Effects of feeding early-harvested orchardgrass-perennial ryegrass mixed silage instead of heading stage harvested timothy silage on digestion and milk production in dairy cows.

We evaluated the effects of replacement of heading stage harvested timothy silage with early-harvested orchardgrass-perennial ryegrass mixed (OP) silage while maintaining or reducing concentrate input on dry matter intake (DMI), milk production, nutrient digestibility, and N balance in dairy cows. Nine multiparous Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments: TYL, a diet containing timothy silage where forage-to-concentrate ratio (FC) was 50:50; OPL, a diet containing OP silage where FC ratio was 50:50; and OPH, a diet containing OP silage where FC ratio was 60:40. We observed that an equal replacement of timothy with OP silage increased DMI, milk yield, milk protein production, and nutrient digestibility but decreased milk fat content (TYL versus OPL). We observed that replacing timothy with OP silage while reducing concentrate input increased milk fat and protein yield, nutrient digestibility, and feed efficiency and reduced urinary N loss with no effect on DMI or milk fat content (TYL versus OPH). These results show that replacing timothy with OP silage can be a good approach to improve milk production, feed efficiency, and N utilization and reduce concentrate input. However, milk fat depression should be considered when an equal substitution is performed.

Effects of the presence of grazing-experienced heifers on the development of foraging behavior at the feeding station scale for first-grazing season calves.

In this study, effects of grazing-experienced heifer presence on foraging behavior development at the feeding station (FS) scale for first-grazing season calves were determined. A group of four calves grazing alone (C), and another comprising four calves (Wc) and three grazing-experienced heifers (Wh), were alternately stocked every day for 2 h on the same pasture for 26 days. The foraging time budget for Wc was significantly longer than that for C (P < 0.05) on day 7, and was similar to that for Wh on all days. Bite rate per FS was significantly higher for Wc (15.5 bite/min) than for C (13.2 bite/min) from day 1 to 14 (33.4 vs. 29.0 bite/min, respectively; P < 0.01) and significantly lower than that for Wh on all days. The number of steps taken between adjacent FSs by Wc (4.7) was significantly lower than that for C (7.2) on days 1 and 14 (2.1 vs. 2.9 steps, respectively; P < 0.01) and was similar to Wh on all days. This suggests that grazing-experienced heifers have positive effects on the foraging behavior development of new-season grazing calves through 14 days after the start of stocking.

Compound 48/80, a Mast Cell Stimulator, Enhances Synthesis of IgE and IgG Induced by Intranasal Application of Ovalbumin in Mice.

Mast cells are well established effector cells of type I hypersensitivity reactions such as allergic rhinitis. However, recent studies have suggested that activated mast cells enhance local immunoglobulin E (IgE) synthesis in the nasal mucosa of allergic rhinitis patients. Therefore, we hypothesized that non-immunological mast cell activators may have the potential to enhance local IgE synthesis. Here, we examined the effect of compound 48/80 (C48/80), a mast cell activator, on IgE and immunoglobulin G (IgG) synthesis. Female Balb/c mice were intranasally administered a mixture of ovalbumin (OVA) (1-10 µg/nose) and C48/80 (1-100 µg/nose) on days 0, 7, 14 and 21 and on consecutive days from day 28 to day 42. Intranasal administration of C48/80 with OVA increased serum OVA-specific IgE and IgG. Double staining with fluorescent-labeled OVA and fluorescent-labeled IgE- or IgG-specific antibody demonstrated the presence of OVA-specific IgE- or IgG-producing cells in the nasal mucosa of sensitized mice. Moreover, intranasal administration of C48/80 with OVA increased the nasal mucosal interleukin (IL)-4 level and enhanced the OVA-induced symptom of sneezing. These results suggested that simultaneous activation of mast cells with antigen exposure enhances local IgE and IgG synthesis.

Fractal analysis for quantification of grazing paths of cows on homogeneous pastures.

Fractal analysis was applied to grazing paths in non-patchy environments to clarify the behavioral information available from the analysis and to evaluate the effect of social factors on grazing paths. The grazing paths of Holstein Friesian cows in groups of 4 (GROUP-4) and 10 cows (GROUP-10) on a spatially homogeneous pasture were observed. Application of fractal analysis could quantify three aspects of grazing paths of cows: (1) hierarchical scales, (2) structure and (3) sinuosity by scale. In this study, regardless of the group size, the hierarchical scale of grazing paths was approximately 10 m. The paths showed different patterns below and above the 10 m scale. For both group sizes, fractal dimension (an index of sinuosity) below the 10 m scale was smaller than fractal dimension above 10 m scale suggesting that the paths below the 10 m scale were straighter than that above the 10 m scale. The fractal dimensions below and above the 10 m scale were significantly larger for GROUP-4 than for GROUP-10 (P<0.05). Sinuosity of paths of GROUP-4 was higher than that of GROUP-10 over the entire scale. From these three aspects, fractal analysis can clarify the factors related to grazing paths of herbivores.