For economical and ecological reasons, efficiency and profitability ofswine production relies heavily on the way pigs utilize key nutrients such as P,which is considered a potential pollutant of water ecosystems. Although cerealgrains and oilseed meals contain enough P to fulfill the biological needs of pigs,most of this P is tightly bound as phytate. As pigs do not have enough phytase(PHY) to cleave P from phytate, it is excreted in the feces. To prevent adeficiency, diets have traditionally been supplemented with highly availableinorganic sources of P. Today, an environmentally-friendly alternative is tosupplement diets with PHY.Growth promoting antibiotics are also used to enhance the utilization ofdietary components such as energy and N. It has been suggested that theantibiotic virginiamycin (VIR) could also improve phytate-P utilization by pigs.Eight experiments evaluated the effects of VIR and/or PHY amendmentson digestibility, retention, excretion, growth, bone characteristics, meat traits, andileal microflora populations of growing pigs fed corn–soybean meal (SBM) diets(seven experiments) or corn-SBM-rice bran diets (one experiment). Additionally,a comparison between two digestibility procedures was conducted for two of theexperiments.On average, VIR improved P digestibility and total P excretion by 5.0%,and P retention as a percent of absorption by 1.0%. Phytase amendmentsimproved P digestibility between 14 and 27%, and P retention (as a % ofabsorption) between 0.7 and 2.5%. In the growth trial, VIR supplementation wasassociated with numerical differences favoring bone mineralization and ilealphytate-utilizing bacteria populations. These observations demonstrate additionalresearch is warranted with this antibiotic under conditions of higher stress andbacterial load in the environment.According to the comparisons between digestibility methods, a single grabfecal collection was not reliable. Further, a cumulative grab collection for fivedays was not as good an option as the total collection method.It is concluded that VIR does improve P utilization in pigs fed corn-SBMdiets not supplemented with inorganic P. Similar effects, but of greatermagnitude, were confirmed for PHY-amended diets with either normal or highlevels of phytate P.

The objective of this research was to express a fungal phytase gene in transgenic soybean cells to to study the potential for improving phosphorus utilization in soybean meaL A simple and inexpensive particle inflow gene gun was constructed and bombardment was optimized as assayed by β-glucuronidase reporter gene expression. A somatic embryogenesis approach was used for soybean regeneration from culture. The efficiencies of embryo induction and embryo conversion to form roots and shoots were compared in commercial soybean cultivars to identify optimal cultivars for recovery of transgenic plants. To study the expression of a recombinant fungal phytase gene (<i>Phy</i>A from <i>Aspergillus niger</i>), four expression vectors were constructed in soybean transformation vectors. <i>Phy</i>A was placed under the control of either a constitutive cauliflower mosaic virus 35S promoter or a soybean seed specific β-conglycinin promoter, each with or without a patatin endoplasmic reticulum (ER) signal sequence. All four vectors were sequenced and introduced into 'Williams 82' suspension culture cells by particle bombardment. Stably transformed cell lines were selected and tested for stable integration by Southern analysis. The presence of the phytase protein product was detected by immunoblotting. Activity of recombinant phytase was characterized by enzyme assay. Cell lines containing the <i>phy</i>A gene under control of the CaMV 35S promoter and ER signal sequence secreted active phytase into the culture medium. The pH and temperature optima were determined for recombinant phytase. / Ph. D.

The objective of this thesis was to investigate the effect of age and feeding length on phytase efficacy in broiler chickens during the starter phase. Two studies were carried out to evaluate this objective.<br>Study 1 was a randomized complete block design with 4 × 5 factorial arrangements of treatments. There were four diets; a positive control (PC), negative control (NC) and two phytase supplemented diets with inclusion levels of 1,000 and 2,000 phytase units/kg. There were five age and duration of feeding groups; Three 2-d feeding lengths terminated at d 8, 14, and 22 (d 6 to 8, d 12 to 14, and d 20 to 22), a 5-d feeding length terminated at d 14 (d 9 to 14) and a 16-d feeding length terminated on d 22 (d 6 to 22). Growth performance and sample collections were collected at the end of each phase i.e. d 8, 14 and 22. There was a difference (P < 0.01) in weight gain, feed intake, and feed efficiency between birds fed the PC diets and birds fed the NC diets across all groups as birds on the NC diets had lower performance (P < 0.05) than birds on the PC diet. However, birds fed the phytase supplemented diets had higher (P < 0.05) growth performance compared with birds fed the NC diet across all groups. Similarly, phosphorus (P) and calcium (Ca) digestibility and retention of birds fed the NC were lower (P < 0.05) as compared with birds fed the PC diet while birds fed the phytase supplemented diets had higher mineral digestibility and retention (P < 0.05) compared with birds on the NC diet. Age effect was evaluated by comparing the performance of birds fed the experimental diets for 2 d until d 8, 14, and 22. Birds fed until d 14 had the highest impact of the NC diet on mineral utilization, and the largest improvement of phytase on mineral utilization as compared with birds fed until d 8 and 22. Similarly, when feeding length effect was considered, birds fed for a shorter period had greater response to phytase (P < 0.05) on nutrient utilization than birds fed for a longer period at d 14 and 22. Tibia ash was higher (P < 0.05) in birds fed phytase supplemented diets for a longer period (i.e. 16 d) compared with birds fed or 2 or 5 d. The results from this study observed that age and duration of feeding influenced phytase efficacy especially in younger birds fed for a short period. However, it could not be determined if feeding birds for a short period at different ages in the starter phase would have a similar effect.<br>In study 2, the effects of age and feeding low P diets to birds for a short period of time on phytase efficacy and super dosing were evaluated at two critical points in the starter phase. This study had 3 × 2 × 2 factorial arrangements of treatments comprising 3 diets; a PC, NC, and a NC with phytase supplemented at 2,000 phytase units/kg; and 2 ages (i.e d 14 and 22) and 2 feeding lengths (i.e 2-d and 5-d). Thus, birds were fed the experimental diets from d 12 to 14, 9 to 14, 20 to 22, and 17 to 22 respectively. Results observed were similar to the first study. Birds fed the NC diet had lower (P < 0.01) performance as compared with birds fed the PC diets across all age and feeding length groups. Similarly, birds fed diets with the super dose level of phytase had greater growth performance (P < 0.01) compared with birds fed the NC diets. When age effect was considered, birds fed for 2 or 5 d until d 14 had the greatest improvements of phytase on nutrient utilization and bone mineralization compared with birds fed for both periods until d 22. When effect of feeding was considered, birds fed for 2-d at both ages had greater responses to phytase in performance and nutrient utilization compared with birds fed for 5-d at both ages. Plasma myo-inositol was higher (P < 0.01) in birds fed the super dose level of phytase compared with birds fed the NC diet.<br>In summary, we could conclude that the efficacy of phytase both at 1,000 and 2,000 FTU/kg was higher in birds fed for 2 d until d 14 as compared with the other groups. This could potentially help in designing studies to evaluate new phytase products or for comparing the efficacy of phytase from various sources. Feeding broiler chickens during the suggested time phase would potentially reveal the maximum efficacy of the phytase product.<br>

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-20T17:57:53Z No. of bitstreams: 2 Tese - Carla Eloiza B. C. Seabra.pdf: 1211089 bytes, checksum: 1125d30550099fb430808207eb415619 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-20T17:58:36Z (GMT) No. of bitstreams: 2 Tese - Carla Eloiza B. C. Seabra.pdf: 1211089 bytes, checksum: 1125d30550099fb430808207eb415619 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-20T17:59:00Z (GMT) No. of bitstreams: 2 Tese - Carla Eloiza B. C. Seabra.pdf: 1211089 bytes, checksum: 1125d30550099fb430808207eb415619 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-02-20T17:59:00Z (GMT). No. of bitstreams: 2 Tese - Carla Eloiza B. C. Seabra.pdf: 1211089 bytes, checksum: 1125d30550099fb430808207eb415619 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-07-29 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Mahogany (Swietenia macrophylla King) is in high demand world-wide, and is one of Brazil’s most highly valued forestry species. Balsa (Ochroma pyramidale Cav. ex. Lamb.) also has broad usage and great market potential owing to extremely rapid growth rates. Rather than harvesting these increasingly rare timber species from native forests, high density commercial plantings have been established. However, there is little information concerning the nutritional requirements of both species, especially regarding the response to soil phosphorous (P). Phosphorous is expensive in Brazil and over use is associated with adverse environmental consequences. In this study, we examined the effects of four levels of P fertilization (0, 1, 10 and 100 kg ha-1) on biometric and physiological parameters of mahogany and balsa wood seedlings grown in the greenhouse. The response to P was markedly different for the two species. For mahogany, seedling height, seedling diameter, leaf area, leaf weight, stem dry weight, and total dry weight increased at the 100 kg/ha-1 P level. The greatest increase (3- to 5- fold) occurred for leaf area and leaf weight, whereas root dry mass was not influenced by P. Similarly, %N and %P (but not %C) in leaf, stem and root tissue increased with increasing P level, but increased drastically at the 100 kg/ha-1 P treatment. The divalent cations (Ca and Mg) increased in foliar tissue, yet the concentrations of organic acids in xylem fluid declined with increasing P. Leaf macro- and micro-nutrients concentrations were influenced by P treatments, with the exception of Zn and Fe. Leaf, stem and root P utilization efficiency was highest at the 0, 1 or 10 level. Root phosphatase activity was unaffected by P level. By contrast, balsa responded greatly to increasing P concentration, although the most dramatic increase was at 100 kg/ha-1. For example, there was a 9-, 4-, 66-, 25-, 65-, 25- and 32-fold increase for seedling height, seedling diameter, leaf area, leaf dry mass, stem dry mass, root dry mass, and total dry mass, respectively, for the 0 compared to the 100 kg/ha-1 treatment. Leaf, stem and root %N decreased and %P increased with increasing P levels. Macro and micro nutrient levels wereinfluenced by P treatment, with the exception of Mn. The concentrations of organic acids in xylem fluid were altered by P fertilization; and malic, succinic, and lactic acids were highest at the 100 kg/ha-1 treatment. Leaf, stem and root P utilization efficiency increased greatly with increasing P level; however, root phosphatase activity decreased with increasing P levels. The implications of these physiologic data are discussed in relation to management strategies for the culture of mahogany and balsa. / Plantios comerciais de mogno e pau-de-balsa, com maiores relações custo/benefício, podem alavancar o mercado de madeira de espécies nativas, tanto interno quanto externo. Mogno e pau-de-balsa estãoentre as mais valiosas espécies de madeira com diversos usos, sendo ambas economicamente promissoras. Todavia, informações sobre a influência do fósforo (P) na nutrição e desenvolvimento das mesmas são incipientes. Em condições de casa de vegetação, avaliou-se os efeitos de quatro doses de P (0; 1; 10 e 100 kg ha-1) sobre parâmetros biométricos e fisiológicos dessas espécies. Para mogno, as doses crescentes de P elevaram o crescimento da parte aérea, os conteúdos de carbono, nitrogênio, P e, as concentrações foliares de macronutrientes e manganês, e diminuíram a eficiência de utilização de P, as concentrações foliares de boro e cobre e, a concentração dos ácidos orgânicos no fluido do xilema. Não foi verificado efeito sobre o crescimento de raiz, as concentrações foliares de Zn e Fe, e a atividade de fosfatase de raiz. Destaca-se que houve correlação inversa entre a atividade de fosfatase ácida de raiz e o crescimento da parte aérea e, P e N acumulados na planta. Para pau-de-balsa, o aumento das doses de P elevou o crescimento da parte aérea, a eficiência de utilização de P e a concentração de ácidos orgânicos no fluido do xilema. As concentrações foliares de nutrientes foram afetadas de forma variada pela aplicação de doses de P: P, magnésio e cálcio aumentaram e, nitrogênio, potássio, enxofre, boro, zinco e cobre diminuíram. Doses crescentes de P diminuíram a atividade de fosfatase ácida de raiz. Não foi verificado efeito sobre as concentrações foliares de manganês, ferro e do ácido oxálico no fluido no xilema. Em geral, doses crescentes de P melhoram a formação das mudas dessas espécies. Porém, uma adubação equivalente a 100 kg P ha-1 pode causar desequilíbrio de crescimento em mudas de pau-debalsa.