scholarly journals Direct and Maternal Genetic Trends for Some Productive and Reproductive Traits in Egyptian Buffaloes

2020 ◽  
Vol 25 (1) ◽  
pp. 1
Author(s):  
Ibrahim Abu El- Naser
Keyword(s):  
Genetic Correlations ◽  
Reproductive Traits ◽  
Breeding Value ◽  
Lactation Period ◽  
Production Research ◽  
Days Open ◽  
Productive Traits ◽  
Set Up ◽  
Maternal Heritability ◽  
Daily Milk

This study was done to determine the direct and maternal genetic and phenotypic trends for productive traits such as first lactation milk yield (FLMY, kg), first lactation period (FLP, d) and first lactation daily milk (FLDM, kg), and reproductive traits such as age at first calving (AFC, mo), First days open (FDO, d) and first calving interval (FCI, d). Data were collected over consecutive 25 years (1991 to 2015) of 1104 first lactation of 135 sires and 482 dams maintained at Mahallet Mousa farms of Animal Production Research Institute. Data were analyzed by Animal model to determine genetic parameters for studied traits. Means of FLMY, FLP, FLDM, AFC, FDO and FCI were 1546.5kg, 189d, 7.9kg, 37.9mo, 120.8d and 428d, respectively. The direct heritability (h2a) for same traits were 0.25, 0.18, 0.24, 0.45, 0.18 and 0.19, respectively. Corresponding maternal heritability (h2m) for mentioned traits was 0.12, 0.19, 0.22, 0.25, 0.12 and 0.12, respectively. Genetic correlations (rg) among studied traits were varied between -0.19 to 0.38. Accuracy of predicted breeding value varied between 69 to 94, 0.37 to 94 and 42 to 91% for FLMY, FLP, FLDM, AFC, FDO and FCI of sires, cows and dams, respectively that revealed the genetic improvement could be actualized through each of cows or sires or dams. Additive and maternal genetic, permanent environmental and phenotypic trends were not significant for all studied traits. It indicated that it is important to set up a plan to improve genetic and environmental conditions thus, increasing productivity and realization of high profitability.

scholarly journals A comparison between different selection indices for some productive traits on Egyptian buffaloes

2009 ◽  
Vol 52 (5) ◽  
pp. 476-484 ◽  
Author(s):  
K. A. M. Mourad ◽  
A. S. Khattab
Keyword(s):  
Animal Model ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Lactation Period ◽  
Environmental Correlations ◽  
Selection Indices ◽  
Total Milk ◽  
Production Research ◽  
Productive Traits

Abstract. A total of 2 262 normal lactation records of Egyptian buffaloes kept at Mehallet Mousa Farm belonging to Animal Production Research Institute, Ministry of Agriculture during the period from 1985 to 2003 were used to estimate phenotypic and genetic parameters for total milk yield (TMY, kg), lactation period (LP, day), birth weight (BW, kg) and weaning weight (WW, kg). In addition, eleven selection indices were constructed. Data were analyzed using multi trait animal model (MTAM). The model included individuals, permanent environmental and errors as random effects, month and year of calving and parity as fixed effects. Heritability estimates were 0.172, 0.134, 0.046 and 0.257 for TMY, LP, BW and WW, respectively. Genetic correlations among all traits studied are positive highly significant and ranged from 0.50 to 0.99. Permanent and temporary environmental correlations among all traits studied are similar to genetic correlations, while the correlations between WW and all traits studied are negative. Eleven selection indices were constructed, index I1 which incorporating TMY, LP, BW and WW or index I2 which incorporating TMY, LP and WW are the best (RIH =0.86), both indices are recommended to improve productive traits in Egyptian buffaloes.

Genetic correlations and trends for traits of economic importance in dairy buffalo

2020 ◽  
Vol 60 (4) ◽  
pp. 492 ◽  
Author(s):  
Ranielle Nogueira da Silva Vilela ◽  
Thomaz Marques Sena ◽  
Rusbel Raul Aspilcueta-Borquis ◽  
Leonardo de Oliveira Seno ◽  
Francisco Ribeiro de Araujo Neto ◽  
...  
Keyword(s):  
Milk Fat ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Milk Quality ◽  
Calving Interval ◽  
Age At First Calving ◽  
Productive Traits ◽  
Dairy Buffalo ◽  
Genetic Trends ◽  
Low Magnitude

Context The planning and execution of selection programs requires estimates of the genetic correlations between traits. As genetic change is achieved for a given trait, it is important to consider possible genetic changes for other traits. Understanding the magnitude and direction of genetic correlations can assist in selection decisions. Aims The aim of the present study was to estimate the genetic correlations of reproductive traits with productive traits and with percentages of fat and protein in the milk of dairy buffalo. Additionally, genetic trends were estimated for the traits under study over the years. Methods Data from 11530 complete lactations of 3431 female buffalo were used. The following traits were analysed: milk, fat and protein yields; percentages of fat and protein; age at first calving; and calving interval. The (co)variance components were estimated by Bayesian inference in multi-trait analyses, considering a linear animal model. To calculate the genetic trends, the average annual genetic values were regressed on the year of birth. Key results The means of genetic correlations estimated between reproductive (age at first calving and calving interval) and productive (milk, fat and protein yields) traits were positive, but of moderate to low magnitude. The association between the reproductive and milk quality (fat and protein percentages) traits were negative and of low magnitude. Genetic trends for the productive traits were positive (5.25 ± 0.63, 0.15 ± 0.034 and 0.09 ± 0.038 kg/year for milk, fat and protein yields respectively). Genetic trends for the reproductive traits of age at first calving and calving interval increased by 0.47 ± 0.09 and 0.48 ± 0.10 days/year respectively. In terms of milk quality, however, the percentages of fat and protein decreased by 0.016 ± 0.003 and 0.011 ± 0.001%/year respectively. Conclusions Genetic gains in productive traits may elevate the number of days at first calving and extend the calving interval, in addition to leading to the production of milk of lower quality. Implications The use of a multi-trait selection index is an alternative, as it combines information from different sources, such that an optimal selection criterion can be achieved over time by virtue of its emphasis on appropriate weighting for all traits.

scholarly journals Analysis of Genetic Parameters for Reproductive Traits in Crossbred Dairy Cattle Maintained at Holetta Agricultural Research Center.

2020 ◽  
Vol 39 (01) ◽  
Author(s):  
Kefale Getahun ◽  
Million Tadesse ◽  
Direba Hundie
Keyword(s):  
Dairy Cattle ◽  
Genetic Parameters ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Agricultural Research ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Breeding Value ◽  
Research Center ◽  
Phenotypic Correlation

This study was aimed to generate information on variance components and the resulting genetic parameters (heritability, repeatability, genetic and phenotypic correlations and genetic trends) of some economic traits of Borena and its crosses with Holstein Friesian dairy cattle maintained at Holetta agricultural research center dairy farm. Traits studied were age at first service (AFS), age at first calving (AFC), calving interval (CI), days open (DO) and number of service per conception (NSC). Overall, 11331 dairy cattle reproductive performance records were used for the study. WOMBAT, which is a software package for quantitative genetic analysis of continuous traits, fitting a linear, mixed model; estimates of covariance components and the resulting genetic parameters were employed and obtained. Heritability values of reproductive traits were from very low (0.071, 0.082 and 0.012) for CI, DO and NSC to moderate (0.3 and 0.22) for AFC and AFS traits. Repeatability estimate for CI, DO and NSC were low (0.17, 0.17 and 0.129). Strong and positive genetic correlation (0.98) was appeared between AFS and AFC traits. Negative genetic correlations were observed between AFS and DO (-0.001), AFC and DO (-0.05), AFS and NSC (-0.022), AFC and NSC (-0.29) and CI and NSC (-0.31). AFS were negative phenotypic correlation with CI, DO and NSC. Similarly, AFC was negative phenotypic correlation with CI and DO. Low phenotypic correlation was observed between AFC and NSC, CI and DO, CI and NSC and, DO and NSC. Strong and positive phenotypic correlation was appeared between AFS and AFC. The regression coefficient of mean breeding value for NSC, CI, DO, AFC and AFS on year of birth were -0.0066x+13.25 times/year, -1.19x+2387.4 days/year, -1.23x+2445.6 days/year, 0.2x-410 months/year and 0.48x-980 months/year, respectively.

scholarly journals Restricted Selection Index to Relieve the Negative Repercussion in Reproductive Performance of Holstein Cows

2021 ◽  
Vol 10 (3) ◽  
pp. 202-207
Keyword(s):  
Repeated Measures ◽  
Selection Index ◽  
Reproductive Traits ◽  
Breeding Value ◽  
Holstein Cows ◽  
Sources Of Information ◽  
True Breeding ◽  
Productive Traits ◽  
Restricted Selection ◽  
True Breeding Value

The aim of this investigation was to develop restricted selection index aiming to improve 305-day yields of milk (MY), fat (FY) and protein (PY), while keeping the deterioration in days open (DO), calving interval (CI) and number of services per conception (NSPC) at minimum levels in Holstein cows. The data represent 3682 records of 1122 cows, daughters of 95 sires and 712 dams. The data were analyzed by multi-trait animal model with repeated measures. Eight selection indexes (five unrestricted and three restricted) were derived using MY, FY, PY, CI, DO and NSPC in various combinations as sources of information in the indexes. However, the true breeding value included MY, FY and PY. The highest accuracy of selection (0.60) resulted from selection based on the full index. Milk yield and SPC appeared to be the most valuable traits in the full index. Combining the two traits into one index (the best reduced index) gave 0.57 accuracy of selection. The index based on MY alone (the most accurate single trait index) gave 0.53 accuracy. It seems possible to reduce the expected genetic deterioration in the reproductive traits by restricting the full index to result in zero genetic change in NSPC (rTI=0.48). This restriction will allow the breeder to mitigate the deterioration in DO and CI by 12 and 16 days respectively, by sacrificing with part of the expected genetic improvement in productive traits (29, 40 and 48% in MY, FY and PY, respectively).

The inheritance of wool quantity and live weight in the French Angora rabbit

1999 ◽  
Vol 68 (3) ◽  
pp. 441-447 ◽  
Author(s):  
D. Allain ◽  
H. de Rochambeau ◽  
R. G. Thébault ◽  
J. L. Vrillon
Keyword(s):  
Genetic Correlations ◽  
Live Weight ◽  
Breeding Value ◽  
Accurate Definition ◽  
Live Body Weight ◽  
Fleece Weight ◽  
Definition Of ◽  
Maternal Heritability ◽  
Angora Rabbit ◽  
Multiple Expression

AbstractMore accurate definition of Angora rabbit breeding objectives has been investigated by considering multiple expression of different traits. Data on 9672 fleece harvests produced by 1343 Angora does which had at least one wool harvest were analysed in order to study genetic variability according to age. The animals of the French breed were defleeced and weighed at 8 and 21 weeks of age for the first and second time respectively. Thereafter, does were defleeced every 14 weeks and weighed 9 weeks before defleecing. Total fleece weight and live body weight were recorded at each harvest.Direct heritability estimates of total fleece weight were similar accross ages and ranged from 0·31 to 0·42 . A significant maternal heritability was also observed at all ages of harvest. Maternal genetic estimates decreased with age from 0·44 at the first harvest to 0·10 for an adult harvest. Except for 8 weeks of age, genetic correlations between total fleece weight and live weight were generally not significantly different from zero. Genetic correlations of total fleece weight between the first and subsequent harvests were low (from 0·22 to 0·39) but genetic correlation estimates between consecutive harvests after the first were high, and ranged from 0·68 to 0·89 . The results suggest that the second harvest would be the first good predictor of breeding value for total fleece weight in the adult Angora rabbit.

scholarly journals Breeding value evaluation in Polish fur animals: Estimates of (co)variances due to direct and litter effects for fur coat and reproduction traits

2011 ◽  
Vol 51 (No. 1) ◽  
pp. 39-46 ◽  
Author(s):  
H. Wierzbicki ◽  
W. Jagusiak
Keyword(s):  
Litter Size ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Original Data ◽  
Breeding Value ◽  
The Arctic ◽  
Data Set ◽  
Value Evaluation ◽  
Reproduction Traits ◽  
Fur Animals

5 540 records of the arctic fox fur coat and reproductive traits collected in 1983–1999 were studied. The analyzed traits were: body size (BS), colour type (CT), colour purity (CP), coat density (CD), hair length (HL), general appearance (GA), total score (TS), skin length (SL), litter size at birth (LSB), litter size at weaning (LSW), number of dead pups (NPD), pup weight at weaning (PW), and pregnancy length (PL). (Co)variance components were estimated using a derivative-free algorithm of REML and a multi-trait animal model. Random effects were direct additive, common litter environment and residual. The genetic parameters for the fur coat traits (discrete characters) were estimated twice: using the original data set, and the data set in which the distribution of fur coat scores was normalised using a probit link function. Direct heritability estimates obtained from the original data set ranged from 0.108 for SL to 0.276 for HL, and were somewhat lower than those estimated using the transformed data set (they ranged from 0.109 for GA to 0.315 for CT). Reproductive traits were lowly heritable with direct heritabilities ranging from 0.060 for PW to 0.174 for LSB. Estimates of the portion of litter variation calculated from the original and transformed data set were comparable ranging from 0.045 for GA to 0.156 for CP, and from 0.059 for GA to 0.185 for TS, respectively. Genetic correlations between fur coat traits ranged from high favourable (0.948 between SL and BS, original data) to strong negative ones between CP and GA (–0.405, transformed data). High positive genetic correlations were found between LSB and LSW (0.954), and between LSB and NPD (0.783), whereas PL was negatively correlated with all other reproductive traits.  

Genetic-quantitative analysis for reproductive traits in Nellor cattle selected for sexual precocity

2020 ◽  
Vol 60 (7) ◽  
pp. 896
Author(s):  
L. C. Brunes ◽  
F. Baldi ◽  
M. F. O. e Costa ◽  
R. B. Lobo ◽  
F. B. Lopes ◽  
...  
Keyword(s):  
Genetic Correlations ◽  
Weight Ratio ◽  
Reproductive Traits ◽  
Reproductive Efficiency ◽  
Gestation Length ◽  
Sexual Precocity ◽  
Scrotal Circumference ◽  
Nellore Cattle ◽  
Days Open ◽  
Selection For

Context The selection of animals for sexual precocity and reproductive efficiency is a trend to reduce the production cycle, promote higher economic viability to the system, increase selection intensity and higher genetic gain, as well to promote the profitability of production systems. To include these traits as selection criterion in cattle breeding programs, estimating genetic parameters and studying the possibility of obtaining genetic gains is required. The hypothesis tested was that the indicators of sexual precocity traits present genetic variance and moderate heritability that allows these to be used as a criterion of selection to obtain improvement for sexual precocity, without negative implications for the reproductive efficiency in Nellore cattle. Aims This study was carried out to estimate the genetic parameters for reproductive traits (scrotal circumference at 365 and 450 days of age, gestation length, days open, calving interval, real fertility, cumulative productivity, calf weight:cow weight ratio) and age at first conception and first calving in a Nellore cattle herd under selection for sexual precocity. Methods Data of reproductive traits and indicators of sexual precocity traits from 4081 Nellore cattle born between 2009 and 2015 were used. The covariance components, heritabilities and correlations were estimated using the restricted maximum likelihood method, available in the BLUPF90 package, in single- and multiple-trait animal mixed models. Key results Estimates of heritability and standard errors for scrotal circumference at 365 and 450 days of age, gestation length, days open, calving interval, real fertility, cumulative productivity, calf weight:cow weight ratio, age at first conception (AFCo) and age at first calving (AFCa) were 0.33 ± 0.03, 0.33 ± 0.01, 0.23 ± 0.03, 0.34 ± 0.11, 0.23 ± 0.12, 0.21 ± 0.16, 0.23 ± 0.08, 0.25 ± 0.10, 0.21 ± 0.08 and 0.24 ± 0.08 respectively. The genetic correlations estimated between AFCo and the other reproductive traits ranged from –0.61 to 0.14 (standard error 0.1–0.21), and between AFCa and the other reproductive traits ranged from –0.60 to 0.16 (standard error 0.1–0.19), all of them in a favourable direction. Conclusions Selection for sexual precocity based on AFCo and AFCa may promote improvement in reproductive efficiency and fertility, except for the calf weight:cow weight ratio, whose correlation was close to zero. Implications The estimates of heritabilities and genetic correlations suggest that selection programs for reproductive traits and indicators of sexual precocity traits for the Nellore breed may provide genetic gain. In addition, considering the genetic correlation obtained between AFCo and AFCa (0.96), when the selection objective is to increase the sexual precocity of heifers, we could use the age of the first conception as criterion, as the measurement of this trait occurs at a lower age at first calving, which implies reducing the time required for animal evaluation and decision-making.

scholarly journals Assessment of Genetic Relationships between Growth Traits and Milk Yield in Egyptian Buffaloes

2019 ◽  
Vol 24 (4) ◽  
pp. 143
Author(s):  
Ibrahim Abu El- Naser
Keyword(s):  
Body Weight ◽  
Milk Yield ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Genetic Relationships ◽  
Genetic Correlations ◽  
Live Body Weight ◽  
Body Weights ◽  
Production Research ◽  
Maternal Heritability

Data in this study were collected from live body weight records and milk yield for the first three lactations of Egyptian buffaloes maintained at the Mahallet Mousa Experimental Station of Animal Production Research Institute, relying on 987 records of Egyptian buffaloes spread over 16 years. These data were analyzed to estimate genetic parameters using animal model. Overall means in kilograms of BW, WW, W18, WFC, 1stMY, 2ndMY and 3rdMY were 36.56, 96.95, 322.02, 462.09, 1561.53, 1755 and 1837.71, respectively. Direct additive heritability (h2a) for mentioned traits were 0.31, 0.22, 0.24, 0.27, 0.23, 0.23 and 0.17, respectively. Corresponding computation of maternal heritability (h2m) for same traits were 0.39, 0.34, 0.22, 0.40, 0.29, 0.31 and 0.21, respectively. Evaluation of genetic correlations among different all studied traits were positive and ranged from 0.07 to 0.83, while phenotypic correlations were positive and ranged from 0.02 to 0.55. Accuracy of (PBV's) varying from 62 to 76, 62 to 83 and 41 to 77% for sires, cows and dams, successively; pointing out the genetic improvement could be achieved through any pathway of them. Higher direct and maternal heritability for BW and WFC and genetic correlations between first three lactations milk yield and each of BW and WFC higher than genetic correlations between first three lactations milk yield and WW and W18. Therefore, it is appropriate to select buffalo female calves for live body weight at birth than for live body weights at other ages.

scholarly journals Genetic parameters and breeding values for daily milk production of Holstein cows in terms of heat stress

2020 ◽  
Vol 70 (3) ◽  
pp. 201-209
Author(s):  
Goran Vučković ◽  
Tina Bobić ◽  
Vesna Gantner ◽  
Vladan Bogdanović ◽  
Klemen Potočnik ◽  
...  
Keyword(s):  
Heat Stress ◽  
Milk Production ◽  
Genetic Correlations ◽  
Stress Conditions ◽  
Breeding Value ◽  
Holstein Cows ◽  
Environment Interaction ◽  
Lactation Stage ◽  
Daily Milk Production ◽  
Daily Milk

In order to estimate the variance components as well as the breeding value for daily milk production of Holstein cows in terms of heat stress defined as different THI threshold values (68, 70, and 72) 1,275,713 test-day records from 90,159 cows were used. Temperature-humidity index (THI) calculated from ambient temperature and relative humidity recorded in the barns on the milk recording day was used as the measure of heat stress. Daily milk production was analysed as a bivariate variable, in the normal conditions (under the set THIthreshold value), and in terms of heat stress (above the set THIthreshold value) using a model that accounted variances due to lactation stage, calving season, age at calving, breeding region, parity, permanent environment, interaction between hear and year, and individual animal. The estimated high genetic correlations between the daily milk production in normal and heat stress conditions, as well as high correlations among the EBVs in normal and heat stress conditions, point out that Holstein cows with high productivity in normal condition will sustain an alike level of production even in terms of heat stress. These results indicate that the Holstein cows are very well acclimatized to the environmental conditions at dairy farms in Croatia. However, these findings should be taken with caution, given that measurements of microclimate parameters were conducted only once at a milk recording day, so the reliability of such measurements could be questionable. In conclusion, in order to realize a completely unambiguous conclusion, further studies that include multiple daily measurements of microclimatic parameters in the farms facilities are necessary.

scholarly journals Novel Genes Associated with Dairy Traits in Sarda Sheep

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2207
Author(s):  
Michele Pazzola ◽  
Giuseppe Massimo Vacca ◽  
Pietro Paschino ◽  
Giovanni Bittante ◽  
Maria Luisa Dettori
Keyword(s):  
Association Analysis ◽  
Milk Yield ◽  
Dairy Traits ◽  
Breeding Schemes ◽  
Milk Coagulation ◽  
Set Up ◽  
A Minor ◽  
Daily Milk Yield ◽  
Breed Sheep ◽  
Daily Milk

The aim of the present research was to analyze the variability of 45 SNPs from different genes involved in metabolism and innate immunity to perform an association analysis with the milk yield, composition and milk coagulation traits. A population of 1112 Sarda breed sheep was sampled. Genotyping was generated by a TaqMan Open ArrayTM. Thirty out of the 45 SNPs were polymorphic, and 12 displayed a minor allele frequency higher than 0.05. An association analysis showed that the variability at genes PRKAG3 and CD14 was significantly associated with the daily milk yield. The variability at PRKAG3 was also associated with the protein and casein content, somatic cell score and bacterial score. The variation at the PRKAA2 gene was associated with the milk lactose concentration. The SNPs at CD14 were also associated with the traditional milk coagulation properties, while the SNPs at GHR and GHRHR were associated with kSR, a derived coagulation parameter related to the rate of syneresis. The information provided here is new and increases our knowledge of genotype–phenotype interactions in sheep. Our findings might be useful in appropriate breeding schemes to be set up for the Sarda sheep breed, but these should be confirmed by further studies, possibly performed on independent populations.

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