sire selection
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2021 ◽  
Vol 8 ◽  
Author(s):  
Donagh P. Berry ◽  
Siobhan R. Ring

Understanding dairy producer mindset in service sire selection can provide useful information for different junctures along the commercial and extension animal breeding chain. It can aid the targeted marketing of bulls based on farm production systems but also provide useful information for delivering bespoke extension services. The objective of the present study was to examine if differences exist among dairy producers in their choice of dairy and beef service sires depending on the life stage at which the surplus progeny generated from such matings exit the dairy farm. This was predominantly based on evaluating the breed of beef sires used but also their genetic merit for calving difficulty and carcass traits, namely, carcass weight, conformation, and fat score; differences in genetic merit among dairy sires as well as among the dairy cows themselves were also considered. The objective was accomplished through the cross-sectional analyses of progeny fate data from 1,092,403 progeny born in 4,117 Irish dairy herds. Herd-years were categorized into one of four systems based on when the surplus progeny exited the dairy farm: (1) calves sold <70 days of age, (2) cattle sold as yearlings between 250 and 450 days of age, (3) prime cattle sold for finishing (slaughtered between 8 and 120 days of exiting the dairy farm), or (4) prime cattle sold for immediate slaughter (i.e., slaughtered within 7 days of exiting the dairy farm). The mean genetic merit of both the cows and service sires used across the four different systems was estimated using linear mixed models. Of the beef service sires used in herds that sold their surplus progeny as calves, their mean predicted transmitting ability for carcass weight and carcass conformation score was just 2.00 kg and 0.11 scores [scale of 1 (poor) to 15 (excellent)] inferior to the beef service sires used in herds that sold their surplus progeny as prime cattle for immediate slaughter. Similar trends, albeit of smaller magnitude, were evident when comparing the genetic merit of the dairy service sires used in those systems. Cows in herds that sold their surplus progeny as calves were genetically less likely to incur dystocia as well as to have lighter, less-conformed, and leaner carcasses than cows in herds that sold their surplus progeny post-weaning. Hence, results from the present study suggest that diversity in herd strategy regarding when surplus progeny exit the herd influences service sire selection choices in respect of genetic merit for dystocia and carcass attributes. That said, the biological difference based on the current pool of available service sires is small relative to the dairy producers that sell their surplus progeny as young calves; when expressed on a per standard deviation in genetic merit of the beef service sires used across all herds, the difference between extreme systems was, nonetheless, approximately half a standard deviation for carcass weight and conformation.


2020 ◽  
Vol 138 (1) ◽  
pp. 91-107
Author(s):  
Erin Massender ◽  
Luiz F. Brito ◽  
Angela Cánovas ◽  
Christine F. Baes ◽  
Delma Kennedy ◽  
...  

2020 ◽  
Vol 103 (5) ◽  
pp. 4532-4544
Author(s):  
N. Lopez-Villalobos ◽  
P.G. Wiles ◽  
D.J. Garrick

2019 ◽  
Vol 248 ◽  
pp. 18-24 ◽  
Author(s):  
S. Wang ◽  
E. Strandberg ◽  
Å. Viklund ◽  
J.J. Windig ◽  
S. Malm ◽  
...  

2019 ◽  
Author(s):  
J. Obšteter ◽  
J. Jenko ◽  
J. M. Hickey ◽  
G. Gorjanc

ABSTRACTThis paper compares genetic gain, genetic variation, and the efficiency of converting variation into gain under different genomic selection scenarios with truncation or optimum contribution selection in a small dairy population by simulation. Breeding programs have to maximize genetic gain but also ensure sustainability by maintaining genetic variation. Numerous studies showed that genomic selection increases genetic gain. Although genomic selection is a well-established method, small populations still struggle with choosing the most sustainable strategy to adopt this type of selection. We developed a simulator of a dairy population and simulated a model after the Slovenian Brown Swiss population with ~10,500 cows. We compared different truncation selection scenarios by varying i) the method of sire selection and their use on cows or bull-dams, and ii) selection intensity and the number of years a sire is in use. Furthermore, we compared different optimum contribution selection scenarios with optimization of sire selection and their usage. We compared the scenarios in terms of genetic gain, selection accuracy, generation interval, genetic and genic variance, the rate of coancestry, effective population size, and the conversion efficiency. The results show that early use of genomically tested sires increased genetic gain compared to progeny testing as expected from changes in selection accuracy and generation interval. A faster turnover of sires from year to year and higher intensity increased the genetic gain even further but increased the loss of genetic variation per year. While maximizing intensity gave the lowest conversion efficiency, a faster turn-over of sires gave an intermediate conversion efficiency. The largest conversion efficiency was achieved with the simultaneous use of genomically and progeny tested sires that were used over several years. Compared to truncation selection optimizing sire selection and their usage increased the conversion efficiency by either achieving comparable genetic gain for a smaller loss of genetic variation or achieving higher genetic gain for a comparable loss of genetic variation. Our results will help breeding organizations to implement sustainable genomic selection.


EDIS ◽  
2018 ◽  
Vol 2018 (1) ◽  
Author(s):  
Francisco Peñagaricano

Sire selection is one of the most important decisions that a dairy producer makes. It represents a great opportunity to improve the profitability of the dairy production enterprise. This new 3-page fact sheet reviews some key concepts that should be considered in order to make proper selection decisions and discusses alternative methods for selecting sires based on multiple traits. Written by Francisco Peñagaricano, and published by the UF/IFAS Department of Animal Sciences, January 2018.  http://edis.ifas.ufl.edu/an337


Author(s):  
Govind Mohan ◽  
G. R. Gowane ◽  
Arun Kumar ◽  
A. K. Chakravarthy

The genetics of fitness traits, viz. replacement rate (RR) and selective value (SV) were studied in the flock of Malpura Sheep along the production parameters of the animals. The study was carried out on 10 years records for 2307 lambing sired by 187 sires. Sire wise incidence of replacement traits was as follows: abnormal birth (0.30%), sex ratio (49.98%), mortality (17.26%), culling (15.37%), RR on total lamb basis (33.98%) and RR on female lamb basis (68.44%). The selective value or adaptive value for the flock was 1.37. Sire did not affect abnormal birth, mortality, culling and SV significantly, whereas sire significantly affected sex ratio, and RR on total female lambs born basis. Ranking of the sires for selective value was incoherent with the ranking for production parameters such as age at first service, age at first lambing, weight at first service, productive flock life and longevity. Study indicated that the selection of sires for SV would not bring desired correlated change on any of the production parameter of the animals.


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