José Augusto Gomes Azevêdo

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

The objective of this work was to evaluate the nutritional divergence of the sugarcane varieties, using the principal components analysis, to select three representative varieties of that divergence. The sugarcane varieties (Saccharum spp.) evaluated in this study were: RB855113, RB765418, RB855536, SP79-2233, RB845257, SP80-180, RB855453, RB855336, SP80-1842, SP81-1763, SP80-4445, SP79-1011, RB739359, RB867515 and SP80-3280, harvested at 426, 487 and 549 days post planting. Neutral detergent fiber (NDF), hemicellulose, lignin, undegradable NDF fraction and degradation rate of the potentially degradable NDF fraction were the evaluated discriminatory variables. Differences were observed for all the studied variables, except for the undegradable NDF fraction. The evaluation of the nutritional divergence of the sugarcane varieties based on the first three principal components, that explained 87.8% of the total variation. The NDF and the undegradable NDF fraction were the variables of smaller importance to explain the nutritional variability of the varieties. The SP80-1842 variety, harvested at 426 days post planting, and SP79-1011 variety, harvested at 549 days, were the ones that showed greater score dispersions for the first three principal components, being considered the most dissimilar, while the RB845257 variety, harvested at 487 days post planting, was located in the intermediary position between both. The principal components analysis was also efficient in selecting varieties with different harvesting times.

Composição químico-bromatológica, fracionamento de carboidratos e cinética da degradação in vitro da fibra de três variedades de cana-de-açúcar (Saccharum spp.)

The objectives of this work were to determine the chemical-bromatological composition, to determine the carbohydrates fractions and to estimate the kinetic variables of degradation of the fibrous (FC) and no-fiber carbohydrates (NFC), of three nutritional divergence sugarcane varieties. The studied varieties were SP80-1842, SP79-1011 and RB845257. The varieties of intermediary production cycle showed greater values of NDF and ADF compared to the variety of early cycle. The observed FDN/Pol (sucrose index) ratio was, respectively, 2.73; 2.82 and 2.25 for the SP80-1842, RB845257 and SP79-1011 varieties. The SP79-1011 variety presented smaller C and greater B2 carbohydrate fractions (27.78 and 33.26%). It was possible to observe difference, using the gravimetric technique, for the lag time and the effective degradation of NDF, with higher values for SP 791011 variety (7.90 h and 10.30%, respectively). However, for the gas production technique, there was only a significant effect, for the estimate of the maximum gas volume parameter for NFC, with higher values for the varieties SP79-1011 and RB845257 of intermediary production cycle. The SP79-1011 variety was the one that showed better productive characteristic, composition chemical-bromatological, besides better values of the kinetics variables of degradation of the fiber (FC) and non fiber (CNF) carbohydrates. The gas production technique was more reliable than the results observed by the gravimetric technique.

Consumos e digestibilidades totais e parciais de matéria seca, matéria orgânica, proteína bruta e extrato etéreo em novilhos submetidos a três níveis de ingestão e duas metodologias de coleta de digestas abomasal e omasal

Six castrated steers fistulated in the rumen and abomasum were randomly assigned to two 3 x3 Latin squares (three animals, three intake levels [1.5 supply, 2.0 and 2.5% LW] and three periods) to compare the collection techniques for abomasal and omasal digesta in order to determine the flow as well as to evaluate the effects of the three offer levels (1.5; 2.0 and 2.5% live weight) on both intakes and total and partial apparent digestibilities of DM, OM, CP, EE and TDN. The chromic oxide was used to estimate the digesta flows and the fecal excretion. DM, OM, CP, EE and TDN intakes showed an increasing linear behavior, according to the ingestion levels. DM total apparent digestibility coefficient decreased linearly, as ingestion levels increased. DM apparent digestibility in the rumen did not differ among treatments and averaged 73.2% for the overall equations. OM total digestibility showed decreasing linear behavior, according to the ingestion levels, whereas the ruminal and total intestinal digestibilities were not affected by the treatments (average of 81.6 and 18.4% for the overall equations, respectively). The model identity test showed some differences among the CP total digestibilities obtained by different methodologies were observed. When ruminal and intestinal digestions were compared, no differences among both methodologies were observed. EE total digestibility was not affected by the treatments, with average value of 76.3%. EE total ruminal and intestinal digestibilities exhibited both increasing and decreasing linear behaviors, respectively, as a function of the ingestion levels, showing an average value of 76.3%. EE total ruminal and intestinal digestibilities showed both increasing and decreasing linear behaviors, respectively, as a function of the ingestion levels. Omasal digesta collection, through ruminal fistula, can be used to replace abomasum fistula, becoming the study of digestion locals a less invasive process. TDN content decreased as feed offer levels increased.

Consumos e digestibilidades totais e parciais de carboidratos totais, fibra em detergente neutro e carboidratos não-fibrosos em novilhos submetidos a três níveis de ingestão e duas metodologias de coleta de digestas abomasal e omasal

Seis novilhos ½ sangue Holandes-Zebu castrados, fistulados no rumen e no abomaso, foram distribuidos em dois quadrados latinos 3x3 (tres animais, tres niveis de oferta - 1,5; 2,0 e 2,5% PV e tres periodos) para determinar os consumos e as digestibilidades totais e parciais dos carboidratos totais (CHO), da fibra em detergente neutro (FDN) e dos carboidratos nao-fibrosos (CNF). As digestibilidades foram determinadas com oxido cromico. Os consumos de CHO, FDN, CNF e NDT (kg/dia) e de CHO, FDN e CNF (% do peso vivo - PV) aumentaram linearmente com os niveis de oferta. O teste de identidade de modelos, realizado para as equacoes de regressao para as digestibilidades total, ruminal e intestinais dos CHO, em funcao dos niveis de oferta, indicou nao existir diferencas entre as metodologias de coleta. As digestibilidades total, ruminal e intestinais dos CHO nao foram influenciadas pelos tratamentos. A digestibilidade total da FDN diminuiu linearmente com o aumento dos niveis de oferta, enquanto as digestoes ruminal e intestinais da FDN nao foram influenciadas pelos tratamentos. Nao foi observado efeito dos niveis de oferta para as digestibilidades totais dos CNF. Utilizando a metodologia de coleta de digesta no omaso, foi observado aumento linear da digestibilidade ruminal dos CNF. Quando foi usada a coleta no abomaso, nao houve efeito do aumento do consumo sobre a digestao ruminal dos CNF. A coleta de digesta abomasal pode ser substituida pela coleta de digesta omasal, via fistula ruminal. A coleta de digesta omasal e vantajosa, tornando o estudo de digestao parcial um processo menos invasivo.

Consumo, digestibilidade total, produção de proteína microbiana e balanço de nitrogênio em dietas com subprodutos de frutas para ruminantes

The objective of this study was to evaluate the effects of inclusion of by-product of fresh fruit (pineapple, guava, papaya, mango and passion fruit) used in the diet for bovines partly replacing corn silage on intake and total nutrient digestibility, on the production of microbial protein and the nitrogen balance and on prediction of digestible fractions and total digestible nutrients (TDN) of these by-products. All animals received corn silage and the urea/ammonium sulfate (9:1) mixture so diets would remain isonitrogenous. The intakes of dry matter (DM) (kg/day), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF) and TDN, and the digestibility of CP, non-fibrous carbohydrates (NFC) and ether extract (EE) were affected by the source of the by-product. There was an effect for the level of inclusion of products in the digestibility of CP and EE. The by-products of papaya, mango and pineapple showed energy values of 23.1, 18.0 and 7.1% respectively, higher than corn silage. The source of the by-product influenced urinary excretion of derived from total purine, purine absorbed and production of microbial protein, in addition to the intake (g/day), the excretion in feces and urine (g/day) of nitrogen compounds and nitrogen balance (g/day). The level of inclusion of the by-product in the diet affect the urinary excretion of derived from total purine, purine absorbed and microbial protein production. The by-products of pineapple, papaya and mango have energy value higher than corn silage and they can partly replace energy concentrates in diets for ruminants. The by-product of passion fruit has the potential to partly replace roughage in the diets of ruminants. The by-product of guava has use limitations in diets of ruminants.

Correlações genéticas e fenotípicas entre características de conformação e produção de leite em bovinos da raça Pardo-Suíça no Brasil

Data of type classification from Brown Swiss Cattle Breeder`s Association of Brazil were used to evaluate non-genetic factors, heritability and genetic and phenotypic correlations of the linear type traits, classification traits and final score, as well as to evaluate correlations of type traits and milk yield. For the study of non-genetic factors was utilized the least square metolology using the GLM procedure of SAS, and, for estimate of heritability and genetic and phenotypic correlation was used an animal model. The REML metodology was used to obtain variance and covariance components to estimate heritability and genetic and phenotypic correlations. The non-genetic factors influenced most of the type traits and should be considered in the type evaluation of cattle of this breed. Heritability estimates suggest the possibility of moderate genetic gain for selection of type traits. Genetic correlations among some type traits were high, suggesting that some of them could be excluded from the used classification system. The genetic correlations between some type traits and milk yield suggest the participation of these in the elaboration of selection index of animals of this breed.

Agronomic divergence of sorghum hybrids for silage yield in the semiarid region of Paraiba

The objective of this study was to evaluate the agronomic divergence of 25 sorghum hybrids (Sorghum bicolor L. Moench) in the semiarid region of Paraiba. A randomized block design with three replications was used for evaluation of plant height (PH), total natural matter production (TNMP) and total dry matter production (TDMP) and the percentage of components of DM (panicle, leaf blade, stem and dead matter) of the following hybrids: 866005, 866019, 866033, 866034, 866035, 866036, 866037, 866040, 866041, 866042, 866043, 866044, 870025, 870031, 870035, 870041, 870051, 870067, 870081, 870085, 870095, 1F305, BRS 610, Volumax, and XBS60329. Hybrid 1F305, followed by hybrid 866034, presented the highest average PH. There was a range from 7.679 to 20.948 kg/ha (average of 13,799 kg/ha) for TDMP. Hybrids 1F305, BRS 610 and Volumax presented less potential, and hybrids 866,041 and 866,042 were the most productive. Based on cluster analysis and subjective cut in 50% of dissimilarity, it was possible to establish four hierarchical groups, from which two stood out concerning productive characteristics. The group formed by hybrids Volumax, BRS 610, and XBS60329 presented lower averages for yield and lower percentage of panicle. Hybrids 866041 and 866042 show a higher total dry matter production, with values around 20,000 kg/ha.

Valor nutritivo e características fermentativas de silagens de capim-elefante com adição de casca de café

The experiment evaluated the chemical composition, in vitro DM digestibility (IVDMD), and fermentative characteristics of elephant grass silages with different coffee hull levels. The elephant grass presented 17.2% of dry matter (DM), cut with 45 days of growing. The coffee hull addition levels were 0, 6, 12, 18, and 24%, in fresh matter basis (weight/weight) with four replications per treatment. The material was ensiled in cylindrical plastic silos. In the ensiling process, the forage packing density was 500 kg/m3. It was observed increase of DM, acid detergent fiber, acid detergent insoluble nitrogen, and lignin concentration, as a function of coffee hull levels. Crude protein showed quadratic behaviour, estimating maximum CP value of 9.9% for the 16.4% coffee hull addition level. Neutral detergent fiber reduced linearly and silage lactic acid concentration showed quadratic behaviour as a function of coffee hull levels, estimating maximum value of 11.4% to 25.6% hull level. Coffee hull was efficient to increase silage DM concentration; however, the silage IVDMD decreased. The coffee hulls use in elephantgrass ensilage improved the fermentative characteristics of the silage.

Níveis de inclusão e tempo de exposição da cana-de-açúcar ao óxido de cálcio sobre parâmetros digestivos e o desempenho de novilhas Nelore

It was evaluated in this work the effects of levels of inclusion and exposure times of sugarcane to calcium oxide on the performance of Nellore heifers, digestibility of dietary components and synthesis of ruminal microbial protein and it was compared titanium dioxide to chromium oxide to estimate the individual intake of concentrate. It was used 30 Nellore females at approximately 24 months of age and average body weight of 285 ± 31 kg and age of 24 months housed in six pens (50 m2 approximately), each one of them with five animals (feeding group). The diets were allocated in a 3 × 2 factorial arrangement, containing three levels of calcium oxide (0; 0.5 and 1.0% of sugarcane fresh matter) and two levels of exposure time (0 and 3 days). There were no effects of calcium oxide exposure time on the intake of microbial nitrogen, dry matter (DM), organic matter (OM), crude protein (CP) and total digestible nutrients (TDN) and daily weight gain, but, it affected the intake of ether extract (EE), neutral detergent fiber corrected for ash and CP contamination (NDFcp), and nonfiber carbohydrate (NFC). The levels of whitewash decreased linearly the intake of OM, NDFap, NFC, and ADG. However, it was not observed effects of the markers (titanium dioxide and chromic oxide) nor interactions among exposure time and level of whitewash on intakes of DM, CP, EE, NDFap, NFC and TDN. Significant interactions between exposure time and level of inclusion of whitewash were observed for total aparent digestibility of DM, OM, and NDF and for content of TDN. Titanium oxide and chromic oxide are equally effective for estimating individual intakes of concentrate by bovine fed in group. Supply of sugar cane stored for three days without whitewash does not change performance of growing heifers.

Consumo, digestibilidade total, produção de proteína microbiana e balanço de nitrogênio em dietas para ruminantes de subprodutos

The effects of inclusion of by-products (cocoa, cassava peel, cassava stalk, and corn gluten meal) and their levels (10 and 30%), replacing part of corn silage on intake, digestibility of nutrients, microbial protein production, nitrogen balance, prediction of digestible fractions, and total digestible nutrients were evaluated. The intakes of dry matter and neutral detergent fiber were affected by source of by-product, which affected the digestibility of ether extract and non-fibrous carbohydrates. The energy corn gluten meal was 17% higher than that of corn silage, while the values for cassava peel, cocoa, and cassava stalk were 10, 19, and 38% lower than the value for corn silage. The source and the level of by-product did not affect the urinary excretion of total purine, purine absorbed, microbial nitrogen, and microbial efficiency. The source of by-product affected intake, nitrogen compounds, excretion in feces and urine, and nitrogen balance. The corn gluten meal and cassava peel are by-products with potential to partly replace the energhetic concentrates, with no influence on the intake, digestibility, microbial efficiency, and nitrogen retention