Genomic selection strategies in dairy cattle breeding programmes: Sexed semen cannot replace multiple ovulation and embryo transfer as superior reproductive technology

AbstractRates of genetic improvement in dairy cattle breeding programmes have increased substantially in the last decade, not only in Europe where there has been substantial immigration of North American stock. More accurate statistical evaluation procedures, including the use of best linear unbiased prediction (BLUP) with the animal model, have been introduced; higher selection intensities have been achieved, particularly on production traits, through better organized and focused schemes; and developments in multiple ovulation and embryo transfer (MOET) have been both a stimulus and to some extent a cause. Continued rapid improvement can be expected as research and development enables more accurate and timely use to be made of recording data, because there is evidence that heritability values for milk production are rising, perhaps because of better cow management, and as competition among breeders internationally increases. There are a number of consequent challenges to geneticists and breeders. Attention will have to be given to maintaining the fitness of very high producing animals by recording health, fertility, longevity and parlour traits, and using the results of research to give them appropriate weight in selection decisions. Developments in molecular methods and in reproductive technologies present new opportunities, but are unlikely to do more for some time than complement progress from conventional selection on the important production traits.

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Experiences of including reproduction and health traits in Scandinavian dairy cattle breeding programmes

Livestock Production Science ◽

10.1016/s0301-6226(03)00047-2 ◽

2003 ◽

Vol 83 (2-3) ◽

pp. 99-112 ◽

Cited By ~ 66

Author(s):

J. Philipsson ◽

B. Lindhé

Keyword(s):

Dairy Cattle ◽

Cattle Breeding ◽

Dairy Cattle Breeding ◽

Breeding Programmes

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Policy of selecting bulls to breed bulls

Animal Science ◽

10.1017/s000335610002804x ◽

1987 ◽

Vol 44 (1) ◽

pp. 29-38 ◽

Cited By ~ 5

Author(s):

M. E. Goddard

Keyword(s):

Dairy Cattle ◽

Genetic Variance ◽

Selection Response ◽

Progeny Testing ◽

Cattle Breeding ◽

Sire Evaluation ◽

Dairy Cattle Breeding ◽

Breeding Programmes ◽

Computer Simulation Program ◽

Selection Of

ABSTRACTIn the breeding of dairy cattle the selection of bulls to breed young bulls for progeny testing is a crucial process. This paper compares several policies for making this selection based on the criteria-selection response, inbreeding depression, loss of genetic variance and variability of response. A number called the ‘effective number of new bulls to breed bulls selected each year’ (NBBe) is defined which is closely related to the last three of these criteria. Past studies of the design of dairy cattle breeding programmes have assumed that selection is within a group of bulls progeny tested in the same year (policy I). However, modern sire evaluation methods allow comparison of sires tested in different years. To evaluate the effect of selecting bulls to breed bulls from all available bulls (policy II) a computer simulation program was used. Policy II results in an increase in the response to selection but a substantial decrease in NBBe. When compared at the same NBBe, policy II results in a smaller selection response than policy I. A policy which allows the best bulls to be used for more than 1 year but which limits the maximum number of years for which they can be used, results in the best compromise. If bulls are to be used for several years there is little advantage to be gained from making more matings within each year to more high-rated bulls or to older, more reliably evaluated bulls.

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Relevance of genomic evaluation for egg quality traits in layers

10.1101/704742 ◽

2019 ◽

Author(s):

David Picard Druet ◽

Amandine Varenne ◽

Florian Herry ◽

Frédéric Hérault ◽

Sophie Allais ◽

...

Keyword(s):

Dairy Cattle ◽

Genomic Selection ◽

Egg Quality ◽

Pure Line ◽

Genetic Evaluation ◽

Evaluation Methodology ◽

Quality Traits ◽

Genomic Evaluation ◽

Cattle Breeding ◽

Dairy Cattle Breeding

AbstractBackgroundGenomic evaluation, based on thousands of genetic markers, has become the standard evaluation methodology in dairy cattle breeding programs over the past few years. Despite the many differences between dairy cattle breeding and poultry breeding, genomic selection seems very promising for the avian sector, and studies are currently being conducted to optimize avian selection schemes. In this optimization perspective, one of the key parameters is to properly predict the accuracy of genomic evaluation in pure line layers.MethodsBoth genetic evaluation and genomic evaluation were performed on three candidate populations (male and female), using different sizes of phenotypic records on five egg quality traits and at two different ages. The methodologies used were BLUP & ssGBLUP, and variance-covariance matrices were estimated through REML. To estimate evaluation accuracy, the LR method was implemented. Four statistics were used to assess the relative accuracy of the estimated breeding values of candidates, their bias and dispersion, as well as the differences between genetic evaluation and genomic evaluation.ResultsIt was observed that genomic evaluation, whether performed on males or females, always proved more accurate than genetic evaluation. The gain was higher when phenotypic information was narrowed and an augmentation of the size of the reference population led to an increase in accuracy prediction, for what regards genomic evaluation. By taking into account the increase of selection intensity and the decrease of the generation interval induced by genomic selection, the expected annual genetic gain would be higher with ancestry-based genomic evaluation of male candidates than with genetic evaluation based on collaterals. This advantage of genomic selection over genetic selection requires to be studied in more details for female candidates.ConclusionsIn conclusion, in the population studied, genomic evaluation for egg quality traits of breeding birds at birth seems a promising strategy, at least for what regards males selection.

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189 Choices ahead for dairy cattle breeding programs

Journal of Animal Science ◽

10.1093/jas/skz258.043 ◽

2019 ◽

Vol 97 (Supplement_3) ◽

pp. 22-23

Author(s):

Michael M Lohuis

Keyword(s):

Dairy Cattle ◽

Genomic Selection ◽

Gene Editing ◽

New Technologies ◽

Value Added ◽

Progeny Testing ◽

Cattle Breeding ◽

Breeding Programs ◽

Dairy Cattle Breeding ◽

Selection For

Abstract Dairy cattle breeding programs have been transformed from conventional progeny-testing schemes to genomic selection paired with nucleus herd breeding in the span of one decade. This was spurred by the simultaneous advances in low-cost SNP genotyping, genomic selection methodology and reproductive biotechnologies. The rates of genetic progress have approximately doubled in this time but so have increases in inbreeding levels. This was driven by intense competition between AI studs and farmer adherence to common selection indices which has concentrated selection on very elite segments of juvenile age groups. This has led to speculation on the need for alternative indices and selection for novel traits in order to differentiate breeding programs and customize selection for unique farm conditions. This will be made more possible by the advent of on-farm sensor technology and artificial intelligence algorithms. Large commercial dairies are increasingly experimenting with crossbreeding with varying levels of success and this will require a new approach by breeding programs to focus both on purebred and crossbred performance. In addition, the potential exists for use of gene-editing to further enable value-added traits to be added into breeding programs. In parallel with breeding program advancements, consumer trends are also changing to include more interest in specialty dairy products with implied differences in digestibility, health or environmental impacts. Identifying technologies and traits that will add value either on the farm as well as at the consumer level will be a challenge for today’s breeders and producers. Some new technologies, such as gene editing, can pose consumer acceptance challenges if they are perceived to be used carelessly or for the wrong reasons. Careful choices will need to be made to continue to improve profitability, functionality and health of dairy cattle while also meeting higher consumer standards for animal welfare, health and the environment.

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Optimal strategies for the use of genomic selection in dairy cattle breeding programs

Journal of Dairy Science ◽

10.3168/jds.2010-4101 ◽

2011 ◽

Vol 94 (8) ◽

pp. 4140-4151 ◽

Cited By ~ 15

Author(s):

M. Wensch-Dorendorf ◽

T. Yin ◽

H.H. Swalve ◽

S. König

Keyword(s):

Dairy Cattle ◽

Genomic Selection ◽

Optimal Strategies ◽

Cattle Breeding ◽

Breeding Programs ◽

Dairy Cattle Breeding

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Genetic correlations between 305-day and monthly test day milk yield records in primiparous Iranian Holsteins

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200006013 ◽

2001 ◽

Vol 2001 ◽

pp. 219-219

Author(s):

H. Farhangfar ◽

P. Rowlinson ◽

M.B. Willis

Keyword(s):

Dairy Cattle ◽

Genetic Gain ◽

Genetic Correlations ◽

Cattle Breeding ◽

Breeding Values ◽

Dairy Heifers ◽

The Past ◽

Dairy Cattle Breeding ◽

Adjustment Factors ◽

Breeding Programmes

Traditionally, in most dairy cattle breeding programmes genetic evaluation of dairy sires and cows has been primarily based on 305-day lactation yield. To provide 305-day lactation yields many partial lactations have to be extended by adjustment factors resulting in overestimation or underestimation of 305-day yields which in turn leads to biased prediction of breeding values. Over the past decade there has been a considerable interest in using monthly test day records instead of 305-day lactation yield to predict breeding values of dairy cattle as early as possible and also to increase genetic gain through reducing generation interval. The main objective of present research was to estimate the genetic correlations between 305-day and monthly test day milk yields in Iranian Holstein dairy heifers.

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