A review of feed efficiency in swine: biology and application

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.

Exploring a Possible Link between the Intestinal Microbiota and Feed Efficiency in Pigs

“…However, this study is one of the first to exploit this technology to examine the intestinal microbiota among pigs of varying FE. The metric used for FE was RFI, and ranking pigs according to this measure was particularly useful, as it allowed the selection of pigs that consume less feed to achieve the same weight gain, in agreement with previous findings for pigs divergent in RFI (14,31). To minimize the variability in FE due to external factors, pigs were ranked by RFI within litter (to control for genetic influences), and all pigs were subjected to the same management, environmental, and nutritional conditions.…”

“…Residual feed intake measures the difference between actual and expected feed intake, where the expected feed intake is based on live weight, rate of gain, body fat, and muscle content of the individual pig (31). It was calculated as the residuals from a least-squares multiple-regression model of ADFI on ADG, metabolic live weight, sex, and all relevant two-way interactions, as well as the effects of back fat and muscle depth.…”

Improving the sustainability of global meat and milk production

“…Major improvements were also seen in body composition, with yield of the major breast muscle (per kg body weight) increasing by approximately 80 %. Similar improvements in feed conversion have also been achieved in pigs (11) . While dramatic improvements have been made in the efficiency of animal growth this has been achieved, particularly in monogastric animals, through the use of highly nutritious feed ingredients which often could be fed directly to human subjects.…”

Feed intake, growth performance and carcass traits of broilers fed diets with various inclusion levels of baobab seed oilcake

“…As noted by Amerah et al (2007), the improvements are attributed among other things to higher density, improved starch digestibility from chemical changes during pelleting, increased nutrient intake, changes in physical form, reduced feed wastage and decreased energy spent in eating. The requirements for protein in supplemental feeds is greatly influenced by the levels provided by the natural diet for a targeted production level (Nasr et al, 2011;Patience et al, 2015). Consequently, the incorporation of protein in supplemental diets must be formulated to meet the requirements of increasing broiler biomass (Kilburn & Edwards, 2004;Kamran et al, 2008).…”