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This Article Full Text (PDF) All Versions of this Article: jas.2007-0433v1 87/6/2089    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Larraín, R. E. Articles by Reed, J. D. Search for Related Content PubMed PubMed Citation Articles by Larraín, R. E. Articles by Reed, J. D.

Finishing steers with diets based on corn, high-tannin sorghum, or a mix of both: feedlot performance, carcass characteristics, and beef sensory attributes

R. E. Larraín^*,, D. M. Schaefer^*, S. C. Arp^*, J. R. Claus and J. D. Reed^*

^* Department of Animal Sciences, University of Wisconsin, Madison 53706 , Departamento de Ciencias Animales, Pontificia Universidad Católica de Chile, Santiago, Chile Meat Science and Muscle Biology Laboratory, University of Wisconsin, Madison 53706

jdreed{at}wisc.edu

Abstract

The objective of this work was to compare feedlot performance, carcass characteristics, and beef sensory attributes from steers finished with diets based on corn, high-tannin sorghum (HTS), and a mix of both grains. Angus crossbred steers (n = 11 steers per treatment, initial BW = 404 ± 18 kg) were finished on diets containing 765 g/kg DM of either corn, HTS, or a 1:1 mix of corn and HTS. Final BW (P < 0.01), ADG (P < 0.001), and G:F (P < 0.01) were reduced in steers fed HTS when compared to steers fed corn. Steers fed the Mixed diet had higher G:F than the average between corn and HTS (P = 0.04), which indicates that mixing corn and HTS had positive associative effects. Estimated NE_m of HTS was 1.91 and estimated NE_g was 1.35 Mcal/kg DM. Hot carcass weight (P < 0.01), trimmed carcass weight (P < 0.01), yield grade (P = 0.04), and 12^th rib fat thickness (P = 0.01) were less in steers fed HTS than in those fed corn. Estimated percentage of HCW as boneless, closely-trimmed retail cuts was greater in steers fed HTS compared to those fed corn (P = 0.02) but, due to the lower HCW, estimated amount of boneless, closely-trimmed retail cuts was less in steers fed HTS than in those fed corn (P = 0.03). Steers fed HTS had higher pH on LM (P = 0.02) than steers fed corn, but the difference was small (5.42 ± 0.02 vs. 5.36 ± 0.02, respectively) and within the range of normal beef pH. Diet had no effect on Warner-Bratzler shear values (P 0.72). Multivariate analysis of variance indicated a difference in sensory attributes of beef from corn and HTS steers (Wilks’ Lambda P = 0.04). When evaluating each sensory attribute independently, panelists found beef from steers fed HTS to be less juicy (P < 0.01), less tender (P = 0.03), and more cooked (P < 0.01) than beef from animals fed corn. Data from this study indicate that by using a 1:1 mix of HTS and corn it is possible to finish steers to similar weight and carcass quality as by using a corn-based diet. Also, total replacement of corn by HTS in the diets produced lighter and leaner animals. Total replacement of corn by HTS in the finishing diet changed beef sensory attributes, reducing the perception of beef tenderness and juiciness by panelists but without changing instrumental tenderness.

Key Words: beef • carcass • corn • sorghum • steers • tannins