Marcone Geraldo Costa

Avaliação da qualidade nutricional da silagem de cana-de-açúcar com aditivos microbianos e enriquecida com resíduo da colheita de soja

The objective of this trial was to evaluate the fermentative characteristics and nutritional quality of sugarcane treated with microbial additives and 10% of soybean crop residue based on sugarcane fresh weight. The variety RB855536 harvested at 16 months of age was used in a completely randomized design with tree repetitions. Addition of soybean crop residue reduced 33% of DM losses and 60% of ammonia-N (% total N) although final silage pH increased. Use of inoculants reduced silage pH only in association with soybean crop residue with no significant effects on the remaining variables. For all treatments, silages had higher contents of fiber and lower DM levels than the material before ensiling. In vitro dry matter digestibility (IVDMD) was significantly higher (P<0.05) on treatments with soybean crop residue compared to the other treatments. Moreover, compared with the material used for ensiling, reduction in digestibility was higher for treatments without soybean crop residue (24.3% vs. 9.3%). Combination of soybean crop residue with sugarcane improved nutritional quality and reduced DM and soluble carbohydrates losses, mainly in the form of gases, diluting the proportion of cell wall components and preventing losses in forage IVDMD. The use of the inoculants L. plantarum and L. buchneri during ensiling of sugarcane is not recommended because no improvement was observed on the chemical composition or fermentation profile of silages.

Desempenho produtivo de vacas leiteiras alimentadas com diferentes proporções de cana-de-açúcar e concentrado ou silagem de milho na dieta

Twelve lactating Holstein dairy cows were assigned to three 4x4 Latin squares to evaluate the effects of feeding corn silage or different dietary ratios of sugarcane and concentrate on nutrient intake, apparent digestibility, milk composition and yield, and body weight change. The diets contained 60% corn silage or 60, 50, and 40% of sugarcane supplemented with 1% of urea + ammonium sulphate (9:1). No significant differences were observed between the diet with 60% of corn silage and that with 40% of sugarcane on milk yield (20.81 and 19.78 kg/day), intake of dry matter and almost all remaining nutrients, apparent digestibility of most nutrients, and body weight change. Among sugarcane-based diets, cows fed the diet containing 60% sugarcane had the lowest milk yield (16.90 kg/day), dry matter intake, and body weight change, those fed 50% sugarcane were intermediate, and cows fed the diet with the smallest proportion of sugarcane (40%) had the highest values for these variables. Intake of NDF of cows receiving 50% sugarcane was similar to that of cows fed 40% sugarcane while for apparent digestibilities of NDF and nonfiber carbohydrates similar values were observed for cows fed 60 and 50% sugarcane-based diets. Milk composition did not differ significantly across treatments in the present trial.

Avaliação da divergência nutricional de genótipos de cana-de-açúcar (Saccharum spp.)

The objective of this trial was to study the nutritional divergence of sugarcane genotypes for feeding ruminants. The following sugarcane genotypes were evaluated: RB72454, RB835486, SP80-1842, IAC86-2480, RB977512, RB867515, RB935566, RB925345, RB977625, SP79-1011, SP80-1816, SP81-3250, and SP91-1049 all harvested at 11 months of age. The discriminatory variables were: neutral detergent fiber (NDF), hemicellulose, lignin, NDF to soluble carbohydrate ratio, NDF undegradable fraction, and rates of NDF and DM degradation. Application of the cluster analyses according to the Tocher approach, using the mean Euclidian distance matrix, yielded three groups of genotypes. Neutral detergent fiber and DM degradation rates were the most important variables for group discrimination contributing individually with 25.64% of the total discrimination power while the least contribution was observed with NDF undegradable fraction (11.54%). The variables NDF, NDF undegradable fraction, hemicellulose, and rates of DM and NDF degradation all showed to be effective to evaluate sugarcane nutritional divergence. Group III formed by the clone RB977512 showed the best responses for the studied variables and as such can be considered of higher nutritional quality for ruminants.

Comportamento produtivo e características nutricionais do capim-braquiária cultivado em consórcio com milho

The objective of this work was to evaluate the chemical characteristics of the whole plant and the leaf and stem fractions of signal grass in different sowing arrangements to determine the productive performance of the corn/signal grass intercrop. The production of dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) per area was evaluated, as well as the concentration of CP, digestible crude protein (CPD), neutral detergent insoluble crude protein (NDICP), neutral detergent fiber (NDF), lignin (LIG) non-fiber carbohydrate (NFC) and TDN in DM and the leaf:stem ratio (L:S) at different sowing arrangements and culture age. The sowing arrangements tested were: two lines of signal grass in the corn inter-lines, hand-sowed signal grass in the corn inter-lines, one line of signal grass in the same line of corn, one line of signal grass in the corn inter-lines, exclusive signal grass and exclusive corn culture. The culture age effect was evaluated by sampling plants at 128, 141, 174 and 199 days after sowing. The largest production of DM, CPD and TDN was obtained for signal grass in exclusive culture. During the period when the corn culture shadowed the signal grass, the leaf:stem ratio of intercropped signal grass was lower than the signal grass in exclusive culture. Forages from arrangements with higher shadowing (hand-sowed signal grass and one line of signal grass at the same line of corn) were less productive and presented higher CP concentration in the DM. In general, higher concentrations of CP and lower of NDF and LIG were found in the leaf fraction in relation to the stem fraction, regardless the sowing arrangements. The intercrop did not affect the LIG, NFC and TDN concentration in the DM of the signal grass, but the age had an effect on these variables. The corn production was not affected by the intercrop or by the different arrangements.

The intercrop between signal grass and corn: productive performance of the cultures, nutritional characteristics and silage quality

The objective of this work was to evaluate differences between silages produced from exclusive cultures or intercropped with corn and signal grass cultures in different sowing arrangements (two lines of signal grass in the corn inter-lines and hand-sowed signal grass in the corn inter-lines) The production of dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) for area was evaluated, as well as the qualitative variables of DM in the silages including CP, TDN, NDF, LIG, NFC, NH3, butyric and lactic acids and pH. The corn in exclusive culture, signal grass in two lines and hand-sowed signal grass did not differ in relation to the DM, CP and TDN production or the qualitative variables in relation to the CP, TDN, NDF, LIG, pH, NH3, butyric and lactic acid contents in the silage, showing better behavior than the signal grass exclusive culture. However, the canopy recovery in the area before harvest was faster in the two lines of signal grass in the corn inter-lines.The objective of this work was to evaluate differences between silages produced from exclusive cultures or intercropped with corn and signal grass cultures in different sowing arrangements (two lines of signal grass in the corn inter-lines and hand-sowed signal grass in the corn inter-lines) The production of dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) for area was evaluated, as well as the qualitative variables of DM in the silages including CP, TDN, NDF, LIG, NFC, NH3, butyric and lactic acids and pH. The corn in exclusive culture, signal grass in two lines and hand-sowed signal grass did not differ in relation to the DM, CP and TDN production or the qualitative variables in relation to the CP, TDN, NDF, LIG, pH, NH3, butyric and lactic acid contents in the silage, showing better behavior than the signal grass exclusive culture. However, the canopy recovery in the area before harvest was faster in the two lines of signal grass in the corn inter-lines.

Consórcio capim-braquiária e soja, produtividade das culturas e características qualitativas das silagens

The objective was to evaluate the culture of signal grass and soybean intercropping or in single cultures on the production of dry matter (DM) and crude protein (CP) and total digestible nutrients (TDN) per ha. It was evaluate, also, contents of CP, neutral detergent fiber (NDF), lignin (LIG), non-fibrous carbohydrates (NFC), NDT, butyric acid and lactic acid, ammonia nitrogen, the content of DM and pH of these silage cultures harvested in two phenological stages (R6 and R7) of the soybean plants. The production of DM was greater in signal grass in single culture, regardless of the vegetative stage. The DM content of signal grass silage in single culture was low in both vegetative stages (19.55 and 19.49%). In silages from signal grass and soybean intercropping and soybean in single culture, the content of DM was higher in the R7 vegetative stage. Regardless of the vegetative stage, soybean in single culture produced higher content of CP, NFC, LIG, TDN and higher amount of CP, followed by signal grass and soybean intercropping and signal grass in single culture, which showed inverse behavior for NDF content. The amount of TDN obtained in signal grass and soybean intercropping and soybean in single culture increased from the R6 to R7 vegetative stage, whereas in signal grass in single culture, decreased with advancing of the crop maturities. In all silages, harvested in the two vegetation stages, the values of pH and butyric acid were high and the values of lactic acid were low. In the R7 stage, ammonia nitrogen level of the silages was lower than the R6. It is feasible to use the signal grass and soybean intercropping for silage production, being recommended to harvesting the crops in R7 vegetative stage of the soybean plants.The objective was to evaluate the culture of signal grass and soybean intercropping or in single cultures on the production of dry matter (DM) and crude protein (CP) and total digestible nutrients (TDN) per ha. It was evaluate, also, contents of CP, neutral detergent fiber (NDF), lignin (LIG), non-fibrous carbohydrates (NFC), NDT, butyric acid and lactic acid, ammonia nitrogen, the content of DM and pH of these silage cultures harvested in two phenological stages (R6 and R7) of the soybean plants. The production of DM was greater in signal grass in single culture, regardless of the vegetative stage. The DM content of signal grass silage in single culture was low in both vegetative stages (19.55 and 19.49%). In silages from signal grass and soybean intercropping and soybean in single culture, the content of DM was higher in the R7 vegetative stage. Regardless of the vegetative stage, soybean in single culture produced higher content of CP, NFC, LIG, TDN and higher amount of CP, followed by signal grass and soybean intercropping and signal grass in single culture, which showed inverse behavior for NDF content. The amount of TDN obtained in signal grass and soybean intercropping and soybean in single culture increased from the R6 to R7 vegetative stage, whereas in signal grass in single culture, decreased with advancing of the crop maturities. In all silages, harvested in the two vegetation stages, the values of pH and butyric acid were high and the values of lactic acid were low. In the R7 stage, ammonia nitrogen level of the silages was lower than the R6. It is feasible to use the signal grass and soybean intercropping for silage production, being recommended to harvesting the crops in R7 vegetative stage of the soybean plants.

Exigências nutricionais em macronutrientes minerais (Ca, P, Mg, Na e K) para novilhos de diferentes grupos genéticos

The objective of this trial was to determine the macrominerals requirements (Ca, P, Mg, Na, and K) for young bulls from different genetic groups. Forty-four young bulls from the following genetic groups were used: Nellore, F1 Nellore x Aberdeen-Angus, F1 Nellore x Brown Swiss, and F1 Nellore x Simmental. Animals averaged 362 ± 35 kg of initial body weight and between 10 to 11 months of age. Diet contained signal grass hay (Brachiaria decumbens, Stapf.), soybean meal, ground corn, molasses, and macro and microminerals premix. The net requirements for weight gain of each macromineral were obtained by the first derivative of their respective equations generated from non-linear regression of the mineral content (Ca, P, Mg, Na, and K) in function of the animal empty body weight. The equation obtained from regressing empty body weight on weights taken immediately before slaughter was used for the conversion of body weight into empty body weight. The macrominerals requirements for maintenance were estimated using the NRC and ARC models recommendation while absorption coefficients used were those proposed by the ARC model. The model test of identity indicates no difference comparing regression equations for all studied macrominerals among the four genetic groups.

Desempenho de novilhas leiteiras sob manejo para crescimento compensatório recebendo suplementação com ionóforo

ABSTRACT - The objective of this trial was to compare the effect of different feeding strategies with or withoutionophore (monensin) supplementation on performance of dairy heifers. Twenty Brown-Swiss heifers averaging 200 kgof body weight and five months of age were used in a completely randomized design with a 2 x 2 factorial arrangementof treatments. Treatments were: two feeding regimes (conventional vs. compensatory growth) with (200 mg/animal/day) or without monensin supplementation. Animals in the conventional feeding regime were fed ad libitum while thosein the compensatory growth were fed as follows: P1) period of energy restriction (90 days); and P2) realimentation period(60 days). Efficiency of conversion of ingested DM and metabolizable energy on daily weight gain was lower during therealimentation period. However, nitrogen (N) balance did not differ on heifers receiving the conventional feeding regimecompared to those receiving the compensatory growth regime. Inclusion of monensin in diet of heifers reduced theexcretion of N in urine leading to greater N retention in the restriction period and lower during the realimentation phase.There was not effect of treatments, monensin or period on the development measurements and final body weight. Heifersin the compensatory growth regime had greater average daily gain at 135 and 150 days when compared to conventionalfeeding heifers.Key Words: biological efficiency, daily gain, monensin, nitrogen balance, realimentation, restriction

Levels of concentrate in the diet of calves

The objective of this study was to evaluate the levels of concentrate for growing calves. Four Holstein × Brahman crossbred calves with average age of 7 months and 155 kg of body weight were used, distributed into one Latin square design (4 × 4). The animals were fed ad libtum in the form of complete diet containing levels of 20, 40, 60 and 80% of concentrate on the dry matter basis (DM). The diets were composed of Cynodon dactylon hay, corn, soybean meal and mineral mixture, and were isoprotein (15.4%). The DM, organic matter (OM), neutral detergent fiber (NDF) and total carbohydrate (TC) consumption showed linear response; and crude protein (CP) and total digestible nutrients (TDN), quadratic response; expressed in kg/day. When expressed in %BW, the OM, CP, EE and TDN consumption presented quadratic behavior; as DM, NDF and TC showed linear behavior. The apparent total digestibility DM and CP coefficients were quadratic influenced by the levels of concentrate, while OM, EE, NDF and TC showed linear behavior. No effect was observed for the average concentration of ammoniac nitrogen, depending on the levels of concentrate, for each time of analysis. However, for pH, there was influence of the levels for the times analyzed. Likewise, no effect was observed for the average concentration of serum glucose, however, for urea nitrogen serum (UNS), a linear negative effect was observed, depending on the levels for each post-feeding time. Therefore, up to 60% of concentrate could be included in the diet of calves; however higher levels can affect the use of bulky.

Consórcio capim-braquiária e milho: produtividade das culturas e características qualitativas das silagens feitas com plantas em diferentes idades

The objective of this work was to evaluate the silage produced from signal grass intercropping with corn or in exclusive culture and harvesting at 100, 120, 140 and 160 days after sowing. Productions of dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) were evaluated. It was also evaluated, the quality characteristics as contents (%DM) of CP, NDT, non-fibrous carbohydrates (NFC), neutral detergent fiber (NDF), ammonia nitrogen, butyric acid, lactic acid and pH, these silages. DM content was higher in the forages, regardless of intercropping with corn or in exclusive culture was higher at 140 and 160 days after sowing. Intercropping exclusive culture differed in DM production only at 120 days after sowing. Simultaneous cultivation of corn with two rows of signal grass in interlines (intercropping) was higher than exclusive culture of signal grass. Whatever culture ages, forage obtained from the intercropping of signal grass and corn had higher amounts of TDN/ha and resulted in silages with higher TDN contents and lactic acid and lower contents of NDF, lignin, ammonia nitrogen and acid butyric and lower pH.