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.

Microbe-microbe interactions

Abstract: The previous chapters have shown that the rumen harbours a large number of different species of bacteria, phycomycete fungi and protozoa. Metabolic interactions between these different populations are essential for sustaining the microbial community and its collective activities. Products of the metabolism of some species of microorganisms are sources of energy for other species. Similarly, products of vitamin synthesis and nitrogen metabolism of some species become the sources of the vitamins and nitrogen compounds required by other microorganisms. The kinds and extents of these microbial interactions regulate the concentrations and activities of individual species and the qualitative and quantitative nature of the products of the fermentation of dietary substrates. Products that are used by, and are essential for, the ruminant include acetate, propionate and butyrate and the constituents of microbial cells. The amounts of CH4 and CO2 produced by the fermentation are determined by the same microbial interactions. The purpose of this chapter is to describe the major metabolic interactions that define the nature of the microbial community and its contributions to the host. Some of these interactions have, of necessity, been mentioned in connection with the topics of other chapters in the book.

Increased concentration of water-soluble carbohydrate in perennial ryegrass (Lolium perenne L.) : milk production from late lactation dairy cows

Abstract: Eight multiparous Holstein‐Friesian dairy cows in late lactation were used to investigate the potential of using perennial ryegrass with a high concentration of watersoluble carbohydrate (WSC) to increase the efficiency of milk production. After a pretreatment period on a common pasture, the cows were each given ad libitum access to one of two varieties of zero-grazed grass continuously for 3 weeks. Treatments were: high sugar (HS), an experimental perennial ryegrass variety bred to contain high concentrations of WSC; or control, a standard variety of perennial ryegrass (cv. AberElan) containing typical concentrations of WSC. The two grass varieties were matched in terms of heading date. All animals also received 4 kg day ‐1 standard dairy concentrate. Grass dry matter (DM) intake was not significantly different between treatments (11AE6 vs. 10AE7 kg DM day ‐1 ; s.e.d. 0AE95 for HS and control diets respectively), although DM digestibility was higher on the HS diet (0AE71 vs. 0AE64 g g ‐1 DM; s.e.d. 0AE23; P <0 AE01) leading to higher digestible DM intakes for that diet. Milk yield from animals offered the HS diet was higher (15AE3 vs. 12AE6 kg day ‐1 ; s.e.d. 0AE87; P <0 AE05) and, although milk constituent concentrations were unaffected by treatment, milk protein yields were significantly increased on the HS diet. The partitioning of feed N was significantly affected by diet, with more N from the HS diet being used for milk production (0AE30 vs. 0AE23 g milk N g ‐1 feed N; s.e.d. 0AE012; P <0 AE01) and less being excreted in urine (0AE25 vs. 0AE35; s.e.d. 0AE020; P <0 AE01). In a separate experiment, using the same grasses harvested earlier in the season, the fractional rate of DM degradation, measured by in situ and gas production techniques, was higher for the HS grass than for the control. It is concluded that increased digestible DM intakes of the HS grass led to increased milk yields, whereas increased efficiency of utilization of the HS grass in the rumen resulted in the more efficient use of feed N for milk production and reduced N excretion.

Determinants of meat quality: tenderness.

Abstract: Meat quality is a term used to describe a range of attributes of meat. Consumer research suggests that tenderness is a very important element of eating quality and that variations in tenderness affect the decision to repurchase. The present paper highlights recent information on the factors that affect tenderness. While the precise aetiology is not fully understood, a number of factors have been shown to affect tenderness. Of these factors, postmortem factors, particularly temperature, sarcomere length and proteolysis, which affect the conversion of muscle to meat, appear most important. However, it is now becoming clear that variation in other factors such as the muscle fibre type composition and the buffering capacity of the muscle together with the breed and nutritional status of the animals may also contribute to the observed variation in meat tenderness.