Effects of flavomycin on ruminal fermentation, In situ degradability and In vivo digestibility in bovine fed sugarcane diets

Problem statement: The aim of the present study was to characterize and differentiate the effects of addition of flavomycin or monensin on ruminal fermentation and degradability as well as on total digestibility in bovine. Approach: Twelve non-pregnant and non-lactating cows (736 kg of BW) were randomly assigned to three treatments: control, flavomycin (20 mg animal-1 day-1) and monensin (300 mg animal-1 day-1). The trial lasted 21 days. The last 10 days were used for external marker administration (15 g of chromic oxide animal-1 day-1). The last 5 days of the trial were used for feces collection and evaluation of corn grain, soybean meal or sugarcane ruminal degradability and the 21st day was used for ruminal fluid sampling. Results: Monensin increased 27.2%, on average, propionate molar proportion at 0, 4, 6, 8, 10 and 12 h after feeding, compared to control and flavomycin groups. When compared to control, flavomycin reduced the degradation rate of soybean meal CP in 31.0%, decreasing the effective degradability when passage rates of 5 and 8% h-1 were used. Dry matter intake, pH, total Short Chain Fatty Acids (tSCFA) or ammoniacal Nitrogen (NH3-N) concentration were not influenced by the addition of either antibiotics. Effective degradability of sugarcane NDF was not influenced by the use of either antibiotic; neither were the TDN nor the digestibility of DM, CP, EE, NFE, ADF, NDF, GE or starch of the diet. Conclusion/Recommendations: In the present study, it was possible to show the beneficial effects of monensin but not of flavomycin, on rumen fermentationFundação de Amparo à Pesquisa do Estado de São Paul

Avaliação do potencial da polpa cítrica em provocar acidose láctica ruminal aguda em bovinos

With the aim to evaluate the risk of citrus pulp to induce acute rumen lactic acidosis (ARLA), 15 rumen cannulated cattle didn't adapted to concentrates were randomly allocated in 3 groups: G1- CONTROL - group fed only the basal diet; G2 - SUCROSE animals with ARLA induced by rumen administration of sucrose; G3 CITRUS PULP animals received citrus pulp into rumen (1.65% of BW). Blood and rumen samples were drawn throughout the next 24 h to determine pH, lactic acid concentration and the packet cell volume, blood base excess. Clinical signs were also recorded and food intake followed by the next 7 days. Sucrose caused a systemic and ruminal acidosis and characteristic ARLA signs such as, apathy, dehydration, diarrhea and tachycardia, while citrus pulp gave rise to mild and brief rumen acidosis, reaching the lowest pH (5.35) at the 6th h, without any changing in the blood pH and any typical clinical sign, but temporary reduction in the rumination and excretion of semi liquid feces. Appetite was fully recovered after two and seven days in the pulp and sucrose group, respectively. These results showed that citrus pulp may be used as a feedstuff for cattle with low risk to cause ARLA.Com o objetivo de avaliar o potencial da polpa cítrica (PC) em provocar acidose láctica ruminal aguda (ALRA), 15 bovinos com peso médio de 160 kg providos de cânula ruminal não-adaptados à dieta contendo concentrado foram alocados aleatoriamente em três grupos: CONTROLE animais receberam apenas a dieta basal; SACAROSE animais receberam sacarose diretamente no rumem a fim de provocar ALRA; POLPA - grupo que recebeu subitamente alta quantidade de PC no rúmen (equivalente a 1,65% do peso corporal). Em vários tempos no decorrer de 24 horas, após administração dos substratos, foram determinados o volume globular, pH, excesso de bases (BE) e lactato total no sangue e pH e concentração de ácido láctico total no conteúdo ruminal. Exame clínico foi realizado no decorrer do 1º dia e o consumo de alimento acompanhado nos próximos sete dias. A administração de sacarose provocou um característico quadro de ALRA com o desenvolvimento de acidose ruminal e sistêmica, apatia, desidratação, diarréia e taquicardia. Por outro lado, a polpa cítrica produziu discreta e temporária acidose ruminal, atingindo na 6ª hora o pH ruminal mais baixo (5,35), sem provocar acidose sistêmica e quadro clínico mais evidente de ALRA, com exceção de uma diminuição temporária na ruminação e eliminação de fezes semilíquidas. A regularização do apetite ocorreu após dois dias no grupo com PC e sete dias no grupo com sacarose. Tais resultados indicam que a polpa cítrica pode ser utilizada na alimentação de bovinos com baixo risco de provocar ALRA

Long term dietary deficiency in steers: vital functions and T3 and IGF-1 relationships

To evaluate the influence of diets with different degrees of energy deficiency on the hormonal profile and vital functions, 12 steers were randomly distributed into 3 groups of 4 animals. For 140 days, each group received (G1) a diet to promote a weight gain of 900gr/day (17.7 Mcal/d DE and 13% CP), (G2) 80% of the maintenance requirements (5.8 Mcal/d DE and 7% CP), or (G3) 60% of the maintenance requirements (4.7 Mcal/d DE and 5% CP). In G2 and G3, the energy deficit caused a marked decrease in the heart rate and respiratory rate and a reduction in the blood levels of Insulin like growth factor-1 (IGF-1) and triiodothyronine (T3). The decrease in heart rate, respiratory movement and, to a lesser extent, reduction of the rectal temperature, reflected the low status of energy and was negatively impacted by the low levels of T3. There was a strong correlation between the hormones T3 and IGF-1 (r=0.833). There were also strong correlations between T3 and HR (r=0.701), T3 and RR (r=0.632), IGF-1 and HR (r=0.731), and IGF-1 and RR (r=0.679). There were intermediate correlations between T3 and TºC (r=0.484), T3 and insulin (r=0.506), IGF-1 and insulin (r=0.517), and IGF-1 and TºC (r=0.548). This study showed the influence of a long period of providing an energy-deficient diet on animal performance, correlating hormonal status and vital functions in growing cattle. The results indicated that the evaluated parameters represent an important tool for the early detection of dietary deficiency

Efeito da suplementação in vitro de selênio sobre neutrόfilos do leite e sanguíneos em vacas leiteras

The study was designed to assess the effects of in vitro selenium addition on intracellular hydrogen peroxide production by neutrophils from the milk and blood of dairy cows. Blood from 10 dairy cows and 20 milk samples from five dairy cows were incubated with 0 mg (control) or 10μM of sodium selenite. Then, milk and blood neutrophils were submitted for evaluation of intracellular hydrogen peroxide production by flow cytometry using 2',7'-dichlorofluorescein diacetate as a probe. The selenium status of the animals was evaluated by determination of the blood glutathione peroxidase activity. The results of the present work showed that in vitro selenium supplementation leads to an enhancement in intracellular hydrogen peroxide production, which indicates an improvement in the bactericidal effects of blood and milk neutrophils even in cows with a selenium-adequate status. Thus, the present study showed that in vitro Se supplementation leads to an enhancement in intracellular hydrogen peroxide production, indicating an improvement in the bactericidal effects of blood and milk neutrophils in cows with Se-adequate status

Meat quality of lambs supplemented with intramuscular vitamin E

ABSTRACT: This study evaluated the effects of intramuscular alpha-tocopherol (vitamin E) supplementation on meat quality characteristics of Santa Inês and Dorper crossbreed lambs. All animals were feed with a high concentrated diet in feedlot. Eight days before slaughter, the animals were distributed into four blocks according to weight gain. At the seventh and fourth days before slaughter, they were intramuscularly treated with 0, 10 or 20 IU of DL-alpha-tocopherol per kg of metabolic body weight. At slaughter they had 138 days of age and 43.6 kg of live weight, in average. Carcasses were stored for 24 hours under refrigeration at 2°C. Longissimus thoracis muscle pH (pH24h) and color (lightness, yellowness and redness) were analyzed and its samples were collected for evaluation of shear force (SF), cooking loss (WLC), fatty acid composition (FA) and thiobarbituric acid reactive substances after one (TBARS1m) and after five months (TBARS5m) of freezing. Linearity deviation effect was observed for lightness (L*; P=0.0042) and yellowness (b*; P=0.0082). Intramuscular administration of 10 or 20 IU of alpha-tocopherol/kg of metabolic weight did not influence the conservation of fatty acid in the carcasses, but benefit L* and b* values