nearly every 15 days.Two methods of estimating growth rate were compared:R1 = weaning weight — birth weight/age at weaningand R2 = the regression coefficient of weight on age. The effect of method of estimation on heritabilities and genetic and phenotypic correlations was examined.Heritability estimates of birth weight, R1 and genetic and phenotypic correlations between them were 0·18 ± 0·10, 0·24 ± 0·11, 0·50 and 0·12 respectively. From the data collected during the period 1963–64 to 1965–66 alone the heritability estimates of birth weight, R1 and R2 and the genetic and phenotypic correlations between birth weight and each of R1 and R2 were 0·15 ± 0·14, 0·39 ± 0·20 and 0·39 ± 0·20; 0·84 and 0·96; 0·28 and 0·27 respectively.For preweaning growth rate the method of dividing the gain in weight until weaning by age at weaning was virtually as good a method as using the regression of body weight on age. The correlation between the two methods was estimated as 0·91.

Healthy Body Weight may Modify Effect of Abnormal Birth Weight on Metabolic Syndrome in Adolescents

Obesity ◽  
2019 ◽  
Vol 27 (3) ◽  
pp. 462-469
Author(s):  
Bin Dong ◽  
Yan-Hui Dong ◽  
Zhao-Geng Yang ◽  
Xi-Jie Wang ◽  
Zhi-Yong Zou ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Body Weight ◽  
Birth Weight ◽  
Healthy Body Weight ◽  
Modify Effect ◽  
Healthy Body
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