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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.

Grande parte da energia obtida pelos animais ruminantes em ambiente de criação é proveniente da fermentação dos carboidratos solúveis e estruturais, os quais são convertidos, pela fermentação microbiana, em produtos metabólicos que podem ser destinados à síntese de carne, leite, lã e trabalho.Deste modo o objetivo deste estudo é revisar sobre a importância da fibra solúvel no metabolismo energético de ruminantes e demonstrar as principais diferenças em relação às outras fibras. As fibras solúveis são as pectinas, betaglicanas, gomas, mucilagens, e algumas hemiceluloses, já as fibras insolúveis são a celulose, lignina, hemiceluloses e pectinas insolúveis. A pectina é o único componente da parede celular que é completamente e rapidamente fermentável e, portanto, não é, em contraste com a hemicelulose, uma das substâncias lignificadas da matriz. Pesquisadores ao testarem dois tipos de processamento de grãos de milho (floculado ou moído grosso) e sua substituição por 50% polpa de citrus peletizada em vacas da raça Holandês alimentadas com silagem de milho, observaram que a inclusão parcial de polpa SOUZA, C.G. et al. Fibra solúvel no metabolismo energético de ruminantes. PUBVET,