Lucerne Plant Extract Improves Beef Fatty Acids And Meat Quality
Supplementing beef diets with a lucerne based extract will enhance the health beneficial fatty acids in beef animals when finished on grass silage or concentrates, according to teams at Aberystwyth University and the University of Bristol. Feeding incremental plant extract to grass-silage-fed beef steers resulted in enhancement of the fatty acid 18:3n-3 and increased the longer chain derivatives eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), resulting in improved polyunsaturated:saturated fat and n-6:n-3 ratios.
A study by teams at Aberystwyth University and the University of Bristol also found that, within the concentrate treatments, feeding a lipid-rich plant extract also increased 18:3n-3 and EPA.
“We have previously demonstrated the ability of a lipid-rich plant extract to enhance levels of polyunsaturated fatty acid (PUFA) in beef,” Eun Joong Kim told delegates at the 2010 British Society of Animal Science’s annual conference, held at Queen’s University, Belfast.
“The plant extract (PX) is developed from the liquid fraction extracted from fresh lucerne and then heat-treated and dried. The PX has a high degree of rumen protection.
“And our study investigated the effect of incremental inclusion of PX in steers fed on grass silage relative to concentrate on the fatty acid composition of beef and meat quality. Effects of additional vitamin E within the concentrate were also investigated,” he explained.
Following summer grazing on perennial ryegrass/white clover swards, 40 Belgian-Blue × Holstein steers were allocated to one of five dietary treatments: grass silage ad lib (GS); grass silage ad lib plus 75 g PX/dry matter intake (DMI; GS-LPX); grass silage ad lib plus 150 g PX/DMI (GSHPX); restricted barley straw and control concentrate (40:60 on a DM basis; S-CC); and 5) restricted barley straw and concentrate with PX (25% in concentrate on a DM basis) (40:60 on a DM basis; S-PXC) and additional vitamin E.
The PX was manufactured by Désialis–France Luzerne, France. Liveweight was monitored every 28 days and the liveweight gain was used to modify feed intake of the S-CC and S-PXC animals to achieve a similar growth rate to those fed on ad lib forage. Animals were slaughtered when they achieved fat class 3 and samples of longissimus thoracis et lumborum were taken at 48 hours post-mortem for fatty acid analysis, vitamin E analysis, and 10-day aged samples for shelf life studies in modified atmosphere packs.
“And we found no difference in liveweight gain between treatments, averaging 1.1 kg/d whilst conformation score and fatness score were also,” said Dr Kim. “Small differences in carcass weight were noted, but total fatty acids and amounts of the major saturated fatty acids were not different.”
Feeding grass silage relative to concentrate increased deposition of n-3 relative to n-6 PUFA. And incremental PX on grass silage resulted in additional deposition of 18:3n-3 (and 18:2n-6) and longer chain derivatives EPA and DHA resulting in improvements in P:S and n-6:n-3 ratio. Additional vitamin E in the diet of SPXC increased its content in muscle impacting on lipid stability (TBARS),” he added.