Performance and ruminal and intestinal morphometry of Santa Inês sheep submitted to feed restriction and refeeding

Abstract

A study was carried out to evaluate the performance and ruminal and intestinal morphology of Santa Inês sheep subjected to feed restriction followed by refeeding. A total of 40 uncastrated lambs with an approximate age of 120 ± 15 days and mean body weight (BW) of 17.04 ± 1.18 kg were randomly divided into two groups of BW (20 and 25 kg of BW), which were subjected to different levels of feed restriction (0%, 25%, and 40% of feed restriction). For performance variables, six treatments were considered (0, 25%, and 40% of feed restriction for both groups (20 and 25 kg of BW)) and five treatments for morphometric variables (ad libitum, 25% and 40% for both groups (20 and 25 kg of BW)). All animals were slaughtered with 14 weeks of experimentation. During the feed restriction phase, the dry matter intake (DMI), feed efficiency (FE), and average daily gain (ADG) decreased (P < 0.05) as the level of restriction increased. During the refeeding phase, lambs with 20 kg of body weight subjected to restriction presented lower (P < 0.05) DMI in the ad libitum treatment. However, lambs with 25 kg of body weight under feed restriction presented DMI, FE, and ADG similar (P > 0.05) to the group ad libitum. The final body weight of restricted lambs after refeeding (both groups 20 and 25 kg of body weight) was lower (P < 0.05) than lambs feed ad libitum. In relation to morphology, restricted lambs showed greater height ruminal papillae and larger (P < 0.05) area of ruminal absorption and intestinal absorption, especially the lambs under treatment 40% of feed restriction. The feed restriction followed by refeeding in sheep provided partial compensatory gain, in addition, caused morphological changes in the rumen and intestine that allowed greater absorption and possibly compensatory gain in periods of greater refeeding.

Effects of feeding methods on growth and slaughter performance, blood biochemical indices, and intestinal morphology in Minxinan black rabbits (Oryctolagus cuniculus)

“…Feed restriction programs have been used in post-weaning animals to improve feed efficiency and resistance to digestive system disorders, reducing carcass fat and production costs (Tumova et al 2021 ). Studies on feed restriction in pigs (Le Floc'h et al 2014 ), broilers (Van der Klein et al 2017 ), and sheep (Lima et al 2022 ) showed that animals can compensate the growth inhibition of feed restriction by improving feed efficiency. Moreover, feed restriction can be used to reduce morbidity and mortality in growing rabbits (Boisot et al 2003 ; Gidenne et al 2009 ; De Blas 2013 ), improve farm feed efficiency (Knudsen et al 2014 ; Birolo et al 2020a ), and reduce nitrogen emissions and environmental pollution (Birolo et al 2016 ; Birolo et al 2017 ).…”