|Neel, James - Jim|
Submitted to: American Society of Animal Science
Publication Type: Proceedings
Publication Acceptance Date: 6/30/2005
Publication Date: 7/24/2005
Citation: Sonon, R.N., Duckett, S.K., Neel, J.P., Sellapan, S., Fontenot, J.P., Clapham, W.M. 2005. Effects of stocker growth rate and finishing diet on beef longissimus vitamin and mineral composition. #W75, J. Anim. Sci., Vol. 83, Suppl. 1, p. 275.
Technical Abstract: Longissimus muscle (LM) of Angus-cross steers (n=68, year 1; n=63, year 2) was assayed to determine the effects of winter stocker growth rate (LOW, MED, or HIGH) and finishing diet (corn silage-concentrate, CONC or pasture, PAST) on the fat-soluble vitamins (retinol, '-carotene and '-tocopherol), water-soluble vitamins (thiamine and riboflavin), and mineral (Ca, Mg, K, Zn and Fe) content of this tissue. Results showed that LM retinol content did not differ between years (P = 0.132), stocker growth rates (P = 0.727) and finishing diets (P = 0.286). However, '-carotene content of LM was higher (P < 0.01) in year 2 whereas, '-tocopherol content was greater (P = 0.033) in the LM from year 1. The LM of PAST had about 1.4 and 3.3 times greater (P < 0.01) '-carotene and '-tocopherol contents, respectively than that of CONC. A year by growth rate by finishing diet interaction occurred for LM thiamine content (P = 0.060). In year 1, thiamine content was greater (P < 0.05) for MED than LOW finished on CONC and greater (P < 0.05) for HIGH than MED or LOW among PAST with no observed differences between stocker growth rates in year 2. Regardless of year, thiamine content was about 105% greater (P < 0.05) for PAST than CONC. Riboflavin content of LM from PAST was 193% greater (P < 0.01) than that of CONC. Mineral composition of LM varied between years (P ' 0.05) with year 1 showing higher content for Ca whereas, year 2 exhibiting greater contents for Mg, Zn, and Fe. PAST LM Ca content was greater (P < 0.01) compared with that of CONC (7.89 vs 5.72 mg/100 g tissue) with LM Mg content showing a similar trend (P = 0.076). On LM K content, PAST was greater (P < 0.01) than CONC when steers were grown at HIGH but no differences between diets were observed from those grown at LOW and MED. PAST appears to support greater storage of '-carotene, '-tocopherol, thiamine and riboflavin, and Ca and Mg in beef longissimus tissue.