Recipient Organization
MONTANA STATE UNIVERSITY
(N/A)
BOZEMAN,MT 59717
Performing Department
Animal & Range Sciences
Non Technical Summary
Many reproductive management strategies have been developed in an attempt to circumvent the problems associated with longpostpartum anestrous periods in beef cattle. In general, most of the technologies are not cost effective, time and labor intensive,yield inconsistent results or return, are difficult to implement, or social unacceptable. Results of studies such as these describeabove will culminate in the developing new reproductive management strategies and biotechnologies to overcome theselimitations and will contribute to the body of knowledge regarding mechanisms that regulate postpartum anestrous physiology inbeef cattle. This research will produce scientific and practical data in the form of peer-reviewed journal article, station bulletins orproceeding, and popular articles. Furthermore, if this hypothesis proves to be correct, it could substantially improve ourunderstanding of the important role of bulls in the reproductive activity of anestrus cows. With such understanding, newstrategies may be developed and tested that employ bulls to enhance the reproductive efficiency and sustainability of beef cattleproduction.
Animal Health Component
20%
Research Effort Categories
Basic
80%
Applied
20%
Developmental
(N/A)
Goals / Objectives
Discover mechanisms within five years that have potential to translate into applicable biotechnologies to improve reproductive efficiency in domestic ruminants.
a. Further understand mechanisms of gonadotropin synthesis and release to improve management of reproductive behavior, the reproductive cycle, gamete development and the ovulatory event.
c. Improve management of reproductive cycles through increased understanding of follicle recruitment, ovulation and corpus luteum development.
Project Methods
To meet a component of this Objective, crossbred primiparous, anovulatory beef cows will be exposed or not exposed to thephysical presence of bulls or bull urine during the postpartum anestrous period. Olfactory epithelial tissue will be obtained atdiscrete intervals after calving to assess changes in functional olfactory "signaling" proteins and/or their messages. Analyses ofprotein and volatile and semi-volatile components of urine samples from bulls will be performed and tested for biostimulatoryeffects on postpartum anovulatory cows. On these same cows we will again evaluate changes in olfactory epithelial "signal" thatwould be specific to the biostimulatory effect of bulls. Likewise, we will determine if these "biostimulatory" components of urinealter KiSS expression or its mRNA levels in concert with inducing changes in LH pulse frequency. Various exposure protocolswill be employed and assessed by ultrasonic examination of ovaries for follicular wave development and ovulation, and systemicblood samples will be collected for assay of progesterone to establish the resumption of luteal function after biostimulation bybulls or urinary components of bulls. Collaboration will include sharing of: expertise on experimental methods and techniques,hormone analyses of blood samples, assay urinary components, molecular biology techniques and equipment, andinterpretation of data.