Determining the appropriate selection index for Rayeni Cashmere goat under pasture-based production system

2018 ◽  
Vol 58 (9) ◽  
pp. 1595
Author(s):  
Najmeh Kargar Borzi ◽  
Ahmad Ayatollahi Mehrgardi ◽  
Masood Asadi Fozi ◽  
Mahmood Vatankhah
Keyword(s):  
Production System ◽  
Selection Criteria ◽  
Selection Index ◽  
Economic Value ◽  
Herd Size ◽  
Cashmere Goat ◽  
Economic Values ◽  
Economic Weights ◽  
Selection Indices ◽  
Beneficial Traits

The aim of the present study was to identify the significance of Rayeni Cashmere goat’s socioeconomic traits so as to derive economic weights for the selection criteria that can be used easily by goat breeders. A deterministic bio-economic model was used to estimate economic value for adult bodyweight of doe (BWD), annual milk yield (MW), annual cashmere weight (CW), bodyweight of kids sold at 6.5 months (WK), and number of kids sold at 6.5 months per doe (NK). The relative importance of traits was determined on the basis of the estimated economic values, and, consequently, the most beneficial traits were applied to construct selection indices. Five selection indices with different herd sizes and buck ratios were proposed (I1–I5). The traits included in each index were as follows: BWD, MW, CW, WK and NK (I1); MW, CW, WK and NK (I2); BWD, MW, WK and NK (I3); BWD, MW and CW (I4); and BWD, CW, WK and NK (I5). Absolute economic values (US$) of BWD, MW, CW, WK and NK traits were $–0.870, $0.111, $5.660, $21.655 and $1.712 respectively. The results indicated that in all indices, the genetic and economic gains were elevated by an increased herd size and a decreased buck ratio. The maximum values of genetic and economic gains were obtained in herd size of 400 and buck ratio of 0.04. The highest genetic gain was obtained under Index 1, while the highest amount of economic gain was acquired under Index 2; however, the maximum accuracy of selection index was achieved under Index 1. The obtained results revealed that the most appropriate selection index for this breed is Index 1, which includes BWD, MW, CW, WK and NK. By applying Index 1, we could concurrently promote improvement of all traits, which highlights the potential of this index as a good promising strategy for developing selection criteria of Rayeni Cashmere goat under a pasture-based production system.

Effects of production and marketing circumstances on economic values for beef production traits

1998 ◽  
Vol 78 (1) ◽  
pp. 47-55 ◽  
Author(s):  
K. R. Koots ◽  
J. P. Gibson
Keyword(s):  
Beef Cattle ◽  
Key Words ◽  
Production System ◽  
Economic Value ◽  
Fixed Costs ◽  
Production Traits ◽  
Beef Production ◽  
Fixed Amount ◽  
Economic Values ◽  
Mature Size

The effect of altering production and marketing circumstances on economic values is quantified for a complete beef production system. Absolute and relative economic values were found to vary substantially with large, but realistic fluctuations in prices and costs. In addition, several examples of different management and different genotypes gave markedly different economic values than in the base situation. Also investigated were the effects of rescaling the enterprise to accommodate three alternative limitations; fixed feed available from pasture, fixed dollars available for feed or fixed amount of beef produced. The effects of rescaling were highly dependent on whether or not fixed costs were accounted for. When fixed costs were ignored (corresponding to a small positive profit) the economic value for mature size decreased while that for fertility increased, but other traits were largely unaffected by rescaling. Overall, production circumstances that reduced survival and fertility yielded the largest changes to economic values. Key words: Economic values, beef cattle, rescaling

scholarly journals Optimizing Selection for Yield Using Selection Index

Zuriat ◽  
2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Sugiono Moeljopawiro
Keyword(s):  
Selection Index ◽  
Economic Value ◽  
Selection Procedure ◽  
Panicle Length ◽  
Diallel Crosses ◽  
Individual Trait ◽  
Selection Indices ◽  
Selection For ◽  
Grain Width ◽  
Half Diallel

An experiment was conducted to construct selection indices for yield. F2 populations of half diallel crosses involving six cultivars were analyzed to calculate phenotypic and additive genetic variances and covariances which were used to construct selection indices. Results of the selection index indicated that selection applied to several traits simultaneously was more efficient than selection based on an individual trait or a combination of only one or two traits. However, the choice of traits to be included in a selection index should be determined by their economic value and Index involving panicle length, grain length, and grain width, was a promising index in this study. A selection index properly constituted can be used to improve the selection procedure, once homozygousity is assured.

Quantitative genetic studies on wool yellowing in Corriedale sheep. II. Clean wool colour and wool production traits: genetic parameter estimates and economic returns

2000 ◽  
Vol 51 (2) ◽  
pp. 191
Author(s):  
M. V. Benavides ◽  
A. P. Maher
Keyword(s):  
Selection Criteria ◽  
Selection Index ◽  
Genetic Parameter ◽  
Genetic Correlations ◽  
Fibre Diameter ◽  
Economic Losses ◽  
Direct Selection ◽  
Parameter Estimates ◽  
Selection Indices ◽  
Visual Colour

The potential for improvement of clean wool colour (CWC) in Corriedale sheep via selection was examined. The heritability, and phenotypic and genetic correlations, of CWC, brightness (Y), greasy (GFW) and clean (CFW) fleece weights , yield percentage (Yield), mean fibre diameter (MFD), and visual colour score were estimated from 440 progeny of 19 sires of a Corriedale flock using restricted maximum likelihood (REML) procedures with average information algorithm (AIREML). The heritability of CWC was estimated at 0.27±0.13. Clean wool colour showed strong positive genetic correlations with CFW and MFD. Visual colour score and CWC were also positively genetically correlated. As expected, direct selection criteria against MFD, CWC, or visual colour score would reduce CWC; however, direct selection against MFD would improve clean wool colour with negligible reductions on CFW, thus resulting in small economic gains. Several selection indices were calculated having either CFW, MFD, and CWC or CFW and MFD as selection criteria. The b-values of an unrestricted index were estimated at I1 = + 1.15 CFW + 0.13 MFD + 0.43 CWC, with positive correlated responses for all 3 breeding objective traits (CFW, MFD, and CWC). A second index, where CFW was restricted to nil genetic change, was estimated at: I2 = + 0.14 CFW − 0.02 MFD + 0.01 CWC. This index was expected to cause a negligible genetic gain for CWC (−0.04 Y–Z units/head.year). To avoid economic losses with the reduction on CFW, a third selection index was calculated where CWC was restricted to nil change. The index was estimated at I3 = +0.61 CFW − 0.07 MFD + 0.02 CWC with expected increases in CFW and decreases in MFD. Selection indices with (a) CFW and MFD (I4) and (b) CFW, MFD, and visual colour score (I5) as selection criteria would increase CFW, MFD, and CWC at the same rates observed in I1.

The use of product traits such as lean growth rate as selection criteria in animal breeding

1987 ◽  
Vol 45 (2) ◽  
pp. 307-316 ◽  
Author(s):  
G. Simm ◽  
C. Smith ◽  
R. Thompson
Keyword(s):  
Growth Rate ◽  
Selection Criteria ◽  
Genetic Parameters ◽  
Selection Index ◽  
Genetic Correlations ◽  
Or Efficiency ◽  
Economic Values ◽  
Lean Growth ◽  
Component Traits ◽  
Economic Selection

ABSTRACTIn meat animals there is some interest in lean growth rate or lean food conversion efficiency as selection criteria. These traits may be estimated as the product of growth rate (or efficiency), killing-out proportion and carcass lean proportion. When used as selection criteria these product traits do not require estimates of genetic parameters or economic values for component traits. Hence, they may be more stable, and of longer-term use than classical economic selection indices. The purpose of this study is to compare expected responses to selection on product traits with expected responses from selection, either on individual component traits, or on an economic selection index. Formulae were derived for predicting the phenotypic and genetic correlations between a product and one component, and for predicting the heritability of the product trait; these depend on the coefficients of variation and heritabilities of components, and on the genetic correlations among them. When the coefficient of variation of one component is much higher than that of the other, (× 3), this component will tend to dominate the product trait. In cattle and sheep, and to a lesser extent in pigs, killing-out proportion and leanness are usually less variable than growth rate or efficiency. Thus, in many cases, there is little loss in response in lean growth (or lean efficiency) from selection solely on growth rate (or efficiency) regardless of leanness. Although product traits do not require derivation of economic values, their component traits do have implied economic values. Often more appropriate weightings will be given to components by using an economic selection index, even when economic values and genetic parameters are not estimated precisely.

scholarly journals Incorporating economic weights into radiata pine breeding selection decisions

2015 ◽  
Vol 45 (1) ◽  
pp. 135-140 ◽  
Author(s):  
David C. Evison ◽  
Luis A. Apiolaza
Keyword(s):  
Modulus Of Elasticity ◽  
Selection Criteria ◽  
Selection Index ◽  
Radiata Pine ◽  
Equal Weight ◽  
Wood Stiffness ◽  
Selection Strategies ◽  
Economic Weights ◽  
Wide Range ◽  
Breeding Selection

This article introduces the concept of “robust selection”, which proposes tree selection based on the stochastic simulation of economic values to account for the inherent uncertainty of economic weights used in tree selection for breeding programs. The proposed method uses both median ranking and ranking variability as criteria for breeding selection. Using consensus genetic and economic parameters from the New Zealand Radiata Pine Breeding Company program, we compare three selection strategies: deterministic application of economic weights from a vertically integrated bioeconomic model, an equal-weight index often used in operations, and robust selection. All strategies aim to increase value for a breeding objective that includes four traits, i.e., volume, stem sweep, branch size, and wood stiffness (measured as modulus of elasticity), based on a selection index that considers five criteria, i.e., stem diameter at breast height (1.3 m), straightness, branching score, wood density, and modulus of elasticity. Two-thirds of the selected trees were unique for each of the selection strategies. Robust selection achieved the best realised gain for three of the four selection criteria and was the middle performer in the last selection criteria. Considering the high intrinsic uncertainty of economic weights, we suggest that the relevant criterion for the selection of individuals is the maximum median ranking, subject to an acceptable level of variation in that ranking, rather than their narrow performance under a single economic scenario. This will lead to tree selections that perform well under a wide range of economic circumstances.

Developing breeding objectives for radiata pine structural wood production. II. Sensitivity analyses

2006 ◽  
Vol 36 (11) ◽  
pp. 2932-2942 ◽  
Author(s):  
Miloš Ivković ◽  
Harry X Wu ◽  
Tony A McRae ◽  
Colin A Matheson
Keyword(s):  
Modulus Of Elasticity ◽  
Production System ◽  
Selection Index ◽  
Basic Density ◽  
Radiata Pine ◽  
Sensitivity Analyses ◽  
Annual Increment ◽  
Breeding Objective ◽  
Economic Weights ◽  
Mean Annual Increment

In a companion paper we describe a bioeconomic model of a production system for radiata pine (Pinus radiata D. Don) structural timber and estimated economic weights for four breeding-objective traits: mean annual increment, stem sweep, average branch size, and modulus of elasticity. In this paper we show estimation errors and the sensitivity of the economic weights to the input parameters of the production-system model. We also illustrate the linearity and independence of the economic weights and the sensitivity of selection indices to variation in economic weights and genetic parameters. Estimated standard errors of economic weights were generally low. Among the production-system parameters studied, discount rate and roundwood and sawn-timber prices had the largest impact on the estimates of economic weights. The relationship between the change in values of breeding-objective traits and the corresponding change in profit was nonlinear. The profit change due to change in one objective trait was not independent of the values of the other traits. The most important factors affecting the sensitivity of the selection index were the phenotypic variances of early selection traits such as tree diameter and wood basic density and the economic weights of mean annual increment and modulus of elasticity.

scholarly journals Development of a breeding objective for Estonian Holstein cattle

2008 ◽  
Vol 16 (3) ◽  
pp. 212 ◽  
Author(s):  
E. PÄRNA ◽  
H. KIIMAN ◽  
M. VALLAS
Keyword(s):  
Functional Traits ◽  
Milk Fat ◽  
Economic Value ◽  
Economic Values ◽  
Substantial Impact ◽  
Productive Life ◽  
Breeding Goal ◽  
Breeding Objective ◽  
Economic Weights ◽  
Marketing Systems

Economic weights for milk carrier (water plus lactose), fat and protein yields, calving interval, age at first service, interval between the first service and conception of heifers and length of productive life of Estonian Holsteins were estimated under assumed milk production quota and for non-quota conditions. A bio-economic model of an integrated production system of a closed herd was used. Economic values of milk carrier yield and length of productive life differed between quota and non-quota conditions, but there were only minor differences between those marketing systems in economic values for functional traits. The standardised economic values of the most important traits varied in magnitude between18 to 81% of the economic value for milk yield. Discounting had a substantial impact on the economic value of length of productive life. When defining the breeding objective for Estonian Holstein, the interval between the first service and conception of heifers, and the length of productive life should be included in the breeding goal along with the traits with the highest economic value, milk, fat and protein yield. In the optimum breeding objective, relative weights of production vs. functional traits were 79 and 21%, respectively.;

Economic selection index in small rural dairy farms

2019 ◽  
Vol 86 (1) ◽  
pp. 25-33
Author(s):  
Marcos Jun-Iti Yokoo ◽  
Leonardo de Oliveira Seno ◽  
Luiza Corrêa Oliveira ◽  
Pedro U N da Costa ◽  
Gustavo M da Silva ◽  
...  
Keyword(s):  
Milk Production ◽  
Selection Criteria ◽  
Production Systems ◽  
Selection Index ◽  
Live Weight ◽  
Productive Performance ◽  
Selection Indices ◽  
The Difference ◽  
Economic Selection ◽  
Bioeconomic Models

AbstractThis study aimed to calculate economic values (EVs) and economic selection indices for milk production systems in small rural properties. The traits 305-d milk yield in kg (MY), fat (FP) and protein (PP) percentage, daily fat (FY) and protein (PY) yield, cow live weight in kg (LW), calving interval (CI), and logarithm of daily somatic cell count (SCC) in milk were considered the goals and selection criteria. The production systems were identified from 29 commercial properties based on the inventory of revenues and costs and of zootechnical field data. Later, bioeconomic models were developed to calculate the productive performance, revenues, and costs concerning milk production to estimate EVs, which were calculated as the difference in annual profit with dairy production resulting from a change in one unit of the trait while keeping the others constant and dividing the value by the number of cows. After the EVs were known, ten economic selection indices were estimated for each system so they could be compared by modifying the selection criteria and calculating the relative importance of each selection criteria, the accuracy of the economic selection index, and response expected to the selection in USD, among other parameters. One of the systems detected was called less intensive (LS) and was characterized by having ten cows in lactation that produced 13·5 l/d and consumed 1·8 kg of concentrate/d. The second system detected was called more intensive (IS) and had 22 cows in lactation that produced 17·5 l/d and consumed 3·4 kg of concentrate/d. Monthly profits per cows in lactation of USD 2·60 and USD 68·77 were recorded for LS and IS, respectively. The EVs of the traits MY, FP, and PP were all positive, while for the other traits they were all negative in all situations. The best economic selection indices were those featuring selection criteria MY, LW, and CI, while the trait LW had the greatest importance in both systems. These results indicate that animal frame must be controlled in order to maximize the system's profit.

scholarly journals Including protein yield and mastitis resistance in dairy cattle breeding goal optimizes response to selection

2020 ◽  
Vol 49 (6) ◽  
pp. 1148-1157
Author(s):  
C.B. Sagwa ◽  
T.O. Okeno ◽  
A.K. Kahi
Keyword(s):  
Dairy Cattle ◽  
Selection Index ◽  
Economic Value ◽  
Milk Quality ◽  
Protein Yield ◽  
Quality Traits ◽  
Response To Selection ◽  
Economic Values ◽  
Breeding Goal ◽  
Daily Gain

Selection response from a two-tier nucleus breeding scheme using the current Kenyan breeding goal was compared with an alternative that also accounts for protein yield (PY) and mastitis resistance (MR). The economic value for PY was estimated using a bio-economic model. For mastitis resistance, like other disease resistance traits, the economic value cannot be estimated with profit equations because they have multi-fold effects on input and output, which affects profitability. Therefore, selection index methodology was used. Somatic cell count (SCC) was used as an indicator trait for MR. The ZPAN computer program was used to model the breeding schemes and evaluate response to selection. The alternative breeding goal, which included PY and MR, realized additional KES358.48, 613.55, and 613.65 in annual genetic gain, returns and profit per cow per year, respectively, compared with the current breeding goal. Economic values for PY and MR were KES778.99 and -2364, respectively. Relative economic values for milk yield (MY, kg), fat yield (FY, kg), protein yield (PY, kg), MR, calving interval (CI, days), preweaning daily gain (DG, g/day), postweaning daily gain (PDG, g/day), live weight (LW, kg), preweaning survival (SR1, %), postweaning survival (SR2, %), and length of productive life (PLT, days) were 23 689.80, 4 146.77, 34 665.50, -992.88, 33.66, 62.40, 159.80, 391.94, 987.04, 4 474.37, and 7.56, respectively. This implies that including milk quality traits such as PY in the breeding goal would optimize response to selection in dairy cattle production. Keywords: breeding objective, economic values, genetic evaluation, milk quality, traits, udder health

THE SENSITIVTY OF A TWO-TRAIT SELECTION INDEX TO CHANGES IN ECONOMIC WEIGHTS AND GENETIC PARAMETER ESTIMATES

1985 ◽  
Vol 65 (1) ◽  
pp. 21-29
Author(s):  
B. B. ALLAN ◽  
G. M. WEISS ◽  
H. T. FREDEEN
Keyword(s):  
Genetic Parameters ◽  
Selection Index ◽  
Genetic Parameter ◽  
Average Daily Gain ◽  
Economic Value ◽  
Parameter Estimates ◽  
Genetic Response ◽  
Feed Conversion ◽  
Component Trait ◽  
Economic Weights

Two-trait selection indexes comprising average daily gain (G) and adjusted average backfat depth (F) were constructed utilizing several permutations of economic and genetic parameters. In these permutations the ratio of economic weights employed (value per kg G: value per mm F) ranged from 5:1 to 75:1, the ratios of heritabilities (G:F) ranged from 0.625:1 to 1:1 and the genetic and phenotypic correlations ranged from zero to 0.25. The relative merits of these indexes were evaluated by comparing the expected genetic merit of progeny produced by the top 10% of the boars identified by each index as applied to a population of 590 boars station tested under the Canadian Record of Performance (ROP) system. Responses were estimated for each component trait (G,F), for feed conversion (FC) and the aggregate genetic response (G + F + FC) in standard deviation units. The net economic value of the aggregate genetic response was calculated as the sum of the values of the genetic responses for the individual traits weighted by their economic values. Variation in the economic and genetic parameters influenced the expected genetic response for the component traits but the aggregate response and its economic value varied little over the range of parameters employed. Indeed, an index constructed from estimates of the actual genetic, phenotypic and economic parameters gave net returns that were only $0.04 per hog greater than an index based on equal economic weights, equal heritabilities and zero correlations. This index, of course, is the simple phenotypic index which leads to the conclusion that results of selection based on a phenotypic index will be fully comparable to those of a highly sophisticated genotypic index. Key words: Selection index sensitivity to parameter variation, genotypic selection index, phenotypic selection index, effectiveness of index selection

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