Yes / This paper presents a case study of a young infant, from a larger isotopic and osteological investigation of Bronze/Iron Age (14th-4th century BC) skeletal assemblages from Croatia and Slovenia. The osteological analysis of this infant identified pathological lesions including abnormal porosity and new bone formation consistent with malnutrition and phases of recovery. The distribution and appearance of these pathological lesions (i.e. diffuse micro-porosities and plaques of subperiosteal new bone formation on the skull and long bones) led to the conclusion that this infant probably suffered from scurvy (vitamin C deficiency). The diet and nitrogen balance of this individual were investigated by incremental dentine sampling and stable carbon and nitrogen isotope analysis. This sampling method provided a high resolution record of dietary and metabolic changes from pre-birth to around the time of death. The resulting isotope data exhibited unusually high δ13C values for this region and time period (between -11.3‰ and -12.6‰), while δ15N values were observed to be c. 3‰ above that of rib collagen sampled from contemporary adults recovered from the same site. The isotope profiles generated from the incremental dentine analysis show that δ13C and especially δ15N continue to increase until death. The evidence from the skeletal remains and high resolution isotopic data support the hypothesis that this infant suffered from severe malnutrition and an increasingly negative nitrogen balance. The paper discusses some scenarios which could have resulted in these unusual isotope ratios, whilst considering the diagnosis of possible metabolic disease. The paper also addresses the need for context when interpreting isotopic results. The isotope data should not be viewed in isolation, but rather as part of a multidisciplinary approach, considering the multiple causes of isotopic variability.

Four multiparous Holstein cows, averaging 44 days in milk and previously fitted with rumina1 and duodenal cannulae, were utilized in a 4 x 4 Latin square design to evaluate effects of dietary nonfibrous carbohydrate (NFC) and rumen undegradable protein (RUP) on metabolic and lactational parameters. Diets were isonitrogenous (17.4% CP) and structured in a 2 x 2 factorial arrangement with levels of NFC at 41 or 47% of dietary OM and RUP at 27 or 41% of dietary CP with inclusion of corn gluten meal, fish meal, and feather meal to increase dietary RUP. When cows were fed diets containing 47% NFC, intake of DM, OM, NFC, and N increased (P ± .05) while those containing 41 % NFC increased (P±.01) intake of NDF and ADF. Ruminal digestibility coefficients were not affected leading to greater quantities of NFC digested resulting in suppressed pH (P ±.01) and acetate (P ±.05) and increased propionate (P ± .05), Diets containing 27% RUP increased (P ±.01) ruminal ammonia and plasma urea nitrogen (N) with 41 % NFC eliciting higher ammonia N concentrations at each RUP level. Bacterial yields (averaging 220 g/d) were slightly higher when 41% NFC diets were consumed with no dietary effects on efficiency. Flow of ammonia N to the small intestine (SI) increased (P ± .01) with 27% RUP. When compared to 41% NFC, diets containing 47% NFC increased (P ± .05) flow of methionine (38.6 vs. 32.5 g/d). Fifty percent of the essential amino acids entering the SI were of bacterial origin. Diets containing 41% RUP elicited lower total tract digestion of N while enhancing that of hemicellulose. Total tract digestion of NFC and ADF was greater when 41% NFC diets were consumed. Yields of milk (38.7 vs. 37.7 kg/d) and lactose (1.94 vs 1.88 kg/d) increased with 27% RUP. Efficiency of production was increased by both 41% NFC and 27% RUP. Total and whey N in milk increased (P 5 ±.05) while milk urea N decreased (P ± .01) with higher (41%) dietary RUP. Increased (P ± .05) absorption of N (490.4 vs. 461.6 g/d) at the SI occurred with the 47 vs. 41 % NFC diets, respectively, with no effects observed on that retained or excreted in the urine or milk. Although supply of methionine to and the absorption of N from the S1 was greater with the 47% NFC diets, no positive effects were observed on nitrogen balance or milk production. Rather, dietary RUP provided greater promise in that lower dietary RUP increased milk production and efficiency while increased RUP enhanced milk N content. Therefore, economics regarding feed costs as well as price for milk and milk components may largely dictate preferential dietary RUP content. Abbreviation key: ADC = apparent digestion coefficient, CGM corn gluten meal, CRN = carbon hydrogen nitrogen, CHO = carbohydrate, CNCPS = Cornell Net Carbohydrate and Protein System, MUN = milk urea nitrogen, N = nitrogen, NAN = nonammonia N, NANMN = nonammonia nonmicrobial N, NFC = nonfibrous carbohydrate, NPN = nonprotein N, PUN = plasma urea N, RDP = rumen degradable protein, RUP = rumen undegradable protein, SI = small intestine, TDC = true digestion coefficient, 41:27 = 41% NFC and 27% RlUP, 47:27 = 47% NFC and 27% RUP, 41:41 = 41% NFC and 31% RUP, 47:41 = 47% NFC and 41% RUP. / Ph. D.

Einleitung: Die Kationen-Anionen Bilanz (DCAB) des Futters modifiziert den Säure-Basen Status von Tieren und findet Anwendung in der Prävention von Milchfieber bei Kühen, MMA bei Sauen und Urolithiasis bei Haustieren. Durch die Veränderung des Kationen-Anionen-Verhältnisses in Futterrationen können biologische Prozesse beeinflusst werden, der Stickstoffmetabolismus. Ziel der Untersuchung: Die vorliegende Studie befasst sich mit der Frage, ob eine kaliumbedingte Variation der DCAB des Futters für wachsende Schweine einen Einfluss auf bestimmte Parameter des Säure-Basen-Haushaltes und möglicherweise auch auf die Stickstoffbilanz hat. Materialien und Methoden: Dem Versuch standen insgesamt 38 männlich kastrierte Mastschweine (Dreirassen-Kreuzung von Pietrain x Deutsches Edelschwein x Deutsche Landrasse) mit einem Einstallungsalter von ca. 12 Wochen und einer Lebendmasse von 17,3 kg bis 30,3 kg zur Verfügung. In randomisierter Reihenfolge erfolgte die Zuteilung der Schweine zu den acht Versuchsfuttern; Rohproteingehalt von 140 g kg-1 Futter und 200 g kg-1 Futter, sowie je 4 g, 10 g, 14 g oder 20 g Kalium kg-1 Futter. Die Versuchsfutter wiesen eine konstante Konzentration an Natrium und Chlorid auf. Die Hauptfutterkomponenten waren Mais und Weizen. Die beiden Rohproteingehalte wurden durch unterschiedliche Sojaextraktionsschrot- und Maisklebermengen gewonnen. Über Kaliumhydrogencarbonat (KHCO3) und Kaliumchlorid (KCl) resultierte die Einstellung der genannten Kaliumkonzentrationen sowie der vier DCAB-Stufen von -125 mEq kg-1, 66 mEq kg-1, 168 mEq kg-1, und 342 mEq kg-1 Futter. In einer Adaptionsphase von 15 Tagen gewöhnten sich die Scheine an das Versuchsfutter und die Umgebung. Die Einstallung erfolgte in Einzelboxen und die Versuchstiere erhielten Wasser ad libitum. Während der anschießenden zwei Bilanzphasen von je fünf Tagen wurden die Schweine in Bilanzkäfigen gehalten. Zwischen den beiden Bilanzphasen kam es zu einer fünftägigen Pause ohne Änderung der Fütterung. In der Bilanzzeit wurden der gesamte Harn und Kot der Tiere gesammelt sowie der dazugehörige pH-Wert kontinuierlich bestimmt. Harn- und Kotaliquots wurden für Stickstoff- und Elektrolytanalysen einbehalten. Jede fünftägige Bilanz endete mit der Gewinnung einer Blutprobe von jedem Schwein aus der Vena jugulares zur Bestimmung von Kalium, Natrium, Chlorid, pH-Wert, Hydrogencarbonat, Basenüberschuss und Aminosäuren. Ergebnisse: Kalium hat einen Einfluss auf den Harn pH-Wert. Analog zur steigenden Kaliumaufnahme (DCAB↑) wurden die Harn pH-Werte basischer (-125 mEq kg-1 Futter = Ø 5,93; 342 mEq kg-1 Futter = Ø 8,37). Die Blut pH-Werte, die im Durchschnitt bei 7,21 lagen, wie auch die Hydrogencarbonat- und Basenüberschusskonzentration, reagierten aufgrund der renalen Kompensation nicht wesentlich auf die unterschiedlichen DCAB im Futter. Die dazugehörigen Kot pH-Werte waren bei -125 mEq kg-1 Futter und 66 mEq kg-1 Futter um 0,16 höher als bei den anderen beiden DCAB-Stufen. Die Stickstoffaufnahme variierte zwischen 0,90 g kg-1KM d-1 und 1,22 g kg-1KM d-1 aufgrund der beiden Rohproteingehalte (14 und 20 %) in den Versuchsrationen. Eine Senkung der DCAB im Futter bewirkte eine Verbesserung der Stickstoffverdaulichkeit von 86,1 % auf 89,9 % (p<0,05). Hingegen zeigten die Diäten mit der kaliumärmsten Konzentration die höchsten renalen Stickstoffexkretionen von 442 mg kg-1KM d-1 gegenüber den anderen drei Kaliumkonzentrationen (345 mg kg-1KM d-1). In Folge dessen ergibt sich eine Stickstoffretentionssteigerung mit zunehmender DCAB im Futter. Jedoch wurde bei 66 mEq kg-1 Futter (Kalium 10 g kg-1 Futter) die höchste Stickstoffretention von 643 mg kg-1KM d-1 festgestellt. Die Untersuchung der Blutproben ergab keine Beeinflussung der Summe aller Aminosäuren, die bei ø 44,66 mg dl-1 lag. Die Summe der essentiellen Aminosäuren war bei einer DCAB von 66 mEq kg-1 Futter im Blut geringer als bei den übrigen Variationen. Einige Parameter der Elektrolytbilanzen waren zwischen den Futtervariationen verschieden: Bei dem Versuchsfutter mit einer DCAB von -125 mEq kg-1 Futter (Kalium 4 g kg-1 Futter) schieden die Schweine Na: 2,83 mg kg-1KM d-1 und Cl: 1,54 mg kg-1KM d 1 weniger mit dem Kot und Na: 7,05 mg kg-1KM d-1 weniger mit dem Harn aus gegenüber den weiteren Versuchsgruppen. Die renale Chloridexkretion zeigte keine Variabilität. Die renale, als auch die fäkale Kaliumausscheidung nahm analog zur DCAB des Futters zu (DCAB im Futter: -125 mEq kg-1; 66 mEq kg-1; 168 mEq kg-1; 342 mEq kg-1; K-Abgabe in mg kg-1KM d-1, renal: 74,0; 273,3; 431,1; 609,1; fäkal: 24,5; 31,2; 32,6; 44,0). In der Gesamtheit betrachtet ergibt sich für die Natrium- und Chloridretention keine richtungsweisende Beeinflussung im Zusammenhang mit der DCAB der Versuchsrationen. Die Kaliumretention hingegen stieg von 66,5 mg kg-1KM d-1 (-125 mEq kg-1 Futter) auf 167,0 mg kg-1KM d-1 (342 mEq kg-1 Futter) an, was nicht von den Kaliumkonzentrationen im Blut wiedergegeben wurde. Entsprechendes gilt für die Natrium- und Chloridkonzentrationen im Blut. Schlussfolgerungen: In der Alkalisierung des Harns zeigt sich, dass der DCAB des Futters Einfluss auf den Säure-Basen Status nimmt. Der systemische pH-Wert blieb aufgrund der Puffersysteme des Organismuses weitestgehend unberührt. Durch die KHCO3-Zulagen wurde das intragastrale bzw. das intestinale pH-Milieu verändert, was sich in der schlechteren Verdaulichkeit von Stickstoff bei höherer DCAB wiederspiegelt. Die Stickstoffretention steht in keinem Zusammenhang mit der Stickstoffverdaulichkeit. Mit dem DCAB von 66 mEq kg-1 Futter bzw. K: 10 g kg-1 Futter wurde die beste Retention für Stickstoff beobachtet. Die täglichen Gewichtszunahmen und die Futterverwertungen der Versuchsschweine konnten dies allerdings nicht reflektieren. Anzumerken sei, dass für einen eindeutigen Effekt auf die tägliche Zunahme eine längere Beobachtungsphase notwendig wäre (Sprung der täglichen Zunahmen von 520 g für -125 mEq kg-1 Futter auf das Niveau von 692 g für 66 mEq kg-1 Futter und mehr). Eine Empfehlung in Anlehnung an diese Studie wäre ein DCAB-Wert um die 66 mEq kg-1 Futter. Wird dieser Wert erhöht sinkt die Stickstoffverdaulichkeit auf der anderen Seite verschlechtert sich die Stickstoffretention bei Verringerung der DCAB. / Initiation: The dietary cation-anion balance (DCAB) of the feed modifies the acid-base balance and is used in the prevention of milk fever in cows, MMA in sows and urolithiasis in pets. The modification of the cation-anion ratio in diets can take an impact on biological processes inducting nitrogen metabolism. Objectives of investigations: This study objectively clarifies, whether potassium-based variation of the DCAB of the food has an influence on certain parameters of the nitrogen balance and the acid-base balance. Materials and Methods: The trial covered a total of 38 male castrated pigs (three racial crossing Pietrain x Large White x German Landrace) with a housing-age of approximately 12 weeks and a live weight of 17.3 kg to 30.3 kg. In randomized order, the pigs were allocated to the eight experimental feed: crude protein content of 140 g per kg feed and 200 g per kg feed, as well as 4, 10, 14 or 20 g of potassium per kg feed. The sodium and chloride concentrations in the feed were kept constant. The main food components were corn and wheat. The two crude protein levels were determined by various soybean meal and corn gluten quantities. Potassium hydrogen carbonate (KHCO3) and potassium chloride (KCl) were used to establish the four DCAB levels of -125 mEq kg-1, 66 mEq kg-1, 168 mEq kg-1, and 342 mEq kg-1 feed. In an adaptation period of 15 days pigs were accustomed to food and environment. They were kept in individual pens and were given water ad libitum. During the following two trial phases of five days each, the pigs were kept in balance cages. Between the two trial periods, there was a break of five days (no diet change). During the trial period all urine and excrement of the animals was collected, and the respective pH-value was continuously measured. Aliquots of urine and faeces were used in nitrogen and electrolyte analyses. At the end of each five-day record a blood sample from the jugular vein was taken from each pig for determination of potassium, sodium, chloride, pH-value, hydrogen carbonate, base excess, and amino acids. Results: Potassium has a significant influence on renal pH values. Analogous to increasing potassium intake (DCAB ↑), the urine pH value turned more basic (-125 mEq kg-1 feed = 5.93; 342 mEq kg-1 feed = 8.37). The blood pH levels, which averaged at 7.21, as well as the hydrogen carbonate concentration and base excess concentration, did not respond to the different DCAB in the feed because of the renal compensation. The associated feces pH values at -125 mEq kg-1 feed and 66 mEq kg-1 feed were higher by 0.16 than at the other two DCAB levels. The nitrogen intake varied between 0.90 g kg-1BM d-1 and 1.22 g kg-1BM d-1, based on both crude proteins (14 % and 20 %) in the experimental feeds. A reduction of DCAB in the feed resulted in an improvement of the nitrogen digestibility from 86.1 % to 89.9 % (< 0.05). However, diets with the lowest concentration of potassium showed the highest renal nitrogen excretions of 442 mg kg-1BM d-1 compared to the other three concentrations of potassium (345 mg kg-1BM d-1). As a consequence, nitrogen retention increases with increasing DCAB in the feed. However, the highest nitrogen retention of 643 mg kg-1KM d-1 was found with a 66 mEq kg-1 diet (potassium 10 g kg-1 feed). The examination of blood samples revealed no influence on the sum of the amino acids, which was 44.66 mg dl-1. The sum of the essential amino acids was reduced at a DCAB of 66 mEq kg-1 in blood, similar to the other variations. Some parameters of the electrolyte balances were different between the feed variations: In the experimental diet with a DCAB of -125 mEq kg-1 diet (potassium 4 g kg-1 feed), the pigs eliminated Na: 2.83 mg kg- 1BM d-1 and Cl: 1.54 mg kg– 1BM d-1 less in the feces and Na: 7.05 mg kg- 1KM d-1 less in the urine with respect to the other experimental groups. Renal chloride excretion showed no variability. The renal and fecal excretion of potassium increased proportionally to the DCAB of the feed (DCAB in the feed: -125 mEq kg-1, 66 mEq kg-1, 168 mEq kg-1; 342 mEq kg-1; K output in mg kg- 1BM d-1, renal: 74.0; 273.3; 431.1; 609.1; fecal: 24.5; 31.2; 32.6; 44.0). When viewed against the totality of results for the sodium and chloride retention, there were no trend-setting influences in connection with the DCAB of the experimental diets. The potassium retention, however, increased from 66.5 mg kg- 1BM d-1 (-125 mEq kg-1 feed) to 167.0 mg kg- 1BM d-1 (342 mEq kg -1 feed), which was not reproduced from the potassium concentrations in the blood. The same applied to the sodium and chloride concentrations in the blood. Conclusions: The alkalization of the urine shows that the DCAB of the feed influences the acid-base status. The systemic pH remained largely unaffected due to the buffer systems of the organism. The intragastric, respectively the intestinal, pH medium was changed by the addition of potassium hydrogen carbonate, which is reflected in the poorer digestibility of nitrogen at higher DCAB. The nitrogen retention is not related to the nitrogen digestibility. The best retention of nitrogen was observed with the DCAB of 66 mEq kg-1 feed (K: 10 g kg-1 feed). The daily weight gain and feed utilizations of the pigs certainly could not reflect this. It should be noted, however, that a longer observation period would be necessary for a clear effect on daily gain (jump of the daily weight gain from 520 g of -125 mEq kg-1 feed to the level of 692 g for 66 mEq kg-1 feed and more). A recommendation based on this study would be a DCAB value of 66 mEq kg-1 feed. If this value increases, the nitrogen digestibility decreases; on the other hand, the nitrogen retention deteriorated with reducing DCAB.

Mudanças no hábito alimentar têm sido descritas como prováveis causas da obesidade. Estudos mostram que o peso depende do balanço energético definido pela relação entre a energia ingerida e o gasto energético. Sugere-se que o padrão alimentar, levando em consideração a freqüência de refeições e sua distribuição durante o dia, possa estar relacionado com a obesidade. Um efetivo programa de perda de peso tem como objetivo a perda do excesso da gordura corporal e a manutenção da massa livre de gordura apropriada para manutenção da saúde. O cortisol é um dos principais hormônios secretados pelo córtex supra-renal com ação predominante no metabolismo intermediário, incluindo a regulação das proteínas, carboidratos, lipídeos e ácidos nucléicos.O presente estudo teve como objetivos determinar se a ingestão alimentar hipocalórica em pacientes obesas grau III, feita exclusivamente no período das 9:00 às 11:00 h em contraposição à mesma dieta oferecida das 18:00 às 20:00 h, é capaz de alterar a perda de peso, a composição corporal, o ritmo de cortisol, o gasto energético e o balanço nitrogenado. As pacientes foram internadas na Unidade Metabólica da Divisão de Nutrologia do Departamento de Clínica Médica do Hospital das Clínicas de Ribeirão Preto USP durante um período de 64 dias, sendo divididos em 3 internações de 18 dias. Na 1ª fase receberam dieta fracionada em 5 refeições /dia, considerada controle. Na 2ª fase, receberam a mesma dieta, no período das 9:00 às 11:00 h. E na 3ª fase receberam, também, a mesma dieta no período das 18:00 às 20:00 h. Entre uma internação e outra, as pacientes tiveram alta hospitalar por 5 dias, recebendo dieta domiciliar usual. Durante cada fase realizou-se dosagem de nitrogênio urinário e de cortisol salivar. Além disto, as pacientes foram submetidas à avaliação nutricional incluindo: antropometria, bioimpedância e calorimetria indireta. O cortisol salivar obedeceu ao mesmo ritmo nas 3 fases, tanto no 1º quanto no 18º dias de internação, apresentando o pico máximo às 8:00 h, diminuindo progressivamente até atingir o nadir às 21:00 h. Não houve alteração no ritmo do cortisol quando se alterou o horário da alimentação. Houve uma diminuição significativa (p< 0,05) para todos os parâmetros antropométricos, exceto para o índice cintura/quadril durante as três fases, não havendo diferença entre as 3 fases. Houve, nas 3 internações, uma diminuição significativa tanto na quantidade de nitrogênio ingerido quanto na quantidade de nitrogênio excretado a partir do 4º dia de internação. No 10º dia de internação, o balanço nitrogenado estava negativo nas 3 fases da dieta. Não houve diferença entre as fases para ingestão, excreção ou balanço nitrogenado. Mudanças no padrão do horário da ingestão alimentar por períodos de 18 dias não foram estímulo suficiente para provocar diferentes alterações de peso, da composição corporal, da ritmicidade e níveis de produção de cortisol, da taxa metabólica de repouso e balanço nitrogenado em mulheres grau III. / Changes in dietary habits have been implicated as potential causes of obesity. Studies have suggested that weight depends on the energetic balance, which is the relation between energy intake and energy expenditure. Dietary behavior, specially eating frequency and temporal distribution of eating events during the day, may be related to obesity. An effective weight loss program should reduce body fat and preserve lean body mass. Cortisol is an important corticosteroid produced by the adrenal. It exerts metabolic effects on intermediary metabolism, regulating protein, carbohydrates, lipids and nucleic acids metabolism. The present studys goals were: compare differences in weight loss, body composition, energy expenditure and nitrogen balance using hypo caloric diet offered in two different time intervals, first from 9:00 to 11:00, second from 18:00 to 20:00; determinate if there is difference on urinary nitrogen when food is offered on different time intervals, comparing with salivary cortisol levels, and show salivary cortisol secretion rhythm of obese females undergoing hypo caloric diet in different day times. The patients were under hospital regimen in the Metabolic Unit of the Nutrology Division of the Internal Medicine Department of the HCFMRP USP for a 64 days period, divided in 3 periods of 18 days each. On phase 1, the patients received food five times a day. On phase 2, they received the same diet, but the meals were between 09:00 and 11:00. On phase 3, the same diet was offered between 18:00 and 20:00. After each 18 day period, patients went home for a 5 day wash-out period, eating their regular home food and respecting their usual dietary behavior. On each phase urinary nitrogen and salivary cortisol were measured. Also a nutritional evaluation, including anthropometry, bioimpedance and indirect calorimetry were done. There were a reduction (p< 0,05) in all parameters, except the Waist/ Hip Ratio during all phases, but there were no difference between the phases. On the 3 phases there were a reduction on both, nitrogen intake and excretion. After the 10th in hospital day, nitrogen balance was negative on the 3 phases. There are no differences on nitrogen intake, excretion or balance between the 3 phases of food intake. Salivary cortisol followed the same rhythm on all 3 phases, both on the 1st and on the 18th in hospital days, having the peak salivary level at 08:00 h and the nadir level at 21:00 h. Changing meal times for 18 days did not change salivary cortisol circadian rhythm and did not promote changes in weight loss, body composition and rest energy expenditure in grade III obese females.

An improved understanding of nitrogen metabolism in the gastrointestinal tract of the pig is required in order to provide accurate estimates of nitrogen and amino acid (AA) bioavailability in feed ingredients and for adequate diet formulation. Research objectives were to estimate the extent of fermentative AA catabolism (FAAC) in the upper gut of pigs. Further objectives were to determine the impact of lower gut nitrogen absorption on measures of apparent ileal digestibility of AA and nitrogen, whole-body nitrogen balance, and urea kinetics in pigs fed a valine-limiting diet. It was determined that simple isotope dilution calculations are inappropriate for determining ileal ammonia flux and FAAC from a continuous infusion of labelled ammonia and urea. A static model with two-pools (blood urea and digesta ammonia) was then developed to determine possible value ranges for FAAC in the upper gut of pigs. Maximum estimated FAAC based on this model was lower when dietary protein content was decreased (P < 0.001). The model presented is limited to minimum and maximum estimates of FAAC due to the sampling and isotope infusion protocol used. Refinements to the model and experimental protocol could allow for more accurate estimates of FAAC. Infusion of casein or urea into the lower gut of pigs did not affect measures of apparent ileal digestibility of AA or nitrogen. These results further validate the methodology available for determination of ileal digestibility and the use of ileal digestibility to estimate bioavailability of AA and nitrogen. Infusion of casein or urea into the lower gut resulted in an increase in nitrogen balance and urea flux in growing pigs fed a valine-limiting diet. Nitrogen absorbed from the lower gut of pigs is likely in the form of ammonia which is converted to urea. Lower gut nitrogen can contribute to whole-body protein deposition via urea recycling and microbial AA production in the upper gut. Lower gut nitrogen absorption should be accounted for when estimating bioavailability of nitrogen in feeds and foods. / Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA); Ontario Pork; Canadian Swine Research and Development Cluster; Natural Sciences and Engineering Research Council of Canada (NSERC); Evonik Industries AG

Unintentional nitrogen (N) loss from agroecosystems produces greenhouse gases, induces eutrophication, and is costly for farmers; therefore, adoption of conservation agricultural management practices, such as no-till and cover cropping, has increased. This study assessed N loss via leaching, NH3 volatilization, N2O emissions, and N retention in plant and soil pools of corn conservation agroecosystems across a year. Three systems were evaluated: 1) an unfertilized organic system with cover crops Vicia villosa, Triticum aestivum, or a mix of the two; 2) an organic system with a Vicia cover crop employing three fertilization schemes (0 N, organic N, or a cover crop N-credit approach); 3) a conventional system with a Triticum cover crop and three fertilization techniques (0 N, urea N, or organic N). During cover crop growth, species affected N leaching but gaseous emissions were low across all treatments. During corn growth, cover crop and fertilizer approach affected N loss. Fertilized treatments had greater N loss than unfertilized treatments, and fertilizer type affected gaseous fluxes temporally and in magnitude. Overall, increased N availability did not always indicate greater N loss or yield, suggesting that N conserving management techniques can be employed in conservation agriculture systems without sacrificing yield.

Made available in DSpace on 2014-06-11T19:33:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-18Bitstream added on 2014-06-13T20:45:12Z : No. of bitstreams: 1 siqueira_jc_dr_jabo.pdf: 879860 bytes, checksum: 0bbdea44a6c2523dc3a29d105184e7a2 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / As exigências de lisina de frangos de corte vêm sendo estudadas por décadas pelo método dose resposta, contudo, as recomendações são amplamente contrastantes. Assim, cresce o interesse pela elaboração de modelos capazes de predizer as exigências de aves de diferentes genótipos e idades mantidas sob diferentes condições de criação. Os objetivos deste trabalho foram: (1) padronizar um método para estimar as exigências de lisina digestível para mantença; (2) comparar as respostas de frangos de corte alimentados com dietas formuladas pelas técnicas da suplementação dos aminoácidos e da diluição das dietas; (3) estimar as exigências de lisina digestível de frangos de corte nas fases pré-inicial (1 a 8 dias), inicial (8 a 22 dias), crescimento (22 a 35 dias) e terminação (35 a 42 dias) pelo método dose resposta; (4) elaborar modelos para estimar as exigências de lisina digestível de frangos de corte com base no método fatorial. Concluiu-se que: (1) ensaios de metabolismo com alimentação controlada pelo peso metabólico são satisfatórios para determinar as exigências de lisina para mantença; (2) a técnica da diluição das dietas favoreceu o desempenho das aves, exceto na fase de crescimento, sendo recomendada para a formulação de dietas experimentais; (3) frangos de corte Cobb 500 exigem níveis de lisina digestível de 1,361; 1,187; 1,073 e 0,916% nas fases pré-inicial, inicial, crescimento e terminação, com base no método dose resposta; (4) os modelos foram capazes de predizer as exigências de lisina de frangos de corte de diferentes linhagens e idades, sugerindo a redução dos níveis de lisina digestível após a segunda metade do ciclo de produção. / The lysine requirements of broiler chickens have been studied for decades by the dose response method, however, the results of different studies are widely contrasting. In this sense, the growing interest in the development of models capable of predicting the requirements of birds of different genotypes reared under different conditions. This work aimed: (1) standardize a method to estimate the lysine requirements for maintenance, (2) compare the responses of broilers fed diets formulated based on the supplementation technique and the dilution technique , ( 3) estimate the lysine requirements of broilers during pre-starter (1 to 8 days), starter (8 to 22 days), growth (22 to 35 days) and finishing (35 to 42 days) phases, by dose response method, (4) develop models to estimate the digestible lysine requirements for broiler chickens based on the factorial approach. It was concluded that: (1) metabolism assay with diets controlled by metabolic weight are satisfactory to determine the lysine requirements for maintenance, (2) the dilution technique was superior to the supplementation, except in the growth phase and is recommended to evaluate lysine requirements of broilers, (3) Cobb 500 broiler chickens require levels of lysine to 1.361, 1.187, 1.073 and 0.916% during the pre-starter, starter, growth and finishing phases, estimated by dose response method; (4) the models developed were able to predict the digestible lysine requirements of broilers of different strains and ages, suggesting the reduction in digestible lysine levels after the half of the production cycle.

Made available in DSpace on 2014-06-11T19:28:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-04Bitstream added on 2014-06-13T18:57:28Z : No. of bitstreams: 1 martins_ms_me_jabo.pdf: 1334577 bytes, checksum: 558ffb190a2980722ebcf5da43d4c243 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O objetivo do presente estudo foi determinar por meio dos métodos de substituição, os coeficientes de digestibilidade aparente (CDA) das leveduras de cerveja e de cana-de-açúcar autolisada e íntegra, e de inclusão de teores crescentes das leveduras de cana-de-açúcar em dietas extrusadas para cães adultos. Dois ensaios foram conduzidos; no primeiro foi utilizado o método de substituição e 4 dietas experimentais, uma dieta referência isenta de levedura e outras três compostas pela substituição de 15% da dieta basal por leveduras de cerveja e de cana-de-açúcar autolisada e íntegra, respectivamente. Para o segundo ensaio foram utilizados 35 cães adultos distribuídos em 5 tratamentos e 7 repetições por dieta, estas sendo: 0 (basal), 7,5 e 15% de levedura de cana-de-açúcar autolisada e 7,5 e 15% de íntegra. No primeiro ensaio, os CDA da PB são 96,47, 62,98 e 74,70% e da EB 84,01, 68,43 e 75,95%, respectivos as leveduras; havendo diferença entre as leveduras avaliadas apenas para o CDA da PB (p<0,05). No segundo ensaio, os tratamentos não se mostraram diferentes quanto a digestibilidade para os nutrientes MS, MO, EEA, FDN e EB (p>0,05). As energias das dietas acima são respectivamente (Kcal/Kg MS): ED (4107,74; 3995,23, 3922,53; 4066,7; 3921,15) e EM (3714,96; 3749,46; 3667,53; 3876,23; 3673,16) e os CDA (%): MS (81,95; 82,13; 79,14; 80,79; 80,59), MO (86,56; 85,88; 83,68; 85,09; 85,07), PB (84,68; 85,20; 81,90; 83,31; 82,89), EEA (83,68; 83,58; 81,28; 83,82; 82,69), FB (44,99; 33,10; 30,14; 37,33; 22,37), FDN (47,40; 54,20; 45,36; 46,70, 50,99) e EB (86,03; 85,09; 82,54; 84,81; 84,13). A utilização da levedura de cana-de-açúcar não influenciou o CDA das dietas para MS, MO, PB, EEA, FDN, EB e EM das dietas (p<0,05), porém prejudicou linearmente, conforme aumento na inclusão das leveduras de cana-de-açúcar, o CDA da FB e ED (p>0,05). Conforme aumento na... / The present study aimed to determine, for dogs, the digestibility of the brewer’s yeast and sugar cane yeast, autolyzed and integral, and the diets’ nutrients that used the sugar cane yeast in increasing inclusions. Two metabolism assays were performed, the first one had used the substitution method to define the digestibility of the ingredients tests, being made one without yeast (control) and others 3 tests diets (15% brewer’s yeast, sugar cane autolyzed and integral + 85% control diet). In the second assay, it was used 35 adult dogs distributed in 5 treatments with 7 replications for each diet. These were: 0 (control), 7,5 and 15% sugar cane yeast autolyzed and 7.5 and 15% of integral yeast. In the first assay, the coefficients of apparent digestibility (CAD) of the CP were 96.47, 62.98 and 74.70%, and CE 84.01, 68.43 and 75.95%, respectively from yeasts; just the CP was different between the yeast evaluated (p<0,05). In the second assay, the treatments weren’t difference for the dry matter (DM), organic matter (OM), acid ether extract (AEE), neutral detergent fiber (NDF) and crude energy (CE) between the ingredients. The energies from diets were respectively (Kcal/Kg CM): digestible energy (DE) (4,107.74; 3,995.23; 3,922.53; 4,066.7; 3,921.15) and metabolizable energy (ME) (3,714.96; 3,749.46; 3,667.53; 3,876.23; 3,673.16) and the CAD (%): DM (81.95; 82.13; 79.14; 80.79; 80.59), OM (86.56; 85.88; 83.68; 85.09; 85.07), CP (84.68; 85.20; 81.90; 83.31; 82.89), AEE (83.68; 83.58; 81.28; 83.82; 82.69), crude fiber (CF) (44.99; 33.10; 30.14; 37.33; 22.37), NDF (47.40; 54.20; 45.36; 46.70, 50.99) and CE (86.03; 85.09; 82.54; 84.81; 84.13). The sugar cane yeast did not affect the diets’ CAD of DM, OM, AEE, NDF and ME of the diets (p<0.05); but, the CDA had a linear reduction in CP, CF, CE and DE (p>0.05) with the increasing inclusions. Therefore, the brewer’s yeast presented ... (Complete abstract click electronic access below)

Resumo: O objetivo do presente estudo foi determinar por meio dos métodos de substituição, os coeficientes de digestibilidade aparente (CDA) das leveduras de cerveja e de cana-de-açúcar autolisada e íntegra, e de inclusão de teores crescentes das leveduras de cana-de-açúcar em dietas extrusadas para cães adultos. Dois ensaios foram conduzidos; no primeiro foi utilizado o método de substituição e 4 dietas experimentais, uma dieta referência isenta de levedura e outras três compostas pela substituição de 15% da dieta basal por leveduras de cerveja e de cana-de-açúcar autolisada e íntegra, respectivamente. Para o segundo ensaio foram utilizados 35 cães adultos distribuídos em 5 tratamentos e 7 repetições por dieta, estas sendo: 0 (basal), 7,5 e 15% de levedura de cana-de-açúcar autolisada e 7,5 e 15% de íntegra. No primeiro ensaio, os CDA da PB são 96,47, 62,98 e 74,70% e da EB 84,01, 68,43 e 75,95%, respectivos as leveduras; havendo diferença entre as leveduras avaliadas apenas para o CDA da PB (p<0,05). No segundo ensaio, os tratamentos não se mostraram diferentes quanto a digestibilidade para os nutrientes MS, MO, EEA, FDN e EB (p>0,05). As energias das dietas acima são respectivamente (Kcal/Kg MS): ED (4107,74; 3995,23, 3922,53; 4066,7; 3921,15) e EM (3714,96; 3749,46; 3667,53; 3876,23; 3673,16) e os CDA (%): MS (81,95; 82,13; 79,14; 80,79; 80,59), MO (86,56; 85,88; 83,68; 85,09; 85,07), PB (84,68; 85,20; 81,90; 83,31; 82,89), EEA (83,68; 83,58; 81,28; 83,82; 82,69), FB (44,99; 33,10; 30,14; 37,33; 22,37), FDN (47,40; 54,20; 45,36; 46,70, 50,99) e EB (86,03; 85,09; 82,54; 84,81; 84,13). A utilização da levedura de cana-de-açúcar não influenciou o CDA das dietas para MS, MO, PB, EEA, FDN, EB e EM das dietas (p<0,05), porém prejudicou linearmente, conforme aumento na inclusão das leveduras de cana-de-açúcar, o CDA da FB e ED (p>0,05). Conforme aumento na ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present study aimed to determine, for dogs, the digestibility of the brewer's yeast and sugar cane yeast, autolyzed and integral, and the diets' nutrients that used the sugar cane yeast in increasing inclusions. Two metabolism assays were performed, the first one had used the substitution method to define the digestibility of the ingredients tests, being made one without yeast (control) and others 3 tests diets (15% brewer's yeast, sugar cane autolyzed and integral + 85% control diet). In the second assay, it was used 35 adult dogs distributed in 5 treatments with 7 replications for each diet. These were: 0 (control), 7,5 and 15% sugar cane yeast autolyzed and 7.5 and 15% of integral yeast. In the first assay, the coefficients of apparent digestibility (CAD) of the CP were 96.47, 62.98 and 74.70%, and CE 84.01, 68.43 and 75.95%, respectively from yeasts; just the CP was different between the yeast evaluated (p<0,05). In the second assay, the treatments weren't difference for the dry matter (DM), organic matter (OM), acid ether extract (AEE), neutral detergent fiber (NDF) and crude energy (CE) between the ingredients. The energies from diets were respectively (Kcal/Kg CM): digestible energy (DE) (4,107.74; 3,995.23; 3,922.53; 4,066.7; 3,921.15) and metabolizable energy (ME) (3,714.96; 3,749.46; 3,667.53; 3,876.23; 3,673.16) and the CAD (%): DM (81.95; 82.13; 79.14; 80.79; 80.59), OM (86.56; 85.88; 83.68; 85.09; 85.07), CP (84.68; 85.20; 81.90; 83.31; 82.89), AEE (83.68; 83.58; 81.28; 83.82; 82.69), crude fiber (CF) (44.99; 33.10; 30.14; 37.33; 22.37), NDF (47.40; 54.20; 45.36; 46.70, 50.99) and CE (86.03; 85.09; 82.54; 84.81; 84.13). The sugar cane yeast did not affect the diets' CAD of DM, OM, AEE, NDF and ME of the diets (p<0.05); but, the CDA had a linear reduction in CP, CF, CE and DE (p>0.05) with the increasing inclusions. Therefore, the brewer's yeast presented ... (Complete abstract click electronic access below) / Orientador: Nilva Kazue Sakomura / Coorientador: Aulus Cavalieri Carciofi / Banca: Walter Motta Ferreira / Banca: Jane Maria Bertocco Ezequiel / Mestre

Resumo: O experimento teve por objetivo determinar o efeito da temperatura ambiente e da idade da ave sobre o valor energético do milho. Foram utilizados 288 pintos de corte da linhagem Cobb distribuídos em delineamento experimental inteiramente casualizado com esquema de parcelas subdivididas no tempo, sendo as três temperaturas de criação (fria: 18ºC; termoneutra: 25ºC e quente: 33ºC) as parcelas e as três idades de avaliação (inicial: 11 a 14; crescimento: 25 a 28 e final: 39 a 42 dias) as subparcelas, com seis repetições de seis aves cada. A ração basal para o experimento foi formulada à base de milho e farelo de soja e a dieta teste obtida com substituição de parte da ração basal pelo alimento teste: 40% do milho + 60% da ração basal. Foram calculados os coeficientes de metabolizabilidade aparente e verdadeira da matéria seca, do nitrogênio, do extrato etéreo da dieta teste e os valores de energia metabolizável aparente e verdadeira (EMA e EMV); e corrigidas pelo balanço de nitrogênio do milho (EMAn e EMVn), em kcal/kg, com base na matéria natural. Foram encontrados valores médios de EMAn do milho, para aves criadas em temperatura fria, termoneutra e quente de 3322, 3279 e 3233 kcal/kg, respectivamente, e para as fases de criação inicial, crescimento e final de 3215, 3218 e 3400 kcal/kg, respectivamente. Os valores de energia metabolizável do milho, os balanços e os coeficientes de metabolizabilidade dos nutrientes da dieta teste aumentam com a idade do frango de corte, porém as energias metabolizáveis do milho não foram afetadas pela temperatura ambiente. Os balanços e os coeficientes de metabolizabilidade dos nutrientes da dieta teste foram reduzidos em estresse por calor para aves na fase de crescimento e final / Abstract: The aim of this study was to evaluate the effects of environmental temperature and age of broilers chicks on energy value of corn. Two hundred and eighty-eight Cobb chicks were distributed in a complete randomized design with a splitplot arrangement with six replication of six chicks each, the main plots were the three temperatures (cold: 18°C; thermoneutral: 25°C and hot: 33°C) and age was the secondary plot (initial: 11 to 14, growing: 25 to 28 and final: 39 to 42 days). The basal diet was based on corn and soybean meal. The test diet was produced by replacing the basal diet for test food: 40% of corn + 60% of the basal diet. The coefficient of apparent and true metabolizability of dry matter, nitrogen, ether extract of the test diet and apparent and true metabolizable energies (AME and TME) of corn were calculated and energy values were corrected for nitrogen balance (AMEn and TMEn) of corn, in kcal/kg, as fed basis. The mean values of AMEn observed for broilers chicks in cold, thermoneutral and hot temperature of 3322, 3279 and 3233 kcal/kg, respectively, and the phases initial, growing and final of 3215, 3218 and 3400 kcal/ kg, respectively. The metabolizable energy values of corn, the balance and coefficients of metabolizability of the nutrients of the test diet increased with the age of broiler; however the metabolizable energies were not affected by environmental temperature. The balance and coefficients of metabolizability of the nutrients of the test diet were decreased by heat stress for broiler in the growing and final phase / Orientador: José Roberto Sartori / Coorientador: José Henrique Stringhini / Banca: Antonio Celso Pezzato / Banca: Elisabeth Gonzales / Banca: Valquiria Cação da Cruz / Banca: Nadja Susuna Mogyca Leandro / Doutor