ASSESSMENT OF COMPLETELY PELLETED DIETS FOR PERFORMANCE TESTING OF RAMS

1986 ◽  
Vol 66 (3) ◽  
pp. 817-820
Author(s):  
J. S. WALTON ◽  
B. W. McBRIDE ◽  
N. A. MARTINEAU ◽  
T. D. BURGESS
Keyword(s):  
Growth Rate ◽  
Key Words ◽  
Performance Test ◽  
Performance Testing ◽  
Ingestive Behavior ◽  
Test Procedures

Completely pelleted diets were fed to rams under a facsimile of Ontario Ram Performance Test procedures. Twenty rams were fed for 50 d on completely pelleted rations without impairment of growth rate and without any effects on rumen health or ingestive behavior. Key words: R.O.P. testing, rams, pelleted feeds, growth rate, rumen lining

Selection for efficient lean growth in a pig herd

1981 ◽  
Vol 32 (4) ◽  
pp. 681 ◽  
Author(s):  
CP McPhee
Keyword(s):  
Growth Rate ◽  
Food Intake ◽  
Performance Test ◽  
Subcutaneous Fat ◽  
Performance Testing ◽  
Restricted Feeding ◽  
Food Conversion ◽  
Muscle Area ◽  
Eye Muscle ◽  
Lean Growth

A pig herd was selected for 6 years by using an economic index combining growth rate, food conversion efficiency and carcass leanness. These three traits were all measured in a performance test which permitted appetite variation between pigs to be expressed. Boars selected with an intensity of 118 were used for 6 months, and sows with an intensity of 114 were kept for two farrowings. An unselected control herd was maintained concurrently. To measure selection response, selected (S) and control (C) pigs were compared as they grew from 25 to 90 kg liveweight on ad lib. and restricted feeding during the last 2 years of selection. The following significant (P < 0.05) responses occurred in the selection herd: (i) A slight increase in growth rate on restricted feed, balanced by a similar decrease on ad lib, feeding. (ii) A decline in food conversion ratio of 5 % (C, 2.79; S, 2.65) due mainly to a reduction in appetite. (On ad lib. feeding, food intake per day declined by 6 % (C, 2.30 kg/d; S, 2.16 kg/d.)). (iii) A decline in average subcutaneous fat depth by 11 % (C, 27.8 mm; S, 24.7 mm) and in fat dissected from the ham by 7 % (C, 2.80 kg; S, 2.61 kg). (iv) An increase in estimated lean in the carcass by 2% (C, 30.3 kg; S, 31.0 kg). (v) A decline in dressing percentage of the carcass by 1 % (C, 77.1 %; S, 76.2 %). There was no change in eye muscle area or carcass length. The results are discussed in terms of changes in the ratio of food intake to lean growth. In the group fed ad lib., this ratio declined by 7 %, mainly because of a decline in food intake. On restricted feeding it fell by 6 %, mainly owing to an increase in lean growth. That portion of the selection effort absorbed in reducing food intake may have been more profitably directed to increasing lean growth by suppressing appetite variation during performance testing, rather than allowing it to be expressed.

The effect of duration of performance test on genetic gain in pigs

1978 ◽  
Vol 29 (2) ◽  
pp. 423
Author(s):  
CP McPhee
Keyword(s):  
Growth Rate ◽  
Performance Test ◽  
Performance Testing ◽  
Breeding Value ◽  
Test Facility ◽  
Equal Weight ◽  
Feed Conversion ◽  
Two Stage ◽  
Selection Scheme ◽  
Value Determination

The problem of making the best use of a limited number of performance-testing places in the genetic improvement of pigs is examined. A model is given which balances the duration of testing and its effect on the accuracy of breeding value determination, against throughput and its effect on selection intensity. The model is a phenotypic one with easily estimated parameters in lieu of the more exact genetic one whose parameters are difficult to estimate. It is illustrated with data taken from the Queensland performance-testing station which evaluates boars on an index combining feed conversion ratio, growth rate and back fat. Full performance records from 26 to 90 kg liveweight are subdivided into four consecutive parts of equal weight interval. A range of feasible one and two stage selection schemes based on performance in one or more of these parts are compared. Relative to the present full testing scheme, the best single stage selection, that based on performance in the last two parts (3 + 4), is 14% more efficient. The best two stage selection scheme, also a 3 + 4 part test with a 50% culling at the end of part 3, is 19 0%, more efficient. Highest efficiencies are achieved by imposing a preliminary culling on growth rate before entry to the testing facility; e.g. selection of the best 25% on part 3 growth rate followed by part 4 index selection within the test facility is 36% more efficient than the present full test. The limitations of the model and some practical problems of part testing schemes are discussed.

Influence of the correlation between growth rate and backfat on selection response in pigs

1990 ◽  
Vol 1990 ◽  
pp. 84-84
Author(s):  
P. R. Bampton ◽  
A. J. Webb
Keyword(s):  
Growth Rate ◽  
Performance Test ◽  
Performance Testing ◽  
Selection Response ◽  
Economic Traits ◽  
Lean Growth ◽  
Genetic And Phenotypic Correlations ◽  
Ad Libitum ◽  
Selection For ◽  
Ad Libitum Feeding

Backfat levels in pigs have declined rapidly in the last decade and are approaching an economic optimum. As optimal levels of backfat are achieved this has two important implications for selection objectives. First, the relative emphasis of selection will shift to other traits, particularly lean growth rate. Second, there will also be a move towards ad libitum feeding on performance test to allow expression of appetite and to increase response to selection for lean growth rate. The effect of very lean pigs coupled with ad libitum feeding may result in changes in the genetic and phenotypic relationship between growth rate and fat depths. Reported genetic and phenotypic correlations between growth rate and backfat range from +0.3 on ad libitum feeding to -0.3 on restricted feeding. In most performance testing regimes the key relationship is between growth rate and ultrasonic fat depths which in contrast to other economic traits are often unfavourably correlated.

Corrigendum - The effect of duration of performance test on genetic gain in pigs

1978 ◽  
Vol 29 (3) ◽  
pp. 423
Author(s):  
CP McPhee
Keyword(s):  
Growth Rate ◽  
Performance Test ◽  
Performance Testing ◽  
Breeding Value ◽  
Test Facility ◽  
Equal Weight ◽  
Feed Conversion ◽  
Two Stage ◽  
Selection Scheme ◽  
Value Determination

The problem of making the best use of a limited number of performance-testing places in the genetic improvement of pigs is examined. A model is given which balances the duration of testing and its effect on the accuracy of breeding value determination, against throughput and its effect on selection intensity. The model is a phenotypic one with easily estimated parameters in lieu of the more exact genetic one whose parameters are difficult to estimate. It is illustrated with data taken from the Queensland performance-testing station which evaluates boars on an index combining feed conversion ratio, growth rate and back fat. Full performance records from 26 to 90 kg liveweight are subdivided into four consecutive parts of equal weight interval. A range of feasible one and two stage selection schemes based on performance in one or more of these parts are compared.Relative to the present full testing scheme, the best single stage selection, that based on performance in the last two parts (3 + 4), is 14% more efficient. The best two stage selection scheme, also a 3 + 4 part test with a 50% culling at the end of part 3, is 19%, more efficient. Highest efficiencies are achieved by imposing a preliminary culling on growth rate before entry to the testing facility; e.g. selection of the best 25% on part 3 growth rate followed by part 4 index selection within the test facility is 36% more efficient than the present full test. The limitations of the model and some practical problems of part testing schemes are discussed.

Sensitivity to dietary lysine: energy content in pigs divergently selected for components of efficient lean growth rate

2003 ◽  
Vol 76 (2) ◽  
pp. 175-189 ◽  
Author(s):  
N.D. Cameron ◽  
G.B. Garth ◽  
J.C. Penman ◽  
A. Fiskin
Keyword(s):  
Growth Rate ◽  
Performance Test ◽  
Energy Content ◽  
Genetic Correlations ◽  
Performance Testing ◽  
Energy Utilization ◽  
Selection Line ◽  
Diet Choice ◽  
Genetic Merit ◽  
Lean Growth

AbstractThe sensitivity to dietary lysine: energy content of pigs from lines divergently selected over seven generations for components of efficient lean growth rate was quantified by the within-selection line regression of performance test traits on diet class. Large White pigs were performance tested over three 14-day test-periods starting at 30, 50 and 75 kg and offered, to appetite, isoenergetic diets differing in dietary total lysine: energy (0•59, 0•69, 0•81, 0•91, 1•01, 1•12 and 1•23 g/MJ digestible energy (DE)). Within each litter, full-sibs were performance tested on different diets. Pigs were also performance tested on a diet-choice procedure using diets with total lysine: energy of 0•69 and 1•12 g/MJ DE to determine the correlation between performance on phase-feeding and diet-choice.The study consisted of 578 animals with 459 pigs tested with phase-feeding and 119 tested on diet-choice procedures. The study detected significant selection line and dietary effects on performance test traits, but no significant between-selection line differences in sensitivity to dietary total lysine: energy. When combinations of performance test traits were transformed into predicted lysine and energy utilization traits there were significant selection line effects on predicted nutrient allocation, but not in responses to increasing dietary total lysine: energy. The lack of between-selection line differences in sensitivity to dietary total lysine: energy indicated that the consequences of changing dietary total lysine: energy will be broadly similar across a range of genotypes, as spanned by the selection lines of the study.Genetic correlations between performance traits of phase-fed and diet-choice pigs suggested that predictions of genetic merit will be similar with animals tested on either procedure between 30 and 75 kg but post 75 kg predicted genetic merit for growth rate and lysine intake should be estimated separately for performance on diet-choice or for performance on a given diet. In contrast, predicted genetic merit for fat deposition with performance testing on diet-choice will be highly correlated with predicted genetic merit with testing on a single diet.

Performance test procedures for meat production amongst dairy bulls used in AI

1970 ◽  
Vol 12 (4) ◽  
pp. 577-583 ◽  
Author(s):  
C. J. M. Hinks
Keyword(s):  
Performance Test ◽  
Performance Testing ◽  
Progeny Test ◽  
Meat Production ◽  
Capital Investments ◽  
Test Procedures ◽  
Dual Purpose ◽  
Potential Benefits ◽  
Dairy Bulls

SUMMARYThe potential benefits to be obtained from the adoption of performance testing for meat production in a dual-purpose breed have been examined and contrasted with those obtainable from improvements in dairy progeny test procedures.It was concluded that capital investments in performance testing are likely to prove profitable, but less profitable than similar investments in the improvement of the dairy progeny test. Where performance testing is practised, there appears to be little advantage to be gained from the application of selection rates in excess of 1 in 3.

Evaluation of Asphalt Mixture Performance Using Cracking and Durability Tests at a Full-Scale Pavement Facility

2021 ◽  
pp. 036119812110218
Author(s):  
Amir Golalipour ◽  
Varun Veginati ◽  
David J. Mensching
Keyword(s):  
Performance Test ◽  
Asphalt Mixture ◽  
Performance Testing ◽  
Field Performance ◽  
Optimization Procedure ◽  
Cyclic Fatigue ◽  
Intermediate Temperature ◽  
Index Test ◽  
Reclaimed Asphalt ◽  
Indirect Tensile

In the asphalt materials community, the most critical research need is centered around a paradigm shift in mixture design from the volumetric process of the previous 20-plus years to an optimization procedure based on laboratory-measured mechanical properties that should lead to an increase in long-term pavement performance. This study is focused on advancing the state of understanding with respect to the value of intermediate temperature cracking tests, which may be included in a balanced mix design. The materials included are plant-mixed, laboratory-compacted specimens reheated from the 2013 Federal Highway Administration’s (FHWA’s) Accelerated Loading Facility (ALF) study on reclaimed asphalt pavement/reclaimed asphalt shingle (RAP/RAS) materials. Six commonly discussed intermediate temperature (cracking and durability) performance testing (i.e., Asphalt Mixture Performance Tester [AMPT] Cyclic Fatigue, Cantabro, Illinois Flexibility Index Test [I-FIT], Indirect Tensile Cracking [ITC, also known as IDEAL-CT], Indirect Tensile Nflex, and Texas Overlay Test) were selected for use in this study based on input from stakeholders. Test results were analyzed to compare differences between the cracking tests. In addition, statistical analyses were conducted to assess the separation among materials (lanes) for each performance test. Cyclic fatigue and IDEAL-CT tests showed the most promising results. The ranking from these two tests’ index parameters matched closely with ALF field performance. Furthermore, both showed reasonable variability of test data and they were successful in differentiating between different materials.

Performance Testing of Coal Fired Power Plants

2007 ◽  
Author(s):  
Shane E. Powers ◽  
William C. Wood
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Performance Test ◽  
Model Development ◽  
Performance Testing ◽  
The United States ◽  
Plant Performance ◽  
Cycle Performance ◽  
Test Program

With the renewed interest in the construction of coal-fired power plants in the United States, there has also been an increased interest in the methodology used to calculate/determine the overall performance of a coal fired power plant. This methodology is detailed in the ASME PTC 46 (1996) Code, which provides an excellent framework for determining the power output and heat rate of coal fired power plants. Unfortunately, the power industry has been slow to adopt this methodology, in part because of the lack of some details in the Code regarding the planning needed to design a performance test program for the determination of coal fired power plant performance. This paper will expand on the ASME PTC 46 (1996) Code by discussing key concepts that need to be addressed when planning an overall plant performance test of a coal fired power plant. The most difficult aspect of calculating coal fired power plant performance is integrating the calculation of boiler performance with the calculation of turbine cycle performance and other balance of plant aspects. If proper planning of the performance test is not performed, the integration of boiler and turbine data will result in a test result that does not accurately reflect the true performance of the overall plant. This planning must start very early in the development of the test program, and be implemented in all stages of the test program design. This paper will address the necessary planning of the test program, including: • Determination of Actual Plant Performance. • Selection of a Test Goal. • Development of the Basic Correction Algorithm. • Designing a Plant Model. • Development of Correction Curves. • Operation of the Power Plant during the Test. All nomenclature in this paper utilizes the ASME PTC 46 definitions for the calculation and correction of plant performance.

A Comparative Study of Genetic Algorithms and Gradient Methods for RM12 Turbofan Engine Diagnostics and Performance Estimation

2004 ◽  
Author(s):  
Tomas Gro¨nstedt ◽  
Markus Wallin
Keyword(s):  
Gas Turbine ◽  
Performance Test ◽  
Gradient Methods ◽  
Performance Testing ◽  
Performance Estimation ◽  
Data Sets ◽  
Data Set ◽  
Turbofan Engine ◽  
Local Optima ◽  
Bypass Ratio

Recent work on gas turbine diagnostics based on optimisation techniques advocates two different approaches: 1) Stochastic optimisation, including Genetic Algorithm techniques, for its robustness when optimising objective functions with many local optima and 2) Gradient based methods mainly for their computational efficiency. For smooth and single optimum functions, gradient methods are known to provide superior numerical performance. This paper addresses the key issue for method selection, i.e. whether multiple local optima may occur when the optimisation approach is applied to real engine testing. Two performance test data sets for the RM12 low bypass ratio turbofan engine, powering the Swedish Fighter Gripen, have been analysed. One set of data was recorded during performance testing of a highly degraded engine. This engine has been subjected to Accelerated Mission Testing (AMT) cycles corresponding to more than 4000 hours of run time. The other data set was recorded for a development engine with less than 200 hours of operation. The search for multiple optima was performed starting from more than 100 extreme points. Not a single case of multi-modality was encountered, i.e. one unique solution for each of the two data sets was consistently obtained. The RM12 engine cycle is typical for a modern fighter engine, implying that the obtained results can be transferred to, at least, most low bypass ratio turbofan engines. The paper goes on to describe the numerical difficulties that had to be resolved to obtain efficient and robust performance by the gradient solvers. Ill conditioning and noise may, as illustrated on a model problem, introduce local optima without a correspondence in the gas turbine physics. Numerical methods exploiting the special problem structure represented by a non-linear least squares formulation is given special attention. Finally, a mixed norm allowing for both robustness and numerical efficiency is suggested.

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