Thesis (M.S.)--West Virginia University, 2010. / Title from document title page. Document formatted into pages; contains v, 88 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Thesis (M. Sc.(Agric.))( Animal Science)--University of Pretoria, 2006. / Includes bibliographical references. Available on the Internet via the World Wide Web.

Made available in DSpace on 2014-06-11T19:32:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-13Bitstream added on 2014-06-13T20:44:24Z : No. of bitstreams: 1 pacheco_rdl_dr_botfmvz.pdf: 836072 bytes, checksum: c4d361ff1ec1e97c14ef8f5e7fb6adbd (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / O presente ensaio de pesquisa objetivou avaliar o preparado de anticorpos policlonais contra as bactérias ruminais precursoras de distúrbios nutricionais (Streptococccus bovis, Lactobacillus ssp. e Fusobacterium necrophorum) na forma sólida, como aditivo alimentar preventivo à acidose ruminal em bovinos e substituto à monensina. Nove vacas canuladas no rúmen com 677±98 kg de peso vivo médio foram agrupadas em baias individuais através de delineamento inteiramente casualizado com dois períodos de 20 dias. Separaram-se os animais em três tratamentos: controle (CTL), preparado de anticorpos policlonais (PAP) e monensina sódica (MON). Nos primeiros cinco dias de cada período, os animais receberam apenas cana e úreia como alimento. Em seguida, foi fornecida a dieta desafio com aproximadamente 74% de concentrado por 15 dias, com o intuito de causar acidose ruminal. Houve um tempo de 15 dias entre cada período para a readaptação dos animais à dieta de volumoso. As variáveis experimentais foram: ingestão de matéria seca (em kg, IMKG; % do peso vivo, IMPV; e metabólico, IMPM, respectivamente), flutuação da ingestão de matéria seca (FIMS) dos dias subseqüentes ao desafio com a dieta de concentrado e os parâmetros de fermentação ruminal (pH do líquido ruminal, lactato ruminal, concentração de ácidos graxos de cadeia curta, nitrogênio amoniacal e lactato ruminal). Não houve efeito de tratamento (P > 0.05) tanto para a ingestão de matéria seca quanto para a flutuação da ingestão de matéria seca. Os animais tratados com monensina apresentaram pH mais alto (P < 0.0001) que os demais tratamentos (MON = 6.06 vs. PAP = 5.89 e CTL = 5.91), independente de tempo. A concentração ruminal de lactato permaneceu baixa (0.23 mM), mesmo após o desafio com concentrado. A concentração de N-amoniacal do CTL foi menor (P = 0.0039), comparado à MON e PAP... / This study was designed to evaluate the potential of the dry form of a multivalent polyclonal antibody preparation against several nutritional disturbs precursors ruminal bacteria (Streptococccus bovis, Fusobacterium necrophorum and Lactobacillus ssp.), as acidosis preventative feed additive to high concentrate fed cattle and as an alternative to monensin. It was used nine cannulated cows (677±98 kg of BW) allocated in a completely randomized desing with two periods of 20 d. Animals were separated in three treatments: control (CTL), multivalent polyclonal antibody preparation (PAP) and monensin sodium (MON). During the first five days of each period, animals were fed all forage diet. Ruminal acidosis was induced by an abrupt diet switch to a 74% concentrate diet during 15 d. An interval of 15 d was considered as ruminal washout in the meantime of the two periods, when animals were refed all forage diet to restablish normal ruminal pH conditions and cellulolitic microbial population. Ruminal acidosis evaluation parameters were: dry matter intake (kg/d, % of BW and % of BW0,75; DMIK, DMIB and DMIM respectivelly), dry matter intake fluctuations (DMIF) during the subsequent days after concentrate challenge, ruminal fermentation (pH; SCFAs, lactate and NH3-N concentrations). There were no treatment main effects (P > 0.05) for DMIK, DMIB, DMIM or DMIF. Higher pH was measured (P < 0.0001) in MON, compared to the other two treatments (MON = 6.06 vs. PAP = 5.89 and CTL = 5.91). Ruminal lactate concentration remained low (0.23 mM) throughout the entire experimental period. Ruminal ammoniacal-N concentration of CTL was lower (P = 0.0039), compared to MON and PAP (14.74 and 13.64 vs. 11.20 mg/dl, for MON, PAP and CTL, respectivelly). Molar concentration of acetate was not affected (P = 0.3288) by treatments. However, an interaction day x treatment (P = 0.0079) for propionate molar concentration was... (Complete abstract click electronic access below)

This study was conducted to evaluate the effect of microbial feed additives Megasphaera elsdenii NCIMB 41125 and Saccharomyces cerevisiae 1026, individually and combined on rumen pH,ammonia-N and volatile fatty acids (VFAs) fermentation. An in vitro batch fermentation was conducted using rumen fluid from two early lactating Holstein cow donor fed the TMR for lactating cows which was evaluated under two diets, differing in concentrate to forage ratio. The diets were high concentrate, a 60:40 concentrate to forage ratio diet (HC) and low concentrate, a 40:60 (LC) concentrate to forage ratio diet. The treatments were; Control (diet with no additives), Me (diet with M. elsdenii NCIMB 41125 10mm (108 CFU/ml)), LY (diet with live yeast, S. cerevisiae 1026), and Me+LY (diet with mixture of M. elsdenii and S. cerevisiae). The average rumen pH was 5.8 and ammonia nitrogen was not affected by Me and LY supplemented separately or in combination (Me+LY) in both low and high concentrate diets. Total VFAs were increased with the addition of LY alone and in combination Me+LY+Me) in high concentrate diet only but the addition of Me had no effect in both diets. Acetate, lactate and A: Pr were decreased (P<0.05) by all the treatments (Me and LY alone and in combination) on both diets, except in high concentrate diet where the addition of Me tended to decrease (P<0.07) acetate and had no effect on lactate. Propionate was increased by all the treatments in low concentrate diet and tended toincrease (P<0.08) by addition of Me and Me+LY in high concentrate diet. In a low concentrate diet, butyrate was increased by LY but tended to be decreased by Me, however, all the treatments lacked effects on high concentrate diet. Live yeast appears to act differently compared to Me by showing two times more effects on high than low concentrate diets.This in vitro study showed that both Me and LY had a tendency to modify rumen fermentation and that might indicate their potential to mitigate the metabolic challenges and improve energy status of Holstein dairy cows during the transition and early lactation period. However, there is a need for further research that will include in vivo study. / Agriculture, Animal Health and Human Ecology / M.Sc. (Agriculture)

Made available in DSpace on 2014-06-11T19:27:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-01-11Bitstream added on 2014-06-13T19:15:05Z : No. of bitstreams: 1 mariani_tm_me_botfmvz.pdf: 521848 bytes, checksum: 2d5f794a732e1c41512018d52c981410 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / Esse estudo foi realizado para avaliar o preparado de anticorpos policlonais (PAP) sobre o comportamento ingestivo (CING) e desempenho de bovinos Brangus (BR) e Nelore (NE) confinados. Foram utilizados 32 machos inteiros (254,1 ± 12,7 kg), de cada um dos 2 grupos genéticos, e estes foram alimentados por 144 dias com dietas contendo ou monensina sódica (MON) ou PAP nas dosagens de 30 e 300 mg/kg de matéria seca (MS) respectivamente. Medidas no tempo foram coletadas de acordo com os períodos avaliados durante o estudo: adaptação, crescimento, terminação 1 e terminação 2. As observações foram feitas a cada 5 minutos durante 24h, aonde os dados das variáveis de CING foram coletados: tempos médios de ruminação (TR), de alimentação (TAL), de ócio, número de idas ao bebedouro, e número de refeições ao dia (REF/dia). As eficiências de alimentação (EAL) e ruminação (ERU) da MS e do FDN foram calculadas usando-se combinações dos dados de CING com os dados de consumo de MS e FDN. Não foi observado (P > 0,05) efeito dos aditivos alimentares sobre as EAL e ERU da MS e do FDN. Houve efeito sobre REF/dia e TAL despendido por refeição (TALREF), onde animais suplementados com MON apresentaram maiores (P < 0,05) REF/dia, TR e animais recebendo PAP tiveram maior (P < 0,05) TALREF. Animais recebendo PAP e MON apresentaram similares (P > 0,05) GPD, CMS e CA. Os animais BR apresentaram maior (P < 0,05) TALREF e CMS por refeição. Observouse (P < 0,05) efeito dos grupos genéticos sobre EAL e ERU da MS e da FDN (P < 0,01), onde bovinos BR apresentaram melhores eficiências quando comparados aos animais NE. Assim sendo, devido às similaridades nos resultados de CING, EAL, ERU e desempenho, PAP pode ser uma eventual alternativa à MON em dietas de alto teor de concentrado. / This study was designed to test polyclonal antibody preparation (PAP) against several rumen microorganisms on feeding behavior and feedlot performance of Brangus (BR) and Nellore (NE) cattle. The experiment was designed as a 2 × 2 factorial arrangement of treatments using repeated measures over time, replicated 4 times (4 bullocks/pen), in which 32 9-mo-old bullocks (254,1 ± 12,7 kg) of each of two breeds evaluated were fed for 144 days, diets containing either monensin (MON) or PAP at 30 or 300 mg/kg of dry matter (DM) daily; respectively. Measures over time were taken according to the periods evaluated during the study: adaptation, growing, finishing 1 and finishing 2. Visual appraisal was made every five minutes during 24h, and feeding behavior data was collected as follows: time spent eating (EAT), ruminating (RUM), resting, visits to water through and number of meals per day (MEA). Feed offerings and refusals were weighed daily. Feeding (FEEF) and rumination efficiencies (RUEF) of DM and NDF were calculated using combinations of feeding behavior data with DM and NDF intakes data. No significant (P > 0,05) feed additives main effects were observed for FEEF and RUEF of DM and NDF, and for any of feeding behavior variables evaluated with the exception of RUM, MEA and EAT per meal (EATMEA); in which bullocks fed MON presented longer (P < 0,05) RUM and greater (P < 0,05) MEA and bullocks receiving PAP had longer (P < 0,05) EATMEA. In addition, a similar feedlot performance was observed (P > 0,05) between bullocks fed either MON or PAP. BR bullocks had longer (P < 0,05) EATMEA and greater (P < 0,05) DM intake per meal. Significant (P < 0,05) breeds main effects were observed for all of FEEF and RUEF of DM and NDF, indicating that BR bullocks were more efficient than NE bullocks in all variables evaluated. In terms of feedlot performance, BR bullocks presented greater (P < 0,05) average daily gain ...

Orientador: Mario De Beni Arrigoni / Banca: Rafael Cervieri / Banca: Renata Helena Branco / Resumo: Esse estudo foi realizado para avaliar o preparado de anticorpos policlonais (PAP) sobre o comportamento ingestivo (CING) e desempenho de bovinos Brangus (BR) e Nelore (NE) confinados. Foram utilizados 32 machos inteiros (254,1 ± 12,7 kg), de cada um dos 2 grupos genéticos, e estes foram alimentados por 144 dias com dietas contendo ou monensina sódica (MON) ou PAP nas dosagens de 30 e 300 mg/kg de matéria seca (MS) respectivamente. Medidas no tempo foram coletadas de acordo com os períodos avaliados durante o estudo: adaptação, crescimento, terminação 1 e terminação 2. As observações foram feitas a cada 5 minutos durante 24h, aonde os dados das variáveis de CING foram coletados: tempos médios de ruminação (TR), de alimentação (TAL), de ócio, número de idas ao bebedouro, e número de refeições ao dia (REF/dia). As eficiências de alimentação (EAL) e ruminação (ERU) da MS e do FDN foram calculadas usando-se combinações dos dados de CING com os dados de consumo de MS e FDN. Não foi observado (P > 0,05) efeito dos aditivos alimentares sobre as EAL e ERU da MS e do FDN. Houve efeito sobre REF/dia e TAL despendido por refeição (TALREF), onde animais suplementados com MON apresentaram maiores (P < 0,05) REF/dia, TR e animais recebendo PAP tiveram maior (P < 0,05) TALREF. Animais recebendo PAP e MON apresentaram similares (P > 0,05) GPD, CMS e CA. Os animais BR apresentaram maior (P < 0,05) TALREF e CMS por refeição. Observouse (P < 0,05) efeito dos grupos genéticos sobre EAL e ERU da MS e da FDN (P < 0,01), onde bovinos BR apresentaram melhores eficiências quando comparados aos animais NE. Assim sendo, devido às similaridades nos resultados de CING, EAL, ERU e desempenho, PAP pode ser uma eventual alternativa à MON em dietas de alto teor de concentrado. / Abstract: This study was designed to test polyclonal antibody preparation (PAP) against several rumen microorganisms on feeding behavior and feedlot performance of Brangus (BR) and Nellore (NE) cattle. The experiment was designed as a 2 × 2 factorial arrangement of treatments using repeated measures over time, replicated 4 times (4 bullocks/pen), in which 32 9-mo-old bullocks (254,1 ± 12,7 kg) of each of two breeds evaluated were fed for 144 days, diets containing either monensin (MON) or PAP at 30 or 300 mg/kg of dry matter (DM) daily; respectively. Measures over time were taken according to the periods evaluated during the study: adaptation, growing, finishing 1 and finishing 2. Visual appraisal was made every five minutes during 24h, and feeding behavior data was collected as follows: time spent eating (EAT), ruminating (RUM), resting, visits to water through and number of meals per day (MEA). Feed offerings and refusals were weighed daily. Feeding (FEEF) and rumination efficiencies (RUEF) of DM and NDF were calculated using combinations of feeding behavior data with DM and NDF intakes data. No significant (P > 0,05) feed additives main effects were observed for FEEF and RUEF of DM and NDF, and for any of feeding behavior variables evaluated with the exception of RUM, MEA and EAT per meal (EATMEA); in which bullocks fed MON presented longer (P < 0,05) RUM and greater (P < 0,05) MEA and bullocks receiving PAP had longer (P < 0,05) EATMEA. In addition, a similar feedlot performance was observed (P > 0,05) between bullocks fed either MON or PAP. BR bullocks had longer (P < 0,05) EATMEA and greater (P < 0,05) DM intake per meal. Significant (P < 0,05) breeds main effects were observed for all of FEEF and RUEF of DM and NDF, indicating that BR bullocks were more efficient than NE bullocks in all variables evaluated. In terms of feedlot performance, BR bullocks presented greater (P < 0,05) average daily gain ... / Mestre

Os aditivos alimentares monensina e óleos funcionais foram avaliados em dietas com elevada proporção de concentrado fornecida de forma abrupta a 12 novilhos canulados no rúmen. Foi utilizado delineamento de blocos ao acaso com medidas repetidas no tempo em dois períodos experimentais de 21 dias, com no mínimo seis semanas para readaptação dos animais à dieta volumosa (feno de Tifton). A dieta basal composta por 92,25% de concentrado (82,41% de milho quebrado, 6,78% de farelo de soja, 7,75% de feno de Tifton picado, 1,77% núcleo mineral e 1,29% ureia) foi fornecida no dia 1 de cada período experimental. Os animais receberam um dos aditivos alimentares, como seguem: sem aditivos (CTR), 400 mg de óleos funcionais de mamona e líquido da casca de caju/kg de MS ingerida (OF), 30 mg de monensina/kg de MS ingerida (M30) e 40 mg de monensina/kg de MS ingerida (M40). As variáveis ruminais e sanguíneas, o comportamento ingestivo e os microrganismos ruminais foram avaliados. Cada novilho foi considerado uma unidade experimental. Os dados foram analisados com o Proc Mixed, tendo o tempo após o fornecimento da alimentação como medidas repetidas. Animais alimentados com M40 reduziram a concentração total de ácidos graxos de cadeia curta (P = 0,017), a concentração de lactato (P = 0,0012) e osmolaridade ruminal (P = 0,04). Houve interação entre tratamento e dias após transição abrupta sobre a ingestão de matéria seca expressa em kg/dia (P = 0,008) e peso corporal (P = 0,045), bem como para o pH médio do rúmen (P = 0,04), a proporção molar de propionato (P = 0,034) e a proporção molar de valerato (P = 0,031). O tratamento M30 apresentou a menor relação acetato:propionato (P = 0,03). Os tratamentos não alteraram o comportamento ingestivo (P &ge; 0,05) ou as atividades comportamentais (P &ge; 0,05), bem como a expressão relativa de F. Succinogenes (P = 0,465), S. bovis (P = 0,781) e M. elsdenii (P = 0,972). O tratamento CTR apresentou maior propensão à ocorrência de desbalanço no sistema ácido-básico do sangue. Porém, o volume globular sanguíneo, o pH e a osmolaridade do sangue não foram alteradas pelos tratamentos (P &ge; 0,05). Os aditivos alimentares utilizados em dietas com elevada proporção de concentrado fornecidas de forma abrupta agiram sob formas distintas na redução da acidose subclínica. De forma geral, a inclusão de OF e M40 não resultou em melhoria expressiva no ambiente ruminal diante da situação desafiadora da dieta, especialmente na primeira semana, quando o tratamento M30 apresentou melhor capacidade de estabilizar a fermentação ruminal. / Monensin and functional oils were evaluated in high-concentrate diet abruptly fed to 12 ruminally canullated steers. A randomized complete block design with repeated measures over time within two experimental periods of 21 days each was used, with at least six weeks for readaptation of steers to forage diet. In the high-concentrate basal diet (92.25% of concentrate) the follow treatments were added: no additives (CTR); 400 mg of castor oil and cashew nut shell liquid/kg of DMI (FO); 30 mg monensin/kg of DMI (M30) and 40 mg monensin/kg of DMI (M40). The ruminal variables, blood metabolites, feeding behaviour and microbial variable were determined. Each steer was analysed as an experimental unit. Data were analysed by Proc Mixed with time after feeding used as repeated measures.Treatment M40 showed lower ruminal total short chain fatty acids (P = 0.017), lactate concentration (P = 0.0012) and osmolality (P = 0.04). The dry matter intake expressed by kg/day (P = 0.008) and porcenteage of body weight (P = 0.045), as well as mean rumen pH (P = 0.04), propionate (P = 0.034) and valerate (P = 0.031) molar proportion had significative interaction between treatment and day. The treatment M30 showed lower acetate:propionate ratio (P = 0.03). Treatments did not change the feed behaviour (P &ge; 0.05), behavioural activities (P &ge; 0.05), and relative expression of Fibrobacter succinogenes (P = 0.465), Streptococcus bovis (P = 0.781) and Megasphaera elsdenii (P = 0.972). The blood packed volume cell, osmolality and pH were unaffected by treatments (P &ge; 0.05), but high propensity to systemic acid-base imbalance were observed in CTR diet. Feed additives had different effects to reduce the subacute acidosis. The use of FO and M40 did not change most of the rumen fermentation variables, especially in the first week after abrupt transition, where M30 provided higher protection against acidosis.

Antibiotic Feed Additives (AFA) have been used to prevent many bacterial infections during weaning of livestock. The use of these AFA’s resulted in the development of multiresistant bacterial strains and was therefore banned by the European Union. The United States also restricted the use of these feed additives considerably. Many scientists have started to search for alternatives in the prophylactic and therapeutic treatment of bacterial infections. Plants have been used traditionally by resource poor people all over the world to treat many infections. Diarrhoea not only causes many problems in the high intensity production of livestock but also leads to many human deaths. A large number of plants have been used to treat diarrhoea in humans and animals. Several authors have selected one or two species based on traditional use to evaluate in depth. In this project several different relevant parameters of 53 plant species used traditionally to treat diarrhoea were investigated in order to develop a model that would identify the species with the highest chance of delivering a useful antibacterial product. Antibacterial activities against two pathogens important in diarrhoea (Staphylococcus aureus and Escherichia coli) were positive parameters in selecting species. Because tannins frequently have antibacterial activity, but are not useful as prophylactic agents due to their effect on production, high tannin content was considered to be a negative indication. Cellular toxicity was also used as a negative parameter at a later stage. In addition to the in vitro assays there are also other parameters to be investigated to evaluate the potential use of plants. The influence of season of collection was determined on the antibacterial activity and tannin content of acetone leaf extracts of five plant species traditionally used to treat diarrhoea. They were Acacia karroo, Acacia sieberiana var. woodii, Peltophorum africanum, Trichilia emetica and Ziziphus mucronata. The antibacterial activity varied depending on the season of collection with the best activity generally in the months of late summer to autumn (January to April). The activity of Acacia karoo against E. coli was best in the month of April (MIC = 0.11 mg/ml (TA = 332 ml/g)) and against S. aureus in the month of March (MIC = 0.06 mg/ml (TA = 334 ml/g)). Acacia sieberiana subsp. woodii extracts had the best activity against E. coli (MIC = 0.10 mg/ml (TA = 303 ml/g)) in March against S. aureus in April (MIC = 0.08 mg/ml (TA = 303 ml/g)). <i.Peltophorum africanum extracts were most active against E. coli in February (MIC = 0.05 mg/ml (TA = 1188 ml/g)) and against S. aureus in February and March (MIC = 0.04 mg/ml (TA = 1188 ml/g and 1075 ml/g)). Trichilia emetica extracts were generally not very active against the bacterial strains (best activity: MIC = 0.22 mg/ml (TA = 74 ml/g) against E. coli in May and MIC = 0.28 mg/ml (TA = 26 ml/g) against S. aureus in December). Ziziphus mucronata was most active against both bacterial strains and in May (E. coli: MIC = 0.10 mg/ml (TA = 589 ml/g); S. aureus: MIC = 0.04 mg/ml (TA = 1099 ml/g)). The tannin content varied in the extracts as well. The antibacterial activity however did not seem to be directly correlated to the tannin content. Another important parameter in the use of plant species is to determine the interspecies variation of plants based on genetic or environmental influences. Leaves from 42 plants of Combretum molle were collected at different locations during the same season. The average MIC against E. coli was 0.227 mg/ml. The low standard deviation of 0.07 indicates that there was very little variation in activity. The average value against S. aureus was 0.399 mg/ml with a slightly higher standard deviation of 0.16. However due to the fact that the samples from different areas extracted different amounts, the total activity varied. The tannin assays revealed that there was with one exception no correlation between the antibacterial activity and the tannin content. So it can be safe to assume that genetic variation does not influence the activity too much at least in C. molle leaves Fifty three plant species traditionally used to treat diarrhoea in published literature were then ranked using a novel system in order to determine which species had the most potential value. Ranking was based on the lowest MIC value against E. coli, lower activity against S. aureus (to limit selecting for general metabolic toxins), low tannin concentration and high extract yield. From this ranking, five plants were chosen to investigate their potential value further: Acacia sieberiana var. woodii (E. coli: MIC = 0.13 mg/ml, TA = 108 ml/g; S. aureus: MIC = 0.13 mg/ml, TA = 108 ml/g; Yield = 14 mg), Albizia adianthifolia (E. coli: MIC = 0.14 mg/ml, TA = 239 ml/g; S. aureus: MIC = 0.04 mg/ml, TA = 765 ml/g; Yield = 34 mg), Deinbollia oblongifolia (E. coli: MIC = 0.17 mg/ml, TA = 158 ml/g; S. aureus: MIC = 0.08 mg/ml, TA = 338 ml/g; Yield = 27 mg), Spirostachys africana (E. coli : MIC = 0.13 mg/ml, TA = 300 ml/g; S. aureus: MIC = 0.09 mg/ml, TA = 438 ml/g; Yield = 38 mg) and Tetradenia riparia (E. coli : MIC = 0.09 mg/ml, TA = 214 ml/g; S. aureus: MIC = 0.13 mg/ml, TA = 149 ml/g; Yield = 20 mg). None of the plants contained any tannin. The next step towards the recommendation of a plant for the development of a commercial product was to evaluate the cytotoxicity of the selected five species. The following values were obtained: Acacia sieberiana var. woodii LC50 = 0.026 mg/ml, Albizia adianthifolia LC50 = 0.068 mg/ml, Deinbollia oblongifolia LC50 = 0.078 mg/ml, Spirostachys africana LC50 = 0.025 mg/ml and Tetradenia riparia LC50 = 0.028 mg/ml. Deinbollia oblongifolia (for its low LC50 value) and Spirostachys africana (for its good antibacterial activity and total activity) were potentized by removing inactive compounds through solvent-solvent fractionation. The antibacterial activity against E. coli was increased this way (MIC = 0.08 mg/ml for Deinbollia oblongifolia (chloroform fraction) and MIC = 0.08 mg/ml for Spirostachys africana (chloroform fraction)) The LC50 values for both chloroform fractions were determined (LC50 = 0.188 mg/ml for Deinbollia oblongifolia and LC50 = 0.062 mg/ml for Spirostachys africana ). The selectivity index (SI) was also determined and proved that the potentization was indeed successful (Deinbollia oblongifolia SI = 2.35 compared to a value of 0.45 for the crude extract; Spirostachys africana SI = 0.78 compared to a value of 0.19 for the crude extract). Based on these values, the chloroform fraction of Deinbollia oblongifolia was chosen as the less toxic one with similar activity and a higher selectivity index to be worked on further. One of the active compounds was isolated and evaluated for its activity against E. coli (MIC = 0.74 mg/ml) The LC50 value of 0.042 mg/ml indicated that the activity of the extract was a result of synergism rather than being due to a single active compound (the selectivity index (SI) was 0.06 compared to the values of 0.45 for the crude and 2.35 for the potentized extract). The plant extracts should of course be as effective against pathogenic strains as they were against the ATCC strains and so the extracts and pure compound of Deinbollia oblongifolia were tested for their activity against four different pathological E. coli strains. The results showed that the crude extract and the fraction were as active as in the preliminary screening results against only one of the four pathological strains. The pure compound on the other hand was more active against all four pathological strains than against the ATCC strain. The next step was to test the safety of the extracts of Deinbollia oblongifolia in mammals. Unfortunately neither the crude extract nor the chloroform fraction of Deinbollia oblongifolia could be used safely in a living organism or in an isolated organ study. A part of the problem may have been caused by the vehicle used in the study despite reports in the literature that an acetone water mixture is safe to use. In general all the species investigated had good antibacterial activity against E. coli this supports the traditional use of these species although we used acetone as extractant rather than the water used traditionally. There were major differences in antibacterial activity over a season indicating that mature leaves were more active than young leaves before senescence started. At least in the case of Combretum molle there was little difference in the antibacterial activity of many plants collected at different locations during the same season. The results obtained in this study could be useful in further studies to develop extracts that can be used to control diarrhoea in animals. Possibly more emphasis should be put on the difference in activity towards E. coli and S. aureus to eliminate the presence of general metabolic toxins. Such an approach would lead to a different priority order for species to examine. A major first step would probably be to test the in vitro and in vivo toxicity of selected species. / Thesis (PhD)--University of Pretoria, 2010. / Paraclinical Sciences / unrestricted

No description available.

<p>Gastrointestinal health in the young pig is a constant challenge for the swine industry. Weaning introduces many stressors such as a new solid diet, being separated from their mother, new pen mates, transportation, and an entirely new environment. Therefore, this dissertation primarily focuses on research aiding the pig immediately post-weaning. In chapter 2, a developmental bacillus direct fed microbial (DFM) was added to nursery pig diets to evaluate its effects on pig growth and health in two 35-d experiments, both randomized complete block designs based on initial BW and sex. Experiment 1 used 376 weaned pigs (17.8 d of age; 5.99±0.18 kg initial BW) allotted to one of four diets. 1) Negative Control (NC; no antibiotics with pharmacological Zn or Cu), 2) NC+DFM 0.275x109 CFU, 3) NC+DFM 0.55x109 CFU, 4) NC+DFM 1.1x109 CFU. Experiment 2 used 420 weaned pigs (20.1 d of age; 6.11±0.34 kg initial BW) allotted to one of four diets: 1) Negative Control (NC; no antibiotics with pharmacological Zn or Cu), 2) NC+DFM 0.55x109 CFU, 3) NC+DFM 1.1x109 CFU, 4) NC+BioPlus 2B 1.1x109 CFU. Experiment 1; during week 1 there were no treatment effects. During week 3 ADFI (P=0.053) quadratically increased while G:F (P=0.028) quadratically decreased as DFM increased in the diet. During d21-35 of experiment 2, ADG (P=0.092) quadratically increased and G:F (P=0.014) quadratically decreased as DFM increased.  Overall, for Experiment 1, ADFI numerically increased (4.3%) with no increase in ADG, resulting in a quadratic decrease in G:F (P=0.010) as the DFM increased in the diet.  For Experiment 2, during week 1, DFM fed pigs tended to have linearly decreased ADFI (P=0.092) and linearly increase G:F (P=0.072). Pigs fed the Bioplus2B bacillus had greater ADFI (P=0.018) than the same dose of the experimental bacillus. During week 2 pigs fed the experimental bacillus at 1.1x109 CFU tended to have improved G:F (P=0.084) than the similar DFM concentration from, the Bioplus 2B. During week 4 ADG tended to linearly (P=0.057) improve with increasing DFM in the diet and the average of all DFMs tended to have improved ADG (P=0.075) over the NC. During week 5 ADFI linearly increased (P=0.029) as DFM increased in the diet and all DFM treatments had greater ADFI (P=0.009) than the NC.  During d 21-35 of experiment 2, DFM fed pigs had linearly increased ADG (P=0.04) and ADFI (0.090). All pigs fed DFM had improved ADG (P=0.068) and ADFI (P=0.032) compared to NC fed pigs. Summarizing these two studies, the DFM product had its greatest effect improving gain feed intake and efficiency during late nursery when simplest diets are fed.</p> <p>In chapter 3, Dacitic tuff breccia (DTB) and poultry by-products (PBP) were added to nursery pig diets to evaluate their effects on growth performance and jejunal characteristics in a 35 d experiment. PBP were added as a replacement for fishmeal and was expected to provide an increased immune challenge to the newly weaned pigs. DTB was added as a functional trace element source and was hypothesized to ameliorate some of the negative impacts of PBP on the gut. A randomized complete block design based on BW and sex was used. Newly weaned pigs (N=564, 20.1±1.2 d of age, 6.18±1.13 kg initial BW). allotted to four diets (15 replicates/treatment; 9 or 10 pigs/pen): 1) Control (C; no DTB or PBP), 2) C+DTB (0.5% inclusion), 3) C+PBP (4% chicken by-product meal + 2% feather meal – replacing fishmeal, corn, and synthetic amino acids in the C), 4) C+DTB+PBP. Phase 1-3 were each 7-d and Phase 4 was from d 21-35. One barrow/pen was harvested 11d post-weaning. Jejunal tissue and mucosa were collected for histological measures and gene expression. In week 2, pigs fed DTB tended to increase ADG (323 vs. 303 g/d; P=0.068) and ADFI (376 vs. 356 g/d; P=0.055) compared to pigs not fed DTB and pigs fed PBP tended to have increased ADG (P=0.093). In week 3 pigs fed PBP had reduced ADG (460 vs 483 g/d; P=0.011) and G:F (0.689 vs. 0.723; P<0.001), and there tended to be an interaction for G:F (P=0.083) with DTB improving G:F when fed in combination with PBP but reducing G:F in the control diet.  In week 4, feeding PBP decreased ADG (384 vs 415 g/d; P<0.01) and ADFI (629 vs 666 g/d; P<0.01) compared to pigs fed no PBP.  For Phase 4 (d21-35) pigs fed PBP had decreased ADG (479 vs 497 g/d; P=0.041) and tended to have reduced ADFI (P=0.092) compared to pigs fed no PBP. Overall (d 0-35), there were no significant differences among treatments in pig growth performance.   Pigs fed PBP had increased jejunal expression of interferon-alpha (P=0.041) and interleukin-10 (P=0.037) and tended to have increased expression of claudin-1 (P=0.076).  Pigs fed DTB tended to have decreased jejunal expression of interferon-gamma (P=0.079).  Jejunal gene expression of tumor necrosis factor-alpha and nuclear factor kappa-beta did not differ among treatments. In conclusion, DTB improved nursery pig growth performance early and pigs fed PBP had decreased ADG and feed efficiency late in the nursery period. Feeding PBP had minimal effects on jejunum architecture but increased the gut immune response.</p> <p>Chapter 4 focuses on weaning age in addition to dietary treatments. Changes in weaning age and diet complexity can impact pig growth post-weaning. 432 weanling gilts and barrows (Topigs Duroc Ⅹ (US York X Landrace)) from the same farrowing group were utilized for a 30 or 35 d growth trial to compare early (EW) versus late weaning (LW) and high or low levels of specialty proteins in nursery diets. 216 pigs were EW (18 or 19 d, avg. age=18.4 days, avg. BW=5.96 kg) and 216 pigs were LW 5 days later (24, 25 or 26 d, avg. age=24.6 d, avg. BW=7.50 kg). At weaning pigs were blocked by weaning age, BW, sex and litter, and randomly allotted to 48 pens with 9 pigs/pen. Pigs at each weaning age were fed a High Complexity (HC) or a Low Complexity (LC) diet. The trial was conducted as a 2X2 factorial design: 1) EW+HC; 2) EW+LC; 3) LW+HC; 4) LW+LC. Pigs and feeders were weighed on d 0, 7, 14, 21, 28, and 35 for EW, and on d 0, 7, 14, 21, 28, and 30 for LW.  LW pigs had improved ADG and ADFI from d 0-7, 7-14, 14-21, and the final week of the nursery (P<0.05). G:F decreased for LW pigs from d 21-28 (P<0.01) compared to EW pigs, however for the overall nursery trial LW pigs had increased G:F (P=0.01). LW pigs had increased overall nursery ADG vs EW pigs (452.5 g/d vs 400 g/d; P<0.01). End of nursery BW was greater for LW vs EW pigs (21.70 kg vs 20.74 kg; P=0.001).  There was a weight block by weaning age interaction, EW heavy pigs had lower ADG compared to LW heavy pigs, however when comparing light weight pigs, the EW light pigs had improved ADG compared to LW light weight pigs (P=0.017). EW pigs were lighter at market (approximately d146 of age) compared to LW pigs (120.78 vs 124.16 kg; P=0.014). An interaction between weaning age, nursery diet, and sex (P<0.07) was observed for market weight, EW barrows fed LC diets were lighter at market (120.77 kg) than EW barrows fed HC diets (126.54 kg).  Whereas for LW barrows fed LC had higher market weights (130.04 kg) than LW barrows fed HC diets (127.59 kg). A similar, but non-significant pattern was observed for gilts. Weaning age and feeding pigs the correct diet for their age in the nursery can have a lifelong effect on the pig. </p> <p>In conclusion, feeding a DFM containing bacillus licheniformis did not impact nursery pig growth performance early in the nursery period. From d21-35 ADG and ADFI was improved in both experiments 1 and experiment 2. While the growth results were sporadically improved throughout the nursery period, the DFM’s greatest effect was it ability to improve ADFI. The improvement in the late nursery phase may be due to the need for the DFM to establish itself in the GIT. DTB tended to improve ADG and ADFI in week 2 of the nursery period, however there were no differences for growth overall. PBP reduced ADG in week 3 of the nursery period, as well as reduced ADG and ADFI in week 4 of the nursery. While there were differences in individual weeks of the trial there were no overall differences in growth performance. However, when looking at gene expression in the jejunum at d11 post-weaning, there was an increase in IFN-α and IL-10 in pigs fed PBP. In pigs fed DTB there was a decrease in IFN-γ jejunal gene expression as well. Feeding a high complexity and low complexity diet had no impact on the nursery pigs growth performance, in hindsight the low complexity diet was perhaps not low enough in specialty proteins. When comparing weaning age, pigs weaned later had increased ADG and ADFI from d0-21 post-weaning. For the overall nursery performance, LW pigs had a higher ADG, and ended the nursery period 0.96 kg heavier than the EW pigs. Comparing pigs of similar bodyweight at weaning, EW pigs were 1.5 kg heavier than LW pigs at the end of the nursery period, but the LW pigs were more feed efficient. There was a weight block by weaning interaction in this trial, as the heaviest LW pigs had higher ADG compared to the heaviest EW pigs. However, when looking at the lightest pigs, the EW pigs outperformed the LW pigs. Looking at market weights of each age group, LW pigs were 3.5 kg heavier on average at d146 of age. Although there was not a difference in diet found in the nursery phase, interestingly there were interactions discovered between treatments at market weight. Barrows are more sensitive to nursery diet compared to gilts, as LW barrows fed the low complexity diet performed better than the LW high complexity fed barrows. EW barrows were heavier at market when fed the high complexity diet, compared to EW barrows fed the low complexity diet. This shows that while the diet didn’t appear to have an impact in the nursery, feeding the pig the proper diet for their age has a lifelong impact on the pig.</p>