Estimation of genetic differences between Mashona bulls from different production systems using an animal

1994 ◽  
Vol 122 (3) ◽  
pp. 459-463
Author(s):  
C. T. Khombe ◽  
J. F. Hayes ◽  
H. P. R. Tawonezvi ◽  
M. Khombe
Keyword(s):  
Birth Weight ◽  
Production Systems ◽  
Genetic Differences ◽  
Breeding Value ◽  
Research Station ◽  
Indigenous Cattle ◽  
Smallholder Farms ◽  
Weaning Weight ◽  
Breeding Values ◽  
The Mean

SUMMARYThis paper reports genetic differences between 20 Mashona bulls from smallholder farms, 14 from Makoholi Research Station, three from commercial farms and two reference sires, in Zimbabwe. An animal model, fitted through the derivative free Restricted Maximum Likelihood program (DFREML), was used to analyse 707 birth weight and 623 weaning weight records. Both the mean breeding values of the reference sires and the ranch bulls were significantly (P < 0·05) higher than the mean breeding values of smallholder bulls for birth weight (by 1·6 and 1·7 kg, respectively) and weaning weight (by 10·4 and 11·0 kg, respectively). However, seven of the 20 bulls from smallholder farms were among the top 45% of bulls with high breeding values for both birth and weaning weight. The mean breeding value of bulls from Makoholi was not different from any of the other groups, for all traits studied. It was proposed that future efforts to form nucleus herds to improve the weaning weights of indigenous cattle should include the genetic pool in smallholder farms.

Factors affecting birth weight and performance to weaning of Bunaji calves

1988 ◽  
Vol 111 (2) ◽  
pp. 407-410 ◽  
Author(s):  
O. O. Oni ◽  
V. Buvanendran ◽  
N. I. Dim
Keyword(s):  
Birth Weight ◽  
Beef Cattle ◽  
Beef Cows ◽  
Genetic Differences ◽  
Economic Returns ◽  
Weaning Weight ◽  
Breeding Values ◽  
Factors Affecting ◽  
Sources Of Variation ◽  
And Performance

Birth weight and pre-weaning performance are recognized as important components in determing economic returns from beef cattle. The accuracy of ranking animals based on their breeding values, and hence the effectiveness of selection, will be increased when allowance is made for non-genetic sources of variation. Furthermore, the proper evaluation of identifiable sources of variation in calf weaning weight aids in more accurate appraisal of genetic differences in mothering ability among beef cows.

scholarly journals Estimation of heritability, breeding values and genetic trends for growth traits of exotic goat

2016 ◽  
pp. 7-11 ◽  
Author(s):  
MR Hassan ◽  
S Sultana ◽  
A Iqbal ◽  
MAI Talukder
Keyword(s):  
Body Weight ◽  
Birth Weight ◽  
Variance Components ◽  
Growth Traits ◽  
Live Weight ◽  
Weaning Weight ◽  
Breeding Values ◽  
Goat Farm ◽  
The Mean ◽  
Genetic Trends

The present study was considered to estimate the variance components, heritability and prediction of breeding values (PBV) for important growth traits of exotic goat. Traits were considered birth weight, weaning weight, 6 months weight and weight at 9 months. Data were collected from the goat farm of Bangladesh livestock research institute (BLRI), Savar, Dhaka. Heritability values for the studied traits were estimated by Multivariate animal model using principles of Restricted Maximum Likelihood (REML) procedure. The mean birth weight, weaning weight, 6 and 9 months weight of exotic goat were recorded as 1.41, 7.39, 11.06 and 14.09 kgs respectively. Calculated Heritability values were 0.33, 0.39, 0.45 and 0.32 for the birth weight, weaning weight, and weight at 6 and 9 month respectively. Heritability estimates for different growth traits of exotic goat were found higher but the highest for the 6 month body weight (0.45). Among the live weight categories of exotic goat the maximum average PBV was found for the 6-month body weight (7.42). The genetic trends among the generations in birth and 6 month weight were increased from foundation to generation 1 and 2. Therefore, the results revealed that the 6 month’s body weight can be considered as an indicator of growth and sire selection and could be effective for enhancing growth of exotic kids.International Journal of Natural Sciences (2013), 3(1-4) 7-11

scholarly journals Production systems of swine in the rural areas of Rangamati and Khagrachari districts of Bangladesh

2012 ◽  
Vol 40 (1-2) ◽  
pp. 28-33
Author(s):  
ME Hossain ◽  
S Chakma ◽  
MM Khatun ◽  
M Hasanuzzaman ◽  
MY Miah ◽  
...  
Keyword(s):  
Birth Weight ◽  
Litter Size ◽  
Rural Areas ◽  
Economic Condition ◽  
Production Systems ◽  
Economic Benefits ◽  
Disease Prevalence ◽  
Pig Production ◽  
Average Litter Size ◽  
The Mean

The study was undertaken for a period of 60 days to investigate the production systems of swine in Rangamati and Khagrachari districts, Bangladesh. Production systems, particularly housing, feeding, breeding, disease prevalence, vaccination, bio-security, marketing, socio-economic condition and constraints of pig production were investigated during the study period. It was found that the propensity of rearing pig differed significantly (P<0.01) among the pig owners. Pigs were reared mostly by poor and landless peoples (54.7%) followed by marginal (32.1%), medium (9.4%) and large (3.8%). Rearing systems were also different (P<0.01) and the mean figures were 43.4% for free range, 24.5% for tin shed housing , 20.8% for fencing and 11.3% for girth tethering systems. The average litter size, birth weight, post-weaning weight and weaning period were 9.3, 1.72 kg, 9.0 kg and 40.8 days respectively. Prevalence of diseases differed (P<0.01) and most prevalent diseases were diarrhea (35.8%), coccidiosis (20.8%), pneumonia (17.0%) and hemorrhagic septicemia (13.2%). The economic benefits generated from farming were selling of piglets.DOI: http://dx.doi.org/10.3329/bjas.v40i1-2.10787Bang. J. Anim. Sci. 2011. 40 (1-2): 28-33

scholarly journals Analysis of non-genetic and genetic influences underlying the growth of Kajli lambs

2020 ◽  
Vol 50 (4) ◽  
pp. 613-625
Author(s):  
A. Ali ◽  
K. Javed ◽  
I. Zahoor ◽  
K.M. Anjum
Keyword(s):  
Birth Weight ◽  
Genetic Correlation ◽  
Fixed Effects ◽  
Genetic Correlations ◽  
Breeding Value ◽  
Season Of Birth ◽  
Genetic Trend ◽  
Breeding Values ◽  
Heritability Estimates ◽  
Birth Type

Data on 2931 Kajli lambs, born from 2007 to 2018, were used to quantify environmental and genetic effects on growth performance of Kajli sheep. Traits considered for evaluation were birth weight (BWT), 120-day adjusted weight (120DWT), 180-day adjusted weight (180DWT), 270-day adjusted weight (270DWT), and 365-day adjusted weight (365DWT). Fixed effects of year of birth, season of birth, sex, birth type, and dam age on these traits were evaluated using linear procedures of SAS, 9.1. Similarly, BWT, 120DWT, 180DWT, and 270DWT were used as fixed effects mixed model analyses. Variance components, heritability and breeding values were estimated by restricted maximum likelihood. The genetic trend for each trait was obtained by regression of the estimated breeding values (EBV) on year of birth. Analyses revealed substantial influence of birth year on all traits. Sex and birth type were the significant sources of variation for BWT and 120DWT. Season of birth did not influence birth weight meaningfully, but had a significant role in the expression of 120DWT, 180DWT, and 270DWT. Heritability estimates were generally low (0.003 ± 0.018 to 0.099 ± 0.067) for all traits. With the exception of the genetic correlation of 180DWT and 365DWT, the genetic correlations between trait were strong and positive. Only 365DWT had a positive genetic trend. Although the heritability estimates for almost all weight traits were low, high and positive genetic correlations between BWT and other weight traits suggest that selection based on BWT would result in the improvement of other weight traits as a correlated response.Keywords: bodyweight, breeding value, genetic correlation, sheep

scholarly journals Quantitative traits under selection: derivations of distributions, higher moments, and the effects of recombination

2021 ◽  
Author(s):  
Reginald D Smith
Keyword(s):  
Quantitative Traits ◽  
Exact Formula ◽  
Breeding Value ◽  
Breeding Values ◽  
Mean And Variance ◽  
The Mean ◽  
The Impact ◽  
First Four Moments ◽  
First Time ◽  
Fertile Area

The mathematical theory of quantitative traits is over one hundred years old but it is still a fertile area for research and analysis. However, the effects of selection on a quantitative trait, while well understood for the effects on the mean and variance, have traditionally been difficult to attack from the perspective of analyzing the probability density of the breeding values and deriving higher (third and fourth) moments as well as analyzing the impact of recombination. In this paper, the exact formula for the breeding value distribution after selection is derived and, using new integral tables, the first four moments are given exact expressions for the first time. In addition, the effects of recombination on the full distribution of breeding values are demonstrated. Finally, the changes of GXE covariance in the selected parent population caused by factors similar to the Bulmer Effect are also investigated in detail.

scholarly journals Weaning results of beef Hungarian Fleckvieh calves 2. Genetic parameters, breeding values

2010 ◽  
Vol 53 (1) ◽  
pp. 26-36 ◽  
Author(s):  
S. Bene ◽  
I. Füller ◽  
A. Fördős ◽  
F. Szabó
Keyword(s):  
Genetic Parameters ◽  
Correlation Coefficients ◽  
Breeding Value ◽  
Phenotypic Variance ◽  
Weaning Weight ◽  
Breeding Values ◽  
Estimated Breeding Values ◽  
Genetic Value ◽  
Maternal Heritability ◽  
Daily Gain

Abstract. Weaning weight, preweaning daily gain and 205-day weight of Hungarian Fleckvieh calves (n=8 929, bulls =4 539, heifers =4 390) born from 232 sires between 1980 and 2003 were examined. Variance, covariance components and heritability values and correlation coefficients were estimated. The effect of the maternal permanent environment on genetic parameters and breeding values were examined. Two animal models were used for breeding value estimation. The direct heritability (hd2) of weaning weight, preweaning daily gain and 205-day weight was between 0.37 and 0.42. The maternal heritability (hm2) of these traits was 0.06 and 0.07. The direct-maternal correlations (rdm) were medium and negative −0.52 and −0.74. Contribution of the maternal heritability and maternal permanent environment to phenotype is smaller than that of direct heritabilities (hm2+c2< hd2). The ratio of the variance of maternal permanent environment in the phenotypic variance (c2) changed from 3 to 6 %. Estimated breeding values changed whether the permanent environmental effect of dam wasn’t taken into consideration but the rank of the animals was not modified. The genetic value for weaning results of Hungarian Fleckvieh population has increased since 1997.

scholarly journals Maternal and direct genetic parameters for tail length, tail lesions and growth traits in pigs

2020 ◽  
Author(s):  
Sheila Aikins-Wilson ◽  
Mehdi Bohlouly ◽  
Sven König
Keyword(s):  
Maternal Effects ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Tail Length ◽  
Breeding Value ◽  
Research Station ◽  
Weaning Weight ◽  
Tail Biting ◽  
Breeding Goal ◽  
Positive Direct

Abstract Tail length and tail lesions are major trigger for tail biting in pigs. Against this background, two datasets were analyzed to estimate genetic parameters for tail characteristics and growth traits. Dataset 1 considered measurements for trait tail length (T-LEN) and for the growth traits birth weight (BW), weaning weight (WW), post weaning weight (PWW) and average daily gain (ADG) from 9,348 piglets. Piglets were born in the period from 2015 to 2018, and kept on the university Gießen research station. Dataset 2 included 4,943 binary observations from 1,648 pigs from the birth years 2016 to 2019 for tail lesions (T-LES) as indicators for nail necrosis, tail abnormalities or tail biting. Tail lesions were recorded at 30 ± 7 days after entry for rearing (T-Les-1), at 50 ± 7 days after entry for rearing (end of rearing period, T-LES-2), and 130 ± 20 days after entry for rearing (end of fattening period, T-LES-3). Genetic statistical model evaluation for dataset 1 based on Akaike’s information criterion and likelihood ration tests suggested multiple-trait animal models considering covariances between direct and maternal genetic effects. The direct heritability for T-LEN was 0.42 (±0.03), indicating the potential for genetic selection on short tails. The maternal genetic heritability for T-LEN was 0.05 (±0.04), indicating influence of uterine characteristics on morphological traits. The negative correlation between direct and maternal effects for T-LEN of -0.35 (±0.13), as well as the antagonistic relationships (i.e., positive direct genetic correlations in the range from 0.03 to 0.40) between T-LEN with the growth traits BW, WW, PWW and ADG, complicate selection strategies and breeding goal definitions. The correlations between direct effects for T-LEN and maternal effects for breeding goal traits, and vice versa, were positive, but associated with quite large SE. The heritability for T-LES when considering the three repeated measurements was 0.23 (±0.04) from the linear (repeatability of 0.30) and 0.21 (±0.06) (repeatability of 0.29) from the threshold model. The breeding value correlations between T-LES-3 with breeding values from the repeatability models were quite large (0.74 – 0.90), suggesting trait lesion recording at the end of the rearing period. To understand all genetic mechanisms in detail, ongoing studies are focusing on association analyses between T-LEN and T-LES, and the identification of tail biting from an actor’s perspective.

Heterosis in crossbred hill sheep

1963 ◽  
Vol 5 (3) ◽  
pp. 289-299 ◽  
Author(s):  
H. P. Donald ◽  
J. L. Read ◽  
W. S. Russell
Keyword(s):  
Birth Weight ◽  
The Other ◽  
Weaning Weight ◽  
Bone Length ◽  
The Mean ◽  
Fleece Weight ◽  
Reproductive Characters

SUMMARY1. For ten years purebred Blackface and Swaledale ewes have been kept on a small hill grazing together with first crosses and backcrosses to the Swaledale. The total flock of about 120 ewes was mated and lambed on sown pastures where ewes with twins remained from lambing until weaning. Four new rams (two of each breed) were used each year.2. It is concluded that the Swaledales produced fewer lambs than the other ewes, but these were of greater birth weight (5 %) and cannon bone length (2 %); moreoever, they were better mothers than Blackface (4 %) when rearing singles on hill grazing but not if rearing twins on sown grass.3. Blackface sheep showed greater weights at weaning (5%), at mating (5%), and of fleece (15%) than did pure Swaledales.4. First cross sheep were equal to or slightly superior to the parental mean in birth weight, weaning weight and cannon-bone length. They exceeded the better parent in ewe weight, first fleece weight, and weight of weaned lambs.5. Backcross sheep although not always statistically distinguishable from Swaledale in cannon-bone length and fleece weight or from first cross sheep in reproductive characters tend to confirm the interpretations placed on the relations between the purebred and first cross sheep.6. Heterosis estimated as a superiority of first cross sheep over the mean of the two parental breeds varied from 0% for cannon-bone length to 9·5% for prolificacy of 4-year-old ewes.

scholarly journals Genetic trend for jumping performance in Czech warm-blooded horses

2004 ◽  
Vol 52 (1) ◽  
pp. 97-102
Author(s):  
Iva Jiskrová
Keyword(s):  
Animal Model ◽  
Regression Analysis ◽  
Regression Coefficient ◽  
Breeding Value ◽  
Positive Trend ◽  
Genetic Trend ◽  
Breeding Values ◽  
Jumping Performance ◽  
The Mean ◽  
Estimated Breeding Value

Data on the jumping performance of horses in the period of 1991 - 2002 were analysed. The data included 252781 starts of 10671 horses in 10911 jumping competitions. The performance was characterised on the basis of the obtained bad points (penalties) of the competing horses. The BLUP Animal model was used to estimate the breeding value of the sport horses; the genetic trend in the jumping performance of the Czech warm-blooded horse was assessed on the basis of these results. Regression analysis and calculations of the mean breeding values based on the year of birth were used to determine the dependence of the estimated breeding value on the year of birth. The jumping performance of the population of the Czech warm-blooded horse shows a positive trend. The regression coefficient of –0.1337 shows the genetic trend in the population, which means an increasing jumping performance of the horses expressed in reduced earnings of bad points by 0.1337 in dependence on the year of birth.

Genetic Evaluation of Some Productive Traits in Maraz Goats

2020 ◽  
Vol 23 (2) ◽  
pp. 62-70
Author(s):  
Rabee A. S. Oramari
Keyword(s):  
Birth Weight ◽  
Milk Yield ◽  
Rank Correlation ◽  
Breeding Value ◽  
Model Program ◽  
Milk Traits ◽  
Weaning Weight ◽  
Time To Peak ◽  
Body Weights ◽  
Productive Traits

This study was carriedout at the private project of Maraz goats at Bamerny sub-district/Amadiya district /Duhok governorate/Kurdistan Region of Iraq, and consists of 71 does, 8 bucks, as well as 234, 171 and 162 kids at birth, weaning and six month of age, respectively during two kidding seasons (2015-2016) and (2016- 2017). Milk traits consist of 121 records of each daily (DMY), total (TMY), pre-weaning (PRMY), peak milk yield (PKMY) and time to peak (TPMY), and 120 records of post weaning milk yield (POMY). Animal Model Program for single trait was used to predict the breeding value (PBV) and the real producing ability (RPA) for animals depending on one trait and then these values were ranked in descending order for each sex for selection. Rank correlation was calculated between estimates for both kid body weights and milk yield traits. The average breeding values for sires, dams, male kids and female kids were 0.1322, 0.0845, 0.0369 and 0.0247 kg for birth weight and 0.9877, 0.6804, 2.0072 and -0.6406 kg for weaning weight and 1.4295, 2.0184, 3.0952 and -1.0623 kg for six-month weight, respectively. Rank correlation coefficient (P≤0.001) between the breeding value estimates of birth weight and each of weaning weight and six-month weight were 0.36 and 0.28, respectively and between weaning weight and six-month weight was 0.84. Also the average RPA of 71 dams was estimated depending on their kid body weights at birth, weaning and six-months old were 0.0784, 3.7027 and 4.9492 kg, respectively. Also rank correlations coefficient were estimated between real producing ability of birth weight and each of weaning weight and six-month weight were 0.37 and 0.26, respectively and between weaning weight and SMWT was 0.81. In addition, the average producing ability were estimated for 71 Maraz does depending on their (DMY), (TMY), (PRMY), (PRMY), (PKMY) and (TPMY) were 0.0312, - 7.0378, -3.6234, -2.4199, 0.0477 and 0.2724 kg, respectively. Also rank correlations between real producing ability of all milk traits have been estimated and it was significant except between TPMY and each DMY, PRMY and PKMY, the significant correlation between RPA of milk traits assist to select the best animals and improve the herd genetically.

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