scholarly journals Genetic Improvement Using the Selection Indices for Some Productive and Reproductive Traits in Friesian Cattle Raised in Egypt

2016 ◽  
Vol 7 (12) ◽  
pp. 475-482
Author(s):  
Safaa Sanad
Keyword(s):  
Genetic Improvement ◽  
Reproductive Traits ◽  
Selection Indices ◽  
Friesian Cattle

scholarly journals Genomic Tools and Genetic Improvement of Crossbred Friesian Cattle

2021 ◽  
Vol 8 (1) ◽  
pp. 89-107
Author(s):  
Md Anisur Rahman ◽  
Nasrin Sultana Juyena ◽  
Mohammed Shamsuddin ◽  
Mohammad Musharraf Uddin Bhuiyan
Keyword(s):  
Reproductive Performance ◽  
Genetic Improvement ◽  
Reproductive Potential ◽  
Reproductive Traits ◽  
Production Traits ◽  
Genomic Tools ◽  
The Given ◽  
Friesian Cattle ◽  
Selection Of ◽  
Friesian Cows

Any genetic improvement in dairy cattle requires information on productive and reproductive performance in the given population. Animals have been selected to improve their productivity in order to increase the profitability to the farmer. As a result, selection of animals is made for higher production and a shortened productive life. The reproductive performance of Friesian cows under intensive and semi-intensive management system in Bangladesh is poor. Animal selection has historically been based on production traits, and not much attention was given to AI recording. Many attempts were taken scatterly to increase productive and reproductive potential of Bangladeshi cattle for different periods with variable achievements. Therefore, in this review article we have addressed the new tools and information that could be used to determine the level of productive and reproductive performance and to evaluate genetic factors using admixture analysis of cows bred by AI sires which affect reproductive traits of crossbred Friesian dairy cows reared in selected areas in Bangladesh. Res. Agric., Livest. Fish.8(1): 89-107, April 2021

scholarly journals Genetic selection indices for growth traits in Blanco-Orejinegro cattle

2021 ◽  
Author(s):  
Edison J Ramírez Toro ◽  
Gerson Barreto Mourão ◽  
Rodrigo A Martínez Sarmiento ◽  
Mario F Cerón-Muñoz
Keyword(s):  
Genetic Improvement ◽  
Growth Traits ◽  
Genetic Selection ◽  
Reproductive Traits ◽  
Genetic Progress ◽  
Selection Indices ◽  
Body Weights ◽  
Improvement Programs ◽  
Two Indices ◽  
Estimated Breeding Values

Abstract Selection indices are used in genetic improvement programs, with the purpose of selectins simultaneous for several economically important traits. The objective of this study was to construct equations for selection indices in the Blanco-Orejinegro (BON) breed and to determine the index that would generate the greatest genetic progress. The information used included birth weight (BW), body weights adjusted to 120, 240, 480, and 720 days old (W120, W240, W240, 480 and W720, respectively), age at first calving (AFC) and interval between first and second calving (IBC) estimated breeding values. Two Smith and Hazel indices were calculated using variances (I1) and literature (I2), with a part two indices designed using information from experts and breeders (I3 and I4). Las características de mayor peso fueron para a*=W120, a**, a****=W720 y a***=W240 respectivamente. In general, the estimated indices obtained similar reliability and expected genetic differences I1 generated a decrease in direct BW. I2 generated the largest increases in BW and AFC. I3 and I4 generated positive changes in growth and reproductive traits, with I3 generating the greatest genetic gains in the population, especially for W240.

Reproductive performance and genetic parameters for Australian Dorset Sheep

1994 ◽  
Vol 45 (2) ◽  
pp. 427 ◽  
Author(s):  
LD Brash ◽  
NM Fogarty ◽  
AR Gilmour
Keyword(s):  
Litter Size ◽  
Reproductive Performance ◽  
Genetic Improvement ◽  
Genetic Correlations ◽  
Reproductive Traits ◽  
Reproductive Rate ◽  
Parameter Estimates ◽  
Reproduction Traits ◽  
Component Traits ◽  
Lamb Survival

Reproductive performance of ewes in a large Dorset stud flock is reported. The data included 2488 ewes with 10016 joining records over 25 years. Average performance for reproductive traits were: fertility 92%, litter size 1.31, neonatal lamb survival 91%, lamb survival to weaning 85%, with overall lambs born 1.20 and lambs weaned 1.02 per ewe joined. Differences between breeds (Poll Dorset and Dorset Horn), season of birth (spring and autumn) and season of joining (spring and autumn) were significant for most reproduction traits. Linear and quadratic regressions for age of ewe at joining were highly significant for all traits (P < 0.001) with maximum performance between three and six years of age. Estimates of heritability for ewe reproductive traits were: 0.062 � 0-02 for number of lambs born and 0.04 � 0.01 for number of lambs weaned per ewe joined, and component traits, 0.02 �0 -01 for fertility, 0 08 � 0 -02 for litter size and 0.00 � 0.01 for lamb survival. Estimates of repeatability were less than 0.14 for all the reproduction traits, which resulted in substantially higher predicted heritabilities when repeated records were used. Heritability estimates for average ewe lifetime performance, with approximately four records, were 0.08 � 0 06 for lambs born, 0.12 � 0.05 for lambs weaned, 0.08 � 0.04 for fertility, 0.l9 � 0 -04 for litter size and zero for lamb survival. The genetic correlations between litter size and lambs born and weaned were close to unity, whereas those for fertility were lower and declined from lambs born (0.6l � 0.22) to lambs weaned (0-45 � 0.30). The estimated heritability for ewe longevity, defined as the number of years the ewe remained in the breeding flock, was 0.00 � 0.03. The potential for genetic improvement in reproductive rate is discussed in relation to other reports in the literature and in the context of the roles of the Dorset breed in the Australian lamb industry. Increased reproductive rate in Dorset flocks impacts on stud profitability and the rate of genetic improvement from selection for other traits such as liveweight. The parameter estimates derived will be used in compiling breed-specific parameter sets for genetic evaluation in LAMBPLAN.

Selection Indices for genetic improvement of Japanese quail

2018 ◽  
Vol 53 (2) ◽  
pp. 137
Author(s):  
S.S. Nayal ◽  
C.B. Singh ◽  
D. Kumar ◽  
Brijesh Singh ◽  
Nitesh K. Singh
Keyword(s):  
Japanese Quail ◽  
Genetic Improvement ◽  
Selection Indices

scholarly journals Inheritance of some fertility traits in three successive generations of Holstein-Friesian cattle

2005 ◽  
Vol 48 (1) ◽  
pp. 5-11
Author(s):  
R. Lazarevic ◽  
B. Miscevic
Keyword(s):  
Reproductive Traits ◽  
Service Period ◽  
Holstein Friesian ◽  
Successive Generations ◽  
Fertility Traits ◽  
Friesian Cattle ◽  
Duration Of Pregnancy

Abstract. The aim of the paper was to establish reproductive traits and their heritability during the three successive generations of Holstein-Friesian cattle. Research was conducted on the duration of pregnancy, service period and fertility intensity. In each generation there were 135 first calved cows. Service period and fertility intensity refers to the following calving. Significant differences were established (P < 0.05) regarding duration of pregnancy between I and II generation. Significant (P < 0.05) influence of season on duration of pregnancy and service period was established in I generation (1991), on duration of service period and fertility intensity in II generation (1996) and on duration of pregnancy and service period in III generation (2000). Season effect (summer) was established for all traits of fertility in II generation (P < 0.05). The season (spring) had influence on duration of pregnancy (P < 0.05) and summer had an influence on duration of service period and fertility intensity, and winter effected the duration of service period (P < 0.05) in III generation. Values of heritability coefficients are pretty low for all generations. Considerably greater values for heritability were established for service period and intensity of fertility of cows per generations.

scholarly journals Genetic parameters for test-day milk yield in tropical Holstein Friesian cattle fitting a multiple-lactation random regression animal model

1970 ◽  
Vol 47 (3) ◽  
pp. 352-361
Author(s):  
S. Meseret ◽  
E. Negussie
Keyword(s):  
Animal Model ◽  
Milk Yield ◽  
Genetic Improvement ◽  
Genetic Parameters ◽  
Genetic Correlations ◽  
Random Regression ◽  
Likelihood Method ◽  
Holstein Friesian ◽  
Heritability Estimates ◽  
Friesian Cattle

Accurate estimates of genetic parameters are essential for genetic improvement of milk yield in dairy cattle and for setting up breeding programmes. Estimates of genetic parameters from test-day models, particularly for Holstein Friesian cattle maintained in tropical environments, are scant in the literature. The objective of this study was therefore to estimate genetic parameters for milk yield by fitting a multiple-lactation random regression animal model (RRM) based on data from Ethiopian Holstein Friesian herds. Data were used from the first three lactations of cows that calved between 1997 and 2013. The data comprised 13 421 test-day milk yield records from 800 cows from two large dairy herds. Variance components were estimated using the average information restricted maximum likelihood method fitting an RRM. Heritability estimates for first, second, and third lactations ranged from 0.20 to 0.26, 0.15 to 0.27, and 0.17 to 0.28, respectively. Heritability estimates ranging from 0.15 to 0.28 indicate that effective genetic improvement should be accompanied by a corresponding improvement of the production environment. Across-lactation genetic correlations between first and second, second and third, and first and third lactations, expressed on a 305-day yield basis, were 0.88, 0.83, and 0.70, respectively. These genetic correlations, less than or equal to 0.88, indicate that different lactations are different traits. For an accurate evaluation of the genetic merit of animals for milk yield, lactations should be treated as different, but correlated traits in a multiple-lactation analysis.Keywords: Genetic correlation, heritability, Legendre polynomial, test-day model

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