scholarly journals GENETIC ASPECTS OF PREWEANING PERFORMANCE OF NDAMA CATTLE

2021 ◽  
Vol 11 (2) ◽  
pp. 151-155
Author(s):  
A. O. Leigh ◽  
O. Akinokun ◽  
S. A. Adeyanju

Records on birth weight (BW), preweaning daily gain (PWG) and weaning weight (WW) of Ndama beef cattle were obtained from the Fashola Livestock Farm in Oyo State of Nigeria between 1954 and 1964 and were analyzed to estimate the phenotypic and genetic parameters of preweaning performances of this breed of cattle. For birth weight, preweaning daily gain and weaning weight respectively heritability was estimated as 0.13 ± 0.08, 0.30 ± 0.14 and 0.25 ± 0.12 from paternal half-sib relationship. The estimates of genetic and phenotypic correlations obtained from these data among the three pre-weaning traits were found to be similar to those already in the general literature on beef cattle.

1980 ◽  
Vol 30 (2) ◽  
pp. 271-276 ◽  
Author(s):  
A. P. Mavrogenis ◽  
A. Louca ◽  
O. W. Robison

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.


2012 ◽  
Vol 34 (3) ◽  
pp. 138
Author(s):  
Veronika Yuneriati Beyleto ◽  
Sumadi (Sumadi) ◽  
Tety Hartatik

<p>This research was conducted to estimate heritability, repeatability and genetic correlation values on growth traits of Boerawa goat at Sumber Rejeki farmer group at Campang Village, Gisting District and Karya Makmur I and Karya Makmur II farmer group at Wonoharjo and Sukoharjo Village, Sumber Rejo District, Tanggamus regency, Lampung province. Data consisted of production record and 238 Boerawa goat derived from 93 PE and 7 Boer buck.<br />The research was started on October 30, 2009 up to January 30, 2010. The results indicated that heritability value of birth weight, weaning weight, yearling weigth, average of preweaning daily gain, and average of postweaning weight<br />analyzed by paternal half-sibs correlation were 0.80±0.40; 0.30±0.17; 0.80±0.04; 0.32±0.18 and 0.30±0.17, respectively. The repeatability values of birth weight, weaning weight and yearling weight analyzed based on two<br />recording per every dam were 0.42±0.07; 0.32±0.08; 0.30±0.08; 0.30±0.08 and 0.53±0.06. The genetic correlation values among birth weight and weaning weight, birth weight and yearling weight, weaning weight and yearling weight,<br />average of preweaning weight and postweaning weight daily gain analyzed by paternal half-sibs correlation were 0.50±0.04; 0.44±0.08; 0.21±0.03 and 0.20±0.05, respectively. The result also indicated that the heritability and<br />repeatability values was high and the genetic correlation values were moderate to high.</p><p>(Key words: Boerawa goat, Genetic parameter, Growth character)</p>


2007 ◽  
Vol 2007 ◽  
pp. 71-71
Author(s):  
Mojtaba Hosseinpour Mashhadi ◽  
Mehdi Aminafshar ◽  
Nafise Tabasi

Baluchi is the most common native breed of sheep in Iran, comprising 30% of the sheep population. This breed is native to the eastern part of the country, which has a dry and hot climate. The animals have had to adapt to the harsh environment. In order to improve efficiency, the performance of the animals for economic traits is used to estimate genetic parameters and selection in some nucleus flocks. The genetic and phenotypic correlations between weight traits have been reported for different breeds. The objective of this investigation is to estimate the genetic parameter and genetic and phenotypic correlations between weight traits.


1975 ◽  
Vol 55 (4) ◽  
pp. 503-507 ◽  
Author(s):  
B. W. KENNEDY ◽  
C. R. HENDERSON

Canadian Record of Performance for Beef Cattle data were used to estimate genetic, environmental and phenotypic correlations between pairs of four calf growth traits: weaning weight, preweaning average daily gain (ADG), yearling weight and postweaning ADG. A total of 61,688 Hereford and 22,333 Aberdeen Angus records were studied. Average genetic, environmental and phenotypic correlation estimates, in that order, for the following growth trait combinations were:.997,.974 and.979 for weaning weight and preweaning ADG;.801,.709 and.726 for weaning weight and yearling weight;.784,.692 and.706 for preweaning ADG and yearling weight;.516, −.143 and.104 for weaning weight and postweaning ADG;.494, −.142 and.094 for preweaning ADG and postweaning ADG; and.875,.595 and.741 for yearling weight and postweaning ADG.


2021 ◽  
Author(s):  
Rostam Abdollahi Arpanahi ◽  
Daniela Lourenco ◽  
Ignacy Misztal

Genomic selection has been adopted nationally and internationally in different livestock and plant species. However, understanding whether genomic selection has been effective or not is an essential question for both industry and academia. Once genomic evaluation started being used, estimation of breeding values with pedigree BLUP became biased because this method does not consider selection using genomic information. Hence, the effective start point of genomic selection can be detected in two possible ways including the divergence of genetic trends and Realized Mendelian sampling (RMS) trends obtained with BLUP and Single-step genomic BLUP (ssGBLUP). This study aimed to find the start date of genomic selection for a set of economically important traits in three livestock species by comparing trends obtained using BLUP and ssGBLUP. For this purpose, three datasets comprised a pig dataset with 117k genotypes and 1.3M animals in pedigree, Angus cattle dataset consisted of ~842k genotypes and 11.5M animals in pedigree, and a purebred broiler chicken dataset included ~154k genotypes and 1.3M birds in pedigree were used. The genetic trends for pigs diverged for the genotyped animals born in 2014 for average daily gain and backfat. In beef cattle, the trends started diverging in 2009 for weaning weight and in 2016 for postweaning gain, with little diverging for birth weight. In broiler chickens, the genetic trends estimated by ssGBLUP and BLUP diverged at breeding cycle 6 for two out of three production traits. The RMS trends for the genotyped pigs diverged for animals born in 2014, more for average daily gain than for backfat. In beef cattle, the RMS trends started diverging in 2009 for weaning weight and in 2016 for postweaning gain, with a trivial trend for birth weight. In broiler chickens, the RMS trends from ssGBLUP and BLUP diverged strongly for two production traits at breeding cycle 6, with a slight divergence for another trait. Divergence of the genetic trends from ssGBLUP and BLUP indicates onset of the genomic selection. Presence of trends for RMS indicates selective genotyping, with or without the genomic selection. The onset of genomic selection and genotyping strategies agree with industry practices across the 3 species. In summary, the effective start of genomic selection can be detected by the divergence between genetic and RMS trends from BLUP and ssGBLUP.


2021 ◽  
Vol 19 ◽  
pp. 64-69
Author(s):  
I. K Odubote ◽  
B. Somade

Data on 260 litters were used to provide therefore to estimate the heritability and estimates of heritability, repeatability, genetic and phenotypic correlations for litter traits at birth and at weaning. Breed, sire within breed and doe within sire effects were found to be significant, (P<0.05) for litter size at birth and at weaning and for litter weight at birth and at weaning. Heritability estimates of 0.33±0.08, 0.38±0.02, 0.03±0.02 and 0.16±0.05 were obtained for litter birth weight, litter size at birth, litter size at weaning and litter weaning weight, respectively. Repeatability estimates were found to be generally moderate to high. Genetic and phenotypic correlations were positive and significant (P<0.01). Selection for litter size at birth and litter birth weight are likely to result in improved litter size at weaning and litter weaning weight respectively.


2021 ◽  
Vol 3 (2) ◽  
pp. 117-123
Author(s):  
S. A. Adeyanju ◽  
O. Akinokun ◽  
O. O. Ariyibi

Data on birth weight, preweaning daily rate of gain and weaning weight of Ndama beef cattle were obtained from routine records kept on the Fashola Livestock Farm between 1959 and 1964 and subjected to least-squares analysis to determine the effects of sex, month, year and sire on the performance characteristics. The results indicated that the Ndama weighed 16.95 kg at birth and 97.61 kg at weaning when adjusted to 205 days with a preweaning daily weigh gain of 0.38 kg. The bulls were significantly heavier at birth and weaning and also had a significantly higher preweaning daily weight gain than the heifers. Birth weight, preweaning daily rate of gain, and weaning weight showed significant sex, month, year and sire effects


1968 ◽  
Vol 10 (1) ◽  
pp. 109-112 ◽  
Author(s):  
E. Salah ◽  
E. Galal

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.


2001 ◽  
Vol 137 (3) ◽  
pp. 365-371 ◽  
Author(s):  
S. A. AL-SHOREPY

Genetic parameters were estimated for purebred and crossbred lambs of a local breed using a single trait animal model. The traits recorded were: birth weight (BWT), weight at 30 days (WT30), weaning weight (WWT), average daily gain from 1 to 30 days (ADG1) and average daily gain from 30 to 90 days (ADG2). Five different animal models were fitted for each trait; all including additive direct genetic variance and various combinations of additive maternal and environmental maternal effects. The most appropriate model was chosen based on likelihood ratio tests. Additive maternal and permanent environmental effects were important (P < 0·05) for birth weight in purebred and crossbred lambs, when compared with a model containing only additive direct effects. Inclusion of maternal permanent environmental effects provided a better fit (P < 0·05) for weaning weight in purebred lambs than a model containing only additive direct effects. Estimates of heritability from the model containing additive direct, maternal effects and maternal permanent environmental effects, but not additive direct-maternal correlation, for combined purebred and crossbred lambs were 0·32 for BWT, 0·19 for WT30, 0·24 for WWT, 0·26 for ADG1 and 0·12 for ADG2. Estimates of additive maternal and maternal permanent environmental variances, respectively, as a proportion of phenotypic variance were 0·06 and 0·07 for BWT, 0·05 and 0·02 for WT30, 0·02 and 0·03 for WWT, 0·03 and 0·05 for ADG1 and 0·00 and 0·03 for ADG2. Estimates of direct-maternal correlation in subsequent analyses were significant and ranged from −0·16 to −0·95 for live weights and from −0·73 to −1·0 for daily gains. However, the very large negative correlations probably resulted from undefined non-genetic covariances as well as possible antagonistic genetic effects. These results indicate that it would be possible to improve growth traits in a local sheep breed through genetic selection.


Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1409-1416 ◽  
Author(s):  
Kenneth R Koots ◽  
John P Gibson

Abstract A data set of 1572 heritability estimates and 1015 pairs of genetic and phenotypic correlation estimates, constructed from a survey of published beef cattle genetic parameter estimates, provided a rare opportunity to study realized sampling variances of genetic parameter estimates. The distribution of both heritability estimates and genetic correlation estimates, when plotted against estimated accuracy, was consistent with random error variance being some three times the sampling variance predicted from standard formulae. This result was consistent with the observation that the variance of estimates of heritabilities and genetic correlations between populations were about four times the predicted sampling variance, suggesting few real differences in genetic parameters between populations. Except where there was a strong biological or statistical expectation of a difference, there was little evidence for differences between genetic and phenotypic correlations for most trait combinations or for differences in genetic correlations between populations. These results suggest that, even for controlled populations, estimating genetic parameters specific to a given population is less useful than commonly believed. A serendipitous discovery was that, in the standard formula for theoretical standard error of a genetic correlation estimate, the heritabilities refer to the estimated values and not, as seems generally assumed, the true population values.


Sign in / Sign up

Export Citation Format

Share Document