Home  »  Grass-Fed


The bottom line is that cattle are not “hard wired” to eat grain. Cattle are ruminant animals whose natural diet are grasses.

Studies have shown that a grain diet alters the acidic content of their rumen [1]. This alteration has been shown  to have resulted in a  virulent, acid resistant, Escherichia coli  bacteria species which occasionally results in food poisoning deaths from tainted beef.  Grass fed cattle (i.e. cattle that have not been fed grain or finished on grain) have a normal acid content in their rumen and much less likely to harbor this virulent Escherichia coli species [2,3].

In addition, there are numerous other health benefits to grass-fed beef over grain-fed beef:

  • Grass-fed beef has a similar fat content to chicken breasts.  Research over the last 3 decades shows a more favorable saturated fatty acid (SFA) lipid profile in grass fed beef than in grain fed beef [4,5,6].
  • Grass-fed beef has higher amounts of Omega -3 fatty acids, Conjugated linoleic acid (CLA), and Trans-vaccenic acid (TVA) as compared to grain fed beef [7,8,9,10,11].  Animal studies have shown CLA and TVA to have actions that reduce carcinogenesis, atherosclerosis, diabetes, and adipose accumulation [12,13,14,15,16,17,18].  Research has also shown that Omega-3 fatty acids probably help prevent atherosclerosis, heart attacks, depression, cancer, Alzheimer’s disease, and inflammation from rheumatoid arthritis [19,20,21,22,23,24,25,26,27].
  • Grass-fed beef also has higher levels in the precursors for Vit A and E and cancer fighting antioxidants such as glutathione (GT) and superoxide dismutase (SOD) as compared to grain fed beef [28,29,30,31,5,32,33,34,35,36,37].

It is Stonnington Farm’s belief that further research will continue to show and  highlight the nutritional benefits of natural, grass-fed beef.  Keep in mind,  the studies which have shown potential detrimental  effects of beef were substantially  based on grain-fed, feedlot, and  growth hormone enhanced beef (as this is the majority of beef available to the consumer)[38]…this cannot be a  fair comparison to the beef which is produced at Stonnington Farm.

1.  Diez-Gonzalez F, et.al. Grain feeding and the dissemination of acid-resistant Escherichia coli from cattle. Science. 1998;281(5383):1666-8.

2.  Tkalcic S, et.al. Effects of diet on rumen proliferation and fecal shedding of Escherichia coli O157:H7 in calves. J Food Prot. 2000;63(12):1630-6.

3.  Callaway TR, et.al. Forage feeding to reduce pre-harvest Escherichia coli populations in cattle, a review. J Dairy Sci. 2003;86(3):852-60.

4.  DeSmet S, et.al.  Meat fatty acid composition as affected by fatness and genetic factors: a review. Animal Research. 2004;53:81-98.

5. De la Fuente J, et.al.  Fatty acid and vitamin E composition of intramuscular fat in cattle reared in different production systems. Meat Science. 2009;82:331-7.

6.  Garcia PT, et.al.  Beef lipids in relation to animal breed and nutrition in Argentina. Meat Science. 2008;79:500-8.

7.  Wood JD, Enser M. Factors influencing fatty acids in meat and the role of antioxidants in improving meat quality. British Journal of Nutrition. 1997;78:S49-S60.

8. French P, et.al.  Fatty acid composition, including conjugated linoleic acid of intramuscular fat from steers offered grazed grass, grass silage or concentrate-based diets. Journal Animal Science. 2000;78:2849-55.

9.  Ducket SK, et.al. Effects of time on feed on beef nutrient composition. Journal Animal Science. 1993;71:2079-88.

10.  Rule DC, et.al. Comparison of muscle fatty acid profiles and cholesterol concentrations of bison, cattle, elk, and chicken. Journal Animal Science. 2002;80:1202-11.

11.  Mandell IB, et.al. Effects of diet and slaughter endpoint on carcass composition and beef quality in Charlois cross steers fed alfalfa silage and (or) high concentrate diets. Canadian Journal of Animal Science. 1997;77:403-14.

12.  IP C, et.al. Conjugated linoleic acid. Cancer Supplement. 1994;74(3):1050-4.

13.  Kritchevsky D, et.al. Influence of conjugated linoleic acid (CLA) on establishment and progression of atherosclerosis in rabbits. Journal American Collection of Nutrition. 2000;1994):472S-7S.

14.  Steinhart H, et.al. Identification and analysis of conjugated linoleic acid isomers (CLA). European Journal of Medicine. 1996;20(8):370-2.

15.  Dugan MER, et.al. The effects of feeding conjugated linoleic acid on subsequent port quality. Canadian Journal of Animal Science. 1999;79:45-51.

16.  Park Y, et.al. Effect of conjugated linoleic acid on body composition in mice. Lipids. 1997;32:853-8.

17.  Sisk M, et.al. Dietary conjugated linoleic acid reduces adiposity in lean but not obese Zucker rats. Journal of Nutrition. 2001;131:1668-74.

18.  Smedman A, Vessby B. Conjugated linoleic acid supplementation in humans – Metabolic effects. Journal of Nutrition. 2001;36:773-81.

19.  Simopoulos A. Omega-3 fatty acids in health and disease and in growth and development. american Journal of Clinical Nutrition. 1991;54:438-63.

20.  Thomas BJ. Efficiency of conversion of alpha-linolenic acid to long chain n-3 fatty acids in man. Current Opinion in Clinical Nutrition and Metabolic Care. 2002;5(2)127-32.

21.  Connor WE. Importance of n-3 fatty acids in health and disease. American Journal of Clinical Nutrition. 2000;71:171S-5S.

22.  Kremer JM, et.al. Dietary Omega-3 and Omega-6 fatty acids: biological effects and nutritional essentiality. New York: Plenum Press; 1989. Different doses of fish oil fatty acid ingestion in active rheumatoid arthritis: a prospective study of clinical and immunological parameters.

23.  DiGiacomo RA, et.al. Fish-oil dietary supplementation in patients with Raynaud’s Phenomenon: A double-blind, controlled, prospective study. The American Journal of Medicine. 1989;86:158-64.

24.  Kalmijn S. Dietary fat intake and the risk of incident dementia in the Rotterdam Study. Annals of Neurology. 1997;42(5):776-82.

25.  Yehuda S, et.al. Essential fatty acids preparation (SR-3) improves Alzheimer’s patients quality of life. International Journal of Neuroscience. 1996;87(3-4):141-9.

26.  Hibbeln JR. Fish oil consumption and major depression. The Lancet. 1998;351:1213.

27.  Hibbeln JR, Salem N. Dietary polyunsaturated fatty acids and depression: when cholesterol does not satisfy. American Journal of Clinical Nutrition. 1995;62:1-9.

28.  Dunne PG, et.al. Colour of bovine subcutaneous adipose tissue: A review of contributory factors, associations with carcass and meat quality and its potential utility in authentication of dietary history. Meat Science. 2009;81(1):28-45.

29.  Simmone AH, et.al. Consumer acceptability and beta-carotene content of beef as related to cattle finishing diets. Journal of food Science. 1996;61:1254-6.

30.  Duckett SK, et.al. Corn oil or corn grain supplementation to steers grazing endophyte-free tall fescue. II. Effects on subcutaneous fatty acid content and lipogenic gene expression. Journal of Animal Science. 2009;87:1120-8.

31.  Yang A, et.al. Effect of Vitamin E supplementation on alpha-tocopherol and beta-carotene concentrations in tissues from pasture and grain-fed cattle. Meat Science. 2002;60(1):35-40.

32.  Descalzo AM, et.al. Influence of pasture or grain-based diets supplemented with Vit E on antioxidant/oxidative balance of Argentine beef. Journal of Meat Science. 2005;70:35-44.

33.  Arnold RN, et.al. Effect of long or short-term feeding of alfa-tocopherol acetate to Holstein and crossbred beef steers on performance, carcass characteristics, and beef color stability. Journal Animal Science. 1992;70:3055-65.

34.  Descalzo AM, Sancho AM. A review of natural antioxidants and their effects on oxidative status, odor and quality of fresh beef in Argentina. Meat Science. 2008;79:423-36.

35.  Insani EM, et.al. Oxidative stability and its relationship with natural antioxidants during refrigerated retail display of beef produced in Argentina. Meat Science. 2008;79:444-52.

36.  Descalzo AM, et.al. Antioxidant status and odor profile in fresh beef from pasture or grain-fed cattle. Meat Science. 2007;75:299-307.

37.  Gatellier P, et.al. Effect of diet finishing mode (pasture or mixed diet) on antioxidant status of Charolais bovine meat. Meat Science. 2004;67:385-94.

38.  Swan SH, et.al. Semen quality of fertile US males in relation to their mother’s beef consumption during pregnancy. Hum Reprod. 2007;22(6):1497-502.