other energy depots can be forced, however, genetic associations may remain when phenotypic regression is used. Heritability estimates for phenotypic residual feed intake have been moderate, ranging from 0.26 to 0.43. Genetic correlations of phenotypic residual feed intake with feed intake have been highly positive, suggesting that improvement would produce the correlated response of decreasing...

Little is known of the consequences of divergent selection for residual feed intake (RFI) on intestinal digestion capacity, particularly during immune system stimulation (ISS). Our objective was to evaluate the impact of ISS and divergent selection for RFI on apparent ileal digestibility (AID) and apparent fecal digestibility (AFD) of nutrients and intestinal nutrient active transport and barri...

The objective of the study was to investigate the relationship between health and production traits in chickens. The data were obtained from a closed, fully pedigreed, commercial broiler line. Records included measurements of body weight (BW), residual feed intake (RFI), percent breast meat (PBM), and two health traits (H1 and H2) from 13,665 birds and 1,524 hens with progeny records. Productio...

Abstract Improvement in feed efficiency affects the carbon footprint of a dairy production system. The objective this study was to determine overall effect using EcoFeed index by STgenetics reduce enteric methane, crop and manure related emissions. Genomic estimated breeding values for residual intake (RFI) lactating cows were calculated genetic parameters DMI, energy-corrected milk (ECM), body...

Abstract In dairy, the usual way to measure feed efficiency is through residual intake (RFI) method. However, this method is, in its classical form, a linear regression, which, by construction, does not take into account evolution of RFI components across time, inducing approximations results. We present here new approach that incorporates dynamic dimension data. Using multitrait random regress...

Gompertz growth functions were fitted to longitudinal measurements of daily feed intake (DFI) and BW of 586 boars and 495 gilts from a selection experiment in Yorkshire pigs for residual feed intake (RFI). The selection experiment consists of a line selected for low residual feed intake (LRFI) for 5 generations and a randomly selected control line (CTRL). The objectives of this study were to us...

Providing pigs a diet that matches their nutrient requirements involves optimizing the based on digestibility values of considered feed ingredients. Feeding same quantity to with similar BW but different requirements, however, can result in average daily gain (ADG) and backfat thickness (BF) between pigs. Digestibility may contribute this variation efficiency. We investigated efficiency traits ...

1This research was supported by the Agriculture and Food Research Initiative competitive grant number 2011-68004-30336 form the USDA National Institute of Food and Agriculture. 2Corresponding author: [email protected] ABSTRACT: Little is known of the consequences of divergent selection for residual feed intake (RFI) on intestinal digestion capacity, particularly during immune system stimulati...

Abstract Public opinion has focused on animal agriculture being in competition with growing urban populations for land and water resources. With much of the US drought conditions, improving use efficiency is critical sustainability agriculture. To date, little been done to assess cattle. There evidence a positive relationship between intake DMI, but relationships feed efficiencies are likely mo...