This study was conducted to quantify differences in feed efficiency among 4 sire breeds using records from 1,109 crossbred lambs over 3 yr. Lambs were produced from mating Columbia, USMARC-Composite (Composite), Suffolk, and Texel rams to adult Rambouillet ewes. After weaning, lambs were finished on a high-energy diet in group-fed pens. Efficiency was assessed at 45 and 90 d on study, 50 and 60...

Residual feed intake (RFI) is defined as the difference between the observed ADFI and the ADFI predicted from production and maintenance requirements. The objectives of this study were to evaluate RFI as a selection criterion to improve feed efficiency and its potential to reduce N and P excretion in 4 pig breeds. Data were collected between 2000 and 2009 in French central test stations for 2 d...

Thirty-eight Angus-based, crossbred, nulliparous beef heifers (BW = 280 ± 26.3 kg) sired by 2 Angus sires were used to determine if dam BW affected heifer performance, DMI, residual feed intake (RFI), and endocrine markers. Heifers were housed in individual pens (2.2 by 9.1 m) equipped with 2.2 m of bunk space and fed a diet (90.4% DM, 13.7% CP, 67.2% NDF, and 56.2% TDN) consisting of 87.2% ber...

Feeding efficiency is a multifactorial and economically important trait in pigs. Genetic improvement of feeding efficiency will greatly benefit the pig industry. In the past decades, the hog market weight has increased worldwide. However, whether the genetic architecture of feeding efficiency is same or not at early and late fattening periods is unclear. To map genomic regions for feed efficien...

Intestinal microbe-host interactions can affect the feed efficiency (FE) of chickens. As inconsistent findings for FE-associated bacterial taxa were reported across studies, the present objective was to identify whether bacterial profiles and predicted metabolic functions that were associated with residual feed intake (RFI) and performance traits in female and male chickens were consistent acro...

Objectives of this experiment were to: 1) determine appropriate test length, timing, and repeatability of DMI, ADG, and efficiency over different biological time points; 2) determine the efficacy of using decoupled performance and intake data to generate accurate feed efficiency measures; and 3) determine the relationship between forage-and grain-feed efficiency measures. Over 2 yr, Charolais c...

Feed efficiency has a major influence on the unit cost of beef cattle production. Gibb and McAllister (1999) have reported that a 5% improvement in feed efficiency has an economic impact four times greater than a 5% improvement in average daily gain. In addition, the cost of feed is second only to fixed costs in importance to the profitability of commercial beef operations (Basarab, 1999). The ...

Residual feed intake (RFI), a measure of feed efficiency (FE), is defined as the difference between the observed and the predictable feed intake considering size and growth of the animal. It is extremely important to beef production systems due to its impact on the allocation of land areas to alternative agricultural production, animal methane emissions, food demand and cost of production. Glob...

Seventy-six Angus steers chosen from breeding lines divergently selected for residual feed intake (RFI) were studied to quantify the relationship between RFI and the daily rate of methane production (MPR). A 70-d feeding test using a barley-based ration was conducted in which the voluntary DMI, feeding characteristics, and BW of steers were monitored. The estimated breeding value (EBV) for RFI ...

Selection for improved growth efficiency has the potential to alter meat composition and meat quality. The objective of this study was to determine the extent to which selection for reduced residual feed intake (RFI) affects pork composition and quality. In order to achieve this, pork composition and meat quality traits were compared between a line selected for reduced RFI over five generations...