Evaluation of tenderness aspects of three muscles from carcasses of Bos Indicus cross cattle subjected to oral vitamin D3 supplementation and postmortem electrical stimulation /
The study objectives were to investigate the treatments (TRT) of supplementation of vitamin D₃ (VITD, n=39) or normal finishing (CONT, n=36) and two supplement removal days (SRD) of 0 d (NONE, n=37, with n=18 CONT, and n=19 VITD) or 7 d (SEVN, n=38, with n=18 CONT and n=20 VITD) on feedyard and carc...
| Main Author: | |
|---|---|
| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
2000.
|
| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=731981421&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The study objectives were to investigate the treatments (TRT) of supplementation of vitamin D₃ (VITD, n=39) or normal finishing (CONT, n=36) and two supplement removal days (SRD) of 0 d (NONE, n=37, with n=18 CONT, and n=19 VITD) or 7 d (SEVN, n=38, with n=18 CONT and n=20 VITD) on feedyard and carcass characteristics, blood and muscle calcium levels, liver vitamin D₃ levels, and tenderness components (Warner-Bratzler shear force and SDS-PAGE) of feedlot steers and heifers. Steers (n=59) and heifers (n=16) were allocated randomly to TRT and SRD. Supplementation of VITD was at a level of 3 x 10⁶ IU/head/day for 5 d. Blood calcium and liver vitamin D₃ samples were collected at trial initiation and each slaughter period. All carcasses were high-voltage electrically stimulated. Longissimus lumborum (LL), Triceps brachii (TB), and Semitendinosis (ST) muscle samples were collected prerigor for SDS-PAGE and muscle calcium levels. Warner-Bratzler shear force (WBS) was performed at d 2, 4, 6, 8, and 14 of aging on 2.54 cm LL, TB, and ST samples, while SDS-PAGE was analyzed on prerigor and 8 d aged LL and TB steaks by optical density (OD) of gel bands. Vitamin D₃ increased blood calcium and muscle calcium at SEVN while liver vitamin D₃ levels were higher at NONE for VITD. No liver level differences were noted at SEVN. There were no TRT differences in WBS at NONE for any of the muscles. WBS was lower (P < .05) for LL and TB at 2 and 8 d of aging at SEVN. SDS-PAGE gel band OD differences (P < .05) were noted due to TRT for TB samples of VITD at 8 d of aging, while OD differences for LL were not apparent. Treatment with VITD decreased OD for TB samples aged 8d in the 37 kDa subunit area, which indicated increased proteolysis. This study indicated that 7 d withdrawal of VITD decreased WBS of TB and LL muscles, raised calcium levels, yet lowered liver VITD levels to CONT levels. Overall, though, muscle and aging day showed greater WBS and OD effects than TRT, perhaps due to high-voltage electrical stimulation. |
|---|---|
| Item Description: | Vita. "Major Subject: Animal Science". |
| Physical Description: | x, 70 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 66-69). |