• Adding value to cull cow beef

      O'Donovan, Michael; Minchin, William; Buckley, Frank; Kenny, David A.; Shalloo, Laurence (Teagasc, 01/08/2009)
      This project addressed the prospects of increasing the value of cull cow beef and examined the potential of a number of different management and dietary strategies. In Ireland, the national cow herd contributes 350,000 animals to total beef production annually, which represents 22% of all cattle slaughtered (DAF, 2007). A dominant feature of beef production in Ireland is the disposal of cows from the dairy and beef industries, the time of year at which culling occurs influences the number of cows available for slaughter. Suitability of a cow for slaughter is generally not a consideration for dairy or beef farmers.
    • An examination of the molecular mechanisms controlling the tissue accumulation of conjugated linoleic acid (CLA) in cattle

      Waters, Sinead M.; Hynes, A.C.; Killeen, Aideen P.; Moloney, Aidan P; Kenny, David A. (Teagasc, 01/12/2008)
      Long chain n-3 polyunsaturated fatty acids (n-3 PUFA) and conjugated linoleic acid (CLA) have demonstrable and potential human health benefits in terms of preventing cancer, diabetes, chronic inflammation, obesity and coronary heart disease. Supplementation of cattle diets with a blend of oils rich in n-3 PUFA and linoleic acid have a synergistic effect on the accumulation of ruminal and tissue concentrations of trans vaccenic acid (TVA), the main substrate for ?-9 desaturase which is responsible for de novo tissue synthesis of the cis 9, trans 11 isomer of CLA. This dietary strategy translates into increases in milk concentrations of CLA in dairy cows; however, concentrations in the muscle of beef animals have not always been increased. There is an apparent paradox in that n-3 PUFA supplementation enhances ruminal synthesis of trans-vaccenic acid (TVA), but then inhibits its conversion to CLA possibly through altering the activity of ?-9 desaturase. Recently, the promoter regions of the bovine ?- 9 desaturase gene has been isolated and analysed and has been shown to contain a conserved PUFA response region.