Microorganism composition, chemical composition and fermentation characteristics of the mixed sowing silage of timothy and orchardgrass at different cutting number

Abstract

To clarify the role of serotonin (5-HT) in the regulatory mechanism of L-tryptophan (TRP)--induced growth hormone (GH) secretion in cattle, changes in 5-HT concentrations in the cerebrospinal fluid (CSF) in the third ventricle (3V) and GH in plasma before and after the peripheral infusion of TRP were determined simultaneously. The direct effect of TRP on GH release from the dispersed anterior pituitary cells was also assessed. A chronic cannula was placed in 3V by stereotaxic surgery, then CSF and blood were withdrawn under physiological conditions. TRP (38.5 mg/kg BW) was infused through an intravenous catheter from 12.00 to 14.00 hours and CSF and blood sampling were performed from 11.00 to 18.00 hours at 1-h intervals. The concentration of 5-HT in CSF was determined by high-performance liquid chromatography with electrochemical detection. GH, melatonin (MEL), and cortisol (CORT) concentrations were measured by radio-immunoassay and enzyme-immunoassay. Concentrations of 5-HT were increased by TRP infusion. The TRP infusion significantly increased GH release. On the other hand, TRP did not stimulate GH release from the bovine pituitary cells. MEL and CORT concentrations were not altered by TRP infusion. These results suggest that TRP induced GH release via the activation of serotonergic neurons in cattle.

Identification and characterization of lactic acid bacteria isolated from mixed pasture of timothy and orchardgrass, and its badly preserved silage

“…In addition, the low WSC levels and inadequate moisture contents in these grasses might cause poor quality. In the silages, LAB was detected at levels of < 10 5 –10 8 CFU/g (Kobayashi et al . 2010).…”

“…Mixed pastures of timothy at the late vegetative stage and orchardgrass at the heading stage were obtained from a local field at the Kozu dairy Farm (Shimonita, Gunma, Japan) on June 3, 2008 (first cutting grass), August 18, 2008 (second cutting grass) and October 29, 2008 (third cutting grass) as previously described (Kobayashi et al 2010). Silage was also prepared and stored in a small-scale fermentation system as previously described (Cai et al 1997).…”

“…The chemical compositions of mixed pastures and silages of timothy and orchardgrass were reported as previously described (Kobayashi et al 2010). Briefly, the first cutting grass contained high moisture (83.3% in fresh matter).…”

“…In the present study, we isolated and characterized the LAB strains inhabiting mixed pasture of timothy and orchardgrass and its silage, which were not preserved well with relatively higher pH values and lower lactic acid contents (Kobayashi et al 2010), taking particular interest in the relationship between LAB species and silage fermentation. To determine their taxonomic status, the isolates were also studied using 16S rDNA (ribosomal DNA) sequence and polymerase chain reaction (PCR)-based analyses.…”

Secretory pattern and regulatory mechanism of growth hormone in cattle

“…2006, 2008b) and frequent CSF sampling to measure the concentrations of neurotransmitters considered as regulators of GH secretion (Kasuya et al . 2010). …”