Joanis Tilemahos Zervoudakis

Cromo e indicadores internos na determinação do consumo de novilhos mestiços, suplementados, a pasto

This experiment aimed to evaluate the dry matter intake (DMI) under grazing, obtained through the chromium, in continuous infusion of chromic oxide, dosed once (CR1x) or twice (CR2x) daily, and in mordant form (CRMord), together with the following internal digestibility markers: in vitro dry matter digestibility (IVDMD), indigestible DM (iDM) and indigestible neutral detergent fiber (iNDF) and acid detergent fiber (iADF). Five F1 Limousin x Nelore steers, fistulated in the esophagus and rumen and supplemented in pasture of Brachiaria decumbens, were used. A randomized blocks design, in split plit plot outline was used, in which the supplements were considered as main plot, the methodologies of chromium as split plots and internal markers as split split plots. Supplement effects were not observed on DMI. The use of CR1x methodology underestimated the fecal excretion and DMI (DMI of 2.11% of LW) compared to the methodologies CR2x and CRMord (3.11 and 2.93% LW) that presented better values for DMI, not differing to each other. Interactive effect was observed between supplement and markers, with no differences in the values supplied by the same marker in the different supplements. The IVDMD, the marker of larger precision, presented medium value for DMI of 3.16% LW, overestimating the intake of all supplements. The iDM and iNDF were constant among supplements (2.48 and 2.54% LW of DMI), not differing to each other, being recommended for studies with animals at pasture. The DMI estimated by iADF showed variable results among supplements; the intakes were, on average, by using iADF (2.72% LW) higher compared to iDM and iNDF and lower compared to IVDMD.

Taxas de digestão das frações protéicas e de carboidratos para as silagens de milho e de capim-elefante, o feno de capim-tifton-85 e o farelo de soja

The present work aimed to determine the nitrogen and carbohydrates fractions and to estimate the respective digestion rates for corn silage, Tifton-85 bermudagrass hay, elephantgrass silage and soybean meal. The contents of dry matter (DM), crude protein (CP), ether extract (EE), ash, total carbohydrates (TC), neutral detergent fiber (NDF), NDF corrected for ash and protein (NDFcp), indigestible NDF (INDF), non-protein nitrogen compounds (NPN) and B1+B2, B3 and C nitrogen fractions, nonfiber carbohydrates and B2 and C carbohydrates fractions were determined. TC digestion rates were estimated by in vitro gas production technique, while those of protein fractions were obtained by ruminal proteases utilization. The corn silage and elephantgrass silage showed high NPN proportion, the Tifton-85 bermudagrass hay showed high proportions of B1+B2 and B3 fractions and the soybean meal by high B1+B2 fraction. Corn silage and soybean meal showed high CNF proportion (37.05 and 75.75%) and the Tifton-85 bermudagrass hay and the elephantgrass silage showed high B2 and C fractions (51.20 and 51.70%, 41.77 and 33.56%). The digestion rates of B1+B2 and B3 protein fractions ranged from .0469 to .1512 h-1 for soybean meal and elephantgrass silage and from .0081 to .0757 h-1 for the Tifton-85 bermudagrass hay and elephantgrass silage, respectively. The estimated digestion rates for NFC and B2 fractions ranged from .1294 to .1905 h-1 and from .0254 to .0300 h-1 for Tifton-85 bermudagrass hay and corn silage, respectively.

Consumo de fibra em detergente neutro por bovinos em confinamento

The objective of this work was to evaluate the intake of neutral detergent fiber (NDF) by fedlot cattle, the principal factors that influencing this variable, and to correlate the NDF to total dry matter (DM) intake. The data published at the Brazilian Journal of Animal Science Society and Brazilian Journal of Animal Science among the years of 1991 and 2000, totaling 45 scientific works and 181 averages of treatments, were evaluated. The level of total digestible nutrients was negatively correlated to the level of NDF in diets (r = -0.6006; P .10). The description of the relationship among total DM intake and level of NDF in the diet was accomplished using a biphasic profile, looking for similarity to the curves proposed by the static model of DM intake prediction. The intersection of the curves projected a intake of NDF (NDFI) of 11.93 g/kg LW. However, the evaluation of NDFI estimated during the phase attributed to the physical controllers of intake showed inconstancy, generating divergence among the points of maximum intake of DM and NDF. This profile indicated that the transition among the physical and physiologic mechanisms is, possibly, delimited by an interval with interaction among mechanisms. The evaluation of NDFI according to the level of forage in the diets showed stable profiles in concentrations above to 60%, being of 13.53 g/kg LW in the interval from 80 to 100%. Possible interactions with the indigestible fraction of NDF can dictate the plasticity of the daily limit of NDFI.

Validação de equações preditivas da fração indigestível da fibra em detergente neutro em gramíneas tropicais

The objective of this work was to validate the prediction equations for neutral detergent fiber indigestible fraction (iNDF) employed by the Cornell Net Carbohydrate and Protein System (Sniffen equation) and the National Research Council (Conrads equation). A database with 114 observations taken from tropical grass, with lignin and indigestible neutral detergent fiber (iNDF) contents, was used. Comparison among predicted and observed values was accomplished by adjusting a linear regression model with predicted values as dependent variable and observed values as independent variable. The estimates supplied by Conrads equation were different from observed values, with constant bias of +5.60 percentile points. Alteration of the exponent that composes this equation, from .667 to .85, controlled the bias, guaranteeing the similarity among predicted and observed values. Lack of fitness was observed on the Sniffen equation, which caused under and overestimation of the iNDF contents for lignin concentrations lower and higher than 10.4% of NDF, respectively. This behavior is supported by the absence of non-linear relationships in this equation, constituting its main element of deficiency. The bias free of Conrad equation with empirical correction enlarges the accuracy of estimation process, leading to the lower mean square of the prediction error.

Cinética ruminal das frações de carboidratos, produção de gás, digestibilidade in vitro da matéria seca e NDT estimado da silagem de milho com diferentes proporções de grãos

Foram objetivos do presente trabalho avaliar as alteracoes na composicao bromatologica e nas fracoes nitrogenadas e de carboidratos, estimar a taxa de digestao dos carboidratos fibrosos (CF) e nao-fibrosos (CNF), determinar a digestibilidade in vitro da materia seca (DIVMS) e estimar o teor de nutrientes digestiveis totais (NDT) da silagem de milho com diferentes proporcoes de graos. As silagens foram confeccionadas nas seguintes proporcoes de graos: 0, 15, 30, 45 e 60%. Foram determinados os teores de materia seca (MS), compostos nitrogenados (N), extrato etereo (EE), materia mineral (MM), fibra em detergente neutro (FDN) e fibra em detergente acido (FDA), bem como os compostos nitrogenados nao-proteicos (NNP) e as fracoes nitrogenadas B1+B2, B3 e C. Foram tambem determinados os teores dos carboidratos nao-fibrosos (CNF) e das fracoes potencialmente digestiveis (B2) e indigestiveis da FDN (C). As taxas de digestao dos CNF e da fracao B2 dos carboidratos totais foram estimadas por meio da tecnica de producao de gases. Foram, ainda, realizadas a DIVMS por meio da tecnica de dois estadios e a estimacao do NDT por intermedio da composicao quimica. O acrescimo de graos a silagem aumentou linearmente os teores de MS, N e CNF e reduziu a MM, FDN, FDA e lignina. O NNP e as fracoes B3 e C variaram de 34,04 a 54,62%, 6,63 a 2,61 e 7,83 a 1,32% da PB. Os teores dos CNF e das fracoes B2 e C dos carboidratos totais foram influenciados linearmente pela adicao de graos a silagem, que variaram de 153,55 a 585,10; 489,57 a 203,29; e 233,50 a 85,51 g/kg de MS, respectivamente. As taxas de digestao dos CNF e da fracao B2 apresentaram comportamento quadratico, sendo os valores maximos estimados de 0,2723 e 0,02771 h-1, para as silagens com 40,08 e 14,57% de graos, respectivamente. O volume final de gas, a DIVMS e o NDT estimado, aumentaram linearmente, em funcao da porcentagem de graos, os quais variaram de 20,03 a 28,47 mL, 62,19 a 83,21 e 56,08 a 81,40%, respectivamente.

Níveis de proteína bruta em suplementos múltiplos para terminação de novilhos mestiços em pastejo durante a época seca: desempenho produtivo e características de carcaça

The objective of this study was to evaluate the productive and economical performance of supplemented crossbreed steers during the dry season. Twenty five holstein x zebu steers, with 367.7 kg of live weight and 24 months old, grazing in five paddocks of Brachiaria decumbens (3 ha), were used. The supplements were constituted of grounded corn, whole soybean seeds, urea, ammonium sulfate and mineral salt, and were formulated to contain levels of 12, 16, 20 and 24% crude protein (CP) as fed basis, which constituted the treatments S12, S16, S20 and S24, respectively. The supplements were supplied to the animals in the level of 4 kg/animal/day. A group of animals were allotted to untreated control treatment (SAL) and received exclusively mineral salt. CP levels in the supplements caused quadratic outcome on the variables average daily gain (ADG), final live weight (FLW) and necessary days to reach 450 kg of live weight (D450), which presented critical responses on the CP levels of 19.53% (0.943 kg), 19.38% (465.8 kg) and 19.22% (90.6 days), respectively. The supplementation allowed superior animal performance compared with SAL, which presented averages of daily gain, FLW and D450 of 0.277 kg, 397.4 kg and 312.4 days, respectively. The carcass dressing percentage (CD) and the proportions of muscular, fatty (FT) and bone (BT) tissues in the carcass were not influenced by the composition of supplements. However, supplemented animals presented larger CD and FT and smaller BT compared with SAL. The economical evaluation of the supplements showed larger crude income for S20.

Composição químico-bromatológica, produção de gás, digestibilidade in vitro da matéria seca e NDT estimado da silagem de sorgo com diferentes proporções de panículas

This work had as objective to evaluate the chemical composition alteration in the nitrogen and carbohydrate fractions, to estimate the digestion rate of fiber carbohydrates (FC) and non-fiber carbohydrates (NFC), to determine the in vitro dry matter digestibility (IVDMD) and to estimate the TDN of sorghum silage with different panicle proportions (0, 20 , 40, 60, 80 and 100%). The contents of dry matter (DM), crude protein (CP), ether extract (EE), ash, neutral detergent fiber (NDF), nitrogen fractions: NPN, B1+B2, B3 and C, non-fiber carbohydrate (NFC) and B2 and C fractions of total carbohydrates were determined. The digestion rates of the NFC and B2 fractions of total carbohydrates were estimated by in vitro gas production technique, the IVDMD was determined by two-stage technique and TDN, by chemical composition. The increase in the panicle in sorghum silage increased linearly the amounst of DM, CP, NFC, EE and lignin in NDF and reduced the ash and NDF amount. The NPN and the B1+B2, B3 and C fractions ranged from 9.19 to 21.24, from 67.63 to 75.98, from 3.85 to 6.09 and from 5.09 to 10.98% of total N. The NFC amount increased linearly and of the B2 fraction of total carbohydrates reduced by addition of panicle, ranging from 208.18 to 564.07 and from 381.29 to 0 g/kg of DM, respectively. The digestion rate of NFC and B2 fraction ranged from 0.1358 to 0.1563h-1 and from 0.0247 to 0.0294 h-1. The total gas production was not influenced by panicle addition and the maximum IVDMD of 69.52% was obtained with 60.10% of panicle. Althought the estimated TDN had increased linearly, considering the no alteration of gas production and the quadratical effect of IVDMD, it can be suggested that the utilization of these estimates are not correct.

Consumo e digestibilidade dos nutrientes em bovinos alimentados com dietas à base de volumosos tropicais

The objective of this trial was to investigate the effects of diets containing corn silage, bermudagrass hay, or elephantgrass silage on intake and apparent total tract and partial digestibilities of nutrients in cattle. A forage to concentrate (soybean meal) ratio of 90:10 was used. Six ruminally and omasally fistulated bovines averaging 351 kg of initial body weight were used in two replicated 3 x 3 Latin squares. Each experimental period lasted 16 days with 10 days for animal adaptation and six days for samples collection. The internal marker indigestible neutral detergent fiber (INDF) was used to estimate abomasal DM flow and fecal DM excretion. No significant difference in DM intake was observed between corn silage and bermudagrass hay diets. However, total digestible nutrient intake was greater on corn silage than bermudagrass hay. Animals fed the bermudagrass hay diet had the greatest NDF intake (4.52 kg/day) while those fed corn silage showed the highest NFC intake (1.95 kg/day). In addition, the corn silage diet also resulted in the greatest apparent total tract digestibilities of DM (66.3%), OM (68.9%), NDF (55.7%), and total carbohydrates (68.2%). Rumen was the main site for digestion of total carbohydrates and NDF in all four diets. It was observed an inverse relationship between apparent total tract DM digestibility and INDF intake. Therefore, forage INDF content can be used to estimate digestibility of tropical grasses. Estimated NFC true digestibility averaged 96.6% across diets in the present study.The objective of this trial was to investigate the effects of diets containing corn silage, bermudagrass hay, or elephantgrass silage on intake and apparent total tract and partial digestibilities of nutrients in cattle. A forage to concentrate (soybean meal) ratio of 90:10 was used. Six ruminally and omasally fistulated bovines averaging 351 kg of initial body weight were used in two replicated 3 x 3 Latin squares. Each experimental period lasted 16 days with 10 days for animal adaptation and six days for samples collection. The internal marker indigestible neutral detergent fiber (INDF) was used to estimate abomasal DM flow and fecal DM excretion. No significant difference in DM intake was observed between corn silage and bermudagrass hay diets. However, total digestible nutrient intake was greater on corn silage than bermudagrass hay. Animals fed the bermudagrass hay diet had the greatest NDF intake (4.52 kg/day) while those fed corn silage showed the highest NFC intake (1.95 kg/day). In addition, the corn silage diet also resulted in the greatest apparent total tract digestibilities of DM (66.3%), OM (68.9%), NDF (55.7%), and total carbohydrates (68.2%). Rumen was the main site for digestion of total carbohydrates and NDF in all four diets. It was observed an inverse relationship between apparent total tract DM digestibility and INDF intake. Therefore, forage INDF content can be used to estimate digestibility of tropical grasses. Estimated NFC true digestibility averaged 96.6% across diets in the present study.

Avaliação qualitativa da pastagem diferida de Brachiaria decumbens Stapf., sob pastejo, no período da seca, por intermédio de três métodos de amostragem

ABSTRACT - An experiment was conducted to evaluate the quality of the differed pasture of Brachiaria decumbens under grazingin the dry season. Samples were collected by the total harvesting (TH), hand-plucking sample (HPS) and Extrusa (EXT) collected usingfour Holstein-Zebu steers, with esophageal fistula. The samples were analysed for dry matter content (DM), crude protein (CP), etherextract (EE), mineral matter (MM), total (TC) and non-fibrous carbohydrates (NFC), neutral detergent fiber (NDF), neutral deter gentfiber corrected for ash and protein (NDFap), acid detergent fiber (ADF), insoluble acid detergent fiber (iADF), lignin and in vitro drymatter digestibility (IVDMD). TH was superior (P<0,05) in DM, TC, NDf, NDFap, ADF, iADF and lignin contents. These observationsreflected the low IVDMD for TA. The EXT and HPS did not differ on CP, EE, NFC, NDF, NDFap, ADF, iADF, lignin and IVDMD.The CP content were 5.60 and 6.50 and the ones of NDF were 71.87 e 71.70, respectively to EXT and HPS. These results indicate t hatthe sample HPS, in comparasion with sample TH, would better represent those diet selected by grazing animals.Key Words: beef cattle, extrusa, hand-plucking sample, total harvesting

Desempenho de Novilhos Mestiços na Fase de Crescimento Suplementados Durante a Época Seca

The objective of this study was to evaluate the performance of growing steers, during the dry season, fed supplements with different protein sources. The treatments were constituted of: mineral mixture (control) (MM), and supplements including the protein sources soybean meal (SBM), cottonseed meal (CM), corn gluten meal, (CGM) and wheat bran (WB). The supplements were supplied ad libitum, by using urea end sodium chloride as intake controller, adjusted at the level that allow to intake 1 kg supplement/day. The average urea level was 10%, except for WB (8%), which seems also to act as ingestion controller. Thirty five crossbreed steers with 248 kg of live weight, grazing five Brachiaria decumbens paddocks (8 ha), were used. The average intakes of supplements were 0.046, 1.48, 1.49, 1.50 and 1.48 kg/animal/day for the treatments MM, SBM, CM, CGM and WB, respectively. The values higher than 1 kg/day were justified by elevation of weight of the animals. The average daily gain for MM was 0.09 kg/day, being lower than the supplement treatments, which did not differ to each other, presenting average daily gain of 0.47 kg/day.