Rowett Research Institute

About: Rowett Research Institute is a based out in . It is known for research contribution in the topics: Rumen & Population. The organization has 2986 authors who have published 4459 publications receiving 239472 citations.

Non-starch polysaccharide degrading enzymes in poultry diets: influence of ingredients on the selection of activities

Abstract: The use of non-starch polysaccharide (NSP) degrading enzymes as feed additives has consolidated around their application to barley- and wheat-based diets for broiler chicks. Only with this application has a good understanding of their mode of action been developed and reasons for their effectiveness established. Most of the effect of NSP degrading enzymes can be ascribed to reversing the increase in digesta viscosity caused by polysaccharides leached from grain cell walls. Because digesta viscosity is greatest in the youngest birds and decreases with age, the value of supplementary enzymes for older birds is limited to secondary and less well defined effects. These include the release of nutrients otherwise entrapped in the cellular matrix of the feed. Maize alone amongst the commonly used cereals does not appear to release soluble NSPs in amounts sufficient to produce a detectable depression in performance. However, maize is not a homogeneous commodity and for some samples this may not be the case. Use of NSP degrading enzymes with legume seeds can improve nitrogen retention but effects are generally small. The structures of the soyabean NSPs, particularly the pectic polysaccharides, appear unique and existing commercial formulations are not recognised to contain enzymes capable of their degradation. With the present knowledge of soyabean polysaccharide structure, more informed formulation of enzyme products for use with soyabean should enable better responses to be achieved. When coupled with the lesser response from maize, this could allow the effective use of enzyme additives with maize-soyabean diets.

Modification of the methane production of the sheep by supplementation of ITS diet

Abstract: The normal process of methane production in ruminants is described and it is pointed out that about 8% of the energy of the diet is inevitably lost to the animal as methane. Experiments are described which show that fatty acids and other alkyl compounds added to the diet or infused into the rumen reduce methane production by, in some instances, as much as two-thirds. Although methanogenesis is markedly depressed, with some compounds there is little concomitant depression of the digestion of cellulose or indeed of the non-lipid organic constituents of the diet. The implications of these findings are discussed.

Evaluation of the effects of swainsonine, captopril, tangeretin and nobiletin on the biological behaviour of brain tumour cells in vitro

Abstract: Although intrinsic tumours of the brain seldom metastasize to distant sites, their diffuse, infiltrative–invasive growth within the brain generally precludes successful surgical and adjuvant therapy. Hence, attention has now focused on novel therapeutic approaches to combat brain tumours that include the use of anti-invasive and anti-proliferative agents. The effect of four anti-invasive agents, swainsonine (a locoweed alkaloid), captopril (an anti-hypertensive drug), tangeretin and nobiletin (both citrus flavonoids), were investigated on various parameters of brain tumour invasion such as matrix metalloproteinase (MMP) secretion, migration, invasion and adhesion. A standard cytotoxicity assay was used to optimize working concentrations of the drugs on seven human brain tumour-derived cell lines of various histological type and grade of malignancy. A qualitative assessment by gelatin zymography revealed that the effect of these agents varied between the seven cell lines such that the low grade pilocytic astrocytoma was unaffected by three of the agents. In contrast, downregulation of the two gelatinases, MMP-2 and MMP-9 was seen in the grade 3 astrocytoma irrespective of which agent was used. Generally, swainsonine was the least effective whereas the citrus flavonoids, particularly nobiletin, showed the greatest downregulation of secretion of the MMPs. Furthermore, captopril and nobiletin were most efficient at inhibiting invasion, migration and adhesion in four representative cell lines (an ependymoma, a grade II oligoastrocytoma, an anaplastic astrocytoma and a glioblastoma multiforme). Yet again, the effects of the four agents varied between the four cell lines. Nobiletin was, nevertheless, the most effective agent used in these assays. In conclusion, the differential effects seen on the various parameters studied by these putative anti-invasive agents may be the result of interference with MMPs and other mechanisms underlying the invasive phenotype. From these pilot studies, it is possible that these agents, especially the citrus flavonoids, could be of future therapeutic value. However, further work is needed to validate this in a larger study.