Sunflower cake versus soybean meal and alfalfa for nitrogen utilization when crude protein and non-fiber carbohydrate levels are equivalent.

The reported efficiency of N usage by sunflower cake (SFC) was inferior to that of soybean meal (SBM) in a study in which the non-fiber carbohydrate (NFC) content was lower in the SFC diet. Here, we adjusted crude protein (CP) and NFC levels to near-equivalence among three diets containing SFC or SBM for four non-lactating Holstein cows. Alfalfa hay was also added to the comparison. The results demonstrated that the total digestible nutrient contents were not significantly different among the diets. Intake N, fecal N, absorbed N, urinary N, and retained N did not differ significantly among the diets. The efficiency of N usage in the body (retained N/absorbed N) did not differ significantly among the diets. No between-diet difference was observed in the protein- and energy-related ruminal and blood properties, including the estimated microbial protein synthesis in the rumen. These results suggest that regardless of the quality and balance of amino acids in a feed, the efficiency of N usage can be improved by a supply of digestible carbohydrates, which leads to an increase in ruminal microbial protein.

Heterogeneous electrophysiological and morphological properties of neurons in the mouse medial amygdala in vitro.

Neurons in the medial nucleus of the amygdala (MeA) play a key role in the innate maternal, reproductive, defensive, and social behaviors. However, it is unclear how activation of the vomeronasal system leads to the behavioral outputs that are associated with pheromones. Here, we characterized the electrophysiological and morphological properties of MeA neurons using whole-cell recordings in mice slice preparations. Biocytin labeling revealed that MeA neurons possessed bipolar to multipolar cell bodies and dendritic fields covering projection areas from the accessory olfactory bulb. In 70% of recorded MeA neurons, monosynaptic excitatory postsynaptic currents (EPSCs) were evoked from the accessory olfactory bulb afferent in which the α-amino-3-hydroxy-5-methyl-4-isoxazole propionate component was dominant and was rarely followed by the N-methyl-d-aspartic acid component. Norepinephrine increased the frequency of spontaneous inhibitory postsynaptic currents in some neurons, whereas α-methyl-5-hydroxytryptamine increased spontaneous EPSCs in other neurons. Morphologically and physiologically, heterogeneous MeA neurons appear likely to produce multiplex outputs of instinctive behaviors.