Reduction in incidence of experimental fowl typhoid by incorporation of a commercial formic acid preparation (Bio-Add™) into poultry feed

The experiment described evaluated the effect of a commercial in-feed preparation (Bio-Add™) involving a mixture of formic acid and propionic acid on the incidence of experimental fowl typhoid in groups of 41 and 42 1-wk-old Rhode Island Red chickens. The chickens were infected through contact with 12 identical chickens that had been inoculated orally with 10 8 cfu of Salmonella gallinarum strain 9. The incidence of mortality and morbidity due to fowl typhoid was 31/41 (76%) in birds given untreated feed and 14/42 (33%) in birds given feed treated with Bio-Add™.

Two-Way Selection for Daily Gain and Feed Conversion in a Composite Rabbit Population

We conducted a two-way selection experiment in a composite rabbit population to investigate the responses to selection for postweaning ADG and feed conversion (FC). Two generations of crossing, followed by four generations of random pair matings, preceded three generations of selection. Selection was practiced within four lines: high-feed conversion (HFC), low-feed conversion (LFC), high gain (HG), and low gain (LG). Data on 1,446 rabbits from the random mating and selection generations were fitted to an animal model to estimate heritabilities of and the genetic correlation between ADG and FC. The two-trait model included rabbit and common litter random effects and line, generation, and sex fixed effects. Estimates of heritability of ADG and FC were .48 and .29, respectively, and the genetic correlation between them was -.82. Common litter environmental effects accounted for a proportion of .11 and . 13 of the phenotypic variation of the two traits, respectively. For ADG (in g/d) the regressions of mean breeding values on generation number during the selection period were 1.23 ± .12 (P < .01) in the HG line and -.86 ± .12 (P < .01) in the LG line; the regressions for FC (in g feed/g gain) were -.07 ± .01 (P < .01) in the HFC line and .03 ± .01 (P < .05) in the LFC line. Selection for ADG was effective in improving ADG and FC.

Acute reduction in serum progesterone concentrations after feed intake in dairy cows

This study tested the hypothesis that high feed consumption will acutely decrease circulating progesterone concentrations. In the first experiment, a Latin Square design was used to test whether feeding pattern would alter circulating progesterone in pregnant lactating Holstein cows (n = 12). Feed was removed for 12 h before the experiment and cows were then either fed 100% of the total mixed ration (TMR), 50% of TMR every 12 h, 25% of TMR every 6 h, or left unfed for an additional 12 h. Blood samples were taken every hour for 24 h. Provision of 100 or 50% of TMR decreased circulating progesterone by 1 h after feeding and progesterone remained depressed until 8-9 h after feeding. Feeding 25% of TMR did not reduce circulating progesterone concentrations. Experiment 2 used a crossover design to measure the effect of acute feeding on circulating progesterone and LH concentrations during delivery of a constant amount of exogenous progesterone (Eazi-Breed CIDRs) in lactating Holstein cows (n = 8) and nonpregnant dry Holstein cows (n = 6). Blood samples were taken every 15 min for 8 h. There was no change in serum progesterone during the 8 h treatment period in unfed cows; however, feeding decreased (P < 0.05) circulating progesterone between 2 and 6 h after feeding. In lactating cows, feeding increased mean LH (P < 0.05). There were more LH pulses (P = 0.01) in lactating than nonlactating cows. Thus, acute feeding reduced circulating progesterone in pregnant lactating cows apparently due to an increase in progesterone metabolism. Interestingly, feeding multiple smaller meals eliminated the acute effect of feeding on circulating progesterone. © 2003 Published by Elsevier B.V.

Tracing metabolic routes of feed ingredients in tissues of broiler chickens using stable isotopes

The present study aimed to quantify the proportion of 13C from energy and protein feed ingredients that follow the metabolic routing of the liver and muscle in broiler chickens. A stable isotope of carbon technique was used that is based on the isotopic discrimination that occurs in the plants during the photosynthesis process. One-day-old male chicks were subjected to treatments based on free choice of energy and protein sources. Rice bran (R) and soybean meal (S), C3 plants, have higher isotopic ratios than corn (C), a C4 plant, and corn gluten meal (G). Choices were R+S, C+G, R+G, C+S, or R+C+G+S. A complete feed (CF) was a sixth treatment. Feed intake and BW were measured at 30 d of age, when liver and breast muscle were collected for isotopic analysis. Treatments affected the amount of feed intake and the choices of energy or protein sources. Complete feed had the largest intake, differing from the other treatments that had free-choice feeding. Final BW was a direct reflection of consumption by these birds in all treatments. The isotopic results indicated that the 13C/12C ratio was generally higher in breast muscle than in liver, probably because of higher protein content. Moreover, in the liver, the proportion of 13C retained from the energy ingredient was greater than the proportion from the protein ingredient. That is in contrast to muscle, where the proportion of 13C retained from the protein ingredient was greater than from the energy ingredient that was self-selected.

Different criteria for feed formulation based on digestible amino acids for broilers

An experiment was carried out to evaluate different criteria in feed formulation based on digestible amino acids for broilers during the grower phase. Diets were formulated according to the recommendations for digestible methionine, methionine + cysteine, lysine, and threonine. A total number of six hundred Cobb 500 male day-old chicks were distributed in a completely randomized experimental design, with three formulation criteria supplying the recommendations established by Baker & Chung (1992), Degussa (1997), and Rostagno et al. (2000), with 4 replicates of 50 birds each. No significant differences were observed for weight gain and feed intake. However, feed conversion ratio improved when birds were fed the diets containing the profiles recommended by Baker & Chung (1992) and Degussa (1997). No difference was observed in terms of leg, wings, back, and head yields. Broilers fed with the profile of Baker & Chung (1992) presented worst breast yield, whereas those fed the Degussa (1997) standard had better carcass yield.

Surface area of the tip of the enterocytes in small intestine mucosa of broilers submitted to early feed restriction and supplemented with glutamine

A total of 640 one-day-old male Cobb chicks were used to evaluate the effects of early feed restriction and glutamine on villi density and tip surface of enterocytes in the small intestine of broilers. A two-factor factorial experimental design with glutamine and feed restriction as main factors was used. Treatments consisted of quantitative feed restriction at 30% of ad libitum intake from 7 to 14 days of age, and glutamine addition at 1% in the diet from 1 to 28 days of age. Sections of the small intestine (duodenum, jejunum, ileum) were collected at 14 and 21 days of age for analyses by scanning and transmission electron microscopy. Villi density decreased with age and increased in cranial-caudal direction. Glutamine increased villi density in the small intestine. Microvilli density and height decreased with age. Glutamine increased microvilli width. The jejunum was the segment with the largest surface area of the tip of the enterocytes, followed by the duodenum and the ileum. Feed restriction decreased the surface area of the tip of the enterocytes in the small intestine at 14 and at 21 days of age. Glutamine supplemented in the feed increased the surface area of the tip of the enterocytes of the jejunum and ileum at 21 days of age. © Asian Network for Scientific Information, 2007.

Manganese determination by GFAAS in feces and fish feed slurries

This paper presents a simple, fast and sensitive method to determine manganese in samples of feces and fish feed by graphite furnace atomic absorption spectrometry (GFAAS) by the direct introduction of slurries into the graphite tube. The limits of detection (LOD) and quantification (LOQ) calculated for 20 readings of the blank of the standard slurries (0.50 % m/v of feces or feed devoid of manganese) were 28 and 92 μg kg-1 for the standard feces slurries and 34 and 110 μg kg-1 for the standard feed slurries. The proposed method was applied in bioavailability studies of manganese in different fish feeds and their results proved compatible with those obtained for samples mineralized by acid digestion using microwave oven. ©2007 Sociedade Brasileira de Química.

Determination of copper in fish feed by graphite furnace atomic absorption spectrometry using slurry sampling

The present work develops and optimizes a method to determine copper in samples of feces and fish feed by graphite furnace atomic absorption spectrometry (GFAAS) through the direct introduction of slurries of the samples into the spectrometer's graphite tube coated internally with metallic rhodium and tungsten carbide that acts as chemical modifiers. The limits of detection (LOD) and quantification (LOQ) calculated for 20 readings of the blank of the standard slurries (0.50% m/v of feces or feed devoid of copper) were 0.24 and 0.79 μg L -1 for the standard feces slurries and 0.26 and 0.87 μg L -1 for the standard feed slurries. The proposed method was applied in studies of absorption of copper in different fish feeds and their results proved compatible with that obtained from samples mineralized by acid digestion using microwave oven. © Springer Science+Business Media, LLC 2008.

Iron determination by FAAS in fish feed and feces after ultrasound-assisted extraction

This paper proposes a method to determine iron in samples of fish feed and feces using ultrasound in the extraction of the analyte and in subsequent quantification by flame atomic absorption spectrometry. Using HCl 0.10 mol L -1 as the extraction solution, the optimal conditions of extraction were found to be: granulometry of the sample <60 μm; a sonication time of five cycles of 10 s and sonication power of 136 W. The method was applied in studies of the availability of iron in four food sources used in the diet of Nile Tilapia. The results obtained with the proposed extraction method allowed us to calculate the coefficients of apparent digestibility of iron in the food sources, which was not possible when using results obtained from samples mineralized by acid digestion. © Springer Science+Business Media, LLC 2008.

Economic evaluation of nile tilapia juvenile production, feed with commercial ration and with primary production come from organic and inorganic fertilization

Study objective was to evaluate economically a Nile tilapia juvenile production, employing different feeding techniques. Tilapia fingerlings of 8g were stocked at 5 fish m-2 stocking in 50 and 150 m2 ponds, during 75 days. Treatments were: inorganic fertilization (P205 and N); organic fertilization (poultry manure) and commercial ration (32% CP). Water quality results were considered adequate for fish rearing. In juvenile production there were significant differences among treatments for individual final weight, medians were: for inorganic fertilization 12.92g (13.35g in 50 m2 and 12.49g in 150 m2); for organic fertilization 30.55g (33.69g in 50 m2 and 27.40g in 150 m2) and for commercial ration 51.23g (52.90g in 50 m2 and 50.15g in 150 m2). Survival rate ranged from 63 to 71%, with no statistic difference. Commercial ration was effective to bigger juvenile production, with a better market value. Costs considered in economic analyses were tilapia fingerlings, fertilizer, ration, labor and installation depreciation. Obtained information showed that juvenile production in 50 m2 ponds is not viable economically and, in 150 m2, production is viable only when commercial ration is used.

Meat quality of young Nellore bulls with low and high residual feed intake

Fifty-nine Nellore bulls from low and high residual feed intake (RFI) levels were studied with the objective of evaluating meat quality traits. Animals were slaughtered when ultrasound-measured backfat thickness reached 4. mm, and samples of Longissimus were collected. A mixed model including RFI as fixed effect and herd and diet as random effects was used, and least square means were compared by t-test. More efficient animals consumed 0.730. kg dry matter/day less than less efficient animals, with similar performance. No significant differences in carcass weight, prime meat cuts proportion, chemical composition, pH, sarcomere length, or color were observed between RFI groups. Shear force, myofibrillar fragmentation index and soluble collagen content were influenced by RFI, with a higher shear force and soluble collagen content and a lower fragmentation index in low RFI animals. Feedlot-finished low RFI young Nellore bulls more efficiently convert feed into meat, presenting carcasses within quality standards. © 2012 Elsevier Ltd.

Experimental study of bottom feed updraft gasifier

The updraft biomass gasifiers currently available produce a gas with high tar content. For almost all downstream applications a substantial reduction of the tar concentration is required. The gravimetric tar concentration behavior in producer gas, obtained at a modified updraft fixed bed gasifier, was studied. The feedstock feeding system was modified respect to the traditional updraft gasification design in order to decrease the tar concentration in the producer gas; the material is feeding continuously through a conduit in the base of the reactor over the grate. The caloric power of the syngas obtained was slightly lower than the typical value for this type of reactor and the highest efficiency obtained for the woodchip gasification was 77%. The highest tar concentration obtained during the experiments was 1652.7 mg N m-3 during the first our of experiments, comparable with the smaller value reported for the updraft reactors, this value is reduced significantly after the stabilization of the gasification process in the reactor. The smaller value obtained was 21 mg N m-3. © 2013 Elsevier Ltd.

Ultrasound-assisted extraction of Na and K from swine feed and its application in a digestibility assay: A green analytical procedure

The study is aimed to evaluate the efficiency of ultrasound-assisted extraction (UAE) as a simple strategy focused on sample preparation for metal determination in biological samples. The extraction of sodium and potassium extraction was carried out from swine feed followed by determination of the concentration of these metals by flame atomic emission spectrometry (FAES). The experiment was performed to cover the study of the variables influencing the extraction process and its optimal conditions (sample mass, particle size, acid concentration, sonication time and ultrasound power); the determination of these analytical characteristics and method validation using certified reference material; and the analysis of pre-starter diets. The optimal conditions established conditions were as follows: mass: 100 mg, particle size:<60 μm, acid concentration: 0.10 mol L-1 HCl, sonication time: 50 s and ultrasound power: 102 W. The proposed method (UAE) was applied in digestibility assays of those nutrients present in different piglet pre-starter feeds and their results proved to be compatible with those obtained from mineralized samples (P < 0.05). The ultrasound extraction method was demonstrated to be an excellent alternative for handless sampling and operational costs and the method also has the advantage of does not generating toxic residues that may negatively affect human health and contaminate the environment. © 2013 Elsevier B.V. All rights reserved.

Caracterização do consumo alimentar de frutas, verduras e legumes em adultos na atenção primária

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Impacto de intervenção educacional e grupo sobre o consumo de frutas, verduras e legumes de agentes comunitários de saúde do município de Botucatu-SP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)