The effect of anaerobic digestate derived composts on the metabolite composition and thermal behaviour of rosemary.

The study reports on the effect of anaerobic digestate derived composts on the metabolite composition and thermal behaviour of rosemary (Rosmarinus officinalis L.). Plants were cultivated in semiarid soil under four different fertiliser treatments (composts of anaerobic digested cattle (C) or pig slurry (P) at 30t/ha and 60 t/ha, and two control treatments (inorganic fertiliser and no fertiliser application). Samples of leaves and stems were analysed to investigate the effect of treatment on chemical composition and thermochemical properties. Three orthogonal analytical approaches were used, namely: Fourier transform mid infrared spectroscopy (FTIR), gas chromatography/mass spectrometry (GC/MS) and thermochemical gravimetric analysis (TGA). FTIR and GC/MS showed fertiliser treatment resulted in tissue specific changes in sample metabolite composition. Fertiliser treatment was detected to change the thermogravimetric properties of the leaf samples and from inorganic and composted pig slurry digestate treatments had greater ash content and lower proportions of fixed carbon compared with samples from the unfertilised control treatment. This study provides information on how the composition of rosemary might be altered by fertiliser application in regions of poor soil, and has implications for biomass quality when rosemary is grown on semi-wild sites for the purpose of soil improvement.

Measurement of rumen dry matter and neutral detergent fiber degradability of feeds by Fourier-transform infrared spectroscopy.

This study explored the potential of partial least squares (PLS) and Fourier-transform infrared spectroscopy (FTIR) to predict rumen dry matter (DM) and neutral detergent fiber (NDF) degradation parameters of a wide range of feeds for ruminants, as an alternative to the in situ method. In total, 663 samples comprising 80 different feed types were analyzed. In situ DM and NDF degradabilities were determined as follows: effective degradability (ED), rumen soluble fraction (A), degradable but not soluble fraction (B), rate of degradation of the B fraction (C), and indigestible NDF (iNDF). Infrared spectra of dry samples were collected by attenuated total reflectance from 600 to 4000cm(-1). Feeds were randomly classified into 2 subsets of samples with representation of all feed types; one subset was used to develop regression models using partial least squares, and the second subset was used to conduct an external validation of the models. This study indicated that universal models containing all feed types and specific models containing concentrate feeds could provide only a relatively poor estimation of in situ DM degradation parameters because of compositional heterogeneity. More research, such as a particle size distribution analysis, is required to determine whether this lack of accuracy was due to limitations of the FTIR approach, or simply due to methodological error associated with the in situ method. This latter hypothesis may explain the low accuracy observed in the prediction of degradation rates if there was physical leakage of fine particles from the mesh bags used during in situ studies. In contrast, much better predictions were obtained when models were developed for forage feeds alone. Models for forages led to accurate predictions of DMA, DMB, NDFED, and NDF concentration (R(2)=0.91, 0.89, 0.85, and 0.79, standard error = 4.34, 5.97, 4.59, and 4.41% of DM, respectively), and could be used for screening of DMED, NDFC, and iNDF. These models relied on certain regions of the FTIR spectrum (900-1150 and 1500-1700cm(-1)), which are mainly compatible with absorption of plant cell wall components, such as cellulose, pectin, lignin, cutin, and suberin, but also with nonstructural carbohydrates and certain active compounds. In conclusion, FTIR spectroscopy could be considered a low-cost alternative to in situ measurements in feed evaluation.

Estimation of feed crude protein concentration and rumen degradability by Fourier-transform infrared spectroscopy.

Currently, rapid methods are needed for feed analysis. This study examined the potential of Fourier-transform infrared (FTIR) spectroscopy to predict the nutritional value of a wide range of feeds for ruminants, as an alternative to the in situ technique. Moreover, we investigated whether universal equations could be developed that would allow the low-cost determination of crude protein (CP) concentrations and their kinetics of degradation into the rumen. Protein nutritional values of 663 samples comprising 80 different feed types were determined in terms of concentrations of CP, water-soluble CP (CP(WS)), total-tract mobile bag CP digestibility (CP(TTD)), and in situ CP degradability, including the rumen soluble fraction (CP(A)), the degradable but not soluble fraction (CP(B)), rate of CP(B) degradation (CP(C)), effective degradability (CP(ED)), and potential degradability (CPPD). Infrared spectra of dry samples were collected by attenuated total reflectance from 4000 to 600 cm(-1). Models were developed by partial least squares (PLS) regression in a randomly selected subset of samples, and the precision of the equations was confirmed by using an external validation set. Analysis by FTIR spectroscopy was sufficiently sensitive to allow the accurate prediction of sample CP concentration (R(2)=0.92) and to classify feeds according to their CPWS concentrations using universal models (R(2)=0.78) that included all sample types. Moreover, substantial improvements in predictions were observed when samples were subdivided in groups. Models for forages led to accurate predictions of CP(WS) and fractions CP(A) and CP(B) (R(2)>0.83), whereas models for CP(TTD) and CP(ED) could be used for screening purposes (R(2)>0.67). This study showed that models for protein-rich concentrates alone could also be used for screening according to the feed concentrations of CP(WS), CP(TTD), CP(ED), CP(A), and CP(B), but models for energy-rich concentrates gave relatively poor predictions. The general difficulty observed in predicting CP(C) is because of a low correlation between FTIR spectra and the kinetics of CP degradation, which may be the result of large variation in the reference method (i.e., in situ degradation studies) and perhaps also because of the presence of compounds that can modify the CP degradation pattern in the rumen. In conclusion, FTIR spectroscopy should be considered as a low-cost alternative in the feed evaluation industry.

Effect of scrapie incubation on the concentrations of plasma amino acids and L-lactate in infected lambs.

Three groups of two weeks old growing lambs differing in PrP genotype were orally inoculated with scrapie and maintained under defined conditions until disease endpoint. Plasma concentrations of free alanine and serine, but not L-lactate increased during the final 6 months of the disease. At the same time, plasma concentrations of several essential and non-essential free amino acids decreased linearly, indicating reduced feed intake and are consistent with, but occurring before establishment, of cachexia. These observations are consistent with those reported previously from studies on cattle infected with BSE and with the hypothesis that scrapie may effect peripheral tissue metabolism.

Normal ranges and temporal variation in plasma concentrations of L-lactate and free amino acids in adult sheep.

To determine baseline variation in blood plasma concentrations of free amino acids and l-lactate, samples were collected at a single time point from nine flocks of different breeds of ewes at a common physiological stage and monthly from one flock of crossbred mule ewes over a 12 month period. Significant differences were detected between time points in the concentrations of all plasma metabolites. With few exceptions prion protein genotype had no significant effect on the plasma metabolite concentrations measured.

Changes in plasma metabolites and muscle glycogen are correlated to bovine spongiform encephalopathy in infected dairy cattle.

During the clinical phase of bovine spongiform encephalopathy (BSE), a significant decrease was observed in the ratio of muscle glycogen to plasma L-lactic acid concentrations in BSE infected field case and experimentally infected dairy cattle compared with healthy control cattle (P<0.001), this being due to changes in the concentration of both metabolites in the BSE infected cattle compared with the control group. Furthermore, the concentration of plasma alanine was significantly increased (P<0.05) in the infected animals. No significant difference was detected between these two groups in the ratio of hepatic glycogen to plasma lactate. We infer that BSE infected cattle exhibit signs of altered energy metabolism and when applied in conjunction with changes in other metabolite biomarkers these changes may be useful for discriminating BSE infected cattle from healthy cattle or those suffering with other disorders or diseases.

Isolation and characterization of a genomic region upstream from the ovine Na+/d-glucose cotransporter (SGLT1) cDNA.

d-Glucose and non-metabolisable analogues of D-glucose regulate the expression of intestinal SGLT1 at both transcriptional and post-transcriptional levels. In order to investigate the molecular mechanisms involved in the transcriptional regulation of the ovine intestinal SGLT1 gene, we have isolated an upstream element of about 1 kb in size. This DNA fragment contains a TATA box motif, 48 bp upstream of the transcriptional start site and includes transcription factor binding sites for HNF-1 and AP-2. We have shown that the ovine SGLT1 promoter fragment can drive the transcription of a reporter gene when transfected into the epithelial cell lines STC-1 and LLC-PK1, which endogenously express SGLT1. Deletion analyses of the promoter indicate that -66/+21 bp proximal sequence directs the highest level of reporter gene activity. There are one and possibly two sites of transcriptional suppression.

Expression of genes involved in phycocyanin biosynthesis following recovery of Synechococcus PCC 6301 from nitrogen starvation, and the effect of gabaculine on cpcBa transcript levels.

The effect of the tetrapyrrole biosynthesis inhibitor gabaculine on the expression of specific genes involved in phycocyanin biosynthesis was investigated in cultures of Synechococcus PCC6301 in nitrogen chlorosis, and during recovery to nitrogen sufficiency. Patterns of transcription of the cpcBA (phycocyanin subunits), hemL (glutamate semialdehyde aminotransferase) and hemB (aminolaevulinate dehydratase) genes were visualised by Northern blotting and gene product formation for cpcBA, hemL and the gene for glu tRNA synthetase were monitored by Western blotting. Inhibition of phycobilin biosynthesis by gabaculine greatly decreased production of phycocyanin protein and of cpcBA transcript, indicating a tight coordination of apoprotein biosynthesis with chromophore supply at the level of transcription. Different patterns of response were observed with the other genes at the level of transcript formation or gene product synthesis.