A review of feed efficiency in swine: biology and application.

John F Patience,Néstor A Gutiérrez,Mariana C Rossoni-Serão

doi:10.1186/s40104-015-0031-2

John F Patience, Néstor A Gutiérrez + Show 1 more

Open Access

https://doi.org/10.1186/s40104-015-0031-2

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Abstract

Feed efficiency represents the cumulative efficiency with which the pig utilizes dietary nutrients for maintenance, lean gain and lipid accretion. It is closely linked with energy metabolism, as the oxidation of carbon-containing components in the feed drive all metabolic processes. While much is known about nutrient utilization and tissue metabolism, blending these subjects into a discussion on feed efficiency has proven to be difficult. For example, while increasing dietary energy concentration will almost certainly increase feed efficiency, the correlation between dietary energy concentration and feed efficiency is surprisingly low. This is likely due to the plethora of non-dietary factors that impact feed efficiency, such as the environment and health as well as individual variation in maintenance requirements, body composition and body weight.Nonetheless, a deeper understanding of feed efficiency is critical at many levels. To individual farms, it impacts profitability. To the pork industry, it represents its competitive position against other protein sources. To food economists, it means less demand on global feed resources. There are environmental and other societal implications as well.Interestingly, feed efficiency is not always reported simply as a ratio of body weight gain to feed consumed. This review will explain why this arithmetic calculation, as simple as it initially seems, and as universally applied as it is in science and commerce, can often be misleading due to errors inherent in recording of both weight gain and feed intake.This review discusses the importance of feed efficiency, the manner in which it can be measured and reported, its basis in biology and approaches to its improvement. It concludes with a summary of findings and recommendations for future efforts.

Highlights

Feed represents between 60 and 70 % of the total cost of pork production in modern capital-intensive systems
Energy is the critical dietary constituent that supports maintenance, as well as tissue accretion, and knowledge of energy metabolism and growth is essential to the understanding of feed efficiency [1]
In the Iowa State University herd, seven generations of selection for low residual feed intake (RFI) resulted in a reduction in Average daily feed intake (ADFI) of 0.6 kg/d with only a modest decline in growth rate compared to the high RFI line

Summary

Introduction

Feed represents between 60 and 70 % of the total cost of pork production in modern capital-intensive systems. When restriction is so severe that growth rate is seriously reduced, the additional days required to achieve market weight increases the number of days of maintenance required, such that the savings due to improved efficiency of gain, due to an improved ratio of gain of lipid to protein, is fully offset by the energetic cost of additional days in the barn Table 2 [27]. This example illustrates the importance of conducting research to constant final body weight in order to effectively compare feed efficiency outcomes. Inadequacy of feeder space may result in poorer feed conversion Weber et al reported no impact of feeder space until the pigs reached the final phase of grow-out prior to marketing [6]

Conclusions

Baxter MR

Findings

62. Stark CR