Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/11/2008
Publication Date: 5/1/2009
Citation: Norman, H.D., Wright, J.R., Weigel, K.A. 2009. Alternatives for Examining Daughter Performance of Progeny-Test Bulls between Official Evaluations. Journal of Dairy Science. 92(5):2348-2355. Interpretive Summary: Four alternative sources of data were used to determine whether interim sire evaluations based on first lactation daughters in cooperator herds would provide accurate information for banking semen of potentially elite new bulls. Lactation records from the last 18 mo gave higher correlations with official evaluations than those from the last 12 mo, and records from cooperator herds with >=1 progeny test daughter gave higher correlations than records from with >=5 progeny test daughters. Interim evaluations based on recent data from a subset of herds can provide valuable information between official sire summaries for new progeny test bulls.
Technical Abstract: For the 10 years prior, Interbull and USDA have provided 4 genetic evaluations annually. In August 2007, USDA switched to calculating official genetic evaluations 3 times per year in coordination with Interbull; the new schedule was determined by consensus of the 26 countries which provided national evaluations to Interbull. To offset part of the delay in providing information due to reduced frequency of official evaluations, industry cooperators requested that interim summaries be initiated for progeny test bulls based on lactation records from a limited number of herds. The use of first lactation records from progeny test (PT) daughters and their herdmates that calved recently in cooperator herds was proposed. Interim evaluations of PT bulls were examined to determine whether they could provide useful information for collection and storage (i.e., banking) of semen of potentially elite bulls, thereby enhancing the availability of semen from elite new bulls to US dairy producers. Correlations between interim evaluations and subsequent official sire summaries were high (>=0.98 for bulls of interest), indicating that interim summaries could provide valuable information between official sire summaries. Members of the Council on Dairy Cattle Breeding (CDCB) and the dairy records processing centers (DRPC) subsequently supported the implementation of three interim summaries per year, with distribution of interim evaluations limited to PT bulls with >=10 daughters and that increased in reliability since the most recent official sire summary.