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The present study aimed to evaluate the chemical composition of carbohydrates and nitrogenous fractions of late-crop corn silages with different specific masses (SM; 90, 134, 172, and 214 kg dry matter m -3 ). The silage was held in 20-L mini-silos, and the experimental design was completely randomized, with four replications (mini-silos) per treatment. In the present study, differences in the compression (i.e., SM) of corn silages caused changes in the contents of soluble sugar and nitrogenous constituents; however, SM alone did not explain the entire preservation of the ensiled material. ResumoObjetivou-se avaliar alterações bromatológicas sobre as frações glicídicas e nitrogenadas de silagens de milho "safrinha" com diferentes massas específicas (ME) no momento da ensilagem (90, 134, 172 e 214 Kg de MS.m -3 ). A ensilagem foi realizada em minissilos com capacidade de 20 L. O delineamento experimental foi inteiramente casualizado com quatro repetições (minissilos) por tratamento. O fracionamento foi realizado segundo The Cornell Net Carbohydrate and Protein System (CNCPSv5.0). A ME afetou linearmente os teores de extrato etéreo Ŷ = 1,718 + 0,0041*ME (P = 0,009; R 2 = 39,2), açúcares solúveis Ŷ = 0,9502 -0,003445*ME (P < 0,001; R 2 = 59,9) e fibra solúvel Ŷ = -0,4731 + 0,01158*ME (P = 0,025; R 2 = 31,2). Nos carboidratos, a fração B1 apresentou comportamento linear ascendente Ŷ = 14,88 + 0,2566*ME (P = 0,043; R 2 = 38,4) com o aumento da ME, enquanto as demais frações não foram influenciadas. Nos constituintes nitrogenados houve variação no nitrogênio total Ŷ = 2,003 -0,01065*ME + 0,000036*ME 2 (P = 0,041; R 2 = 38,8), no nitrogênio não proteico Ŷ = 1,436 -0,01103*ME + 0,000036*ME 2 (P = 0,060; R 2 = 35,1), no nitrogênio solúvel Ŷ = 1,715 -0,01450*ME + 0,00005*ME 2 (P = 0,024; R 2 = 43,8) e no nitrogênio insolúvel em detergente neutro Ŷ = 0,4979 -0,001057*ME (P < 0,001; R 2 = 70,6), cujos resultados também contribuíram para as diferenças nas frações A Ŷ = 66,47 -0,5291*ME + 0,00174*ME 2 (P = 0,095; R 2 =30,4), B2 Ŷ = 6,78 + 0,05857*ME (P = 0,076; R 2 =20,8) e B3 Ŷ = 19,03 -0,05565*ME (P = 0,018; R 2 = 34,1) do modelo de Cornell. A ME de compactação, de forma isolada, não serve para explicar, na totalidade, a preservação do material ensilado. Diferentes ME causam alterações no teor de açúcares solúveis das silagens de milho e nos constituintes nitrogenados.

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RESUMO Este trabalho teve como objetivo verificar se há alteração na composição dos carboidratos de silagens de milho safrinha quando colhidas nas alturas de corte (AC) de 20, 45, 70

Four Polwarth castrated male sheep (42 ± 4.4 kg live weight (LW) surgically implanted with chronic indwelling catheters into the mesenteric, portal and hepatic veins, housed in metabolism cages and offered Cynodon sp. hay at rates (g of dry matter (DM)/kg LW) of 7, 14, 21 or ad libitum, were used in a 4 × 4 Latin square experiment to evaluate the effect of the level of forage intake on blood flow and oxygen consumption by the portal-drained viscera (PDV), liver and total splanchnic tissues (ST). The portal blood flow and the oxygen consumption by PDV linearly increased at increased organic matter (OM) intake. No effect of level of OM intake was obtained for the hepatic artery blood flow and oxygen consumption by liver. As a consequence, the level of OM intake only tended to directly affect hepatic blood flow and oxygen consumption by total ST. Oxygen consumption was linearly and positively related to blood flow across PDV, liver and total ST. The heat production by PDV and total ST, as proportion of metabolizable energy (ME) intake, decreased curvilinearly at increased ME intake. In conclusion, the oxygen consumption by PDV, but not by liver, was directly related to the level of forage intake by sheep. Moreover, when ingested at levels below maintenance, most of ME was spent as heat produced by ST.