Levels of replacing corn by cassava starch on performance and carcass characteristics of bulls finished in feedlot

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dimensional versus cut-off renormalization and the nucleon-nucleon interaction

The role of dimensional regularization is discussed and compared with that of cut-off regularization in some quantum mechanical problems with ultraviolet divergence in two and three dimensions with special emphasis on the nucleon-nucleon interaction. Both types of renormalizations are performed for attractive divergent one- and two-term separable potentials, a divergent tensor potential, and the sum of a delta function and its derivatives. We allow energy-dependent couplings, and determine the form that these couplings should take if equivalence between the two regularization schemes is to be enforced. We also perform renormalization of an attractive separable potential superposed on an analytic divergent potential.

Effect of storage of cuttings on the rooting of different cultivars of cut chrysanthemums (Dendranthema grandiflora Tzvelev) for two different seasons

Chrysanthemums are commercially propagated through cuttings. Pre-rooting storage of cuttings in the dark is a common practice among growers and companies that work and trade with chrysanthemum cuttings. Therefore, the maximum storage period for cuttings and differences in tolerance among cultivars has been investigated. Adventitious roots of cuttings can originate in almost any tissue, including the epidermis, stem cortex and pericycle, ray parenchyma, immature xylem and phloem cells, and pith. The aims of this work were to determine the effect of time of cold storage of cuttings (0, 1, 2, 3, 4, 5 and 6 weeks) on the rooting of four cut chrysanthemum cultivars (Super White, Sheena, Dark Orange Reagan and Town Talk) for two seasons of the year (summer and winter), and also to determine the origin of root formation in chrysanthemum cuttings. The study was carried out as a randomized complete block design with 5 replications for each storage treatment. Each plot was comprised of three cuttings that were examined 14 days after the cutting procedure. During the winter, the roots were studied by scanning electron microscopy (SEM) at the Electron Microscope Laboratory. The following conclusions were made: in winter, cold storage affected the rooting of cuttings, mainly after two weeks of storage for all cultivars. The rooting percentage was lower in the winter and the cuttings could be preserved for a shorter period. The source and growth of roots in chrysanthemum cuttings was found to be endogenous. After three days, callus formed in the pericycle and the first emergence of adventitious roots occurred by the fourth day of rooting. During the summer, cold storage could be up to 4 weeks without any problems.

Production and preservation of fresh-cut 'Tommy Atkins' mango chunks

During the 1999/00 and 2000/01 seasons, sliced 'Tommy Atkins' mangoes were packaged with three different types of polymeric films; polypropylene (PP) cups, low-density polyethylene (LPDE) bags or polyethylene terephthalate (PET) clamshell trays, and stored at 3°C for 2 weeks. The mango chunks were evaluated for flavor, appearance, colour, total soluble solids (TSS), total titratable acidity (TTA), ascorbic acid (AA) contents, O2 and CO 2 concentration in the packages, as well as respiration. Shelf life based on visual appearance was 14 days, with the products showing good appearance and agreeable aroma. The TTA content in chunks packaged in PP cups or PET trays were reduced during the storage, and with the color changing from light yellow to dark yellow. The chunks respiration in PP cups or LPDE bags were 64.6 and 87.9 mL CO2.kg-1.h-1, and in PP cups or PET trays were 45.86 and 43.92 mL CO2.kg-1.h -1, respectively for 1999/00 and 2000/01 seasons. The percentages of O2 and CO2 in the packages were stabilized after 2-4 hours, and the atmosphere had 11-17% and 1-10% of them. The microbiological content was lower than the allowed. No differences were observed between the seasons, and the best packages were the cups.

Peso de abate de machos não-castrados para produção do bovino jovem. 2. Peso, Idade e caracteristicas da carcaça

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Nile tilapia, Oreochromis niloticus, productive performance and carcass characteristics as related to food management

Male juveniles of Nile tilapia, Oreochromis niloticus, were stocked in 12, 300-m 2 ponds at a density of 1.7 fish/m 2 to evaluate the effects of different food management methods (natural foods and diets in pellet, floating or minced form) on fish production and carcass characteristics. Water quality variables monitored during the period were within acceptable levels for the species. Total fish production was significantly different (P < 0.05) and the highest values were obtained with diets in pellet (5,997 kg/ha) and floating (5,441 kg/ha) form. The fish fed diets had higher contents of body fat (1.57 to 1.98%) and visceral fat (12.64 to 25.04%) than fish fed natural food, which had levels between 0.17 and 0%, respectively. Natural food treatment yielded lower fish production and fish with lower body fat, while treatments that yielded higher fish production (rations) higher percentage of visceral fat. © 2004 by The Haworth Press, Inc. All rights reserved.

Use of carambola (Averrhoa carambola L. 'Fwang Tung') fruit at two stages of maturity for fresh-cut products

Carambola fruit ('Fwang Tung') were picked at two stages of maturity: mature-green (50% yellow) and mature (100% yellow). Fruit were washed with water, dipped in NaOCl solution (200 mg.L-1 for 5 minutes), and stored over night at 10°C. Fruit were sliced manually in to pieces of approximately 1 cm thickness. Slices were rinsed with NaOCl solution at 20 mg.L-1, drained for 3 minutes, and packaged in polyethylene tereftalate (PET) trays provided with a fit cover (Neoform® N94). Packages were stored at 6.5°C and 85% RH for 9 days, and samples taken every 3 days for physical, chemical and biochemical analysis, respiration, and internal atmosphere composition. Immediately after cutting, slices at both stages of maturity showed a wounding response with a 5-fold increase in respiration rate. Polygalacturonase (PG) and polyphenol oxidase (PPO) activity did not differ between stages of maturity. Despite the less mature stage being less preferred at the sensory evaluation owing to its greenish peel, the best stage of maturity for carambola fresh-cut production was mature-green, due to a higher resistance to cutting, and presenting a better colour and appearance maintenance for up to 9 days.

Respiratory and storage behavior of fresh cut 'Tommy Atkins' mango

The respiratory and storage behavior of fresh cut 'Tommy Atkins' mango, naturally ripened (NR) or with use of ethylene (RE), were studied. Fruits were selected, washed and disinfected (200 mgCl.L-1) and stored for 12 hours at 10°C. After this period, they were processed under hygienic conditions at 10°C, packaged in polyethylene terephthalate (PET) trays or in styrofoam trays wrapped with stretchable polyvinyl chloride (PVC) film and stored for up to 15 days at 3°C. The products were evaluated regarding the evolution of internal atmosphere in the packing (O2 and CO 2), development of weight, appearance, shelf life and consumer acceptability. The respiratory rate was measured before and after processing every two hours. The yield of 'Tommy Atkins' mango to produce fresh cut product was 48.09±0.95%. Increase of the respiration rate of both mango samples was verified one hour after the preparation (NR = 17.75 mL CO 2.kg-1.h-1; RE = 28.29 mL CO 2.kg-1.h-1), followed by stabilization at 3.76 and 8.07 mL CO2/kg.h, respectively. The percentage of O2 in packages was stable in all treatments, 15-20% in PVC trays, 18-20% in PET tray. The percentage of CO2 was steady around 1.5-2.5%. The products lost fresh mass during the storage, from 0.06% to 0.30% for PET trays and from 0.15% to 1.61% for trays covered with PVC. The appearance was considered appropriate for commercialization until the 13th day, whereas product from mangoes ripened with application of ethylene was for 11 days, presenting browning in the external surface. The naturally ripened mango presented the best flavor and consumer preference in relation to the mango ripened with application of ethylene for 11 days of storage. The control of hygienic conditions during the production and storage was good and with safety for until 10 days.

Water relations of cut inflorescences of Alpinia purpurata treated with seven pulsing solutions

Alpinia purpurata (Vieill) K. Schum, common name red ginger belongs to Zingiberaceae family, and is a perennial, with nice inflorescences composed of layers of bracts arranged in spirals. The utilization of keeping-quality solutions seeks to prolong vase-life and to maintain the quality of cut flowers. This research was performed to evaluate the effect of seven pulsing solutions (during 24 hours) on water relations, quality (turgor, browning and curvature) and the longevity of cut red ginger. The experiment followed complete randomized design, in factorial arrangement. The following treatments were studied: 1) distilled water (control), 2) sucrose 2% + 8-hidroxyquinoline citrate 200 ppm, 3) sucrose 2%, 4) sucrose 2% + citric acid, 5) benzyladenine 10 μM, 6) benzyladenine 10 μmol + sucrose 2%, 7) quaternary ammonia 0,5 mL/L. There was no significant (P>0.05) reduction of the relative water content (RWC) of the inflorescence bracts, among solutions, in the first period (7 days) and in the second period (14 days) and, between the two periods for all treatments. Significant differences among RWC of some treatments were recorded after 16 days of vase life. The utilization of benzyladenine, benzyladenine plus sucrose and sucrose plus citric acid, in the pulsing solution, allowed to keep the flowers quality for longer periods than the other treatments.

Benzyladenine and Gibberellic acid pulse on postharvest of Calathea louisae cut foliage

Calathea louisae is an herbaceous ornamental plant native of Brazil whose cut foliage has potential to be used as a new product for the local ornamental market, as well as the international market, due to its decorative dark green leaves with greenish white splotches along midrib, and purple undersides. The objective of this study was to evaluate pulse treatments of benzyladenine and gibberellic acid for maintaining quality and extending keepability of foliage. The experiment was conducted in a complete randomized design with three replications (three stems in each vase) and seven treatments: distilled water (control) and pulsing cut petioles in benzyladenine or gibberellic acid for 4 h at 100, 250 and 500 mg L-1. The senescence symptoms were characterized by leaf rolling and a decrease in the angle formed between leaf and petiole as a response to water stress. Gibberellic acid or benzyladenine pulse treatments (250 and 500 mg L-1) significantly extended the longevity of cut foliage compared to the control. Gibberellic acid pulse (250 and 500 mg L-1) maintained leaves' green coloration and brightness for a longer time compared to control and benzyladenine pulse. Pulsing with gibberellic acid or benzyladenine (at all tested concentrations) maintained upright leaves for a longer time, showing a significantly higher angle between leaf and petiole compared to control. Foliage pulsed with gibberellic acid (500 mg L-1) showed a significantly higher leaf relative water content, a significantly smaller loss of accumulated fresh mass percentage compared to control and other gibbberellic acid and benzyladenine treatments.

Pulse treatments to extend the postharvest life of Ctenanthe setosa cut foliage

Marantaceae leaves have a contrasting color pattern and a decorative design which are interesting traits for its use as cut foliage. No postharvest research has been carried out on the potential as cut foliage for species of Ctenanthe, a member of the Marantaceae. Grey-maranta (Ctenathe setosa) is an herbaceous ornamental plant native of Brazil whose cut foliage has potential to be used as new crop product for local and international ornamental markets. The objective of this study was to evaluate pulse treatments to extend the longevity of foliage. The experiment was conducted in a complete randomized design with three replications and eight treatments: distilled water; pulsing cut petioles-ends in citric acid (pH = 2.8/1h); 2% sucrose (4h); 1% sucrose plus 200 mg L-1 citric acid (4h); 0.01% Tween® 20 (4h); 100 mg L -1 benzyladenine plus 0.01% Tween® 20 (4h); 100 mg L-1 gibberellic acid plus 0.01% Tween® 20 (4h); and maintenance of cut petiole in holding solution with commercial sodium hypochlorite (0.5 mL L-1). The senescence symptoms were mainly characterized by leaf rolling and by a decrease in the angle formed between leaf and petiole as a response to water deficit stress. Gibberellic acid or benzyladenine pulse treatments significantly extended longevity (6 days compared to control) and maintained leaves' green coloration and brightness for a longer time compared to control. However, only the benzyladenine plus Tween® 20 pulse maintained leaves in an erect form for a longer time, showing a significantly higher angle between leaf and petiole compared to control. Also, foliage pulsed with benzyladenine plus Tween® 20 showed a significant smallest loss of accumulated fresh mass percentage compared to control by the T test as to parallelism of treatments lines.

Postharvest characteristics and treatments to overcome latex exuded from cut flowers of lotus

Lotus (Nelumbo nucifera Gaertn.) is a perennial herbaceous aquatic ornamental plant with potential to be used as a new cut flower for the Brazilian ornamental market. It shows exotic and attractive flowers and has a strong market appeal, once it is known as a symbol of purity, holiness and immortality. However, flowers have a short-vase life. Lotus flower stem exudes a large quantity of sticky milky sap from the cut surface, which is produced in laticifers, spatially associated with both xylem and phloem. It has been reported that latex coagulates on the cut surface preventing or reducing water absorption and reducing flowers' vaselife, requiring treatments to stop the flow of latex. The objective of this study was to report observations of lotus postharvest characteristics and evaluate treatments to overcome latex flow. The experiment was conducted as a complete randomized design with three replications of four stems in each vase and eight treatments; a control (distilled water), pretreatment of cut stem-ends with hot water (40° C/1 minute), boiling water (3 seconds), isopropyl alcohol 90% (10 minutes) or citric acid (pH = 2.8/1h) and, maintenance of stems in a holding solution of Tween® 20 (0.01%), citric acid (200 mg L-1) or Tween® 20 (0.01%) plus citric acid (200 mg L-1). Treatments had no significant effect on flowers vaselife which was only about three days, although isopropyl alcohol, hot and boiling water completely stopped latex flow. Cut stem-ends pretreated with citric acid (pH = 2.8/1 h) showed a significantly higher relative water content of petals compared to others treatments. The senescence symptom of lotus cut flowers was mainly characterized by abscission of turgid petals and dehiscence of stamens without any visual change of petal color and brightness.

Associations between microsatellite markers and traits related to performance, carcass and organs in chickens

Associations between four microsatellite markers on chromosome 11 and five on chromosome 13 with performance, carcass and organs traits were investigated in chickens using a least-squares approach applied to single-marker analysis. Three hundred and twenty seven F 2 chickens from the EMBRAPA broiler×layer experimental population were evaluated for 16 traits: five related to performance, five to carcass and five to organs, plus the hematocrit. Two significance thresholds were considered: p<0.05 and p<0.0056; the last value resulted from the application of a multiple tests analyses correction. On chromosome 11, six associations (p<0.05) between the genotypes of two markers with four growth related and one carcass trait were found. On chromosome 13, six associations (p<0.05) between marker genotypes and three performance traits, eight associations (p<0.05) between marker genotypes and two carcass traits and eight associations (p<0.05) between marker genotypes and four organs traits were detected. These associations were indications of the presence of quantitative trait loci on these chromosomes, especially on chromosome 13. In this chromosome, the strongest evidence was for body weight at 41 days of age and percentage of carcass because the p-values exceeded the multiple test threshold (p<0.0056), but also for breast percentage and heart weight due to the large number of markers (four) on chromosome 13 associated with each one of these traits. These associations should be further investigated by interval mapping analyses to find QTL positions and to allow the estimation of their effects. © Asian Network for Scientific Information, 2009.

Características de carcaça de cordeiros alimentados com grãos e subprodutos da canola

The aim of this work was to evaluate the introduction of 8% grains and by-products (meal or cake) of canola in the diets of lambs. To evaluate quantitative carcass characteristics, 24 Santa Ines lambs were used in a completely randomized design. Diets with averages of 15.4% of CP in DM and 80.2% of TDN were composed for 40% Tifton hay and 60% concentrate based on corn grain, soybean meal, whole grain canola, canola meal, canola cake and mineral mixture. The use of whole grains and by-products of canola in the diet of lambs finished in feedlot did not influence (p > 0.05) quantitative carcass characteristics. For cut dressing in relation to the CCW, no effect was observed for the analyzed variables among treatments. It was concluded that the introduction of grains and by-products of canola allow for satisfactory results, and could be recommended in the formulations of lamb diets.

Influence of environmental temperature, dietary energy level and sex on performance and carcass characteristics of pigs

Pigs are quite sensitive to high environmental temperatures and the thermoregulation mechanisms represent great expenses in energy for heating loss, reducing animal well-being and production performance, and altering carcass quality. The aim of this study was to assess the effects of sex and dietary energy level in growing-finishing pigs submitted to characteristic seasonal variation of temperature in subtropical humid climate, and to propose a mathematical model to predict growth performance and carcass characteristics. Twenty-eight crossbred growing-finishing pigs were randomly allotted to twelve treatments, in a 2x2x3 factorial trial (2 sex; 2 environmental conditions, and 3 energy levels). Heat stress condition (climatic chamber) showed temperatures of 31 oC at 7:00 and 22 oC at 17:00 (maximum of 33 °C) and thermal comfort condition (stall) showed temperatures of 18 °C at 7:00 and 24 °C (maximum of 27 °C). Pigs were fed ad libitum with diets containing 12.2 (low), 13.6 (medium) and 15.0 (high) MJ ME/ kg DM. Voluntary feed intake, daily weight gain, and final body weight were higher (P<0.01) at thermal comfort condition and were influenced by sex (P<0.01) in growing pigs. Feed to gain ratio decreased as the energy level increased (P<0.01), with values of 2.67, 2.59, and 2.32 (12.2, 13.6, and 15.0 MJ ME/kg DM, respectively). There was energy level and sex interaction only for daily weight gain. Regarding finishing pigs, environmental conditions also showed effects (P<0.01) on voluntary feed intake, daily weight gain, and final body weight. Performance of pigs was better at thermal comfort condition. Feed to gain ratio values were 3.55, 3.42, and 2.95 for low, medium, and high energy level, respectively. Interactions between energy level and sex were observed for voluntary feed intake, daily weight gain, and final body weight (P<0.05). Carcass yield and quality were affected by environmental condition and dietary energy level. Both hot and cold carcass weight increased as energy of ration increased. Cold carcass weight increased by 1.142 kg/MJ EM whereas backfat thickness was up to 252 mm/MJ EM. Longissimus thoracis muscle thickness was around 16 mm smaller in pigs under heat stress, but lean content was 2.68% higher in those animals. Regression equations were proposed to predict the performance values in the different situations studied.