RESUMOO objetivo deste estudo foi avaliar o desempenho de bezerros lactentes submetidos a dietas com e sem feno de leguminosas. O período experimental foi de 60 dias, sendo o fornecimento dos alimentos sólidos ad libitum e disponibilizados a partir do 10º dia de vida do animal, e o leite in natura fornecido de maneira restrita na porção de 4 litros/dia, divididos em duas refeições equitativas. Foram avaliadas as dietas: ração concentrada; ração concentrada mais feno de leucena (Leucaena leucocephala Lam. De Wit) e ração concentrada mais feno de alfafa (Medicago sativa L.). Utilizou-se 15 animais Girolando, distribuídos em três tratamentos, em um delineamento em blocos ao acaso desbalanceados. Os parâmetros avaliados foram peso corpóreo inicial (nascimento - PCI) e final (PCF), ganho médio diário (GMD), alturas de cernelha (AC) e garupa (AG), perímetro torácico (PT), consumo de matéria seca (CMS) e conversão alimentar (CA). Não foram observadas diferenças no desempenho dos animais em relação aos tratamentos, com médias 32,9 (±2,9) kg; 67,7(±1,2) kg; 0,58(±0,02) kg; 13,1(±0,5) cm; 13,7(±0,3) cm; 20,6(±0,7) cm; 0,46(±0,1) kg e 0,79(±0,1), para os parâmetros PCI, PCF, GMD, AC, AG, PT, CMS e CA, respectivamente. As exigências nutricionais de bezerros lactentes são atendidas com o fornecimento de leite e ração concentrada, não havendo necessidade de inclusão de feno de leguminosas na dieta.

ABSTRACTThe aim of this study was to evaluate the performance of suckling calves fed diets with and without legume hay. The experimental period was of 60 days, with solid food being offered ad libitum and available from the 10 th day of the life of the animal, and milk in natura restricted to 4 litres per day, divided into two equal meals. The following diets were evaluated: concentrated feed, concentrated feed and leucaena hay (Leucaena leucocephala Lam. De Wit) and concentrated feed with alfalfa hay (Medicago sativa L.). Fifteen Girolando animals were used, distributed over three treatments in an unbalanced random block design. The parameters under evaluation were: initial body weight (at birth - IBW), final body weight (FBW), average daily gain (ADG), wither height (HW), croup height (HC), thoracic perimeter (PT), dry matter intake (DMI) and feed conversion (FC). No difference was seen in animal performance in relation to the treatments, with averages of 32.9 (±2.9) kg, 67.7 (±1.2) kg, 0.58 (±0.02) kg, 13.1 (±0.5) cm, 13.7 (±0.3) cm, 20.6 (±0.7) cm, 0.46 (±0.1) and 0.79 kg (±0.1) for the parameters IBW, FBW, ADG, HW, HC, PT, DMI and FC respectively. The nutritional requirements of suckling calves are met by supplying milk and concentrated feed; there being no need to include legume hay in the diet.

The present study evaluates the efficiency of different sulfur sources for ruminant nutrition. The fiber digestibility and the amino acid profile were analyzed in the duodenal digesta of crossbred steers fed Brachiaria dictyoneurahay. The sources utilized were elemental sulfur (ES70S), elemental sulfur (ES98S); calcium sulfate in hydrated (HCS), CaSO4.2H2O, and anhydrous (ACS), CaSO4, forms; and ammonium sulfate (AS), (NH4)2SO4, keeping a nitrogen:sulfur ratio of 11:1. The iso-protein supplements had 50% of protein in the total dry matter (DM). Five Holstein × Zebu steers, which were fistulated in the rumen and abomasum, were distributed in a 5 × 5 Latin square. The different sulfur sources in the supplement did not affect any of the evaluated nutritional factors, such as intake of hay dry matter and protein supplement, crude protein (CP), neutral detergent fiber corrected for ash and protein (NDFap), organic matter (OM), non-fibrous carbohydrate (NFC), ether extract (EE), total digestible nutrients (TDN), NDFap and CP digestibility coefficients, ruminal pH, and ruminal ammonia concentration. The concentrations of amino acids available in the abomasal digesta did not differ significantly in the tested diets. The sulfur sources evaluated in the present study are suitable as supplement for cattle, and their employment may be important to avoid environmental contaminations.