GENETIC IMPROVEMENT OF THE LOCAL SINAI STRAIN FOR EGG PRODUCTION BY USING GENERAL SELECTION INDEX

2019 ◽  
Vol 3 (1) ◽  
pp. 43-44
Author(s):  
M. E. Soltan ◽  
A. A. Enab ◽  
G. M. Gebril ◽  
Kh. R. Mohamed
Author(s):  
N.D. Cameron

Sheep breeding programmes for genetic improvement in carcass composition of terminal sires measure livewelght and ultrasonic backfat and muscle depths for inclusion in a selection index to predict genetic merit. Physiological traits which were genetically correlated with carcass traits could be incorporated into the selection index to increase the accuracy of selection and the rate of genetic improvement.This study examined differences in physiological traits between lines selected for high or low carcass lean content. The measured physiological traits were chosen according to their role in protein and lipid metabolism : b-hydroxybutyrate (BHB) and glucose (GLUC) : indicators of energy balance; triglyceride (TRIG) and non-esterified fatty acids (NEFA) : intermediaries of lipid metabolism; UREA and creatinine (CREA) : indicators of nitrogen / amino acid metabolism and insulin-like growth factor-1 (IGF-1): an Indicator of growth hormone status.


2007 ◽  
Vol 2007 ◽  
pp. 158-158
Author(s):  
Mohammad Hassan Jahandar ◽  
Mohhamad Moradi Shahre Babak ◽  
Mahdi Elahi Torshizi

In order to evaluate genetic improvement in a selected population, variation resulted from environment and genetics should be dissociated. Because of the positive genetic correlation between milk fat yield and milk and protein yield, selection for milk production has often resulted in an increase in fat and protein yields however response for fat percentage is negative. However positive genetic trends between 0.73 to 0.95 kg per annum for milk fat yield in Holstein cattle have been reported in some studies that milk fat yield had less importance in selection index, also negative values are reported. Based on previous research, genetic improvement of milk fat yield up to 1 percent due to selection is possible and from a theoretical view, an improvement of about 2 percent is reported. With attention to selection in the herd and using progeny tested semen from foreign countries that have suitable genetic potential, this study was accomplished in order to estimate genetic parameters for milk fat and investigate genetic and environmental trends during 1990 to 2001.


2007 ◽  
Vol 2007 ◽  
pp. 68-68
Author(s):  
Mani Ghanipour ◽  
Seyed Ziaeddin Mirhosseini ◽  
Abdol Ahad Shadparvar ◽  
Alireza Seidavi ◽  
Alireza Bizhannia

The general aim of selection in animal breeding is to acquire new generation of animals, which under future economic conditions of production system are more efficient than the present generation. In selection index method, genetic trend of important traits is directed based on their weights in economic efficiency of production system to acquire maximum improvement in economic merit (Mirhosseini et al., 2005). Silkworm commercial egg is produced by crossing between Japanese and Chinese origin parent stocks. There are three steps in the cycle of egg production including GGP (great grand parent), GP (grand parent) and P (parent stock). Breeding programs along with high selection pressure are used only in GGP lines which are typically much smaller in size than other stocks. The objective of this study was to evaluate effect of six generations of index selection in the GGP lines on performance of commercial silkworm hybrids.


Author(s):  
J.P. Gibson

The goal of livestock genetic improvement is maximun increase in the economic efficiency of production (economic merit). When several traits contribute to economic merit, optimum genetic improvement can often be achieved by use of a discriminant function of available information (known as a selection index) which maximises expected genetic progress in the aggregate genotype, economic merit. This approach assumes that economic merit is a linear function of genetically controlled outputs. Although this may not always be true, since genetic responses are usually relatively small (0.005 to 0.020 of the mean per year) any non-linear effects are second-order and can generally be ignored. Economic optimization procedures which match production environments to genotypes would generate effectively non-linear functions, such non-linearity will generally be small. Thus the selection index approach can be applied, provided that functions describing economic merit are based on previously optimized production environments.


Author(s):  
M.G.G. Chagunda ◽  
J.P. Gibson ◽  
K. Dzama ◽  
J.E.O Rege

SummaryAnimal breeding for increased productivity over the past 50 to 60 years has been very successful in terms of increasing growth rate, milk yield and egg production in most livestock producing regions of the world (Rauwet al., 1998). However, this success has not registered that well in most countries in sub-Saharan Africa (SSA). Ironically, just like most developing regions, SSA is faced with the challenge to increase rapidly the agricultural productivity to help feed their growing human populations without depleting the natural resource base (Rege, 2005). Genetic improvement of livestock depends on access to genetic variation and effective methods for exploiting this variation (Rege, 2005). This is where human capacity and infrastructure for decision-support systems in animal breeding are required. This paper provides a synthesis of views from a cross-section of livestock production experts working in SSA. These views were collated through an e-conference which was held from 8th March to 20th April 2011. The e-conference discussed future research and development (R&D) needs for animal breeding and genetics in SSA and how they can be met. The e-conference attracted 43 participants from 17 countries. Results from the e-conference demonstrated that the R&D institutions and infrastructure in SSA vary widely in terms of both the physical and human capacity. Equally varied is the level of utilization of these institutions. In terms of training in Animal Breeding and Genetics, although most universities/colleges have programmes in Animal Science and teach animal breeding and genetics, there are very few practicing animal breeders. Lack of mentorship programmes and collaboration, and in some cases lack of appropriate jobs, continue to contribute to this ‘leaking pipeline’ phenomenon. The following is a summary of the consensus stemming from the conference on how the efficiency and effectiveness of livestock genetic improvement in SSA could be enhanced. First, the need to augment the approach that promotes animal breeding and genetics as part of a wider agriculture and rural development system, second, collaboration both within Africa and with those in the Diaspora should be further tapped into and utilized as a source of capacity for R&D and third, initiative of sharing resources and research platforms such as pooling data for genetic analysis from across institutions, and even across countries, should be encouraged in case where this is advantageous to do so.


2008 ◽  
Vol 48 (10) ◽  
pp. 1247 ◽  
Author(s):  
S. W. P. Cloete ◽  
A. Engelbrecht ◽  
J. J. Olivier ◽  
K. L. Bunter

Ostrich farmers rely on skins and meat as their most important sources of revenue, with feathers being of secondary importance. This paper provides a summary of parameter estimates (heritabilities and genetic correlations) estimated from the resource flock held at the Oudtshoorn Research Farm. Traits considered were egg production, chick production, mature liveweight, offspring slaughter weight and skin traits. Feather weight of mature breeding birds was not included, as revenue received for this commodity is comparatively low, and mostly reliant on quality. All the traits considered were moderately to highly heritable, and reproduction traits in particular were highly variable. No substantial unfavourable genetic correlations were noted, and worthwhile gains in all traits appear to be achievable within a selection objective based on economic principles. Economic weights for key traits were obtained from a bio-economical input–output simulation model that was prepared for the industry. A simple preliminary selection index including chick production (as a hen reproductive trait) and slaughter weight (as a measure of growth) appears to be adequate for the present needs, given the limited availability of routinely recorded traits. A key performance trait that is currently missing from the economic assessment is chick survival, which is known to be low and highly variable among ostrich flocks. Further information will be added as it becomes available.


2002 ◽  
Vol 2002 ◽  
pp. 195-195
Author(s):  
A. M. van Heelsum ◽  
R. M. Lewis ◽  
W. Haresign ◽  
D. Jones ◽  
S. Williams ◽  
...  

With increasing emphasis in the meat sector on better and more consistent quality, carcass leanness and conformation is now an important issue for sheep breeders. In 1999, only 47% of all carcasses in the UK met the target specifications for weight, fat and conformation (MLC, 2000), highlighting the potential for improvement. In the current stratified crossbreeding system, crossbred wether lambs are a by-product of the production of dam line ewes for the lowland sector. If their carcass quality is sufficient, they can give a valuable boost to the economics of the breeding programme. Genetic improvement of carcass quality in crossing sire breeds would benefit the crossbred wethers, as well as filter through to the terminal sire cross lambs produced by the crossbred ewes. This work aims to assess the influence of selection index and live conformation score of crossing sires (in this case Bluefaced Leicesters) on growth and carcass quality traits of their crossbred progeny, as a first step towards designing a genetic improvement programme for crossing sire sheep.


2000 ◽  
Vol 27 ◽  
pp. 20-28 ◽  
Author(s):  
Rudolf Preisinger ◽  
Dietmar K. Flock

SummaryIn commercial egg type chicken breeding three and four way crosses are used to produce commercial layers. The primary breeders are using closed nucleus breeding programmes, with birds kept under maximum biosecurity. All grand parents and parents are produced from a closed nucleus for the world wide demand of commercial layers. The breeding goals have been focused for several decades on increasing number of eggs per hen housed. Additional traits have become more important during the last decade, i.e. feed efficiency, internal and external egg quality and general adaptability. Prior to each selection, weights for individual traits within the selection index are adjusted to meet market demands. Breeding stock and commercial layers have to be bred to perform adequately in a variety of systems ranging from large intensive cage units to free range management under different environmental conditions world-wide.Despite intensive selection for egg production the decrease in genetic variation observed in closed commercial lines is not yet critical. Peak production is approaching the biological limit of one egg a day. During this period genetic and phenotypic variation have been significantly reduced. But for early production (sexual maturity) and late production (persistency) genetic variation is still high. In a mating scheme avoiding full and half sib matings no serious inbreeding depression is observed. To achieve continued future genetic progress, selection pressure will shift to other traits like internal and external egg quality and perhaps behaviour traits which still respond to selection.Primary breeders are responding to this challenge by testing pedigreed cross-line hens in a wide range of environments and housing systems while the pure-line elite stock is kept under conditions of maximum biosecurity. Marker assisted selection is already part of commercial breeding programmes. In the past, blood typing has been used to improve Marek's resistance, whereas today anonymous microsatellites which are linked to traits of economic interest are used for selection. In particular, selection between full sib males can give a major improvement.The whole industry is getting more specialised. While the genetic potential of the birds is improved management and nutrition have also to be adapted to changing demands. The general goal for the future is to breed chickens with the ability to function well within a wider range of production conditions and do not respond to the slightest stress.


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