Effects of anabolic growth promotants on rate and composition of growth in finishing beef steers /
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| Other Authors: | , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1991.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | This trial was conducted to determine effects of sequence and timing of implantation with a combination of implants on feedlot variables, carcass composition indicators, and carcass composition for the most economical returns to management. One hundred twenty eight crossbred steers were used in a completely randomized design. All steers were weighed and measured with ultrasound to determine initial backfat and ribeye area. An initial slaughter group consisting of 8 hd was selected utilizing this data. The remaining 120 hd were randomly assigned to one of four treatments. This procedure blocked the lots by weight and comparable muscling and backfat. Treatments consisted of: 1) Control (Ctrl) 2) Synovex-S followed by Finaplix-S/Synovex-S (E/TBA-E) 3) Finaplix-S/Synovex-S followed by Synovex-S (TBA-E/E) 4) Finaplix-S/Synovex-S followed by Finaplix-S/Synovex-S (TBAE/TBA-E). Steers were implanted on d 0 and d 56 of the trial. The five slaughter dates were on d 56, 112, 126, 145, and 154 of the experiment. Live weight was significantly different (P<.01) on d 112 and d 126 for implanted steers versus Ctrl. Average daily gain (ADG) was greater (P<.01) for implanted steers vs. Ctrl throughout the trial. Daily feed intake indicated that TBA-E/TBA-E and TBA-E/E treated steers consumed more feed accumulatively than E/TBA-E and Ctrl steers. Implanted steers outperformed Ctrl steers (p<.01) in feed efficiency throughout the feeding period. Regression analysis for the slaughter variables indicate that TBA-E/TBA-E and E/TBA-E increased (P<.05) ribeye area, and decreased (P<.05) backfat and yield grade over either TBA-E/E or Ctrl steers. At d 154 KPH, dressing percent, and marbling were similar among all treatments. The TBA response disappeared when TBA was not re-implanted later (d 56). The most consistent treatment in attaining greater muscling and less fat was the TBA-E/TBA-E combination. All three implant treatments were superior to Ctrl steers in all categories. Regression analysis for the carcass composition variables indicate that all implant treatments equalized in all categories except total protein deposition by d 154. The androgenic activity of dual TBA/E improved protein accretion (P<.05). The Ctrl steers stored less protein, less retained energy/d or per kg gained (P<.05). |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Nutrition." |
| Physical Description: | xi, 133 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |