Celso Akio Maruta

SUSCEPTIBILIDADE DE BOVINOS DAS RAÇAS JERSEY E GIR À ACIDOSE LÁCTICA RUMINAL: I - VARIÁVEIS RUMINAIS E FECAIS

Medico Veterinario, Mestre, PhD., Professor do Departamento de Clinica Medica, FMVZ-USP, Av. Prof. Dr. Orlando Marques dePaiva, 87, 05508-000, Sao Paulo, Brasil., FAX 055-11 – 38187944, R-283. E-mail: ortolani@usp.br. Autor para correspondencia.RESUMOQuatro garrotes Jersey (J) (Bos taurus) e quatroGir (G) (Bos indicus), providos de cânula ruminal, foramutilizados para comparar a susceptibilidade a acidose lacticaruminal (ALR) aguda. Para a uniformizacao da microbiotaruminal, os animais receberam uma alimentacao padronizadapor dois meses antes da inducao da ALR. Esta foi realizada como uso de sacarose administrada diretamente no rumen, de acordocom peso metabolico corrigido. Amostras de suco ruminal e fezesforam colhidas no decorrer de 24 horas apos a inducao. Emambas as amostras, foram determinados o pH e as concentracoesde acido lactico total e dos seus isomeros D e L. Ambas as racasapresentaram marcante e identica acidose ruminal, naoocorrendo diferencas no pH e nas concentracoes de acido lacticototal, L e D no suco ruminal e nas fezes. Quanto maior foi aconcentracao de acido lactico total nas fezes menores foram osvalores de pH fecal (r = - 0,65). Devido a grande queda no pHfecal, sugere-se que esse pode ser utilizado para se firmar odiagnostico de ALR.Palavras-chave: bovinos, racas, susceptibilidade, acidoselactica, rumen, fezes.SUMMARYTo compare the susceptibility to acute rumen lacticacidosis (RLA) four Jersey (J) ( Bos taurus) and four Gir (G) ( Bosindicus ) rumen-cannulated steers were used. In order tostandardise the rumen microbiota, the steers were fed a standarddiet of hay and concentrates, for two months before the beginningof the induction. The RLA was induced with sucrose administeredintraruminally, on a basis of the corrected metabolic weight.Rumen fluid and faecal samples were collected throughout 24hafter the induction. The pH and the concentration of total lacticacid and its L and D isomers were determined in all samples.Both breeds developed intense rumen acidosis; similar pH andconcentration of total lactic acid and its isomers were found inthe rumen fluid and faecal samples. The higher the total lacticacid concentration in the faeces, the lower the faecal pH (r = -0.65). The faecal pH can be used as a tool to diagnosis RLA.Key words: cattle, breeds, susceptibility, lactic acidosis, rumen,faeces.

SUSCEPTIBILIDADE DE BOVINOS DAS RAÇAS JERSEY E GIR À ACIDOSE LÁCTICA RUMINAL: II - ACIDOSE METABÓLICAE METABOLIZAÇÃO DO LACTATO-L

In order to compare the susceptibility to acute rumen lactic acidosis (RLA), four Jersey (J) (Bos taurus) and four Gir (G) (Bos indicus) steers were used to evaluate the degree of metabolic acidosis (MA) and the metabolism of L-lactate during the RLA. The RLA was induced by the administration of sucrose into the rumen. Blood samples were collected at following times: zero, 14th,16th, 18th, 20th, 22nd and 24th h. Total lactic acid and its isomers, and blood gas determination were measured. At the most critical moments (14th to 18th h) the MA was severe in both breeds, but the MA became moderate in the G steers and remained severe in the J steers at the end of the trial. Higher amounts of D-lactate was absorbed from the rumen to the blood of the J steers; the higher the D-lactate plasma level, the lower the blood pH in this breed (r = - 0.78). Conversely, L-lactate was more absorbed and metabolised in the G steers promoting a partial recovery of the acid-basic homeostasis, as measured by the pO2 and pCO2 changes. The Bos indicus steers were less susceptible to metabolic acidosis than the Bos taurus steers.

TEMPO DE VIABILIDADE DE AMOSTRAS DE SANGUE VENOSO BOVINO DESTINADAS AO EXAME HEMOGASOMÉTRICO, QUANDO MANTIDAS SOB CONSERVAÇÃO EM ÁGUA GELADA

In order to verify the viability of blood gas analysis in bovine venous blood stored on ice water bath, two samples (10ml each) were taken from the jugular vein of 14 healthy animals (7 males and 7 females), 1- to 5-year-old, using plastic syringes and attached needles filled with sodium heparin (1,000IU). The blood samples were obtained anaerobically, the air bubbles observed were immediately removed, and the needle was maintened capped with a rubber stopper. Each syringe of the pair was distinctally stored at room temperature (23-30oC) or in ice water bath (0-4oC) during the experimental period. Values of pH, carbon dioxide (PvCO2) and oxigen (PvO2) tensions, bicarbonate (HCO3-), total carbon dioxide (TCO2), base excess (BE), standard bicarbonate (StB), oxigen saturation (SatO2), and oxigen content (O2) were determined soon after sampling and after 1, 2, 3, 4, 5, 6, 8, 10, 12 and 24 hours. According to the type of storage temperature, the results were analysed through repeated measurements ANOVA, considering the contrast between the mean value of each time and the initial one. On the storage at room temperature, the in vitro changes were characterized from continuous decreases in pH, PvO2, BE, StB, SatO2, and O2 values, and gradual increase in PvCO2, starting at 2- or 3-hour after the collection. In the samples stored at 0-4oC, on the other hand, the changes in pH occurred only at the 4th hour, and the stability of the PvCO2, BE, and StB values were maintened for up to the 6th hour. These results indicated that the diagnostic utility of blood gas analysis is conserved in bovine venous blood samples adequately stored up to 6 hours in ice water bath, at 0-4oC.

Uso de bicarbonato e lactato-L para correção da acidose metabólica sistêmica em bovinos com acidose láctica ruminal aguda

The efficiency of sodium bicarbonate or l-lactate for correcting systemic metabolic acidosis (SMA) caused by rumen lactic acidosis (RLA) was evaluated using six rumen-cannulated steers in a cross-over experimental design. RLA was induced by administration of sucrose, intraruminally. Twenty hours later when the animals developed an intense SMA, the steers were randomly distributed and treated intravenously either with 5l of 15 mMol/l sodium bicarbonate or L-lactate solution, infused throughout 4h. Blood samples were colleted throughout the infusion at zero, 1, 2, 3, 4, 6 and 8h, for blood gas analysis. After 1hour, both sodium bicarbonate and L-lactate solutions increased blood pH and corrected adequately the SMA. Blood bicarbonate, TCO2 and base excess concentrations were also increased at the 2nd hour with L-lactate and at the 3rd hour with bicarbonate. No differences between treatments were observed for blood pH, bicarbonate, TCO2 and base excess concentrations. Treated steers after twenty-four hours showed an effective clinical recovery. L-lactate can adequately replace bicarbonate in the correction of SMA in steers with RLA.

Effect of an energy-deficient diet on populations of ciliate protozoans in bovine rumen

Foram utilizados 10 novilhos mesticos com cânula ruminal, distribuidos em dois grupos: no grupo controle (C; n=4) receberam dieta balanceada para ganho diario de 900g; no grupo tratado com carencia pronunciada de energia (CP; n=6), receberam dieta com 30% a menos do nivel de mantenca em energia. Apos 140 dias sob esses regimes de alimentacao, foram coletadas amostras do fluido ruminal e urina, para realizacao de provas bioquimicas e funcionais, antes e as 1, 3, 6 e 9 horas apos o fornecimento do alimento. A carencia energetica resultou em diminuicao significativa na quantidade dos protozoarios Entodinium, Eodinium, Isotricha, Dasytricha, Eremoplastron, Eudiplodinium, Metadinium, Charonina, Ostracodinium e Epidinium. Nao houve efeito da hora de coleta sobre o total de ciliados nos grupos C e CP. Maior numero de formas em divisao binaria foi registrado no grupo C, na sexta e nona horas pos-alimentacao (P<0,019). Observaram-se altas correlacoes positivas entre a contagem total de protozoarios e a fermentacao de glicose, amonia e o indice de excrecao urinaria de alantoina e negativa entre a contagem total de protozoarios e a reducao do azul de metileno, e correlacao media entre a contagem total de protozoarios e os acidos graxos volateis totais. A determinacao da populacao de protozoarios do rumen e um metodo simples de avaliacao, alem de que particularmente auxilia o diagnostico clinico da funcao ruminal.

The measurement of urine pH to predict the amount of buffer used in the treatment of acute rumen lactic acidosis in cattle

The purpose of the present study was to establish a practical, fast, precise and low-cost procedure to estimate the degree of metabolic acidosis in cattle with acute rumen lactic acidosis for further treatment. The rumen acidosis was induced experimentally in 40 crossbreed rumen-cannulated 1.5-year-old steers. The induction caused the development of the most characteristic clinical signs of acute rumen lactic acidosis, severe rumen acidosis and a moderate metabolic acidosis, which was evidenced by low blood pH, and blood bicarbonate concentration and base excess (BE). A highly positive correlation (r=0.80) between urinary pH and BE concentration, and between urinary pH and blood pH (r=0.75) was observed. The BE concentration estimated by urinary pH was similar to that determined by venous blood gas analysis (P>0.99). Furthermore, the results presented by the predictive formula were very significant. In conclusion, urinary pH is a good tool to predict the quantity of buffers needed to treat metabolic acidosis in cattle with acute rumen lactic acidosis.

Variables on the blood inorganic sulphate concentration in cattle

Quatorze garrotes sadios holandeses, de um ano de idade, foram utilizados num experimento para verificar a influencia do grau de hemolise e de diferentes temperaturas de estoque do soro (4oC, -10oC e temperatura ambiente) sobre a concentracao de sulfato inorgânco serico. Tambem, foi comparada essa concentracao em plasma e soro. Tres diferentes graus de hemolise foram obtidos em amostras de soro, atraves de crescentes adicoes de agua destilada no sangue total. Foram realizadas provas de precisao para avaliar a viabilidade de um teste turbidimetrico para a determinacao de sulfato inorgânico. Nao ocorreram diferencas nos teores de sulfato inorgânico no plasma e no soro (p>0,91), no soro mantido a diferentes temperaturas de estocagem (p>0,87) e em amostras hemolisadas e normais (p>0,85). A crescente presenca de hemolise no soro nao interferiu sobre os teores de sulfato inorgânico nas amostras. O teste turbidimetrico provou ser adequado e preciso para analises rotineiras de sulfato inorgânico serico. Sugere-se que nos levantamentos rotineiros de avaliacao dos teores de enxofre em bovinos seja utilizado soro, mantido em temperatura ambiente.

Avaliação laboratorial do uso de solução salina hipertônica e isotônica e de furosemida no tratamento da intoxicação por amônia em bovinos

Para testar a eficiencia de varios tratamentos de intoxicacao por amonia em bovinos, foram utilizados 25 garrotes que receberam cloreto de amonio por infusao intravenosa (iv) ate o surgimento de quadro convulsivo. Em seguida, os animais foram alocados em um dos cinco grupos experimentais e tratados da seguinte forma: 1) controle: infusao (iv) de 300mL de solucao salina isotonica (SSI), no decorrer de 4h; 2) infusao (iv) de 30mL kg-1 PV de SSI no decorrer de 4h e administracao de 4L de agua intraruminal por meio de sonda esofagica (ASE); 3) mesmo tratamento do grupo 2 e dose unica (iv) de furosemida (2mg kg-1 PV) (F); 4) injecao (iv) de 5mL kg-1 PV de solucao salina hipertonica (SSH) 7,2% nos primeiros 30min, seguida de 20mL kg-1 PV de SSI e 4L de ASE; 5) mesmo tratamento do grupo 4 e dose unica de F. No decorrer de 4h apos a convulsao, foram determinados os teores plasmaticos de amonia e glicose, ureia, creatinina, potassio e sodio sericos, volume e gravidade especifica da urina, e excrecao urinaria de amonio e ureia. No momento da convulsao, os teores de amonia plasmaticos foram muito altos e identicos em todos os tratamentos, mas no 120°min, nos grupos tratados com associacao de SSH+SSI+ASE (grupos 4 e 5), houve diminuicao desse metabolito. O uso de furosemida (grupos 3 e 5) nao aumentou a excrecao total de urina. A terapia com associacao de SSH+SSI+ASE aumentou ainda o volume urinario e a excrecao percentual urinaria de ureia e amonia durante o periodo critico da 1a hora de tratamento, mas o uso de SSI+ASE (grupos 2 e 3) teve resultados intermediarios. A eficiencia do tratamento com SSH+SSI+ASE ou SSI+ASE foi superior ao grupo controle. Embora com efeito menor que o observado com SSH+SSI+ASE, a SSI+ASE promoveu melhora no quadro clinico geral e, ao termino do experimento, promoveu tambem uma adequada desintoxicacao da amonia.

Influência da raça sobre a volemia e função renal de bovinos com acidose láctica ruminal aguda, induzida experimentalmente

To study volemia and renal function in cattle with acute rumen lactic acidosis (RLA) five Jersey (J) (Bos taurus) and five Gir (G) (Bos indicus) steers were used. Blood, urine and ruminal fluid samples were collected throughout 24h after RLA induction. Higher levels of hipovolemia (p < 0.00001), and total rumen volume (p < 0.05), lower glomerular filtration (p < 0.003) and urinary volume (p < 0.05) were detected in the G steers. Nevertheless, these steers excreted more efficiently H+(p < 0.0001); although higher urinary D-lactate fractional excretion was seen in the G steers similar amounts of D-lactate were excreted by both breeds throughout the trial. Lower urinary levels of L-lactate were excreted by G steers. The higher the urinary pH, the lower the D-lactate fractional excretion in both breeds.