Progress 04/01/01 to 09/30/04
Outputs
4. What were the most significant accomplishments this past year? D. Progress Report: This report serves to document research conducted under a specific cooperative agreement between ARS and New Mexico State University, Agricultural Experiment Station, Clayton Research Center, Clayton, NM. Additional details of the research can be found in the report for the parent project 6209-12310-002-00D, Integrated Management Regimens for Minimizing the Environmental Impact of Livestock Manure. Cooperators included Drs. Justin Gleghorn (a post doctorate at NMSU now with private industry), Paul Defoor (former director of the experiment station, now in private Industry), and Glenn Duff (former director of the experiment station and now at the University of Arizona). The project is slated to terminate Sept. 30, 2004. In years one and two of the agreement a beef cattle performance trial was conducted comparing the weight gain and feed efficiency of cattle fed diets that contained 3
levels of protein (11.5, 13, and 14.5%) and three supplemental protein sources (100% urea, 100% cottonseed meal, 50:50 urea+cottonseed meal). The average daily gain and daily dry matter intake of steers fed the 13.0% crude protein diet were greater than for steers fed the 11.5 or 14.5% crude protein diets; however, no differences in feed efficiency were noted. Protein source did not significantly affect average daily gain, dry matter intake, or feed efficiency. Likewise, no major difference in carcass characteristics were noted for either protein concentrations or protein sources. All data have been compiled, analyzed, and presented as an abstract at the National Meetings of the American Society of Animal Science and as a presentation at the Plains Nutrition Council annual meeting. A manuscript that reports this data and data from project 6209-12310-002-06S with Texas Tech University is currently in review by the Journal of Animal Science. One potential method to decrease protein
intake and thus decrease N excretion to the environment is to decrease the dietary protein concentration late in the feeding period as the animal's protein requirements decrease--termed phase feeding. Therefore, in the third year a phase feeding performance trial was conducted. For the 150-day (average) feeding period calves were fed 90% concentrate finishing diets with six treatments as follows: 1) 11.5% protein throughout the trial, 2) 13% protein throughout the trial, 3) 11.5% protein for 90 days and switched to 10% protein for the last 60 days, 4) 13% protein for 120 days and switched to 11.5% protein for the last 30 days, 5) 13% protein for 90 days and switched to 11.5% protein for the last 60 days, and 6) 13% protein for 90 days and switched to 10% protein for the last 60 days. At 56 days on feed, cattle fed the 13% crude protein diet had greater average daily gains than steers fed the 11.5% crude protein diet (3.26 vs 3.37 lb/day). The trial is currently completed. Animal
performance and carcass data currently being analyzed.
Impacts
(N/A)
Publications
- Duff, G.C., Galyean, M.L., Krehbiel, C.R., Cole, N.A. Dietary Protein Levels for Beef Cattle Diets. Proceedings of the Reunion Internacional Sobre Produccion De Carne Y Leche En Climas Calidos, Universdad Autonoma De Baja California. 2002. p. 42-53.
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Progress 10/01/02 to 09/30/03
Outputs
4. What were the most significant accomplishments this past year? D. Progress Report: This report serves to document research conducted under a specific cooperative agreement between ARS and New Mexico State University, Clayton Research Center, Clayton, NM. Additional details of the research can be found in the report for the parent project 6209-12310-002-00D, Integrated Management Regimens for Minimizing the Environmental Impact of Livestock Manure. Cooperators include Drs. Paul Defoor and Glenn Duff (now at the University of Arizona). Results from the performance study indicate that average daily gain and daily dry matter intake can be increased by feeding diets with 13.0% crude protein compared with 11.5 or 14.5% crude protein diets; however, no differences in feed efficiency resulted. No differences in gain, dry matter intake, or feed efficiency were noted with protein sources used in the present experiment. Likewise, no major difference in carcass
characteristics were noted for either protein concentrations (11.5, 13.0, or 14.5%) or protein sources (100% urea, 50% urea: 50% cottonseed meal; or 100% cottonseed meal) used. Serum samples were delivered to Texas Tech University for analysis of serum urea nitrogen. All data have been compiled, analyzed, and presented as an abstract at the National Meetings of the American Society of Animal Science. Performance data and carcass characteristics data were presented at regional meetings. Calves for the final feeding trial under this agreement are currently being purchased in which protein concentrations will be phased down as the feeding period progresses. This feeding trial should begin in early September 2003.
Impacts
(N/A)
Publications
- Duff, G.C., Galyean, M.L., Krehbiel, C.R., Cole, N.A. Dietary Protein Levels for Beef Cattle Diets. Proceedings of the Reunion Internacional Sobre Produccion De Carne Y Leche En Climas Calidos, Universdad Autonoma De Baja California. 2002. p. 42-53.
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Progress 10/01/01 to 09/30/02
Outputs
4. What was your most significant accomplishment this past year? D. Progress Report: This report serves to document research conducted under a specific cooperative agreement between ARS and New Mexico State University, Clayton Research Center, Clayton, New Mexico. Additional details of the research can be found in the report for the parent project 6209-12310-002- 00D, Integrated Management Regimens that minimize the Environmental Impact of Livestock Manure. Performance data and carcass characteristics data have been analyzed and presented in two progress reports. Data have also been forwarded to Dr. Michael Galyean at Texas Tech University and compiled with the study conducted simultaneously with the current study (CRIS 6209-12310-02-06S). Serum samples have been delivered to Texas Tech University for analysis of serum urea nitrogen. Results from the performance study indicate that average daily gain and dry matter intake can be increased by feeding diets with
13.0% CP compared with 11.5 or 14.5% CP diets; however, no differences in feed efficiency resulted. No differences in gain, DMI, or feed efficiency were noted with protein sources used in the present experiment. Likewise, no major difference in carcass characteristics were noted for either protein concentrations (11.5, 13.0, or 14.5%) or protein sources (100% urea; 50% urea:50% cottonseed meal; or 100% cottonseed meal) used.
Impacts
(N/A)
Publications
- Duff, G.C., Galyean, M.L., Cole, N.A. Dietary protein for beef cattle finishing diets. Proceeding of the 17th Southwest Nutrition and Management Conference. 2002. p. 143-155.
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