RESUMO

This study assessed the association between encapsulated nitrate product (ENP) and monensin (MON) to mitigate enteric methane (CH4) in vitro and possible effects on ruminal degradability, enteric fermentation characteristics, and microbial populations. Six treatments were used in randomized complete design in a 2×3 factorial arrangement with two levels of MON (0 and 2.08 mg/mL of buffered rumen fluid) and three levels of ENP (0, 1.5 and 3.0%). The substrate consisted of 50% Tifton-85 hay and 50% concentrate mixture (ground corn and soybean meal). ENP replaced soybean meal to achieve isonitrogenous diets (15% CP). No ENP×MON interaction was observed for any measured variable (P > 0.05) except for the relative abundance of F. succinogenes (P = 0.02) that linearly increased in diets with MON when ENP was added. The ENP addition decreased CH4 production (P < 0.01) without affecting (P > 0.05) truly degraded organic matter nor the relative abundance of methanogens. Hydrogen production was reduced with MON (P = 0.04) and linearly decreased with ENP inclusion (P = 0.02). We concluded that use of nitrate is a viable strategy for CH4 reduction, however, no additive effect of ENP and MON was observed for mitigating CH4 production.

Assuntos

Monensin , Nitratos , Animais , Dieta , Fermentação , Monensin/metabolismo , Monensin/farmacologia , Nitratos/metabolismo , Rúmen/metabolismo , Glycine max

RESUMO

The objective of this study was to evaluate the performance and digestibility of diets containing different levels of crude propolis for growing rabbits. Forty-eight New Zealand White rabbits, 43 days old, of both genders, were used, distributed in a completely randomized design. There were four diets with different inclusion levels of crude propolis (0.0; 0.5; 1.0 and 1.5%). There was no statistical difference for performance regarding the inclusion levels of crude propolis (p = 0.85), as well as for the variables dry matter consumption, neutral detergent fiber and acid detergent fiber (p ≥ 0.07). Crude protein consumption showed a statistical difference in relation to gender (p = 0.04): males showed higher consumption. However, final weight, total weight gain, daily weight gain and feed efficiency were not influenced by the addition of crude propolis (p ≥ 0.37). Dry matter digestibility, crude protein, neutral detergent fiber and acid detergent fiber were not influenced by the inclusion levels of crude propolis in the diets (p ≥ 0.12). This study indicates that the inclusion of raw propolis up to 1.5% in the diets does not affect the performance parameters of rabbits.

Assuntos

Animais , Coelhos , Aditivos Alimentares/análise , Coelhos/crescimento & desenvolvimento , Coelhos/fisiologia , Própole

RESUMO

The objective of this study was to evaluate the performance and digestibility of diets containing different levels of crude propolis for growing rabbits. Forty-eight New Zealand White rabbits, 43 days old, of both genders, were used, distributed in a completely randomized design. There were four diets with different inclusion levels of crude propolis (0.0; 0.5; 1.0 and 1.5%). There was no statistical difference for performance regarding the inclusion levels of crude propolis (p = 0.85), as well as for the variables dry matter consumption, neutral detergent fiber and acid detergent fiber (p ≥ 0.07). Crude protein consumption showed a statistical difference in relation to gender (p = 0.04): males showed higher consumption. However, final weight, total weight gain, daily weight gain and feed efficiency were not influenced by the addition of crude propolis (p ≥ 0.37). Dry matter digestibility, crude protein, neutral detergent fiber and acid detergent fiber were not influenced by the inclusion levels of crude propolis in the diets (p ≥ 0.12). This study indicates that the inclusion of raw propolis up to 1.5% in the diets does not affect the performance parameters of rabbits.(AU)

Assuntos

Animais , Coelhos , Coelhos/crescimento & desenvolvimento , Coelhos/fisiologia , Própole , Aditivos Alimentares/análise

RESUMO

When vocalizations transmit throughout the environment, attenuation and degradation may change the information of the signal; the loss of information is related to changes in both frequency and duration of vocalizations. The variation in frequency and duration of bird calls is related to the functions of each call type. Using a sound transmission experiment, the authors tested the transmission properties of two call types both produced by white-eared ground-sparrows Melozone leucotis; these calls vary in frequency and duration, suggesting that they may transmit at different distances. The authors broadcasted and re-recorded each call type at four different distances (4, 8, 16, and 32 m) inside ground-sparrow territories. The authors found that calls with a narrow bandwidth and longer duration transmitted at longer distances, and showed a lower attenuation and degradation than the calls with a broad bandwidth and shorter duration. These results support the relationship between the transmission properties of a call and the different functions (short and long distance communication) also evidence how the selection of these calls facilitates the communication over different distances.