Author
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Connor, Erin |
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Hutchison, Jana |
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Norman, H |
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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 10/9/2011 Publication Date: 6/27/2012 Citation: Connor, E.E., Hutchison, J.L., Norman, H.D. 2012. Estimating feed efficiency of lactating dairy cattle using residual feed intake. In: Hill, R.A., editors. Feed Efficiency in the Beef Industry. Wiley-Blackwell, NJ. Chapter 11. Interpretive Summary: Rising feed costs and concerns about the negative impacts of animal production on the environment have made the improvement of feed efficiency of all livestock species, including dairy cattle, a high-priority area of agricultural research. One method for estimating feed efficiency of livestock is residual feed intake (RFI), which is defined as the difference between actual feed intake and expected intake based on energy requirements of production and maintenance. This method has been used effectively to select beef cattle that are more efficient at conversion of feed into growth without correlated responses in body size or average daily gain. The benefits of selecting for lower RFI (greater feed efficiency) in beef cattle include reductions in feed requirements and greenhouse gas emissions. This chapter discusses the use of RFI for milk production in dairy cattle, and the benefits of its application to the dairy industry. Technical Abstract: Rising feed costs and ever increasing concerns about the negative impacts of agriculture and animal production on the environment have made the improvement of feed efficiency of all livestock species a high-priority area of agricultural research. Improving production efficiency of lactating dairy cattle has long been a goal of dairy scientists and significant strides have been towards this goal through better nutrition, animal management, and genetic selection to maximize milk yield in the modern-day dairy cow. The tradeoffs in selecting for cows with greater and greater propensities for milk production are the potential long-term effects on other factors such as body condition, metabolic imbalance, longevity, and fertility. Therefore, methods are needed to identify those dairy cattle that are inherently more efficient at conversion of feed into milk, but do not exhibit negative effects on other production characteristics or animal well being due to greater milk production efficiency. One method for estimating feed efficiency is residual feed intake (RFI), which is defined as the difference between actual feed intake and expected intake based on energy requirements of production and maintenance. Advantages of this method are that it provides an assessment of an animal’s metabolic efficiency and is not correlated to other traits such as milk yield or body size. This chapter discusses the use of RFI for milk production in dairy cattle, and the benefits of its application to the dairy industry. |
