HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: jas.2007-0172v1 85/12/3355    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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Gorocica-Buenfil, M. A. Articles by Loerch, S. C. Search for Related Content PubMed PubMed Citation Articles by Gorocica-Buenfil, M. A. Articles by Loerch, S. C.

Effect of low vitamin A diets with high-moisture or dry corn on marbling and adipose tissue fatty acid composition of beef steers

M. A. Gorocica-Buenfil^*, F. L. Fluharty^*, T. Bohn, S. J. Schwartz and S. C. Loerch^*

^* Department of Animal Sciences, The Ohio State University, Wooster 44691; and and Department of Food Science and Technology, The Ohio State University, Columbus 43210

¹ Corresponding author: loerch.1{at}osu.edu

Angus-cross steers (n = 165; 295 ± 16 kg of BW) were used evaluate the effect of low vitamin A diets with high-moisture corn (HMC) or dry corn (DC) on marbling and fatty acid composition. Steers were allotted to 24 pens (7 steers/pen), such that each pen had the same average initial BW. Treatments were randomly allotted to the pens. The experiment had a completely randomized design, with a 2 x 2 factorial arrangement of treatments: low vitamin A (Lo, no supplemental vitamin A) and HMC (LoHMC); LoDC; high vitamin A (Hi, supplemented with 2,200 IU of vitamin A/kg of DM) and HMC (HiHMC); and HiDC. Diets contained 76% corn, 10% corn silage, 11% protein supplement, and 3% soybean oil (DM basis). Samples of feed ingredients were collected for carotenoid analysis. Blood samples were collected for serum retinol determination. Steers were slaughtered after 145 d on feed. Carcass characteristics and LM composition were determined. Samples from the s.c. fat depot were analyzed for fatty acid composition. High-moisture corn had a greater vitamin A content, based on its carotenoid content, than DC (614 vs. 366 IU/kg of DM, P < 0.01). No vitamin A x corn type interactions were detected for feedlot performance, carcass characteristics, or serum, s.c. fat, or liver retinol concentration. Average daily gain, DMI, and G:F were not affected by vitamin A (P > 0.05). Marbling score and USDA quality grade were greater (P < 0.05) in Lo vs. Hi steers. Hot carcass weight, backfat, and yield grade were not affected by the treatments (P > 0.05). Vitamin A and corn type did not affect LM composition (DM, ash, CP, or ether-extractable fat, P > 0.05). Vitamin A supplementation increased (P < 0.06) serum retinol on d 112 and 145 and increased (P < 0.01) liver retinol at slaughter (Lo = 38.7 vs. Hi = 102.9 µg/g). The s.c. fat retinol concentrations were less (P < 0.01) for Lo (0.8 µg/g) than for Hi (1.4 µg/g) at slaughter. Cell diameter of adipocytes in the i.m. depot was not affected by dietary vitamin A (P > 0.05). A vitamin A x corn type interaction was observed (P < 0.05) for the s.c. fat cellularity. Feeding HMC increased the number of cells per square millimeter when Lo diets were fed (LoHMC = 128 vs. LoDC = 100 cells/mm², P < 0.05), but not when Hi diets were fed (HiHMC = 109 vs. HiDC = 111 cells/mm², P > 0.05). The CLA content of adipose tissue was not affected by the treatments. Regardless of the corn type used, feeding low vitamin A diets for 145 d to Angus-cross steers increased marbling and quality grade without affecting yield grade, animal health, or performance.

Key Words: beef • corn • marbling • vitamin A

This article has been cited by other articles:

				M. A. Gorocica-Buenfil, F. L. Fluharty, and S. C. Loerch Effect of vitamin A restriction on carcass characteristics and immune status of beef steers J Anim Sci, July 1, 2008; 86(7): 1609 - 1616. [Abstract] [Full Text] [PDF]