Comportamento ingestivo de vacas leiteiras em pastagem de azevém alimentadas com diferentes fontes proteicas / Ingestive behavior of dairy cows in annual ryegrass pasture, fed with different proteic sources

Estudou-se o efeito da substituição do farelo de soja da ração por pastejo controlado de trevo-branco (Trifolium repens L.) sobre o comportamento ingestivo de vacas da raça Holandesa em pastejo de azevém (Lolium multiflorum Lam.). Utilizaram-se dois grupos de animais, com média de 20 vacas agrupadas por produção, período de lactação e peso corporal, em delineamento experimental em blocos ao acaso. Um grupo recebeu, diariamente, 3kg de suplemento energético e teve acesso controlado à pastagem de trevo-branco por aproximadamente duas horas e meia (TB); o outro recebeu o mesmo suplemento, adicionado de quantidade de proteína equivalente ao consumo diário no tratamento anterior via trevo, na forma de farelo de soja (FS). Para a avaliação de comportamento, procedeu-se à observação e ao registro do ritmo de atividade dos animais, no período de pastejo em azevém durante dois dias consecutivos, quinzenalmente. Observou-se maior tempo de pastejo em minutos (min), 212,00 versus 194,24min dia-1, e frequência de bocados (bocado), 67,78 versus 64,09 bocado min-1, entre os animais do tratamento FS, em relação ao TB. Não houve diferença no consumo de azevém entre os tratamentos, com valores de 3,65 e 4,11kg vaca-1 dia-1 de matéria seca para TB e FS, respectivamente, o que sugere adequada adaptação dos animais às duas situações estudadas...

The effect of the replacement of soybean meal in the ration with controlled grazing of white clover (Trifolium repens L.) on the ingestive behavior of cows of the holstein breed grazing on annual ryegrass (Lolium multiflorum Lam.) was studied. Two groups of animals with an average of 20 cows grouped by production, lactation period and body weight were used in a randomized block experimental design. One group received 3kg from energy supplement daily and had controlled access to the white clover pasture for approximately 2.5 hours (TB); the other received the same supplement, added of a quantity of protein equivalent to daily intake in previous treatment via white clover, in the form of soybean meal (FS). For behavior assessment the observation and recording of the rhythm of activity of the animals, during the grazing period in ryegrass for two consecutive days, fortnightly was done. The longest grazing time in minutes (min), 212.00 versus 194.24min day-1, and bite frequency (bite), 67.78 versus 64.09 bite min-1, between the animals from treatment FS, when compared to TB was observed. There was no difference in the intake of ryegrass between the treatments, with values of 3.65 and 4.11kg cow-1 day-1 of dry matter for TB and FS, respectively, suggesting adequate adaptation of the animals in the two situations studied...

Composição do leite de vacas Holandesas em pastejo de azevém com a utilização do trevo branco como fonte proteica / Milk composition of Holstein cows grazing ryegrass with the use of white clover as a protein source

Avaliou-se a composição do leite de animais em pastejo de azevém (Lolium multiflorum Lam.) alimentados com trevo branco (Trifolium repens L.) como substituição ao componente proteico da ração (farelo de soja), em porcentagens de proteína, lactose, sólidos totais e contagem de células somáticas. Utilizaram-se dois grupos com oito vacas da raça Holandesa, agrupados por produção, período de lactação e peso corporal, em delineamento em blocos ao acaso. Um grupo recebeu, diariamente, 3kg de suplemento energético subtraído de farelo de soja e teve acesso à pastagem de trevo branco por, aproximadamente, 2,5 horas (TB); o outro recebeu o mesmo suplemento, adicionado de quantidade de proteína equivalente ao consumo diário no tratamento anterior via trevo, na forma de farelo de soja (FS). Foram observadas diferenças significativas para teor de proteína e lactose, sendo os maiores valores encontrados de proteína em TB (3,02%) e de lactose em FS (4,64%). Para as demais variáveis não houve diferença, com valores de 10,40 e 10,39% de sólidos totais e 182,88 e 153,53 (x1000) células somáticas em TB e FS, respectivamente, mostrando que a utilização dessa fonte alternativa de proteína foi eficiente.

Was evaluated the composition of milk from animals grazing annual ryegrass (Lolium multiflorum Lam.) fed with white clover (Trifolium repens L.), as a replacement for the protein component of the ration (soybean meal), in percentages of protein, lactose, total solids and somatic cell counts. Were used two groups with eight Holstein cows, grouped by production, lactation period and body weight, in a randomized block design. One group received 3kg of energetic supplement subtracted of soybean meal daily and had access to the white clover pasture for approximately 2.5 hours (TB); the other received the same supplement, added of a quantity of protein equivalent to daily intake in previous treatment via white clover, in the form of soybean meal (FS). Significant differences were observed for protein and lactose content, with the highest values found for protein on TB (3.02%) and lactose on FS (4.64%). For the other variables there was no difference, with values from 10.40 and 10.39% of total solids and 182.88 and 153.53 (x1000) somatic cells on TB and FS respectively, showing that the use of this alternative source of protein was efficient.

Comparison of the efficacy of biodegradable and non-biodegradable scintillation liquids on the counting of tritium- and [14C]-labeled compounds

The widespread use of H and 14C in research has generated a large volume of waste mixed with scintillation liquid, requiring an effective control and appropriate storage of liquid radioactive waste. In the present study, we compared the efficacy of three commercially available scintillation liquids, Optiphase HiSafe 3, Ultima-GoldÕ AB (biodegradable) and Insta-Gel-XF (non-biodegradable), in terms of [14C]-glucose and [ H]-thymidine counting efficiency. We also analyzed the effect of the relative amount of water (1.6 to 50 percent), radioisotope concentration (0.1 to 100 nCi/ml), pH (2 to 10) and color of the solutions (samples containing 0.1 to 1.0 mg/ml of Trypan blue) on the counting efficiency in the presence of these scintillation liquids. There were few significant differences in the efficiency of 14C and H counting obtained with biodegradable or non-biodegradable scintillation liquids. However, there was an 83 and 94 percent reduction in the efficiency of 14C and H counting, respectively, in samples colored with 1 mg/ml Trypan blue, but not with 0.1 mg/ml, independent of the scintillation liquid used. Considering the low cost of biodegradable scintillation cocktails and their efficacy, these results show that traditional hazardous scintillation fluids may be replaced with the new safe biodegradable fluids without impairment of H and 14C counting efficiency. The use of biodegradable scintillation cocktails minimizes both human and environmental exposure to hazardous solvents. In addition, some biodegradable scintillation liquids can be 40 percent less expensive than the traditional hazardous cocktails.

Radioaerosol 99mTc-DTPA characterization produced by some nebulizers

1. The radioaerosol 99mTc-DTPA produced by jet and ultrasonic nebulizers was characterized by measuring the median mass diameter (MMD) and geometric standard deviation (sigma g) and these characteristics were interpreted in terms of the aerodynamic principles of inertial impactation. 2. Jet nebulizers of the same model, with different outflows (NSA = 0.14 ml/min; NSB = 0.24 ml/min and NSC = 0.40 ml/min) showed different radioaerosol mass distribution, with MMD (NSC) > MMD (NSA). The ultrasonic nebulizer US-1000 from Narcosul, which is operated with an air flow of 2 l/min and frequency of 1.6 MHz, generated radioaerosol with MMD = 2.40 microns, higher than that obtained with most of the jet nebulizers evaluated (NSA = 1.50 microns; NSB1V = 1.40 microns; NSB2V = 1.20 microns and PITT#1 - 0.80 microns), and the ultrasonic nebulizer presented the highest outflow of the nebulized solution (1.15 ml/min). 3. Connecting one or two impactation reservoirs to the NSB jet nebulizer modified the mass distribution, which became significantly narrower for NSB2V when compared to the other two nebulizers. NSB2V presented a mass percentage with a diameter of 3 microns or less and a sufficient outflow for use in ventilation and pulmonary permeability studies. 4. Comparison of the mass collected in the cascade impactor and the total mass generated by the NSB, NSB1V and NSB2V nebulizers showed, on average, 4.5 efficiency in radioaerosol generation with a diameter of less than 16 microns and 3.2 efficiency for a diameter of 3 microns or less.