Laurie Huxley

Background

The relationship between dietary fat and coronary heart disease (CHD) are well established and many studies have contributed to the advice that saturated fatty acids (SFA) should not supply >0.10 of total energy intake, that polyunsaturated fatty acids (PUFA):SFA should be >0.45, and that n-6:n-3 PUFA should be <4 for the whole diet.  Despite the fact that the ruminant diet is PUFA-rich, ruminant products are rich in SFA due to bacterial lipolysis and subsequent biohydrogenation of released esterified PUFAs within the rumen (Scollan et al., 2006; Kim et al., 2008; Huws et al., 2011). 

An abundance of esterified PUFAs inhibits biohydrogenation, thus ruminal lipases offer potentially novel feed supplements allowing increased incorporation of PUFA into meat and milk.  At present information on the lipolytic capacity of rumen microbes is scarce.   A recent metagenomic based study by Liu et al. (2009) isolated 3 novel rumen lipases (we have kindly been donated these lipases). We have also isolated 9 novel rumen lipases from metagenomic libraries within our “Plant based strategies to improve the nutritional value of beef for the consumer; Probeef” and “Improving the safety of beef and beef products for the consumer in production and processing; Prosafebeef” projects.

The experiments within this MSc project aim to establish whether the isolated lipases offer a novel strategy of enhancing the fatty acid quality of ruminant products through dietary supplementation in vitro.

Objective

To investigate the effects of addition of these isolated lipases on ruminal lipid metabolism in simple in vitro experiments.

Value to industry

This research will provide proof of principle data with respect to plausibility of pursuing the addition of these lipases to the ruminant diet in order to improve the fatty acid quality of ruminant products.