The effects of starch and phosphorus (P) source on P partitioning and ruminal phytase activity were evaluated in eight lactating cows (113 DIM). Four cows were ruminaly cannulated. Cows were randomly assigned to treatments in a duplicated 4x4 Latin square with four, 18-d periods. Diets included dry ground corn (DG) or steam flaked corn (SF), with a no supplemental P (low P diet; 0.34% P) or supplemental purified phytic acid (PA; 0.45% P) to provide additional P from an organic source. Total collection of milk, urine, feces, and feed were sampled each period, while rumen fluid was sampled on d 18. Excretion of feces, urine, P, and N was lower in cows fed SF than in cows fed DG. Milk yield was unaffected by diet despite a lower DMI by cows fed SF. Cows fed SF tended to have a higher feed efficiency and lower milk urea nitrogen (MUN) concentration than cows fed DG. Rumen pH was unaffected by diet, but milk fat content was lower for cows fed SF. Milk yield, DMI, and feed efficiency were not affected by PA. Cows fed PA had increased P intake and excretion, but a lower milk P as a percentage of intake compared with cows fed the low P diet. An interaction of starch source and P source was observed for ruminal phytase activity. Altering dietary sources of starch and P offers opportunity to improve P availability and reduce manure nutrient excretion. / Master of Science

Measurement of soil phytase activity (PA) and delineation of the impact of this important phosphomonoesterase on the P-cycling process in soil and sediments suffer from the lack of a reliable assay. A method for measuring PA in soil that promises to be accurate and reliable has been recently published. The method involves the use of a novel chromophoric analog of phytic acid, referred to as T(tethered)InsP5 (5-O-[6-(benzoylamino)hexyl]-D-myo-inositol-1,2,3,4,6-pentakisphosphate). This study was conducted to measure PA in a Clymer forest soil, which contained over twice the amount of soil organic C as previously tested soils, using the TInsP5 PA assay. This investigation specifically addresses: (1) the development of a soil dilution technique for determining maximal PA, (2) identification of previously unsubstantiated soil-produced dephosphorylated intermediate probe species, (3) the impact of increasing assay buffer pH on soil PA and (4) testing stability of the probe's amide bond in a highly (bio)active forest soil. PA assays were conducted by measuring dephosphorylation of TInsP5 in citrate-acetate buffered (pH 4.2) active and autoclaved (Control) soil suspensions. Phosphorylated probe intermediates (i.e., TInsP4, TInsP3, TInsP2 and TInsP1) and T-myo-inositol were extracted from samples of soil suspension following incubation. Probe species were quantified using reversed phase high-performance liquid chromatography (RPHPLC) with UV detection. PA was calculated based on a mass balance approach. A soil dilution technique was developed to address the challenge of determining maximal PA in soils containing higher organic matter content. In the initial report on use of the TInsP5 method for measuring PA in soil, two "soil-generated" UV-adsorbing compounds (designated Y and Z) were observed, but never confirmed as probe species. The experimental evidence presented in this report supports inclusion of compound Y as a phosphorylated probe intermediate species (i.e. TInsPy), based primarily on its UV adsorption spectra (diode-array detection analysis). Compound Z could not be substantiated as a probe species based on the evidence presented in this study. PA of Claymer forest soil decreased with an increase in assay buffer pH. Further, the probe's amide bond linkage was stable in a forest soil exhibiting high PA. / Master of Science

The enzyme phytase improves the utilization of various nutrients in plant foods, which are partly unavailable to non-ruminant animals, especially phytic acid, but beyond this also starch, proteins, lipids and other minerals, which are complexed with phytic acid. The effectiveness of this enzyme has been widely proven. Nevertheless, several studies were not successful in its use in feed for monogastric animals. This is due to the characteristics of sensitivity and specificity of phytases instability. Given these facts, the objective with the study to evaluate the most effective way of incorporating phytase in diets for laying hens in relation to performance, quality of eggs (experiment 1) and utilization of protein (experiment 2). The research was conducted in the laboratory of poultry Polytechnic College (UFSM). The experimental performance and egg quality of laying hens used 120 Isa Brown strain, being conducted in three periods of 21 days. The digestibility trial had 72 birds and lasted five days. Both experiments assessed the following diets: basal diet (BD), diet with defatted rice bran (DRB) previously treated with phytase (DRBF) diet with phytase enzyme and DRB incorporated through the traditional method (TMF) and a diet without DRB phytase (DRB). The experiment was a completely randomized design with four treatments, five replicates for experiment 1 and three replicates for experiment 2 with six birds. The data collected were submitted to analysis of variance and the means that differ significantly, Tukey (5%). The treatment of DRBF was efficient, ie, treating only one ingredient of the diet with phytase allows you to incorporate a smaller amount of phytase, while maintaining performance and quality of eggs, which were statistically the same (P> 0.05) in treatments involving phytase, equivalent also to the basal diet, indicating that phytase supplied the reduction of phosphorus in the treatment TMF. The treatment of DRB with phytase enabled better utilization of protein. / A enzima fitase melhora o aproveitamento de vários nutrientes dos alimentos de origem vegetal, que são em parte indisponíveis aos animais não-ruminantes, principalmente o fósforo fítico, mas além deste, também amido, proteínas, lipídios e outros minerais, que são complexados com o ácido fítico. A efetividade desta enzima já foi amplamente comprovada. Apesar disso, inúmeros estudos não obtiveram sucesso em seu uso na alimentação de monogástricos. Isso deve-se as características de sensibilidade, instabilidade e especificidade das fitases. Diante destes fatos, objetivou-se com o estudo avaliar o modo mais eficaz de incorporação da enzima fitase em dietas para poedeiras comerciais, em relação ao desempenho, qualidade de ovos (experimento 1) e aproveitamento de proteína (experimento 2). A pesquisa foi conduzida no laboratório de avicultura do Colégio Politécnico (UFSM). O experimento de desempenho e qualidade de ovos utilizou 120 poedeiras comerciais da linhagem Isa Brown, sendo conduzido em três períodos de 21 dias. O ensaio de digestibilidade contou com 72 aves e teve duração de cinco dias. Ambos experimentos avaliaram as seguintes dietas: dieta basal (DB), dieta com farelo de arroz desengordurado (FAD) tratado previamente com fitase (FADFI), dieta com FAD e enzima fitase incorporada por meio do método tradicional (MTFI) e dieta com FAD sem enzima fitase (SEMFI). O delineamento experimental foi o inteiramente casualizado com quatro tratamentos, cinco repetições para o experimento 1 e três repetições para o experimento 2, com seis aves. Os dados coletados foram submetidos a análise de variância, e as médias que apresentaram diferença significativa, ao teste de Tukey (5%). O tratamento prévio do FAD mostrou-se eficiente, ou seja, tratar somente um ingrediente da dieta com fitase permite incorporar uma quantidade menor de fitase, mantendo desempenho e qualidade de ovos, que foram estatisticamente os mesmos (P>0,05) nos tratamentos que envolveram fitase, equivalendo-se também a dieta basal, comprovando que a fitase supriu a redução de fósforo no tratamento MTFI. O tratamento prévio de FAD com fitase possibilitou melhor aproveitamento da proteína bruta.

Cinque varietà di sorgo (Sorghum bicolor (L.) Moench) provenienti da Nigeria, Senegal, Burkina Faso e due dall’Italia, sono state caratterizzate per il loro profilo nutrizionale, analizzando la modulazione di due marcatori cellulari (contenuto in proteine totali e attività della GPx), il contenuto di fattori chelanti (tannini e fitati), l’attività fitasica e il contenuto, la bioaccessibilità e la biodisponibilità di ferro e zinco e analizzando l’impatto di due importanti processi alimentari, quali fermentazione e cottura. I risultati mostrano che sia la varietà sia il processo influenzano la maggior parte dei parametri. Tannini e fitati, elementi in traccia, contenuto proteico totale e il processo (soprattutto la fermentazione) sono modulati dalla varietà. La fermentazione riduce il contenuto di fattori chelanti e aumenta l’attività fitasica, incrementando, così, la biodisponibilità degli elementi in traccia; mentre la cottura non ha un impatto significativo. D’altra parte, la fermentazione ha un impatto negativo su entrambi i marcatori cellulari, mentre la cottura solo sul contenuto proteico totale. Le varietà africane, soprattutto quella dal Senegal, hanno mostrato il migliore profilo nutrizionale, mentre, globalmente, le italiane il peggiore. I risultati indicano che la selezione di varietà e di adeguati processi alimentari può avere un impatto significativo sul valore nutrizionale del sorgo. / Five sorghum cultivars (Sorghum bicolor (L.) Moench) from Nigeria, Senegal, Burkina Faso and Italy (two), were characterized for their nutritional values by analysing the modulation of cellular functional markers (total protein content and GPx activity), chelating factors (iron-binding phenolic groups and phytates) content and phytase activity, as well as iron and zinc content, bioaccessibility and bioavailability, also considering the impact of food processing methods as fermentation and cooking. The results revealed that both variety and food processing affect most of the tested parameters. Chelating factors, trace elements, cellular total protein content, as well as the effect of processing (mainly fermentation) were modulated by variety. Fermentation decreased chelating factors content, as well as increased phytase activity, leading to enhancement of iron and zinc estimated bioavailability, whereas cooking had no substantial impact. On the other hand, fermentation process had a negative impact on both cellular functional markers while cooking only on the cellular total protein content. The African varieties, particularly the Senegal one, showed the most promising nutritional profile, whereas the two Italian varieties overall showed a poor one. The results indicate that selection of traditional varieties and processing methods can have a significant impact on parameters relevant to sorghum nutritional value.