Breeding and Genetics
In recent years there has been a rapid increase in genetic merit in UK dairy herds. This rapid increase has largely been attributed to the importation of semen from North America and Europe, coupled with advances in progeny testing schemes and the introduction of advanced techniques to evaluate progeny test data from different countries.
£PLI and Sire Selection (PDF 8 MB)
Profitable Lifetime index (£PLI) is the primary selection index used for ranking dairy cattle in the UK. It is based on a series of production traits (milk, butterfat and protein yield) making up 45 percent of the index, and non-production traits such as fertility, locomotion, somatic cell count and lifespan accounting for the remaining 55 percent. CAFRE have developed a short course on what £PLI means and how best to select AI sires using £PLI.
DairyCo Breeding+ (www.dairycobreeding.org.uk/hg_reports.asp
) produce herd genetic reports for milk recorded and pedigree registered herds that are also available from your milk recorder. If you know the average genetic merit of your herd and have clear breeding aims in mind, a herd genetic summary can be used to aid sire selection. CAFRE have developed a short course demonstrating how the herd genetic summary is used to aid sire selection in Greenmount’s Future Herd.
Profitable Lifetime index (£PLI) is the primary selection index used for ranking dairy cattle in the UK. It is based on a series of production traits (milk, butterfat and protein yield) making up 45 percent of the index, and non-production traits such as fertility, locomotion, somatic cell count and lifespan accounting for the remaining 55 percent. CAFRE have developed a short course on what £PLI means and how best to select AI sires using £PLI.
DairyCo Breeding+ (www.dairycobreeding.org.uk/hg_reports.asp
) produce herd genetic reports for milk recorded and pedigree registered herds that are also available from your milk recorder. If you know the average genetic merit of your herd and have clear breeding aims in mind, a herd genetic summary can be used to aid sire selection. CAFRE have developed a short course demonstrating how the herd genetic summary is used to aid sire selection in Greenmount’s Future Herd.Using £PLI for Sire Selection - Key websites (PDF 22 KB)
Useful links to top UK available sires (DairyCo) and milk recording companies (dairy herd management NMR) for the download of your herd genetic report.
Useful links to top UK available sires (DairyCo) and milk recording companies (dairy herd management NMR) for the download of your herd genetic report.
Top 100 sires available in Northern Ireland ranked by £PLI (APR 2012)(PDF 27 KB)
DairyCo Breeding+ conduct independent sire evaluations in the UK three times per year. Full sire listings for all breeds are available by clicking on the DairyCo (www.dairycobreeding.org.uk/default.asp) and then the link for the appropriate breed. CAFRE have summarised this list of around 500 available bulls to the top 100 of these available in Northern Ireland.
DairyCo Breeding+ conduct independent sire evaluations in the UK three times per year. Full sire listings for all breeds are available by clicking on the DairyCo (www.dairycobreeding.org.uk/default.asp
) and then the link for the appropriate breed. CAFRE have summarised this list of around 500 available bulls to the top 100 of these available in Northern Ireland. Genetic codes explained (PDF 135 KB)
In the sire lists produced by DairyCo and breed societies, sire names are followed by various genetic codes. These are summarised by clicking on the above link.
In the sire lists produced by DairyCo and breed societies, sire names are followed by various genetic codes. These are summarised by clicking on the above link.
Lifetime performance of dairy cows in Northern Ireland (PDF 598 KB)
One of the targets of Greenmount’s Future Herd is an average lifetime yield of 40,000 litres per cow. A technology investigation was conducted in collaboration with United Dairy Farmers and Holstein UK which established that the Northern Ireland lifetime yield average is around 27,000 litres though there was considerable variation between herds.
One of the targets of Greenmount’s Future Herd is an average lifetime yield of 40,000 litres per cow. A technology investigation was conducted in collaboration with United Dairy Farmers and Holstein UK which established that the Northern Ireland lifetime yield average is around 27,000 litres though there was considerable variation between herds.
Impact of sire Fertility PTA on daughter fertility (PDF 202 KB)
Sire Fertility Index was developed by scientists at the University of Edinburgh and Scottish Agricultural College with the aim of improving dairy cow fertility through breeding from more fertile bulls. Each one-point increase in a sire’s Fertility Index should increase daughters conception rate by 0.5 percent and decrease daughter calving index by 0.5 days, but analysis of breeding records from Greenmount’s Future Herd show that the benefits are even greater.
Sire Fertility Index was developed by scientists at the University of Edinburgh and Scottish Agricultural College with the aim of improving dairy cow fertility through breeding from more fertile bulls. Each one-point increase in a sire’s Fertility Index should increase daughters conception rate by 0.5 percent and decrease daughter calving index by 0.5 days, but analysis of breeding records from Greenmount’s Future Herd show that the benefits are even greater.
Potential benefits of sexed semen (PDF 31 KB)
Sexed semen has been commercially available to farmers in the UK since 2000. Due to the sorting process, there are fewer sperm cells in each straw than conventional semen and conception rates are generally expected to be around 10 percent lower. Therefore sexed semen is generally only recommended for use on maiden heifers. The benefits of using sexed semen include more rapid genetic progress and increased number of heifer calves allowing more cows to be served with beef semen.
Sexed semen has been commercially available to farmers in the UK since 2000. Due to the sorting process, there are fewer sperm cells in each straw than conventional semen and conception rates are generally expected to be around 10 percent lower. Therefore sexed semen is generally only recommended for use on maiden heifers. The benefits of using sexed semen include more rapid genetic progress and increased number of heifer calves allowing more cows to be served with beef semen.
Impact of Complex Vertebral Malformation (CVM) on dairy cows fertility (PDF 43 KB)
CVM is a genetic condition in Holstein cattle that leads to embryonic loss and abortion. It is only a problem when two CVM carrier animals are mated and was first discovered in 2000 when the effects of a carrier sire, Carlin-M Ivanhoe Bell, became apparent. At Greenmount, genetic testing of cows descended from CVM carrier bulls were tested for CVM and breeding records analysed. Sires are now selected that are tested free of CVM (*TV).
CVM is a genetic condition in Holstein cattle that leads to embryonic loss and abortion. It is only a problem when two CVM carrier animals are mated and was first discovered in 2000 when the effects of a carrier sire, Carlin-M Ivanhoe Bell, became apparent. At Greenmount, genetic testing of cows descended from CVM carrier bulls were tested for CVM and breeding records analysed. Sires are now selected that are tested free of CVM (*TV).
