1Department of Livestock and Pasture Science, University of Fort Hare, Private Bag X1314, Alice, 5700, Republic of South Africa
2Department of Animal Science, University of Free State, P.O. Box 339, Bloemfontein, 9300, Republic of South Africa
*Corresponding Author: Z. Soji-Mbongo, Department of Livestock and Pasture Science, University of Fort Hare, Private Bag X1314, Alice, 5700, Republic of South Africa, Email: zsoji@ufh.ac.za
The onset of an industrial shift from grass to grain-supplemented feed has resulted in a rapid change in human diets, specifically in the ratio of n-6 to n-3 fatty acids; where saturated fats and n-6 fatty acid consumption increased at the expense of n-3 fatty acids. Although recent reports on global nutrition put emphasis on health-related fatty acids, the profiling of fat and fatty acids from different breeds reared by different farmers within the same feeding regime is not efficient.
Fat colour-related proximate fractions (total extractable intramuscular fat, fat-free dry matter and moisture content) and fatty acid profiles of Bonsmara, Beefmaster, Brangus, Hereford and Simbra A2 steers from different feedlot systems were evaluated.
Breed affected pentadecyclic, total saturated fatty acids (SFA) and docosahexanoic. Hereford had high pentadecyclic and SFA content while Simbra had high docosahexanoic content. Differences in SFA, monounsaturated fatty acids, polyunsaturated fatty acids, n-6, n-3, fatty acid ratios and desaturase index were observed between the white, creamy-white and creamy carcass fat colours. This study has shown that breed synthetic pathways and different feed ingredients which cause differences in the fatty acid composition of beef animals from feedlot-based production systems can be reflected through fat colour.
Breed, Desaturase index, Feedlot, Human diets, N-3, N-6
