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.

Virginiamycin (V) and Ionophores, such as Poulcox (active ingredient monensin sodium), are antimicrobial feed additives approved for use in cattle to improve performance. The effect of virginiamycin on Gram positive bacteria is similar to that of monensin (M) although the modes of actions differ. Very little information is available on the potential synergistic effects of V and M, especially in dairy cattle diets. The objectives of this study were to investigate the effect of combinations of V and M on the performance of dairy cows. Forty high producing Holstein cows were blocked according to previous milk production and randomly allocated to one of the following lucerne based total mixed diets: 1) Control, no medication (C); 2) Control plus 20 ppm virginiamycin (V); 3) Control plus 15 ppm monensin (M); 4) Control plus 20 ppm virginiamycin and 15 ppm monensin (V+M). The experimental period was from 21 days prepartum until 60 days postpartum. Data were analysed according to a randomized block design, using the model GLM procedure (SAS, 2001). Dry matter intake varied from 23.6 kg/d to 25.4 kg/d and did not differ between treatments (P>0.10). Milk production was higher (P<0.10) for cows receiving V+M (41.2 kg/d) when compared to cows receiving only V (36.6 kg/d), but did not differ from other treatments (P>0.10). Milk fat % was lower for cows receiving M (3.42 %) and the control (3.62 %) when compared to treatment V+M (3.86 %) (P<0.10). Milk protein and MUN did not differ. Body weight loss for the period from calving until day 60 postpartum, tended (P<0.15) to be less for cows receiving V+M (-8.1 kg) when compared to the control (-34.2 kg) and M (-31.9 kg) treatments. Both treatments M and V respectively, decreased blood BHBA and treatment M increased blood glucose (P<0.10) when compared to the control diet. Results suggest a complementary effect between the two additives monensin and virginiamycin when supplemented to early lactation cows. / Dissertation (MSc(Agric))--University of Pretoria, 2008. / Animal and Wildlife Sciences / unrestricted

(R,S)-[Carboxyl-¹⁴C]–cis-3-hydroxyproline was synthesized from S-[carboxyl-¹⁴C] proline. The oxygen functionality at the three position was obtained by acetylation of 1,2-dehydroproline methyl ester using lead tetraacetate. Reduction of the imine with sodium borohydride gave predominately (R,S)-[caboxyl-¹⁴C]-cis-3-acetoxyproline which was hydrolyzed with hydrochloric acid and purified by ion-exchange chromatography and recrystallization. In order to determine if cis-3-hydroxyproline is a precursor for the dehydroproline moietyof virginiamycin M1, (R,S)-[carboxyl-¹⁴C]-cis-3-hydroxyproline and S-[3,4-³H] proline with a ³H/¹⁴C of 9 were fed simultaneously to a virginiamycin producing strain of Streptomyces. The resulting antibiotic had a ³H/¹⁴C ratio of 41.3. The proline portion of the antibiotic had a ratio of 19.9. Therefore, 45% of the cis-3-hydroxyproline was incorporated, and cis-3-hydroxyproline is a precursor to the dehydroproline moiety. / Master of Science

Some aspects of the biosynthesis of three amino acid residues in virginiamycin S₁ have been studied in Streptomyces virginiae by the incorporation of amino acid precursors labeled with either radioactive or stable isotopes. L-Lysine-U-¹⁴C was incorporated into both the 4-oxo-L-pipecolic acid and 3-hydroxypicolinic acid residues. The formation of the heterocyclic ring of both of these amino acids was shown to occur with retention of the nitrogen from the ε-amino group of lysine, as shown by the incorporation of DL-lysine-6-¹³C-6-¹⁵N. In addition, the 3-hydroxypicolinic acid residue incorporated deuterium from (2RS, 5R)-lysine-5-d₁, but not from (2RS, 5S)-lysine-5-d₁. This finding indicates that the 5-pro-(R) hydrogen of L-lysine is retained during the biogenesis of 3-hydroxypicolinic acid. In the conversion of L-phenylalanine to L-phenylglycine, the amino group moves to the benzylic position. This process could proceed either by an intermolecular mechanism, in which the original nitrogen is lost, or by an intramolecular mechanism, in which that nitrogen is retained. Administration of (RS)-phenylalanine-3-¹³C-¹⁵N resulted in its incorporation with loss of the labeled nitrogen. The process therefore occurs by an intermolecular mechanism. / Ph. D.

Two experiments were conducted to compare the feedlot performance of swine fed diets containing a commercially available lactobacillus probiotic and virginiamycin, a gram-positive antibiotic (experiment I) and to evaluate the feedlot performance of starter and grower-finisher swine housed under conditions of restricted and adequate space allowance fed diets with and without virginiamycin (experiment II). For experiment I, in four starter trials, pigs fed diets containing virginiamycin tended to eat more and grow faster than pigs fed the control diet while lactobacillus probiotic had no effect on performance. In the combined analysis of a starter-grower-finisher and a grower-finisher trial, virginiamycin supplementation had no effect on performance while the pigs fed the probiotic had significantly poorer gains than the control pigs. In three grower-finisher trials, virginiamycin supplementation improved daily gain and feed consumption while lactobacillus probiotic had no significant effect on performance. For experiment II, in four starter trials, increasing the number of pigs in 1.2 x 1.2 m nursery pens from six to 12 caused significant depressions in final weight, daily gain, feed intake, and feed efficiency. Virginiamycin supplementation significantly improved final weight, daily gain and feed efficiency. In two starter trials, reducing space allowance from .24 to .12 m² per pig caused significant depressions in final weight, daily gain and feed efficiency but virginiamycin had no effect on performance. In a series of grower-finisher trials, decreasing space allowance from .78 to .43 m² pig caused significant depressions in final weight, daily gain, feed intake and feed efficiency while virginiamycin improved feed efficiency. The virginiamycin X space allowance interaction was significant in only one instance with virginiamycin improving feed efficiency 6.2% when starter pigs were given adequate space allowance but only 2.5% when crowded. These findings suggest that virginiamycin is superior to the probiotic as a growth promotant for swine. Also, housing pigs under crowded conditions does not increase the level of response to virginiamycin. / Master of Science

The biosynthesis of virginiamycin S₁, a macrocyclic peptidolactone antibiotic, was studied by growing a strain of Streptomyces virginiae in a complex medium and observing the incorporation of radiolabeled compounds into the antibiotic. These studies have established several of the biosynthetic precursors of virginiamycin S₁. L-(U-14C)-Proline and L-(U-14C)-threonine were effectively incorporated into the respective amino acid components in the antibiotic. N-Methyl-L-phenylalanine was shown to arise from L-(U-14C)-phenylalanine and L-(methyl-14C)-methionine. L-(U-14C)-Phenylalanine was also efficiently incorporated into L-phenylglycine. The origin of the remaining three components was less clear. A small amount of L-(U-14C)-threonine was observed in D-α-aminobutyric acid. A biosynthetic pathway is known between these two amino acids which suggests that L-threonine may be the biosynthetic precursor of D-α-aminobutyric acid. Both L-(U-14C)-aspartic acid and L-(U-14C)-lysine were incorporated into 4-oxo-L-pipecolic acid and 3-hydroxypicolinic acid. A biosynthetic pathway was hypothesized to explain these results. / Master of Science

Objetivou-se compreender melhor o modelo de indução de acidose láctica ruminal (ALR) com sacarose destacando-se aspectos básicos da fermentação ruminal e suas consequências, assim como avaliação comparativa da eficácia de dois aditivos (Virginiamicina VM e Monensina MON), associados ou não, na prevenção desta enfermidade em bovinos adultos de corte. Para tal, foram utilizados 30 fêmeas da raça Nelore, providas de cânula ruminal, com cerca de 413 kg de peso corpóreo. Os animais foram mantidos em baias individuais e alimentados com dieta basal composta de 75% de feno de capim de coast-cross e de 25% de ração concentrada comercial, por 30 dias antes da indução de ALR. Durante esse período os bovinos foram distribuídos em cinco grupos iguais de seis animais cada, assim constituídos: controle (CON); MON 30 ppm; VM 25 ppm; VM 34 ppm e MON 30 ppm + VM 25 ppm. Os aditivos foram administrados numa mistura de 500 g fubá, antes do oferecimento do alimento. Em seguida, foi realizada indução individual de ALR com uso de sacarose de acordo com peso metabólico corrigido, administrada pela cânula ruminal. Foram obtidas amostras de conteúdo ruminal, sangue, urina e fezes, assim como realizado exame físico nos seguintes momentos: zero (basal) e após três, seis, 12 e 18 horas da indução. Foi realizada análise de variância (Teste F) dos dados que obedeceram à distribuição paramétrica, e utilizado o comando Proc mix para medidas repetidas no tempo de duas vias considerando os fatores tratamento, tempo e interação entre tratamento e tempo. Alguns dados foram submetidos ao teste T de Student. Os dados que não obedeceram a distribuição paramétrica foram avaliados pelos testes de Kruskal-Wallis e qui-quadrado. Para o estudo da relação entre duas variáveis foi determinado os índices de correlação e determinação. Ocorreu acidose ruminal intensa, por grande produção inicial de ácidos graxos de cadeia curta (AGCC), seguido de ácido láctico, com predomínio do isômero L sobre o D, os quais com a glicose gerada na fermentação provocaram aumento de osmolaridade nesse conteúdo. A acidose sistêmica foi de grau moderado em pequena parte dos bovinos, com presença de desidratação num expressivo número de animais. Boa parte dos bovinos tratados (n =15) apresentavam depressão nervosa e desidratação. Ocorreu pontualmente um quadro de hipertermia no auge da fermentação ruminal. Os melhores resultados preventivos da ALR foram obtidos com a associação VM + MON, a qual postergou a produção de ácido láctico, quer seja pela menor produção deste, como pela conversão de ácido láctico L em ácidos acético e propiônico. Ao término do experimento essa associação promoveu maior pH e menor acúmulo de ácido láctico L, assim como viabilizou que um menor número de animais necessitassem ser tratados, em relação ao grupo controle. As duas diferentes doses de VM tiveram resultados intermediários, seguidos da MON, a qual não se recomenda como único aditivo com fins de prevenção da ALR. / The objective was to better understand the induction model of rumen lactic acidosis (RLA) with sucrose, highlighting the basic aspects of ruminal fermentation and its consequences, as well as comparative evaluation of the efficacy of two additives (Virginiamycin VM and Monensin MON), associated or not, in the prevention of acidosis in adult beef cattle. For this purpose, 30 Nellore ruminally-cannulated females were used, with average body weight of about 413 kg. The animals were kept in individual stalls and fed a basal diet composed of 75% coast-cross grass hay and 25% commercial concentrated feed for 30 days prior to RLA induction. During this period the cattle were distributed into five equal groups of six animals each, as follows: control (CON); MON 30 ppm; VM 25 ppm; VM 34 ppm and MON 30 ppm + VM 25 ppm. The additives were provided in a 500 g corn meal before the feed was offered. Subsequently, individual RLA induction with sucrose was performed according to corrected metabolic weight, via ruminal cannula. Samples of rumen contents, blood, urine and feces were collected, and physical examination at: zero (baseline) and after three, six, 12 and 18 h after induction. Variance analysis (Test F) of the data that obeyed the parametric distribution was performed, and the Proc mix command was used for repeated measurements in two-way time considering the factors treatment, time and interaction between treatment and time. Some data were submitted to Student\'s t-test. The data that did not obey the parametric distribution were evaluated by the Kruskal-Wallis and chi-square tests. The correlation and determination indices were determined for the study of the relationship between two variables.. A severe ruminal acidosis occurred due to the large initial production of short chain fatty acids (SCFA), followed by lactic acid, with predominance of the L over D-isomer, which with the glucose generated in the fermentation caused an increase in osmolarity in this content. Systemic acidosis was moderate in a small number of cattle, with dehydration in an expressive number of animals. Most treated cattle (n =15) presented nervous depression and dehydration. A temporary hyperthermia occurred at the peak of ruminal fermentation. The best results of RLA prevention were obtained from VM + MON association, which postponed the lactic acid production, either by its lower production, or by the conversion of L-lactic acid in in acetic and propionic acids. At the end of the experiment, this association promoted greater pH and lower L-lactic acid accumulation, and a smaller number of animals needed to be treated, compared to the control group. The two different doses of VM had intermediate results, followed by MON, which is not recommended as a single additive for the RLA prevention.

Several types of antibiotics (roxarsone, virginiamycin, and bacitracin) are widely included in poultry feed to improve animal growth yields. Most of the antibiotics are excreted in manure which is subsequently applied to soils. One concern with this practice is that antibiotics may affect several microbially-mediated nutrient cycling reactions in soils that influence crop productivity and water quality. The main objectives of this study were to determine the effects of livestock antibiotics on nitrification, denitrification, and microbial community composition in soils along a topographic gradient. These objectives were addressed in a series of lab experiments by monitoring changes in inorganic N species and ester-linked fatty acid methyl ester profiles after exposing soil microorganisms collected from different topographic positions to increasing levels of antibiotics. It was discovered that roxarsone and virginiamycin inhibited nitrification and soil microbial growth and also influenced microbial community composition, but only at levels that were much higher than expected in poultry litter-applied soils. Bacitracin did not affect nitrification, microbial growth, or microbial community composition at any concentration tested. None of the antibiotics had a strong affect on denitrification. Thus, it is unlikely that soil, water, or air quality would be significantly impacted by the antibiotics contained in poultry litter.

Made available in DSpace on 2015-03-26T13:54:47Z (GMT). No. of bitstreams: 1 texto completo.pdf: 476512 bytes, checksum: 35149364f3cd2d143bdaa4e720565c5a (MD5) Previous issue date: 2009-02-26 / We used six horses, healthy female, adult, 3 / 4 and 1 / 2 blood Breton, with an average weight of 400 kg in a Latin square experimental design 3 X 3, with the objective of determining the levels of virginiamycin to control parameters physiological and hematological animals treated with concentrates with high content of carbohydrates. The animals were divided into three experimental groups and two animals per group. Each experimental cycle consisted of 3 days of collection and 12 days of rest. At the end of this period, the animals were then exchanged group so that at the end of the experiment, all animals underwent all the treatments offered. Group 1 (control) received basal diet rich in carbohydrates, consisting of corn, soybean meal and mineral salt. Groups 2 and 3 received the same basal diet and 2 and 6 g/100 kg body weight of virginiamycin, respectively, via nasogastric tube. As forage, all animals received hay of Tifton 85 (Cynodon dactylon) ad libitum. Collections were made for the evaluation of blood serum concentrations of glucose and lactic acid. Samples of feces were also collected for measurement of moisture contents and pH. Other parameters such as heart rate, respiratory rate and rectal temperature were measured temperature of the hull in order to detect clinical changes resulting from this diet. Despite the large number of animals received concentrate rich in carbohydrates, the levels were not sufficient to trigger a physiological response in the face of challenge proposed. The virginiamycin administered via nasogastric tube, in doses of 2 and 6 g / kg body weight divided into two doses daily, with an interval of 12 hours, caused no change in clinical and laboratory parameters measured in this study, it can be used in horses. / Foram utilizados seis equinos, fêmeas hígidas, adultas, 3/4 e 1/2 sangue Bretão, com média de peso de 400 kg em um delineamento experimental quadrado latino 3 X 3, com o objetivo de determinação dos níveis de virginiamicina no controle de parâmetros fisiológicos e hematológicos dos animais tratados com concentrados com alto teor de carboidratos. Os animais foram divididos em três grupos experimentais sendo dois animais por grupo. Cada ciclo experimental foi constituído de 3 dias de coleta e 12 dias de descanso. Ao final deste período, os animais eram então trocados de grupo de modo que, ao final do experimento, todos os animais passaram por todos os tratamentos propostos. O grupo 1 (controle) recebeu ração basal rica em carboidratos, composta por milho, farelo de soja e sal mineral. Os grupos 2 e 3 receberam esta mesma ração basal e 2 e 6 g/100 kg de peso corporal de virginiamicina, respectivamente, via sonda nasogástrica. Como volumoso, todos os animais receberam feno de Tifton 85 (Cynodon dactylon) ad libitum. Foram feitas coletas de sangue para a avaliação das concentrações séricas de glicose e ácido láctico. Amostras de fezes também foram coletadas para mensuração dos teores de umidade e pH. Outros parâmetros como a freqüência cardíaca, freqüência respiratória temperatura retal e temperatura dos cascos foram mensuradas com o intuito de detectar alterações clínicas decorrentes desta dieta. Apesar dos animais receberam grande quantidade de concentrado rico em carboidratos, os níveis não foram suficientes para desencadear uma resposta fisiológica diante do desafio proposto. A Virginiamicina administrada por via sonda nasogástrica, nas doses de 2 e 6 g/kg de peso corporal, divididas em duas doses diárias, com intervalo de 12 horas, não ocasionou alteração em parâmetros clínicos e laboratoriais mensurados neste estudo, podendo a mesma ser utilizada em equinos.

Submitted by Thamiris Naiasha Minari Ramos (thami.naiasha@gmail.com) on 2018-04-12T12:40:16Z No. of bitstreams: 1 Thamiris Ramos Dissertação correto.pdf: 1558131 bytes, checksum: 1856f8c4c71c4a0070fe9f4a1e01e888 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-12T13:28:40Z (GMT) No. of bitstreams: 1 ramos_tnm_me_jabo.pdf: 1558131 bytes, checksum: 1856f8c4c71c4a0070fe9f4a1e01e888 (MD5) / Made available in DSpace on 2018-04-12T13:28:40Z (GMT). No. of bitstreams: 1 ramos_tnm_me_jabo.pdf: 1558131 bytes, checksum: 1856f8c4c71c4a0070fe9f4a1e01e888 (MD5) Previous issue date: 2018-02-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / As doenças periodontais provocam inflamações dos tecidos de proteção e sustentação dos dentes. Na gengivite e gengivite necrosante, que são percursores da periodontite, a inflamação está associada à formação do biofilme bacteriano e à resposta imune do hospedeiro. O objetivo geral do presente trabalho foi avaliar a eficácia da virginiamicina no controle da gengivite e gengivite necrosante em bezerros, com destaque para o monitoramento da microbiota subgengival associada à doença e da condição periodontal que caracterizam essas enfermidades. Dez bezerros, randomizados e distribuídos em dois grupos, foram mantidos sob o mesmo manejo em pastejo rotacionado em área recém-reformada de Panicum maximum var. Massai e Mombaça. Por 18 semanas consecutivas, um dos grupos (Grupo Virginiamicina, n=5) recebeu via top-dressing, diariamente, 340 mg de Virginiamicina, enquanto o Grupo Controle (n=5) não recebeu o produto. A avaliação clínica da cavidade bucal do Grupo Controle (n=5) e do Grupo Virginiamicina (n=5), foi realizada semanalmente, enquanto que a coleta de material para a avaliação microbiológica foi quinzenal. Na avaliação microbiológica, pela reação da cadeia da polimerase (PCR) utilizou-se os iniciadores de vinte e cinco microrganismos: Actinomyces israelii, Actinomyces naeslundii, Archae, Eikenella corrodens, Campylobacter spp., Fusobacterium nucleatum, Fusobacterium necrophorum, Mollicutes, Parvimonas micra, Porphyromonas asaccharolytica, Porphyromonas endodontalis, Porphyromonas gingivalis, Porphyromonas gulae, Prevotella buccae, Prevotella loescheii, Prevotella intermedia, Prevotella melaninogenica, Prevotela nigrescens, Prevotella oralis, Selenomonas sputigena, Tannerella forsythia, Treponema amylovorum, Treponema denticola, Treponema maltophilum e Treponema pectinovorum. Após 1440 avaliações clínicas periodontais dos dentes incisivos verificou-se que o grupo controle apresentou maior ocorrência de gengivite (n=267) e gengivite necrosante (n=58) do que os animais que receberam tratamento, tanto em relação à gengivite (n=128) quanto à gengivite necrosante (n=31). Na comparação entre as médias dos grupos, o total de dentes com gengivite (p<0,01) e gengivite necrosante (p<0,01) no Grupo Controle, foi significamente superior ao de gengivite (p<0,01) e gengivite necrosante (p<0,05) do Grupo Virginiamicina, de acordo com o teste t (p<0,05). Pela PCR, foram detectados A. israelii (4,74%), Archae (1,58%), E. corrodens (1,05%), F. nucleatum (27,37%), Mollicutes spp. (5,26%), P. endodontalis (5,26%), P. gulae (0,53%), P. buccae (6,32%), P. loescheii (3,68%), P. nigrescens (8,42%), P. oralis (1,58%), T. forsythia (0,53%) e T. denticola (4,21%) no Grupo Controle. Já no Grupo Virginiamicina: A. israelii (3,41%), Archae (0,98%), F. nucleatum (9,27%), Mollicutes sp. (4,39%), P. endodontalis (4,39%), P. gulae (0,49%), P. buccae (8,29%), P. loescheii (6,83%), P. nigrescens (15,61%), P. oralis (1,46%), S. sputigena (0,49%), T. forsythia (0,49%) e T. denticola (2,44%). Nesse contexto, é possível afirmar que os bovinos apresentaram gengivite e gengivite necrosante quando mantidos em pasto recém-reformado, que existe uma microbiota bucal com micro-organismos potencialmente patogênicos e que a virginiamicina foi eficaz no controle dessas doenças periodontais. / Periodontal diseases cause inflammation of the protective and supporting tissues of the teeth. In gingivitis and necrotizing gingivitis, which are precursors of periodontitis, inflammation is associated with the formation of the bacterial biofilm and the immune response of the host. The general objective of the present study was to evaluate the efficacy of virginiamycin in the control of gingivitis and necrotizing gingivitis in calves, with emphasis on the monitoring of the subgengival microbiota associated with the disease and the periodontal condition that characterize these diseases. Ten calves, randomized and distributed in two groups, were kept under the same management in rotational grazing in a newly reformed area of Panicum maximum var. Massai and Mombasa. For 18 consecutive weeks, one of the groups (Virginiamycin group, n = 5) received topical dressing daily 340 mg of Virginiamycin, while the control group (n = 5) received no product. The clinical evaluation of the oral cavity of the Control Group (n = 5) and the Virginiamicina Group (n = 5) was performed weekly, while the material collection for the microbiological evaluation was biweekly. In the microbiological evaluation, primers of twenty-five microorganisms were used: Actinomyces israelii, Actinomyces naeslundii, Archae, Eikenella corrodens, Campylobacter spp., Fusobacterium nucleatum, Fusobacterium necrophorum, Mollicutes, Parvimonas micra, Porphyromonas asaccharolytica, Porphyromonas endodontalis, Porphyromonas gingivalis, Porphyromonas gulae, Prevotella buccae, Prevotella loescheii, Prevotella intermedia, Prevotella melaninogenica, Prevotella nigrescens, Prevotella oralis, Selenomonas sputigena, Tannerella forsythia, Treponema amylovorum, Treponema denticola, Treponema maltophilum and Treponema pectinovorum. After 1440 periodontal clinical evaluations of the incisor teeth, it was verified that the control group presented a higher occurrence of gingivitis (n = 267) and necrotizing gingivitis (n = 58) than the animals that received treatment, both in relation to gingivitis (n = 128) and for necrotizing gingivitis (n = 31). In the comparison between group means, the total number of teeth with gingivitis (p <0,01) and necrotizing gingivitis (p <0,01) in the Control Group was significantly higher than gingivitis (p<0,01) and necrotizing gingivitis (p<0,05) of the Virginiamycin Group, according to the t-test (p=0,05). In this study, A. israelii (4,74%), Archae (1,58%), E. corrodens (1,05%), F. nucleatum (27,37%) and Mollicutes spp. (5,26%), P. buccae (6,32%), P. loescheii (3,68%), P. nigrescens (8,42%), P. endodontalis (5,26%), P. oralis (1,58%), T. forsythia (0,53%) and T. denticola (4,21%) in the Control Group. In the Virginiamicina Group: A. israelii (3,41%), Archae (0,98%), F. nucleatum (9,27%), Mollicutes sp. (4,39%), P. endodontalis (4,39), P. gulae (0,49), P. buccae (8,29), P. loescheii (6,83%), P. nigrescens (15,61%), P. oralis (1,46%), S. sputigena (0,49%), T. forsythia (0,49%) and T. denticola (2,44%). In this context, it is possible to affirm that bovine presented gingivitis and necrotizing gingivitis when kept in freshly reformed pasture, that there is a buccal microbiota with potentially pathogenic microorganisms and that virginiamycin was effective in the control of these periodontal diseases. / CNPq: 143600/2016-8 / CNPq: 130297/2018-6