Submitted to: Joint Abstracts of the American Dairy Science and Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: April 18, 2011
Publication Date: July 10, 2011
Citation: Connor, E.E., Hutchison, J.L., Olson, K., Norman, H.D. 2011. Opportunities for improving milk production efficiency in dairy cattle. Joint Abstracts of the American Dairy Science and Society of Animal Science. Sci. 89 (E-Suppl. 1):2. Abstract 4. Technical Abstract: Increasing feed costs and the desire to improve environmental stewardship have stimulated interest in improving feed efficiency of livestock, including that of U.S. dairy herds. For instance, USDA cost projections for corn and soybean meal suggest a 20% increase over 2010 pricing for a 16% protein mixed dairy cow ration in 2011, which may lead to a reduction in cow numbers to maintain profitability of dairy production. Furthermore, an October 2010 study by The Innovation Center for U.S. Dairy to assess the carbon footprint of fluid milk found that the efficiency of feed conversion is the single greatest factor contributing to variation in the carbon footprint, due to its effects on methane release during enteric fermentation and from manure. Thus, we are conducting research to identify the most efficient dairy cattle at conversion of feed to milk using residual feed intake (RFI), a measure used successfully to identify the most efficient beef cattle at conversion of feed to gain. Residual feed intake is calculated as the difference between predicted and actual feed intake to support maintenance and production (e.g., growth in beef cattle, or milk in dairy cattle). Selection for a lower RFI phenotype can reduce feed intake, methane production, nutrient losses in manure, and visceral organ weights substantially in beef cattle. We have evaluated RFI measures during the first 90 d of lactation for the USDA-Beltsville Holstein herd and found the heritability of RFI to be 0.16 (n = 254). A difference in net feed intake of 8.3 kg/d DM was found between the least and most efficient animals. Mean actual DMI differed by 3.7 kg/d (P < 0.0001) between the efficient and inefficient groups (± 0.5 SD from the mean RFI of 0), with no differences (P > 0.20) in mean BW, ADG, or ECM exhibited between the 2 groups. These results suggest promise for using RFI in dairy cattle to improve feed conversion to milk. Previous and current research on the use of RFI in lactating dairy cattle will be discussed, as well as opportunities to improve production efficiency of dairy cattle using RFI for milk production.