-It was evaluated the effect of the absence and of application of three nitrogen doses (50, 100 and 200 kg ha -1 of N) and four harvest times in the winter/spring season (from July to October) on dry mass yield (DMY), on the relative chlorophyll contents (ICF -leaf chlorophyll index) and on the contents of total digestible nutrients (TDN), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin, and their respective correlations on Tanzania and Mombaça grasses after intercrop with corn in distroferric red latosol (Oxisol) soil as well. It was used a random block design, in split-plot with four replicates. The greatest DMY occured with the increase of photoperiod (from August), neverthless responses to nitrogen fertilization over cuts difered among the grasses. In an irrigated crop-livestock integration system under cerrado conditions, it is technically feasible the establishment of Tanzania and Mombaça grass intercroped with corn at sowing or if cover nitrogen fertilization is performed because even in the abscence of nitrogen fertilization, great satisfactory quantity of forage was produced, with average DMY of 2,000 kg ha -1 per cut during the highest shortage of roughage for animals (winter/spring). Nitrogen fertilization after corn harvest increases DMY and improves bromatologic composition of the grasses, as contents of chlorophyll and CP in winter/spring is increased, besides the increase of contents of TDN and a reduction on the contents of NDF and ADF until September. Leaf chlorophyll index can be used to estimate the DMY and CP content and as a marker of the need of nitrogen fertilization of Tanzania and Mombaça grasses submitted to cutting.Key Words: crop-livestock integration, crude protein, Megathyrsus maximum, neutral and acid detergent fiber, no-tillage system, total digestible nutrients Produtividade, composição bromatológica e teor relativo de clorofila dos capins tanzânia e mombaça irrigados e adubados com nitrogênio após o consórcio com milho RESUMO -Avaliou-se o efeito da ausência e da aplicação de três doses de nitrogênio (50, 100 e 200 kg ha -1 de N) e quatro épocas de corte no inverno/primavera (julho a outubro) sobre a produtividade de massa seca (PMS), os teores relativos de clorofila (ICF -índice de clorofila foliar) e os teores de nutrientes digestíveis totais (NDT), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA) e lignina, bem como suas respectivas correlações nos capins tanzânia e mombaça após o consórcio com milho em um Latossolo Vermelho distroférrico. O delineamento experimental utilizado foi o de blocos casualizados, em parcelas subdivididas, com quatro repetições. As maiores PMS ocorreram com o aumento do fotoperíodo (a partir de agosto), no entanto, as respostas à adubação nitrogenada ao longo dos cortes diferiram entre e dentre os capins. Em sistema de integração lavoura-pecuária irrigado sob condições de cerrado, é tecnicamente viável o estabelecimento dos capins tanzânia e mombaça em consórcio c...

The objective of this study was to evaluate the effect of increased levels (0.0, 0.1, 0.2, 0.4, and 0.8%) of a combination of β-glucans and mannanoligosaccharides (MOS) in isonitrogenous (23% of digestible protein) and isoenergetic (13.38 MJ of digestible energy kg-1) pacu diets, corresponding to five treatments and four replicates. A 30-day feeding trial was conducted to assess the effects on growth performance, hematological parameters, and intestinal morphology. Fish (n = 160, 30.92 ± 0.46 g) were distributed randomly in 20 aquaria (300 L) with a recirculating water system with controlled temperature (26.20 ± 0.32°C) and fed four times a day until apparent satiation. A quadratic effect (P < 0.05) was observed for weight gain (WG), feed conversion ratio (FCR), and protein efficiency ratio (PER). The hepatosomatic and viscerosomatic indexes, hematocrit, hemoglobin, mean corpuscular volume (MCV), and mean corpuscular hemoglobin concentration (MCHC) did not show differences (P > 0.05) among treatments. Pacu fed β-glucans and MOS at 0.1 and 0.2% resulted in the greatest (P < 0.05) villus height and perimeter. The diet containing 0.2% β-glucans and MOS promoted the best growth response, feed efficiency, and intestinal morphology, without detrimental effects on the hematological parameters for juvenile pacu.

No abstract

Morphological and physiological alterations occur in the digestive system of weanling piglets, compromising the performance in subsequent phases. This experiment aimed at verifying the influence of glutamine, glutamate and nucleotides on the carbon turnover in the pancreas and liver of piglets weaned at 21 days of age. Four diets were evaluated: glutamine, glutamic acid or nucleotides-free diet (CD); containing 1% glutamine (GD); containing 1% glutamic acid (GAD) and containing 1% nucleotides (ND). One hundred and twenty-three piglets were utilized with three pigs slaughtered at day zero (weaning day) and three at each one of the experimental days (1, 2, 4, 5, 7, 9, 13, 20, 27, and 49 post-weaning), in order to collect organ samples, which were analyzed for the δ13C isotopic composition and compared by means of time. No differences were found (p>0.05) among treatments for the turnover of the 13C in the pancreas (T50% = 13.91, 14.37, 11.07, and 9.34 days; T95% = 46.22, 47.73, 36.79, and 31.04 days for CD, GD, GAD, and ND, respectively). In the liver, the ND presented accelerated values of carbon turnover (T50% = 7.36 and T95% = 24.47 days) in relation to the values obtained for the GD (T50% = 10.15 and T95% = 33.74 days). However, the values obtained for the CD (T50% = 9.12 and T95% = 30.31 days) and GAD (T50% = 7.83 and T95% = 26.03 days) had no differences (p>0.05) among other diets. The technique of 13C isotopic dilution demonstrated trophic action of nucleotides in the liver.

A B S T R A C TThe aim of this study was to estimate the metabolic rate of broiler tissues by assessing carbon turnover in different growth phases by using the stable isotope technique and by evaluating the natural changes in Carbon-13 ( 13 C) between C3 and C4 cycle plants. Six-hundred 1-day-old broiler chicks were divided into six groups and subjected to dietary changes containing different isotopic values at 7, 14, 21, 28, and 35 days of age. Birds of Group 1 received diets composed predominantly of C 3 cycle plants shortly after accommodation, while birds of other groups remained predominantly fed with C 4 diet. The diet of Group 2 was mainly replaced by C 3 diet on the 7th day of age. Group 3 started to receive C 3 diet on the 14th day of age, whereas the diet of Group 4 was replaced on the 21st, Group 5 on the 28th. In Group 6, the substitution occurred on the 35th day of age. Samples of the pectoral muscle, keel, tibia, legs muscle, intestinal mucosa, blood, plasma, and feathers were collected. Carbon isotope ratios were determined by mass-spectrometry of isotope ratios. To measure the speed of carbon substitution after a set interval (turnover), a time exponential function was employed and obtained by exponential equations of the first order calculated with Minitab ® 16 software. The carbon half-life varied from 1.78 to 8.20 days for the pectoral muscle, from 1.91 to 12.24 days for the keel, from 2.32 to 10.71 days for the tibia, from 1.87 to 9.43 days for the leg muscle, from 0.8 to 1.58 days for the intestinal mucosa, from 0.64 to 1.71 days for the plasma, from 2.61 to 11.07 days for blood, and from 1.84 to 28.41 days for the feathers during the total growth phase. With the exception of tibia and blood, all other tissues presented a high metabolic rate in the first week of the broilers' life. The metabolic rate of tissues is faster in younger animals, and the metabolism slows down as the broilers get older. The metabolic rates in the pectoral muscle, keel, tibia, and feathers decreased with age, whereas those of the plasma and intestinal mucosa were high in all evaluated periods; thus, these tissues can be used to study traceability of feed at all stages of the broilers' life.

RESUMO:A bixina é o principal carotenóide presente na semente de urucum (Bixa orellana). O objetivo deste estudo foi avaliar a inclusão de níveis crescentes de bixina na dieta de frangos de corte e seus efeitos sobre o desempenho zootécnico e características da carne. Foram utilizados 750 pintos de um dia de idade, Cobb 500, distribuídos em delineamento inteiramente casualizado, com cinco tratamentos, cada um com seis repetições de vinte e cinco aves cada. Os tratamentos consistiram em diferentes níveis de inclusão de bixina na ração (0,0; 0,05; 0,10; 0,15%). Foram avaliados os parâmetros de desempenho (ganho de peso-GP, consumo de ração-CR, conversão alimentar-CA, fator de eficiência produtiva-FEP e viabilidade-VB), qualidade de carne (pH, cor, perda de água por exsudação-PPE, perda de água por cocção-PPC e força de cisalhamento-FC), níveis de colesterol e oxidação da carne. A inclusão de 0,25% de bixina resultou em efeito negativo no ganho de peso e no fator de eficiência produtiva. Os valores de b* (intensidade de amarelo) aumentaram linearmente com a inclusão de bixina. A adição de 0,10% de bixina dieta reduziu a perda de peso por cocção e a adição de 0,15% reduziu a força de cisalhamento. A inclusão de 0,25% de bixina na dieta apresentou efeito antioxidante na carne de coxa das aves, 10 dias após o cozimento. A adição de bixina à dieta de frangos de corte não afetou o desempenho das aves, e apresentou efeitos positivos na qualidade da carne, em parâmetros que afetam diretamente na decisão de compra do consumidor. Palavras-chave: Aditivo; antioxidante natural; colesterol; extrato de urucum. ABSTRACT:Bixin is the main carotenoid present in annatto seed (Bixa orellana). The aim of this study was to evaluate the inclusion of increasing levels of bixin in the broiler diets and their effects on growth performance and meat characteristics. A total of 750 one-day-old Cobb 500 chicks were distributed in a completely randomized design with five treatments, with six replications of twenty-five birds each. Treatments consisted in different levels of bixin in diets (0.0, 0.05, 0.10, 0.15%). Were evaluated the parameters of growth performance (weight gain-WG, feed intake-FI, feed conversion ratio-FCR, productive efficiency index-PEI and viability), meat quality (pH, color, drip loss, cooking loss-CL and shear force-SF), cholesterol levels and meat oxidation. The inclusion of 0.25% of bixin resulted in negative effect on WG and PEI. The values of b * (intensity of yellow) increased linearly with the inclusion of bixin. The addition of 0.10% bixin in diet reduced the cooking loss and the addition of 0.15% reduced the shear force. The inclusion of 0.25% of bixin in diet had an antioxidant effect on breast and thigh meat, 10 days after cooking. The addition of bixin in broilers diet did not affect performance and had positive effects on meat quality, in parameters that directly affect the consumer's

Some authors consider minerals from organic sources more bioavailable for pig nutrition in comparison with inorganic sources. To evaluate the relative iron bioavailability from the organic source iron carbo-amino-phospho-chelate (ICAPC) to weanling piglets, it was conducted an experiment with 126 commercial piglets, using iron sulfate monohydrate (S) as standard. The experiment had a randomized block design with seven treatments (diet without adding specific source of iron, diet with 50, 100 and 150 ppm iron from S and diet with 50, 100 and 150 ppm iron from ICAPC), six replications and three animals per experimental unit. Performance parameters (average daily gain -ADG, feed:gain ratio -F:G) and blood variables (hemoglobin -Hb, hematocrit -Ht, transferrin -TR, latent iron-binding capacity -LIBC, total iron-binding capacity -TIBC, serum iron -Fe and transferrin saturation index -TSI) were evaluated. At the end of the experiment a piglet from each experimental unit was slaughtered and its liver and spleen removed for assessment of iron concentration by flame atomic absorption spectrometry (FAAS). The evaluated sources of iron yielded similar results for the variables of interest, but the increase in iron intake was followed by a linear increase in ADG, Hb, Ht, Fe and TSI as well as a linear decrease in the values of F:G, TR, LIBC and TIBC. Iron bioavailabilities from both ICAPC and S sources are similar for weanling piglets.

This study aimed to assess different prebiotic concentrations and principles, in addition to calcium butyrate, aiming to replace colistin as a growth promoter. The sample consisted of 120 piglets weaned at 22 days old with mean initial weight of 5.475 ± 0.719kg. The animals were assigned to random blocks in six treatments corresponding to the use of the following dietary additives: T1) colistin (40 ppm); T2) β-glucan/mannan-oligosaccharides (0.2%); T3) calcium butyrate (0.1%); T4) β-glucan/mannan-oligosaccharides (0.1%) + fructooligosaccharides (0.01%) + galactooligosaccharides (0.09%); T5) β-glucan/mannan-oligosaccharides (0.1%) + fructooligosaccharides (0.03%) + galactooligosaccharides (0.07%); and T6) β-glucan/mannan-oligosaccharides (0.1%) + fructooligosaccharides (0.05%) + galactooligosaccharides (0.05%). The results showed no difference among treatments for the performance parameters in any of the phases evaluated. For diarrhea incidence and intensity, the results indicated that the treatments with alternative additives had similar effects as the group treated with colistin. A significant difference was found for the profile of propionic acid (0.23% colistin and 0.32%, 0.36%, 0.37% additives) and total fatty acids (0.67% colistin and 0.97% additives) values in the caecum. The supplementation with different compositions and concentrations of prebiotics and butyric acid may viably replace colistin in controlling diarrhea and modulating volatile fatty acid production in the caecum.