Growth efficiency of ewe lambs classified into residual feed intake groups and pen fed a restricted amount of feed

Residual intake and gain for the evaluation of performance, non-carcass components, and carcass characteristics of confined crossbred Texel lambs

“…For each kilogram of BW gain, the Yoshihara Carneiro et al 9 animal requires 1.2 Mcal of metabolic energy for the deposition of water and protein and 8.0 Mcal for the deposition of fat (NRC, 2007). Thus, internal fat displays a wider range of variation, and its deposition requires a larger amount of maintenance energy (Redden et al, 2013). Indeed, visceral fat deposition is among the causes for inefficient energy use by farm animals (Redden et al, 2013;Moreno et al, 2014).…”

“…The study of variations in feed efficiency unveils differences in responses of efficient and inefficient animals. Previous work has shown that efficient animals display different BW gain patterns, including reduced fat thickness during finishing, smaller visceral fat depots, and reduced non-carcass weight (Gomes et al, 2012;Redden et al, 2013;Nascimento et al, 2016;Moraes et al, 2017).…”

Residual feed intake in dairy ewes: an evidence of intraflock variability

“…Evaluating factors affecting intraflock variability of feed efficiency, through RFI, increases our knowledge regarding the available spectrum of adaptive capacities which can be found at the intraflock level; this becomes more interesting when the interpretation of RFI is combined with other physiological processes like body reserves mobilisation-accretion. However, the exercise is also interesting from an economic point of view for the industry in question since the identification of animals that require less feed for normal production would clearly increase overall farm productivity, thus leading to the argument that feed conversion efficiency of farm animals could be considered an important component of the profitability of farming systems (Cockrum et al, 2013; Pryce et al, 2014; Redden et al, 2013; Williams et al, 2011).…”

“…Currently, there are several reports arguing the interest, pertinence and possibilities of using RFI as a selection characteristic to increase feed efficiency and farm profitability in non-ruminants (Patience et al, 2015), but also in ruminants (beef: Fitzsimons et al, 2014; Gomes et al, 2012; dairy: Green et al, 2013; Potts et al, 2015; Pryce et al, 2014). There is a lack of information, however, in small ruminants, although some works have been developed mainly during the growth phase in sheep (Cockrum et al, 2013; Meyer et al, 2015; Redden et al, 2013) and the sheep industry has yet to fully investigate the potential impacts associated with selecting for RFI on carcass merit, growth traits, reproduction traits, and fleece characteristics (Cockrum et al, 2013).…”

“…Thus, there is growing interest among producers with respect to using RFI as a tool for genetic improvement, with a greater experience in swine (Patience et al, 2015) and poultry; (Aggrey and Rekaya, 2013), numerous research efforts have investigated the effectiveness of selecting for feed efficiency using RFI in beef cattle (Fitzsimons et al, 2014; Gomes et al, 2012), dairy cattle (Green et al, 2013; Potts et al, 2015; Pryce et al, 2014) or sheep (Cockrum et al, 2013; Meyer et al, 2015; Redden et al, 2013). The sheep industry, however, has yet to fully investigate the potential impacts associated with selecting for RFI on carcass merit, growth traits, reproduction traits, and fleece characteristics (Cockrum et al, 2013).…”