The intense selection and highly accurate genetic evaluations for NRF progeny-tested bulls lead to outstanding sires for use within and outside of Norway. Daughters of Norwegian Red (NRF) sires imported into the U.S. tend to produce more milk and protein and have better fertility than Swedish Red and Finnish Ayrshire sires imported into the U.S. according to the most recent U.S. genetic evaluation results (August 2010). Swedish and Finnish sires tended to be slightly better for fat yield.
Nordic bulls in the U.S.
Thousands of doses of semen from Nordic Red sires have been imported into the U.S. over the past 10 years. Much of this semen has been used in U.S. herds that do not contribute to the national genetic evaluations but a significant percentage of this semen has also been used in herds that are participating in the national genetic evaluation programs. Almost all the NRF and Swedish Red semen that has been used in the U.S. is for crossbreeding and only a very limited amount has been used in the U.S. Ayrshire population. A slightly higher proportion of the Finnish Ayrshire semen may have been used in the U.S. Ayrshire population.
Genetic evaluation by the USDA
The U.S. Department of Agriculture is responsible for genetic evaluations in the U.S. for most traits and a substantial number of the daughters of imported Nordic Red bulls are now included in these genetic evaluations. All the official genetic evaluation details are publicly available in the U.S. so it is easy to track and evaluate how well the daughters of bulls are doing in the U.S.
Table 1 contains the number of bulls, number of daughters and averages U.S. daughter yield deviations for the Nordic Red sires with U.S. daughters in the August 2010 official U.S. genetic evaluations. Daughter yield deviations measure daughter performance compared with contemporaries or herd mates. Daughter yield deviations are adjusted for all the non-genetic factors that systematically impact performance and they are the main component of genetic evaluations.
Table 1 (pdf)
Daughter yield deviations for Nordic Red bulls are given on the Ayrshire scale in the U.S. These daughter yield deviations reflect actual daughter performance with no impact of pedigree or other genetic information. The bulls represented in Table 1 are, of course, bulls selected for import to the U.S. so the results tell us about the performance of daughters of the imported NRF bulls compared with daughters of imported bulls from Sweden and Finland from the same time period. Danish Red sires are not included in Table 1 because only 3 Danish Red sires with 32 daughters total were included in the August 2010 U.S. genetic evaluations.
High milk yield for NRF daughters
Daughters of the NRF bulls used in the U.S. tend to have higher milk yield and protein yield than daughters of the Swedish and Finnish bulls used in the U.S. Of course protein yield is critical in the U.S. because of its value (as in most other countries) so this is good news for the producers who have used NRF bulls within the U.S. In addition, the NRF daughters are better for daughter pregnancy rate (measured in percentage) which is the U.S. measure of cow fertility.
Daughter pregnancy rate in the U.S. is impacted only by reproduction in lactating cows (no virgin heifer data are included) and it reflects the timing of insemination as well as conception rate of the cows. Higher numbers are desirable for daughter pregnancy rate as this reflects increased speed and efficiency at getting pregnant.
Daughters of NRF bulls tend to be slightly behind the Swedish and Finnish bulls for fat yield and fat percentage. Of course fat yield is important in the U.S. and other countries but it is not as critical for payment in the U.S. as protein yield. It is interesting to note that the NRF bull 05848 Oygarden has 56 daughters in the August 2010 genetic evaluation and he has the highest daughter yield deviation for fat yield and the highest daughter yield deviation for protein yield among all the NRF, Swedish and Finnish bulls.
Over time we will see more daughters of the Nordic Red bulls get into the U.S. genetic evaluations and we will have additional bulls with U.S. genetic evaluation data. This will help Geno to continue to evaluate how well the NRF bulls are doing.
The U.S. genetic evaluations are important for understanding the merit of the selected bulls from the Nordic counties because the Nordic bulls are mainly used for crossing in the U.S. and because the U.S. herds represent a level playing field at a high level of production where bulls can be fairly compared with little concern over preferential treatment and other factors that impact performance measures in smaller herds.