Project Number: 5434-31000-016-07
Project Type: Specific Cooperative Agreement

Start Date: Jul 01, 2008
End Date: Jun 30, 2013

Objective:
Research and develop management strategies and tactics leading to more economically and biologically efficient beef production sustainably using rangeland resources. Collaborative research in animal physiology, genetics and nutrition which both the University and ARS co-lead in the preparation, planning, and execution of experiments will be conducted at the 55,000+ acre USDA-ARS Fort Keogh Livestock and Range Research Laboratory (LARRL). Specific objectives include: : 1) Characterizing rumen microbial populations; 2) Determining rumen microbial and host genetic effects associated efficiency under divergent planes of nutrition or different diets; 3) Determining phenotypic and genetic relationships of early-in-life measures and lifetime productivity; 4) Determining if the level of nutrition in utero and prior to puberty affects life-cycle production efficiency; 5) Developing and validating appropriate phenotypes for measuring fertility in; and 6) Identifying and fine mapping quantitative trait loci (QTL) that affecti feed intake, growth and reproduction.

Approach:
Beef cattle owned by the Montana Agricultural Experiment Station (MAES) will be used to develop new reproductive, genetic and nutrient management strategies for rangeland based animal agriculture. Effects of these strategies on the state of the rangeland resource and product characteristics will also be evaluated. Four distinct cattle populations are used: Line 1 Hereford, an intercross (CGC) of Charolais (25%), Red Angus (50%) and Tarentaise (25%), and two predominantly Hereford-Angus crossbred herds. Line 1 Hereford cattle are ~30% inbred, with consequently reduced fitness, and have close ties to the bovine genome sequence and the general US Hereford population. These characteristics facilitate assessing genetic factors affecting fitness and assure relevance to the industry. Two distinct nutritional environments will be imposed on the CGC population to challenge the nutrition-reproduction interrelationship. One Hereford-Angus cowherd provides donor and recipient females for studies using embryo transfer. The other Hereford-Angus cowherd calves in two distinct timeframes and thus has differential synchrony between nutritional value of range forage and nutrient requirements of the cows. To address a broad spectrum of customer interests, we envision a mixture of basic investigations and applied studies. Results will be summarized and disseminated to producers, researchers, rangeland managers, and other interested parties.