Lídia Ferreira Miranda

Ingestive behavior of dairy heifers fed sugar cane based diets

The objective of this work was to evaluate the ingestive behavior of crossbred dairy heifers fed sugar-cane based diets, supplemented with non protein nitrogen [NPN] sources (urea or broiler litter, in replacement of urea) and, or, probiotics addition (without probiotic, with yeast or with ruminal microbiota). Twenty-four heifers, with age and average initial weight of 15 months and 247 kg, respectively, were maintained in individual stalls and ad libitum fed during the experimental period of 84 days. The animals were allotted to a completely randomized design, in a 2 x 3 factorial arrangement (NPN source vs probiotic source), with four replicates. The ingestive behavior of each heifer was visually determined, at 28 days, in intervals of 10 minutes, during 24 hours. There was no difference on the time spent in feeding, rumination and total chewing, in min/day, of the heifers fed different sources of NPN and probiotics. The average rumination time in min/kg of DM and NDF were higher for the animals fed urea. The ingestive behavior of the heifers was not affected by the nitrogen sources or by the probiotic addition.The objective of this work was to evaluate the ingestive behavior of crossbred dairy heifers fed sugar-cane based diets, supplemented with non protein nitrogen [NPN] sources (urea or broiler litter, in replacement of urea) and, or, probiotics addition (without probiotic, with yeast or with ruminal microbiota). Twenty-four heifers, with age and average initial weight of 15 months and 247 kg, respectively, were maintained in individual stalls and ad libitum fed during the experimental period of 84 days. The animals were allotted to a completely randomized design, in a 2 x 3 factorial arrangement (NPN source vs probiotic source), with four replicates. The ingestive behavior of each heifer was visually determined, at 28 days, in intervals of 10 minutes, during 24 hours. There was no difference on the time spent in feeding, rumination and total chewing, in min/day, of the heifers fed different sources of NPN and probiotics. The average rumination time in min/kg of DM and NDF were higher for the animals fed urea. The ingestive behavior of the heifers was not affected by the nitrogen sources or by the probiotic addition.

Consumo e tempo diário de pastejo por novilhos Nelore em pastagem de capim-tanzânia sob diferentes ofertas de forragem

This work aimed to evaluate the effects of forage allowances on canopy changes, the grazing time and forage intake by steers grazing tanzaniagrass (Panicum maximum Jacq.) pasture. The four levels of herbage allowance (HA) (kg of leaf blade /100 kg animal live weight/day, %) were: 6.1 ± 0.59; 11.1 ± 0.77; 18.0 ± 1.24 and 23.9 ± 1.15%. Eight Nelore animals averaging 229.0 and 249.5 kg grazed each paddock in the first and second sampling periods, respectively. A completely randomized block design was used. Grazing time, leaf dry matter availability, leaf:stem ratio and canopy height were highly correlated with forage intake and can be used to develop prediction models of forage intake and performance of the grazing animal. Studies on intake and grazing animal performance in relation to forage allowances should consider the pasture structural traits for data interpretation and comparison. Tanzaniagrass forage allowances induced changes in the pasture structural characteristics and had quadratic effect on the daily grazing time and on the forage intake by Nelore steers. Shortest grazing time and highest forage intake were observed on pasture with herbage allowance of about 22.5 kg leaf blade/100 kg BW, which corresponded to a post-grazing mass of 4323.2 kg/ha dry matter, 2887.6 kg/ha dry green matter and average canopy height of 64 cm.

Determinação das frações protéicas e de carboidratos e taxas de degradação in vitro da cana-de-açúcar, da cama de frango e do farelo de algodão

The objective of the present study was the fractionation and the degradation kinetics of the nitrogenous compounds and of the carbohydrates of the sugar cane, poultry litter and cottonseed meal. The non-protein nitrogenous compounds, soluble and insoluble nitrogen in borate-phosphate buffer, neutral detergent and in acid detergent insoluble protein nitrogen were analyzed for the determination of the nitrogen fractions. The degradation rates of the protein fractions were obtained by the In vitro incubation of the feeds with proteases isolated from ruminal ambient. The total carbohydrates, and its fractions C, B2 and the soluble neutral detergent components were calculated for the determination of the carbohydrates using the Cornell system. The potentially degradable (B2) and undegradable (C) fractions of the neutral detergent fiber, corrected for ashes and protein, and the lag dynamic rates, of degradation and of specific microbial growth, from the fraction B2, were determined. Besides, the coefficient of degradabilities and of the NDF ruminal repletion effect of the feeds, were also determined. The values of 71.01; 45.80 and 71.66% of the fraction B2 of the nitrogenous compounds were observed for sugar cane, poultry litter and cottonseed meal, respectively. The poultry litter stood out for the highest B3 and C fraction (23.57 and 10.11%). The B3 fraction degradation rates were of 0.03; 0.031 and 0.09 h-1 for sugarcane, poultry litter and cottonseed meal, respectively. The fraction C of the carbohydrates varied of 22.74, 28.00 and 32.64% for the three feeds, respectively. The sugar cane presented high soluble components fraction (35,99%), however it presented low digestion of the potentially degradable fiber (3.41% h-1) and a significant repletion effect (6,6 h-1). The feeds, sugarcane and poultry litter present low nutritional value to meet the ruminal microorganisms and of the hostess requirements.

Fontes nitrogenadas e uso de Sacharomyces cerevisiae em dietas à base de cana-de-açúcar para novilhos: consumo, digestibilidade, balanço nitrogenado e parâmetros ruminais

O objetivo do presente estudo foi avaliar os efeitos das fontes nitrogenadas e o uso de Sacharomyces cerevisiae em dietas a base de cana-de-acucar sobre os consumos e as digestibilidades aparentes totais e parciais de materia seca (MS), materia orgânica (MO), proteina bruta (PB), extrato etereo (EE), carboidratos totais (CHO), fibra em detergente neutro (FDN) e carboidratos nao-estruturais (CNE), o balanco nitrogenado e os parâmetros ruminais. Foram utilizados quatro novilhos Holandes-Zebu, fistulados no rumen e abomaso, alimentados com quatro racoes a base de cana-de-acucar, constituidas de duas fontes nitrogenadas (ureia ou cama de frango) combinadas com dois niveis de Sacharomyces cerevisiae (0 e 10 g/dia). Utilizou-se delineamento em quadrado latino 4 x 4. A fibra em detergente neutro indigestivel (FDNi) foi utilizada como indicador, para determinar as digestibilidades aparentes totais e parciais. Os consumos de MS, MO, EE, CT e CNE nao foram influenciados pelas fontes nitrogenadas e pela utilizacao de Sacharomyces cerevisiae. Os consumos de PB e FDN foram maiores para as dietas suplementadas com cama de frango. Os coeficientes de digestibilidades totais de PB e EE foram maiores para as dietas constituidas de ureia. As digestibilidades aparentes totais de MS, MO, CT e FDN nao foram influenciadas pelas fontes nitrogenadas e pela utilizacao de Sacharomyces cerevisiae. O pH do liquido ruminal decresceu linearmente para as dietas suplementadas com ureia e apresentou comportamento quadratico, quando estas dietas foram combinadas com Sacharomyces cerevisiae. As concentracoes de amonia no liquido ruminal apresentaram comportamento quadratico, estimando-se valores maximos de 16,90; 26,12; 18,48; e 14,40 mg/100 mL para os tratamentos constituidos de cana-de-acucar e ureia; cana-de-acucar, ureia e Sacharomyces cerevisiae; cana-de-acucar e cama de frango; e cana-de-acucar, cama de frango e Sacharomyces cerevisiae, respectivamente.

Performance and ponderal development of dairy heifers fed sugar cane based diets

The objective of this work was to evaluate the performance, ponderal development of heifers fed sugar cane based diets, supplemented with non protein nitrogen (NPN) sources (urea or broiler litter, in replacement of urea) and, or, probiotics addition (without probiotic, with yeast or with ruminal microbiota). Cost and gross margin of the use of these diets were also evaluated. Twenty-four heifers, with age and average initial weight of 14 months and 247 kg LW, respectively, were maintained in individual stalls and ad libitum fed during the experimental of 84 days. The animals were distributed in a complete randomized design, in a 2 x 3 factorial arrangement (NPN source vs probiotic source), with four replicates. The heifers were weighed and their thoracic perimeter, hip and croup height were determined at the beginning and at the end of the experimental period and at every 28 days. The blood plasma N-urea levels of the heifers were also determined in blood samples collected immediately before the daily feed supply, zero hour, and at two, four, six and eight hours post feeding. There was no interaction between NPN sources and the probiotic sources, for any studied characteristic. The sugar cane supplementation with the NPN sources had no eefect on the average daily weight gain. However, the yeast or ruminal microbiota addition promoted similar weight gains, although, higher than without probiotic addition. The partial replacement of the urea for the broiler litter did not affect the heifers performance, but the diets supplemented with yeast or ruminal microbiota presented higher weight gain and ponderal development.

Híbridos de Sorgo (Sorghum bicolor (L.) Moench) Cultivados sob Níveis Crescentes de Adubação: Rendimento, Proteína Bruta e Digestibilidade in Vitro

The objective of this research was to evaluate the forage yield, crude protein (CP) contents and dry matter (DM) in vitro digestibility of five forage sorghum hybrids (AG-2002, AG-2005E, AG-X202, AG-X213 e AG-X215), cultivated under four NPK fertilization levels. A randomized blocks design, in a 5 x 4 factorial scheme, with four replicates, was used. The evaluated hybrids showed high average DM/ha yield and positive linear answer in function of fertilization, except for the high productivity (15.47 t/ha) in the plots without fertilization, in function of soil fertilization and climatic conditions. The hybrids showed different answers for the CP contents, according to the fertilization, in a quadratic way, determining the quadratic behavior for the crude protein yield. IVDMD and digestive dry matter yield showed positive linear answers in function of fertilization, and the digestible dry matter yield was highly correlated (0.91**) with the increase of DM/ha yield.

Dinâmica dos nutrientes no trato gastrintestinal de novilhos holandeses alimentados com dietas à base de cana-de-açúcar

RESUMO - Foram objetivos deste trabalho validar as predicoes com base nas estimativas da dinâmica ruminal e pos-ruminal dos nutrientes e do crescimento microbiano no rumen, usando as equacoes que compoem o submodelo Cornell relativo ao trato gastrintestinal. Foram utilizados quatro novilhos Holandes-Zebu com peso medio de 300 kg, canulados no rumen e abomaso, distribuidos em delineamento quadrado latino 4 x 4. Os animais experimentais foram alimentados com racoes a base de cana-de-acucar, suplementada com duas fontes de nitrogenio (ureia ou cama de frango) e dois niveis de levedura (0 ou 10 g dia -1 ), constituindo-se esquema fatorial 2 x 2. A FDN indigestivel e a FDN da cana-de-acucar complexada com cromo foram usadas como indicadores interno e externo, para estimar a producao fecal diaria e a taxa de passagem de particulas no rumen. A dinâmica dos nutrientes baseou-se nas determinacoes do fluxo de nitrogenio total e do fluxo de nitrogenio de origem bacteriana no abomaso e dos carboidratos totais digeridos no rumen. A producao microbiana nao foi influenciada pelas fontes nitrogenadas e pela adicao de Saccharomyces cerevisiae. O Sistema Cornell superestimou os carboidratos totais degradados no rumen, o fluxo de nitrogenio de origem microbiana e subestimou o fluxo de N total no abomaso.

Predição da composição química do sorgo pela técnica de espectroscopia de reflectância no infravermelho próximo

The study aimed to evaluate the near infrared spectroscopy (NIRS) technique potential for predicting the chemical composition of sorghum. One hundred thirty two samples of four sorghum hybrids: AG212 (tall size), AG2002 (tall size), AG 2005 (dual purpose) and AG213 (tall size) were used in the analyses. The chemical composition was evaluated for the following fractions: dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), in vitro dry matter digestibility (IVDMD) and carboydrates (CHO). The coefficients of determination (R2) for the fractions DM, CP, NDF, ADF, IVDMD and CHO were: 95.8, 99.5, 96.4, 98.1, 93.1 and 98.7%, respectively. Low sec-error and high coefficient of determination were observed for the absorbance treatment.

Balanço de nitrogênio, degradabilidade de aminoácidos e concentração de ácidos graxos voláteis no rúmen de ovinos alimentados com feno de Stylosanthes guianensis

ABSTRACT - Seven sheep fed S. guianensis hay were used to evaluate ruminal amino acid degradability, nitrogen balance and rumenvolatile fatty acid (VFA) concentrations. Nylon bags technique was used for determination of the in situ degradabilities of amino acids.Bags were collected at 6, 24 and 48 hours after insertion. Duodenum and feces samples were used to determine amoniacal-N and no n-amoniacal-N. To determine ruminal VFA concentrations, samples of 80 mL were collected immediately before feeding and 2, 4, 6 an d8 hours after. Nitrogen balance was 6.0 g/day. S. guianensis had 10.4 and 6.3 g of methionine and lysine, respectively, per 100 g of totalamino acids. Non essential amino acids had degradation rates twice than essentials. Aminoacitic profile of undegradable protein wasdifferent than the original feed protein. The acetate:propionate ratio was 4.31. High concentrations of methionine and its low degradabilitymake the S. guianensis an important feed when this amino acid is limiting.Key Words: amino acid, degradability, hay, legume forages, sheep

Híbridos de sorgo (Sorghum bicolor (L.) Moench) cultivados sob níveis crescentes de adubação: características agronômicas, carboidratos solúveis e estruturais da planta

The agronomic characteristics, neutral detergent fiber (NDF), acid detergent fiber (ADF) and total soluble and structural carbohydrates contents of five hybrid sorghum (AG-2002, AG-2005E, AGX-212, AGX-213 e AGX-215), cultivated under different fertilization levels, were evaluated. A randomized blocks design, in a 5 x 4 factorial scheme, with four replicates, was used. The qualitative factors means were analyzed by means of Tukey test at 5 and 1% of probability. The evaluated hybrids showed different proportions of stem (29.01 to 53.38%), leaves (16.70 to 22.64%) and panicle (29.91 to 52.43%), where stem and panicle were highly correlated with height, 0.79** and -0,82**, respectively. Dry matter content of whole plant was strongly affected by stem and panicle proportion, where the panicle showed higher DM contents (48.79 to 56,80%) and stem, the smaller (18.86 to 22.54%). The increase in the fertilization levels provided increment in the panicle production, that decreased stem+leaves/panicle proportions and increased panicle proportion and DM content of whole plant. The total soluble carbohydrates contents, in dry matter basis, varied among evaluated hybrids (12.24 to 19.80%) and increased as the fertilization levels increased. The evaluated hybrids showed significant differences among the NDF (57.38 to 62.30), ADF (25.29 to 31.56%), hemicellulose (28.56 to 33.87%), cellulose (19.20 to 24.34%) and lignin (6.04 a 6.51%) contents. The NDF and hemicellulose contents decreased as the fertilization levels increased.