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.

Excretion of chromium sesquioxide administered as a component of paper to sheep.

Abstract: It has been shown (Corbett, Greenhalgh & McDonald, 1958; Corbett, Greenhalgb & Florence, 1959) that the diurnal variation in the concentration of chromium sesquioxide (Cr203) in the faeces of ruminants that have received regular concentrated doses of this marker is due primarily to uneven mixing of the oxide with the contents of the reticulo-rumen and to its passage from this organ in advance of the food residues it is intended to mark. I t is unlikely, however, that a better marker substance than Cr203 will be found (Corbett, Greenhalgh, Gwynn & Walker, 1958). Various sampling techniques have been suggested to obtain an unbiased estimate of the mean concentration of Cr203 in faeces. Kane, Jacobson & Moore (1952) proposed that samples of faeces should be obtained from cows, directly from the rectum if necessary, at the time or times when the concentration of Cr,O, is found to be close to the mean value for the 24 h period. This technique is valid only if the pattern of Cr,O, excretion is constant from day to day, which will be so only when the conditions of management and the feeding behaviour of the animals are strictly uniform. The time of sampling was studied also by Lambourne (1957), who concluded that, if the marker doses were administered and the faecal samples were taken twice daily at intervals of about 9 and 15 h, the mean marker concentration in the samples would yield an unbiased estimate of the general concentration of marker in the faeces. Raymond & Minson (1955) described how representative samples of faeces of a group of grazing sheep could be obtained from the sward, and a similar technique has been used with grazing cattle (Corbett & Greenhalgh, 1960). Any sampling procedure would be more reliable if the passage of Cr,O, through the alimentary tract and its excretion could be made more regular. Balch, Reid & Stroud (1957) concluded that Cr203 should be administered to animals at pasture before the main periods of grazing to ensure that the maximum passage of Cr,03 from the reticulo-rumen coincided with the maximum passage of dry matter. They also suggested that Cr,O, should be given in a form in which it would be carried into the rumen, for example as a ‘macaroni’, the form suggested by Edin, KihlCn & Nordfeldt (1944-5). In earlier work Crampton & Lloyd (195 I ) found that the digestibility of foodstuffs by sheep could be determined satisfactorily from the concentrations of Cr,O, in faeces when the oxide was given in a small quantity of ground food, but not when administered in more concentrated forms. Pigden & Brisson (1956) and Brisson, Pigden & Sylvestre (1957) found that Cr,O, was excreted more regularly

Iron, copper and fetal development.

Abstract: Pregnancy is a period of rapid growth and cell differentiation for both the mother and fetus. Consequently, it is a period when both are vulnerable to changes in dietary supply, especially of those nutrients that are marginal under normal circumstances. In developed countries this vulnerability applies mainly to micronutrients. Even now, Fe deficiency is a common disorder, especially in pregnancy. Similarly, Cu intake in the UK population is rarely above adequate levels, which is a matter of some concern, both in terms of public health and possible clinical consequences. In early studies it was shown that lambs born to mothers on Cu-deficient pastures develop 'swayback,' with neurological and muscular symptoms that cannot be reversed by postnatal supplementation. More recently, rat studies have shown that responses such as the 'startle' response are lost in offspring of Cu-deficient mothers. Data have shown that prenatal Fe deficiency results in increased postnatal blood pressure, even though the offspring have normal dietary Fe levels from birth. These observations emphasise the importance of Fe and Cu in growth and development. In the present review the importance of these metals and the consequences, both short term and long term, of deficiency will be discussed and some possible mechanisms whereby these effects may be generated will be considered.

Eubacterium pyruvativorans sp. nov., a novel non-saccharolytic anaerobe from the rumen that ferments pyruvate and amino acids, forms caproate and utilizes acetate and propionate.

Abstract: Two similar gram-positive rods were isolated from 10(-6) dilutions of ruminal fluid from a sheep receiving a mixed grass hay/concentrate diet, using a medium containing pancreatic casein hydrolysate as sole source of carbon and energy. The isolates did not ferment sugars, but grew on pyruvate or trypticase, forming caproate as the main fermentation product and valerate to a lesser extent. Acetate and propionate were utilized. One of these strains, I-6T, was selected for further study. Strain I-6T was a non-motile coccal rod, 1.2 x 0.4 microm, with a gram-positive cell wall ultrastructure and a G + C content of 56.8 mol%. No spores were visible, and strain I-6T did not survive heating at 80 degrees C for 10 min. Its rate of NH3 production was 375 nmol (mg protein)(-1) min(-1), placing it in the 'ammonia-hyperproducing' (or HAP) group of ruminal bacteria. 16S rDNA sequence analysis (1296 bases) indicated that it represents a novel species within the 'low-G + C' gram-positive group, for which the name Eubacterium pyruvativorans sp. nov. is proposed. Among cultivated bacteria, strain I-6T was most closely related (89% identity) to other asaccharolytic Eubacterium isolates from the mouth and the rumen. It was 98% identical to uncultured bacterial sequences amplified by others from ruminal digesta.

Divergent mechanisms of cis9, trans11-and trans10, cis12-conjugated linoleic acid affecting insulin resistance and inflammation in apolipoprotein E knockout mice: a proteomics approach.

Abstract: Conjugated linoleic acids (CLA) affect atherogenesis, but mechanisms are not well understood. We explored how two isomers of CLA, cis9, trans11-CLA and trans10, cis12-CLA, affected lipid and glucose metabolism, as well as hepatic protein expression, in apolipoprotein E knockout mice. After 12 wk of intervention, plasma triglyceride, NEFA, and glucose concentrations were significantly higher in the trans10, cis12-CLA group, whereas plasma triglyceride, NEFA, glucose, and insulin concentrations were significantly lower in the cis9, trans11-CLA group, compared with control mice consuming linoleic acid. Proteomics identified significant up- or down-regulation of 113 liver cytosolic proteins by either CLA isomer. Principal component analysis revealed that the treatment effect of cis9, trans11-CLA was mainly explained by the up-regulation of different posttranslational forms of heat shock protein 70 kD. In contrast, the treatment effect of trans10, cis12-CLA was mainly explained by up-regulation of key enzymes in the gluconeogenic, beta-oxidation, and ketogenesic pathways. Correlation analysis again emphasized the divergent effects of both CLA isomers on different pathways, but also revealed a linkage between insulin resistance and increased levels of hepatic serotransferrin. Thus, our systems biology approach provided novel insights into the mechanisms by which individual CLA isomers differentially affect pathways related to atherogenesis, such as insulin resistance and inflammation.