Location: Livestock Bio-Systems
Project Number: 3040-31630-001-000-D
Project Type: In-House Appropriated
Start Date: Jul 31, 2022
End Date: Jul 30, 2027
Objective:
Objective 1. Establish the influence of nutrient intake during the peri-pubertal period on gamete quality in young beef animals.
Sub-objective 1.A: Determine if the stair-step development protocol results in increased circulating progesterone concentrations and improved uterine function in replacement beef heifers.
Sub-objective 1.B: Determine if differences in bull rate of gain during the peri-pubertal window influence the contributions of sperm to early embryonic development in-vitro and compare that to siring capacity in the pasture.
Objective 2. Determine the influence of nutritional supplements in vivo during follicle development and early pregnancy on fetal development and progeny performance.
Sub-objective 2.A: Determine if OmniGen-AF supplementation will increase circulating progesterone concentrations in beef heifers with diminished numbers of follicles.
Sub-objective 2.B: Determine if feeding OmniGen-AF to heifers for 50 days prior to the breeding season influences oocyte quality and blastocyst development.
Objective 3. Understand how specific nutrients provided directly to the embryo in vitro during the first seven days after fertilization contribute to proper embryonic development.
Sub-objective 3.A: Supplementing follistatin in combination with choline will increase in-vitro embryonic development.
Sub-objective 3.B: Determine if incorporating guanidinoacetic acid (GAA) and/or methionine during in-vitro embryo production alters blastocyst competence and development.
Objective 4. Apply remote sensors and related technologies for improved measurement of reproductive and production traits of cattle in rangeland and pasture settings.
Sub-objective 4.A: Develop techniques using geophysical mapping of soil spatial variability that can be used for precision grazing management of range beef cows.
Approach:
As the world population continues to grow over the next 50 years, the demand for animal protein products to sustain human health will increase. The sustainable production of animal protein begins with efficient reproduction. Environment and management influence reproductive efficiency in beef cattle; therefore, better management practices by cow-calf producers will increase the reproductive efficiency of their herds. Nutritional status of the herd represents the component of the production system where management practices have the greatest overall impact on reproductive performance in the beef herd because nutrition influences onset of reproductive cycles, quantity and quality of male and female gametes, early embryonic development, maintenance of pregnancy, development of the progeny during pregnancy, and subsequent performance of those progeny after birth. Efforts in the last two project plans identified reproductive traits that predict fertility and implemented nutritional strategies to developmentally program those traits to improve reproductive efficiency. During this time, advancements in sensor technologies increased our ability to monitor reproductive performance and regulate nutrient intake, providing new possibilities for reproductive management in the beef herd. Applying results from our past accomplishments, the current project plan will improve strategies for developing heifers and bulls with the greatest quantity and quality of gametes possible (Objective 1), apply nutritional supplements that will improve deficiencies in reproductive traits in beef females with low fertility (Objective 2), use in-vitro embryo production technologies to explore nutritional strategies that will optimize embryo development (Objective 3), and use electronic sensor systems to assimilate real-time data on reproductive status of animals and nutrient availability of pastures to improve decision making in reproductive management of beef cattle on range (Objective 4). Results will provide cow-calf producers with tools to develop and manage highly fertile breeding stock that wean a greater number of calves at greater weights.
