scholarly journals Breeding for resistance to facial eczema in dairy cattle

1991 ◽  
pp. 221-224 ◽  
Author(s):  
C.A. Morris ◽  
N.R. Towers ◽  
H.J. Tempero
Keyword(s):  
Dairy Cattle ◽  
Performance Test ◽  
Performance Testing ◽  
Heritability Estimate ◽  
Progeny Testing ◽  
Genetic Progress ◽  
Preliminary Screening ◽  
Facial Eczema ◽  
Dairy Bulls ◽  
Resistant Progeny

Facial eczema (FE) is a disease of grazing ruminants caused by ingesting spores of the fungus Pithomyces chartarum. The spores contain a toxic compound, sporidesmin, which causes liver injury, sensitivity to sunlight and reduced performance in susceptible dairy cattle. The extent of production losses is summarised. Research at Ruakura has demonstrated that the resistance of animals to FE is inherited, with a heritability estimate of 0.31 in dairy cattle. Genetic progress in dairy cattle could bc achieved by progeny testing young bulls, and selecting for use as sires those with the most resistant progeny. However, work over the last decade in sheep at Ruakura has demonstrated the success of selection based on performance testing (i.e. dosing potential sires themselves and using those that are most resistant to the challenge). In January 1990 we began to develop a performance test for use in the preliminary screening of young dairy bulls for FE resistance. The details of these tests are described. Keywords facial eczema, dairy cattle, performance testing, production loss

scholarly journals Genomic Analysis, Progress and Future Perspectives in Dairy Cattle Selection: A Review

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 599
Author(s):  
Miguel A. Gutierrez-Reinoso ◽  
Pedro M. Aponte ◽  
Manuel Garcia-Herreros
Keyword(s):  
Dairy Cattle ◽  
Production Efficiency ◽  
Association Studies ◽  
Phenotypic Traits ◽  
Progeny Testing ◽  
Genome Wide Association Studies ◽  
Genetic Progress ◽  
Breeding Programs ◽  
Increased Risk ◽  
Selection Of

Genomics comprises a set of current and valuable technologies implemented as selection tools in dairy cattle commercial breeding programs. The intensive progeny testing for production and reproductive traits based on genomic breeding values (GEBVs) has been crucial to increasing dairy cattle productivity. The knowledge of key genes and haplotypes, including their regulation mechanisms, as markers for productivity traits, may improve the strategies on the present and future for dairy cattle selection. Genome-wide association studies (GWAS) such as quantitative trait loci (QTL), single nucleotide polymorphisms (SNPs), or single-step genomic best linear unbiased prediction (ssGBLUP) methods have already been included in global dairy programs for the estimation of marker-assisted selection-derived effects. The increase in genetic progress based on genomic predicting accuracy has also contributed to the understanding of genetic effects in dairy cattle offspring. However, the crossing within inbred-lines critically increased homozygosis with accumulated negative effects of inbreeding like a decline in reproductive performance. Thus, inaccurate-biased estimations based on empirical-conventional models of dairy production systems face an increased risk of providing suboptimal results derived from errors in the selection of candidates of high genetic merit-based just on low-heritability phenotypic traits. This extends the generation intervals and increases costs due to the significant reduction of genetic gains. The remarkable progress of genomic prediction increases the accurate selection of superior candidates. The scope of the present review is to summarize and discuss the advances and challenges of genomic tools for dairy cattle selection for optimizing breeding programs and controlling negative inbreeding depression effects on productivity and consequently, achieving economic-effective advances in food production efficiency. Particular attention is given to the potential genomic selection-derived results to facilitate precision management on modern dairy farms, including an overview of novel genome editing methodologies as perspectives toward the future.

Progeny Testing of Dairy Bulls at Different Levels of Management

1954 ◽  
Vol 1954 ◽  
pp. 83-85 ◽  
Author(s):  
I. L. Mason
Keyword(s):  
Dairy Cattle ◽  
Experimental Evidence ◽  
Environmental Conditions ◽  
The Other ◽  
Progeny Testing ◽  
Laboratory Mice ◽  
Dairy Bulls ◽  
The Tropics ◽  
Different Levels ◽  
European Cattle

There are two schools of thought concerning the most appropriate environment in which to select breeding animals. One says ‘ Always select animals under environmental conditions similar to those where they are to be used ‘. The other says ‘ Select breeding animals in the optimum environment so that they have the best chance of revealing their genetic capabilities ‘. Experiments on growth of laboratory mice and experience with European cattle in the tropics have shown the advisability of the first course in these cases. In regard to hill sheep and dairy cattle in Britain, on the other hand, practice favours the second course, but there is little experimental evidence to support it.

An evaluation of performance-testing of rams using artificial rearing

1978 ◽  
Vol 27 (3) ◽  
pp. 247-259 ◽  
Author(s):  
J. B. Owen ◽  
Lesley E. Brook ◽  
J. L. Read ◽  
D. E. Steane ◽  
W. G. Hill
Keyword(s):  
Performance Testing ◽  
Heritability Estimate ◽  
Regression Coefficients ◽  
Progeny Testing ◽  
Performance Tests ◽  
Early Weaning ◽  
Artificial Rearing ◽  
Evaluation Of Performance ◽  
Progeny Tests ◽  
Low Performance

ABSTRACTIn two trials, male Suffolk sheep were weaned at birth and reared artificially. Animals were ranked on weight at about 90 days and groups comprising the fastest- and slowest-growing animals were selected. The selected rams were subsequently progeny-tested to the same age, with some progeny reared with their dams in normal field conditions and others reared artificially.In Trial I, performance tests were obtained on 35 rams and progeny tests of seven of these (three low and four high), with records on 34 artificially reared and 144 naturally reared progeny on one farm. The regressions of progeny on sire 90-day weight were 0·29 ± 0·12 and 0·19±0·09, respectively.In Trial II, performance tests were obtained on 86 rams, sampled from five source flocks. Rams were selected in pairs of high and low performance from each source, and both members of the pair sent to the same one of seven farms for progeny testing. Ten pairs had progeny tests, comprising 62 artificially reared and 567 naturally reared progeny. The regressions of progeny on sire weight were, respectively, 0·05 ± 0·06 and 0·13 ± 0·03 if source of sire was fitted in the model, and little different, 0·06 ±0·05 and 0·14 ± 0·03 if source of sire was ignored. Progeny from a 2nd year from some sires in Trial II gave rather smaller regression coefficients: 0·06 or 0·09, with source of sire fitted or ignored, respectively.Taking the two main trials together the pooled estimates (ignoring source of sire) of doubled progeny-on-sire regression for 90-day weight were 0·20 ± 0·10 for artificial rearing (a heritability estimate) and 0·30 ± 0·06 for natural rearing. These results suggest that early weaning is an effective method of selecting sires for growth rate.

Selection of dairy cattle for growth rate and milk production

1966 ◽  
Vol 8 (1) ◽  
pp. 109-119 ◽  
Author(s):  
M. Soller ◽  
R. Bar-Anan ◽  
H. Pasternak
Keyword(s):  
Growth Rate ◽  
Milk Production ◽  
Economic Value ◽  
Performance Testing ◽  
Live Weight ◽  
Economic Conditions ◽  
Progeny Testing ◽  
Genetic Progress ◽  
Weight For Age ◽  
Selection Of

The genetic progress in live-weight-for-age (LFA), milk production, and in overall economic value expected as a result of performance and progeny testing of young bulls with respect to milk production and LFA was computed. It was shown that performance testing can contribute considerably to overall progress in economic value, while under certain circumstances progeny testing for LFA can also contribute to genetic progress in overall economic value, but to a lesser degree than performance testing. The relative economic value of LFA and milk production was derived and found to be relatively stable under differing economic conditions.

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.

scholarly journals Genetic and economic evaluation of genetic improvement schemes in pigs. – II. Comparison of selection strategies in a three-way crossbreeding scheme

2000 ◽  
Vol 43 (2) ◽  
pp. 139-150
Author(s):  
U. Wuensch ◽  
G. Nitter ◽  
U. Bergfeld ◽  
L. Schueler
Keyword(s):  
Genetic Gain ◽  
Performance Test ◽  
Performance Testing ◽  
Progeny Testing ◽  
Large White ◽  
Noticeable Effect ◽  
Selection Strategies ◽  
Female Line ◽  
Wide Range ◽  
One Year

Abstract. Alternative selection strategies for a three-way cross in pigs (Pietrain as the sire line and Large White boars mated to German Landrace sows to produce the F1-female) are investigated to maximise both genetic gain and profit. The number of nucleus sows in the main female line (German Landrace) can vary within a wide range without noticeable effect on the genetic and economic response. Productive lifetimes of approximately one year are recommended for nucleus boars and sows after the progeny test. Boars mated to produce crossbreds should be used longer, especially in the terminal sire line. F1-sows can have a productive lifetime of more than two years and can be used close to their biological maximum. Four testing schemes are compared and the contribution of the three breeds to the return is evaluated. Testing crossbred animals at a central test Station cannot be recommended. This capacity should be used to test purebred animals. Both monetary genetic gain and profit are higher in a scheme with a self-performance testing of boars at Station, in comparison to a scheme with only progeny testing at Station, by 36 and 68%, respectively. Due to a reduced generation interval, using boars to produce breeding boars straight after their self-performance test leads to a further increase of monetary genetic gain by 5% and profit by 13%. In all schemes, selection in Pietrain leads to the highest return due to the highest gene proportion in and its shorter distance to the terminal product and the therefore faster transfer of genetic gain.

The value of indicator traits in the genetic improvement of dairy cattle

1988 ◽  
Vol 46 (3) ◽  
pp. 333-345 ◽  
Author(s):  
J. A. Woolliams ◽  
C. Smith
Keyword(s):  
Dairy Cattle ◽  
Genetic Improvement ◽  
Heritability Estimate ◽  
Progeny Testing ◽  
Breeding Values ◽  
Selection For ◽  
Combined Selection ◽  
And Performance ◽  
Indicator Traits ◽  
Indicator Trait

ABSTRACTThe value of indicator traits (7), such as physiological or biochemical traits in the genetic improvement of dairy cattle for milk yield (M) was studied. First, some corrections were made to the base rates of genetic change possible by improvement systems based on progeny testing and on multiple ovulation and embryo transfer (MOET), and on combinations of these. Efficient field progeny-testing systems can be competitive with current adult MOET nucleus herd schemes but juvenile MOET nucleus herd schemes offer substantial increases in rates of response. With high co-heritability, selection for the T alone may allow greater rates of response than those currently considered feasible using progeny testing. However, faster rates are obtained with combined selection. When breeding values are accurately measured by pedigree and performance records on M, as in the progeny test, the extra rates of response with combined selection may be small. Where breeding values are less accurately assessed, as in juvenile MOET nucleus schemes, the extra rates of response can be appreciable. For T with co-heritability (hMrGhT) of 0·27 and the CV for M from 0·15 to 0·20, response rates of 2·0 to 2·7% of the mean per year possible by traditional methods could be increased to 2·2 to 2·9% in progeny testing schemes, 2·3 to 3·1% and to 4·3 to 5·7% for adult and juvenile MOET nucleus schemes respectively.A possible useful indicator trait is blood urea nitrogen (BUN) measured in young animals after a short fast. Results from four experiments with calves having high or low genetic merit for M were summarized. The pooled co-heritability estimate was —0·27 (s.e. 0·05). With this, or even a more modest effect, BUN would be a useful indicator trait in selection for milk production. Its use in practice in high and low selection lines or in a section of the industry, would allow assessment of the merit of the method.

Selection of dairy bulls on half-sister records

1975 ◽  
Vol 20 (1) ◽  
pp. 1-10 ◽  
Author(s):  
J. B. Owen
Keyword(s):  
Dairy Cows ◽  
Annual Cost ◽  
Genetic Improvement ◽  
Large Population ◽  
Progeny Testing ◽  
Genetic Progress ◽  
Testing Scheme ◽  
Normal Procedure ◽  
Dairy Bulls ◽  
Selection Of

SUMMARYA scheme is described for the genetic improvement of milk yield in a large population of dairy cows, based on half-sister selection of young bulls, as an alternative to the normal procedure of progeny testing. The results indicate that the suggested scheme would lead t o an eventual rate of genetic progress very similar to the progeny testing scheme. However, the annual cost of the new scheme is less than a progeny testing scheme, largely because the ‘laying off’ of candidate bulls, to await selection, is completely eliminated. In addition, improvement of the dairy cows shows up sooner in the new scheme; by the 10th year from the start the cumulative genetic improvement is four times greater than for progeny testing.

Maternal effects and selection response with an application to sheep data

1976 ◽  
Vol 22 (3) ◽  
pp. 359-369 ◽  
Author(s):  
J. P. Hanrahan
Keyword(s):  
Maternal Effects ◽  
Performance Test ◽  
Performance Testing ◽  
Selection Response ◽  
Genetic Effects ◽  
Progeny Testing ◽  
Test Selection ◽  
Selection Strategies ◽  
Maternal Performance ◽  
And Performance

SUMMARYThe implications of genetic variation in maternal performance for the relative merits of common selection strategies have been investigated. If the accuracy of progeny testing is computed without taking maternal effects into account, the estimate is biased upward. This bias increases as the correlation between direct and maternal genetic effects decreases from positive to negative values. The relative efficiency of progeny and performance test selection is a function of the heritability of direct and maternal genetic effects and the correlation between them. In terms of genetic gain per unit time, progeny testing is almost always less efficient than performance testing. For sire line improvement progeny testing is relatively more useful but is still likely to be less efficient than performance test selection unless there is a negative correlation between direct and maternal genetic effects or the correlation between purebred and crossbred direct genetic effects is very low or negative.Analysis of body weight at 6 and 14 weeks of age in Galway sheep has shown that maternal genetic effects are an important source of variation in this population.

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.

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