Source: MONTANA STATE UNIVERSITY submitted to NRP
A NOVEL HYPOTHESIS FOR PHEROMONAL MEDIATION OF THE BIOSTIMULATORY EFFECT OF BULLS INVOLVING ADRENAL CORTICAL ACTIVATION IN POSTPARTUM COWS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
NRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
0208797
Grant No.
2007-35203-17743
Cumulative Award Amt.
(N/A)
Proposal No.
2006-00890
Multistate No.
(N/A)
Project Start Date
Dec 1, 2006
Project End Date
Nov 30, 2011
Grant Year
2007
Program Code
[41.0]- (N/A)
Recipient Organization
MONTANA STATE UNIVERSITY
(N/A)
BOZEMAN,MT 59717
Performing Department
ANIMAL & RANGE SCIENCES
Non Technical Summary
The presence of a bull can accelerate resumption of estrous cycles in postpartum anestrus in suckled beef cows. The precise mechanism for this so-called biostimulatory effect of bulls is not known but appears to be caused by a pheromone in the excretory products of bulls. We will attempt to identify substances in urine that may act as pheromones and test these substances for the ability to mimic the biostimulatory effect of bulls. We will also determine whether activation of the adrenal glands to increase cortisol is required in the neuroendocrine-endocrine mechanism of this effect and establish a working hypothesis for why bulls cause this biostimulatory effect in postpartum, anestrous cows. The outcomes of this work are two-fold: 1) advancement of our understanding of the physiology of postpartum cows and testing hypotheses regarding the nature of male-female interactions; and, 2) technological developments for increasing reproductive efficiency of cow-calf operations by providing management strategies that are low cost, time and labor saving, yield consistent results and returns, are easily applicable, socially acceptable, and sustainable.
Animal Health Component
75%
Research Effort Categories
Basic
25%
Applied
75%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
30133101020100%
Knowledge Area
301 - Reproductive Performance of Animals;

Subject Of Investigation
3310 - Beef cattle, live animal;

Field Of Science
1020 - Physiology;
Goals / Objectives
The long-term goal of this research is to determine the physiological mechanism(s) and pheromonal pathways by which the biostimulatory effect of bulls decreases the postpartum anovulatory interval in suckled cows. We will evaluate the novel hypothesis termed the "Temporal-Quantal-Threshold Hypothesis" (TQTH) involving activation of the hypothalamic-pituitary-adrenal (HPA) axis that may be the underlying mechanism for understanding the biostimulatory effect of bulls in regulating postpartum reproductive events of anovulatory cows. The specific objectives of this proposal are to:1) define the role of the HPA in the biostimulatory effect of bulls and determine if HPA can be used to asses the biostimulatory effect of bulls; 2) determine if bull urine is the source of the pheromone(s) involved with the biostimulatory effect of bulls; 3) investigate the validity of the TQTH for the mechanism of pheromonal action involved with the biostimulatory effect of bulls; and, 4) identify semi-volatile and volatile organic components and proteinaceous compounds of bull urine as possible pheromone(s) candidates and carrier proteins of pheromone that may be involve with the biostimulatory effect of bulls.
Project Methods
Four experiments will be performed utilizing primiparous, suckled beef cows that will be exposed to bulls or excretory products of bulls during these experiments. In Experiment 1, we attempt to establish the role of the HPA and its relationship to resumption of ovulatory activity by evaluating temporal changes in patterns of cortisol and LH concentrations in cows exposed or not exposed acutely or chronically to bulls. In Experiment 2, we attempt to verify that bull urine is the source of the biostimulatory pheromone of bulls by exposing cows to bull or cow urine for 12-hr daily and evaluating the difference in resumption of ovulatory activity between treatments. In Experiment 3, we test the validity of the primary assumption of the TQTH by exposing cows to decreasing levels of intensity of pheromonal stimulation followed by longer intervals of non-stimulation. This will show that the intensity of pheromonal stimulation must be presented to cows in a pulsatile manner with periods between pulses required for adjustments in the hypothalamic regulation of LH release patterns for resumption of ovulation. Experiment 4 is designed to identify possible volatile urinary compounds that may be the pheromone(s) and their carrier proteins that may involved in the biostimulatory effect. This will be accomplished by comparing spectrograms and 1-D gel patterns for these two classes of compounds from bull urine and androgenized cow and steer urine to steer and diestrous cow urine.

Progress 12/01/06 to 11/30/11

Outputs
OUTPUTS: Our first objective for this project was to determine if the presence of bulls acutely alters the temporal cortisol concentrations in postpartum, anestrous, suckled beef cows. We found that bull exposure changed temporal patterns of cortisol concentrations by decreasing the frequency, increasing the duration of pulses and synchronizing the pulsatile rhythm of cortisol in anestrous, suckled beef cows. Then it was necessary to determine if bulls alter temporal patterns of cortisol concentrations in postpartum beef cows before or during resumption of ovulatory activity. Results of these experiments indicate that changes in characteristics of cortisol concentrations patterns precede the biostimulatory effect of bulls to induce resumption of ovulatory activity in postpartum, anovular, suckled beef cows. The next objective was to determine if duration of daily bull exposure influences length of postpartum anestrus in primiparous, anovular, suckled, beef cows. Indeed, the duration of daily bull exposure that anovular, suckled cows each day is an integral component of the mechanism whereby cows respond to this stimulus and undergo physiological changes necessary for resumption of ovulatory activity. The next objective was to determine if daily exposure to bull urine alters resumption of luteal activity and artificial insemination pregnancy rates of postpartum, anovular, suckled, beef cows. Interval from the start of urine or saline exposure to resumption of luteal activity by 52 d did not differ between bull urine- and saline-exposed cows. Likewise, there was no difference in the proportions of cows that resumed luteal activity by the end of the 52-d exposure period. We determined if the biostimulatory effect of bulls would alter in metabolic hormones which in turn regulate the hypothalamic-pituitary-ovarian (HPO) axis of anovular cows. We found that as duration of daily bull exposure increases, the biostimulatory effect of bulls alters temporal leptin concentrations. Additionally, we evaluated follicular wave dynamics of anovular postpartum cows exposed to bulls. The results showed the effects of bull exposure in altering follicular growth and developmental patterns, shortening the inter-wave interval and increasing the dominant follicle diameter. PARTICIPANTS: J.G. Berardinelli, Principal Director; K. C. Davis, Research Associate; S. A. Tauck, PhD Graduate Student; J. R. Olsen, MS Graduate Student; J. R. W. Wilkinson, MS Graduate Student; R. McCosh, MS Graduate Student; M. Borgreen, MS Graduate Student; Carson Butler; Undergraduate Research Intern; Rachael Spangelo, Undergraduate Research Intern; T. Gibbs, Undergraduate Research Intern; Eli Berry, Undergraduate Research Intern; P. Crampton, Undergraduate Research Intern; K. Phillips, Undergraduate Lab Assistant; Chris Sundquist, Undergraduate Research; K. Hendry, Undergraduate Research Intern; E. Richards, Undergraduate Lab Assistant; L. Runnion, Undergraduate Lab Assistant; L. Tauck, Undergraduate Lab Assistant; R. Wedlake, Undergraduate Research Intern; R. Goodfriend, Undergraduate Research Intern; T. Morris, Undergraduate Research Intern; M. Hove. TARGET AUDIENCES: Research Scientists, Academics, Extension and Outreach Specialists, Beef Cattle Producers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The biostimulatory effect of bulls appears to initially involve a change in cortisol concentrations patterns that have an immediate effect on activity of the hypothalamic-pituitary-ovarian axis. The effect of bulls decreases pulse rhythm of cortisol which facilitates an increase in LH frequency that, in turn, accelerates ovulatory cyclicity in primiparous, postpartum, anestrous, suckled cows. This represents a fundamental change in the knowledge of the physiological mechanism whereby the biostimulatory effect of bulls accelerates resumption of ovarian cycling activity and increase reproductive efficiency in beef cattle. We now have shown that the variation associated with this action involves a minimum length of time during any day that cows must be in close proximity to bulls to respond to the stimulatory effect of bulls. This result changes fundamental knowledge regarding the physiological mechanism whereby the biostimulatory effect of bulls accelerates resumption of ovarian cycling activity and increase reproductive efficiency in beef cattle and can be used by producers to more effectively take advantage of the bull effect. Exposing primiparous, postpartum, anovular, suckled, beef cows to mature bull urine for 12 h daily did not accelerate resumption of ovulatory activity it did appear to improve artificial insemination pregnancy rates. Significantly, bull urine may carry an additional pheromone(s) that is associated with fertility in the bovine. Changes in temporal leptin concentrations may facilitate or support the function of the HPO axis and accelerate resumption of ovarian cycling activity in primiparous, postpartum, suckled, anestrous cows. This again resents a change in the knowledge base for the biostimulatory effect of bull. Though the mechanism through which bull exposure alters postpartum follicular development is not entirely understood, these data provide new understanding into how bull exposure accelerates the resumption of luteal activity in postpartum, primiparous, suckled, beef cows.

Publications

  • Wedlake, R., and J. G. Berardinelli. 2008. Characteristics of cortisol concentrations in postpartum, suckled beef cows before and after exposure to androstadieneone. 25th Annual Montana State University-Bozeman Student Research Celebration. Poster Number 117, Abstr. 89.
  • Wilkinson, J., and J. G. Berardinelli. 2008. Biostimulatory Effect on Postpartum Follicular Wave Development in Postpartum, Anestrous, Suckled Beef Cows. 25th Annual Montana State University-Bozeman Student Research Celebration. Poster Number 127, Abstr. 128.
  • Tauck, S. A., and J. G. Berardinelli. 2007. Putative urinary pheromone of bulls involved with breeding performance of primiparous beef cows in a progestin-based estrous synchronization protocol. J. Anim. Sci. 85:1669-1674.
  • Wilkinson, J. R. C., and J. G. Berardinelli. 2009. Biostimulatory effect of bulls on follicular wave dynamics of postpartum , anovular, suckled cows. Montana Acad. Sci. Annual Meeting, Program and Abstracts. MSU Student Research Celebration. Montana State University, Conference Program, p. 22(Abstr.): Poster 96.
  • Olsen, J. R., S. A. Tauck, J. R. C. Wilkinson, D. H. Keisler, J. G. Berardinelli. 2009. Daily bull exposure on leptin concentrations during resumption of ovulatory activity in primiparous, postpartum, anestrous, beef cows. MSU Student Research Celebration. Montana State University, Conference Program, p. 21(Abstr.): Poster 2.
  • Sundquist, C. and J. G. Berardinelli. 2009. Estrus synchronization response and artificial insemination rates in beef heifers exposed to bulls during an estrus synchronization protocol that included a 14-d CIDR, PGF2α, and, timed AI and GnRH. MSU Student Research Celebration. Montana State University, Conference Program, p. 40(Abstr.): Poster 60.
  • Wilkinson, J. R. C., S. A. Tauck, J. R. Olsen, and J. G. Berardinelli. 2009. Biostimulatory effect of bulls on follicular wave dynamics of postpartum , anovular, suckled cows. Montana Acad. Sci. Annual Meeting, Program and Abstracts. Page 13.
  • Wilkinson, J. R. C., S. A. Tauck, J. R. Olsen, R. J. Wedlake, and J. G. Berardinelli. 2008. Effects of oro-nasal administration of androstadienone on characteristics of cortisol concentrations in postpartum, suckled beef cows. J. Anim. Sci. 86(E-Suppl. 2): (Abstr. 480).
  • Tauck, S. A., Olsen, J. R., J. R. C. Wilkinson, and J. G. Berardinelli. 2008. The biostimulatory effect of bulls in postpartum, anestrous, suckled beef cows alters cortisol concentrations and characteristic of cortisol concentration patterns before resumption of ovulatory activity. J. Anim. Sci. 86(E-Suppl. 2): Abstr. 479.
  • Berardinelli, J. G. 2008. A novel hypothesis for pheromonal mediation of the biostimulatory effect of bulls involving adrenal cortical activation in postpartum, suckled, beef cows. Program Abstracts of CSREES, USDA National Research Initiative, Animal Reproduction. Page 48.
  • Gibbs, T. and J. B. Berardinelli. 2008. Changes in energy-related metabolites and hormones from breeding to calving in female elk. 25th Annual Montana State University-Bozeman Student Research Celebration. Poster Number 52, Abstr. 34.
  • Olsen, J., and J. G. Berardinelli. 2008. Effect of chronic wasting disease on energy related metabolites and hormones in wild cervids. 25th Annual Montana State University-Bozeman Student Research Celebration. Poster Number 87, Abstr. 97.
  • Phillips, K., and J. G. Berardinelli. 2008. Biostimulatory effect of bulls on leptin and ghrelin concentrations in primiparous, anestrous, suckled beef cows. 25th Annual Montana State University-Bozeman Student Research Celebration. Poster Number 90, Abstr. 40.
  • Olsen, J. R. 2007. Changes in patterns of cortisol concentrations involved with the biostimulatory effect of bulls in postpartum, anestrous, suckled beef cows. Montana State University, Undergraduate Scholars Conference Program. Abstr. No. 13:13.
  • Tauck, S., and J. G. Berardinelli. 2008. Characteristics of Cortisol Concentration Patterns in Postpartum, Anovular, Suckled Beef Cows Continuously Exposed to Bulls. 25th Annual Montana State University-Bozeman Student Research Celebration. Poster Number 139, Abstr. 126.
  • Olsen, J. R., S. A. Tauck, J. R. C. Wilkinson, and J. G. Berardinelli. 2007. The adrenal response of postpartum, suckled beef cows during acclimatization to facilities and protocols necessary for intensive blood sampling. Montana Acad. Sci. Annual Meeting, Program and Abstracts. Page 3.
  • Wilkinson, J. R. C., S. A. Tauck, J. R. Olsen, and J. G. Berardinelli. 2007. Effect of bull exposure on glucose, NEFA, thyroxine, and triiodothyronine in primiparous, anestrous, suckled beef cows. Montana Acad. Sci. Annual Meeting, Program and Abstracts. Page 3.
  • Wilkinson, J. R. C., S. A. Tauck, J. R. Olsen, and J. G. Berardinelli. 2007. Concentrations of glucose, NEFA, thyroxine, and triiodothyronine in primiparous, anestrous, suckled beef cows exposed to bulls. 85(Suppl. 2):169 (Abstr. 63).
  • Tauck, S. A., Olsen, J. R., Wilkinson, J. R. C., and J. G. Berardinelli. 2007. Changes in patterns of cortisol concentrations involved with the biostimulatory effect of bulls in postpartum, anestrous, suckled beef cows. Biol. Reprod. 77(Special Issue):106 (Abstr. 131).
  • Olsen, J. R., S. A. Tauck, J. R. C. Wilkinson, and J. G. Berardinelli. 2007. Cortisol concentration patterns during acclimatization to facilities and protocols necessary for intensive blood sampling in primiparous, postpartum, suckled beef cows. J. Anim. Sci. 85(Suppl. 2):170 (Abstr. 64).
  • Wilkinson, J. R. C., S. A. Tauck, J. R. Olsen, and J. G. Berardinelli. 2007. Concentrations of glucose, NEFA, thyroxine, and triiodothyronine in primiparous, anestrous, suckled beef cows exposed to bulls. Proc. West. Sec. Amer. Soc. Anim. Sci. 58:262 -265.
  • Berardinelli, J. G. 2007. Management practices to overcome problems with puberty and anestrus. Applied Reproductive Strategies in Beef Cattle Symposium. September 11 and 12, Billings, MT. pp. 149-162.
  • Olsen, J. R., S. A. Tauck, J. R. C. Wilkinson, and J. G. Berardinelli. 2007. Cortisol concentration patterns during acclimatization to facilities and protocols necessary for intensive blood sampling in primiparous, postpartum, suckled beef cows. Proc. West. Sec. Amer. Soc. Anim. Sci. 58:266-270.
  • Olsen, J. R., S. A. Tauck, J. R. C. Wilkinson, D. H. Keisler, J. G. Berardinelli. 2009. Duration of daily bull exposure on leptin concentrations during resumption of ovulatory activity in primiparous, postpartum, anestrous, beef cows. Proc. West. Sec. Amer. Soc. Anim. Sci. 60:285-289.
  • Tauck, S. A., J. R. Olsen, J. R. C. Wilkinson, and J. G. Berardinelli. 2009. Duration of daily bull exposure on resumption of ovulatory activity in postpartum, primiparous, anovular, suckled, beef cows. Proc. West. Sec. Amer. Soc. Anim. Sci. 60:259-262.
  • Berardinelli, J. G., S. A. Tauck, J. R. C. Wilkinson, J. R. Olsen, T. Gibbs, and L. Runnion. 2009. Reproductive performance of beef heifers exposed to bulls during an estrus synchronization protocol that included a 14-d CIDR, PGF2α, and, timed AI and GnRH. Proc. West. Sec. Amer. Soc. Anim. Sci. 60:241-244.
  • McCosh, R. B. E.M. Berry, M.E. Wehrman, R.R. Redden, R.W. Kott, D. Hallford, and J.G. Berardinelli. 2010. Effect of ram exposure on temporal patterns of progesterone and metabolic hormones concentrations in 18-mo-old virgin Targhee ewes during the transition into the breeding season. Proc. West. Sec. Amer. Soc. Anim. Sci. 61:82-85.
  • McCosh, R., J. G. Berardinelli, M. Wehrman, E. Berry, R. Redden, K.C. Davis, and R. Kott. 2009. Acute effect of rams and on temporal cortisol and LH concentrations in 2-year-old Targhee ewes of varied relative feed indices during the transition between seasonal anestrous and the breeding season. Sheep Program Advisory Committee Reports. pp. 69 - 70.
  • Class gives experience on reproductive technology. AgExcellence 2007. The College of Agriculture and Montana Agricultural Experiment Station in Review. Page 16.
  • Montana researcher uses bulls to jumpstart estrus in breeding females. Shanon Ruckman, Editor, The Prarie Star, Friday, Oct. 12, 2007. p.37.
  • Putative urinary pheromone of bulls involved with breeding performance of primiparous beef cows in a progestin-based estrous synchronization protocol. S. Tauck., J. Berardinelli. American Association of Bovine Practitioners, July 2007 Newsletter. p. 3.
  • Tauck, S. A., J. R. Olsen, J. R. C. Wilkinson, K. M., R. Wedlake, and J. G. Berardinelli. 2012.Biostimulatory effect of bulls alters characteristics of cortisol concentration patterns associated with resumption of ovulatory activity in postpartum, anovular, suckled beef cows. Domestic Anim. Endocrinol. (Pending)
  • Tauck, S. A., J.R. Olsen, J.R.C. Wilkinson, and J.G. Berardinelli. 2010. Duration of daily bull exposure on resumption of ovulatory activity in postpartum, primiparous, suckled, beef cows. Anim. Repro. Sci.. 118: 8-13.
  • Tauck, S. A., J. R. Olsen, and J. G. Berardinelli. 2007. Adrenal involvement in the biostimulatory effect of bulls. Reprod. Biol. Endocinol. 5: 33-39.
  • Tauck, S. A., J. R. C. Wilkinson, J. R. Olsen, J. N. Janitell, and J. G. Berardinelli. 2007. Comparison of controlled internal drug release device and melengesterol acetate as progestin sources in an estrous synchronization protocol for beef heifers. Theriogenology 68:162-167..
  • Berardinelli, J. G., and S. A. Tauck. 2007. Intensity of the biostimulatory effect of bulls on resumption of ovulatory activity in primiparous, suckled, beef cows. Anim. Reprod. Sci. 99:24:33..
  • Berardinelli, J. G., and S. A. Tauck. 2007. Conception rates to artificial insemination in primiparous, suckled cows exposed to the biostimulatory effect of bulls before and during a gonadotropin-releasing hormone-based estrus synchronization protocol. J. Anim Sci. 85:848-852.
  • McCosh, R. B., C. Butler, N. Cloutier, R. W. Kott, and J. G. Berardinelli. Preparation of an atlas of the ovine hypothalamus for co-localization of key signaling peptides in reproduction. 2011. Montana Acad. Sci. Program and Montana Local Sect. Amer. Chem. Soc. Abstracts. p. 22.
  • Butler, C. and J.G. Berardinelli. 2011. Effect of exposing twenty-month-old virgin ewes to mature rams on kisspeptin in arcuate nucleus and preoptic area during the early breeding season. Student Research Celebration Program and Abstracts, Montana State University. Abstr. p. 73.
  • McCosh, R. B., E. M. Berry, M. E. Wehrman, and J. G. Berardinelli. 2010. Acute effect of exposing virgin ewes to rams on temporal characteristics of cortisol and LH concentration patterns during the transition into the breeding season. Biol. Repro. 81[Suppl.]:106, Abstr. 544.
  • Berardinelli, J. G., S. Tauck, J. Wilkinson, J. Olsen, T. Gibbs, K. C. Davis, J. Dafoe, and D. Boss. 2010. Estrous response and pregnancy rates of beef heifers exposed to bulls during an estrus synchronization protocol that included a 14-d CIDR, PGF2α, and, timed AI and GnRH. J. Anim. Sci. 87, [E-Suppl. 3]:152, Abstr. 49.
  • McCosh, R.B., E.M. Berry, M.E. Wehrman, R.R. Redden, R.W. Kott, D. Hallford, and J.G. Berardinelli. 2010. Effect of ram exposure on temporal patterns of progesterone and metabolic hormones concentrations in 18-mo-old virgin Targhee ewes during the transition into the breeding season. J. Anim. Sci. 87, [E-Suppl. 3]:152, Abstr. 49.
  • Berardinelli, J. G. 2009. New insight into the biostimulatory effect of bulls on reproductive processes of postpartum, anovular, suckled, beef cows. Repro. Physiol. Alum. Reunion Symposium. West Virginia University, Morgantown, WV. July2009. Page 49: Abstr. 10.
  • Berardinelli, J. G. 2009. A novel hypothesis for pheromonal mediation of the biostimulatory effect of bulls involving adrenal cortical activation in postpartum, suckled, beef cows. Program Abstracts of CSREES, USDA National Research Initiative, Animal Reproduction. Page 37.
  • Berardinelli, J. G., S. A. Tauck, J. R. C. Wilkinson, J. R. Olsen, T. Gibbs, and L. Runnion. 2009. Reproductive performance of beef heifers exposed to bulls during an estrus synchronization protocol that included a 14-d CIDR, PGF2α, and, timed AI and GnRH. J. Anim. Sci. 87,[E-Suppl. 3]:148, Abstr. 38.
  • Berardinelli, J. G., J. R. C. Wilkinson, S. A. Tauck, J. R. Olsen, and R. Wedlake. 2009. Duration of daily bull exposure on follicular wave dynamics of postpartum, anovular, suckled cows. Biol. Repro. 81[Suppl.]:106, Abstr. 544.
  • Berardinelli, J. G., S. A. Tauck, J. R. C. Wilkinson, J. R. Olsen, T. Gibbs, and L. Runnion. 2009. Reproductive performance of beef heifers exposed to bulls during an estrus synchronization protocol that included a 14-d CIDR, PGF2α, and, timed AI and GnRH. Montana Acad. Sci. Annual Meeting, Program and Abstracts. Page 2.
  • Gibbs, T., and J. G. Berardinelli. 2009. Daily bull exposure duration on resumption of ovulatory activity in primiparous, postpartum, anovular, suckled, beef cows. MSU Student Research Celebration. Montana State University, Conference Program, p. 36(Abstr.): Poster 28.
  • Tauck, S. A., J. R. Olsen, J. R. C. Wilkinson, and J. G. Berardinelli. 2009. Duration of daily bull exposure on resumption of ovulatory activity in postpartum, primiparous, anovular, suckled, beef cows. Montana Acad. Sci. Annual Meeting, Program and Abstracts. Page 7.
  • Olsen, J. R., S. A. Tauck, J. R. C. Wilkinson, D. H. Keisler, J. G. Berardinelli. 2009. Duration of daily bull exposure on leptin concentrations during resumption of ovulatory activity in primiparous, postpartum, anestrous, beef cows. J. Anim. Sci. 87,[E-Suppl. 3]:152, Abstr. 50.
  • Olsen, J. R., S. A. Tauck, J. R. C. Wilkinson, D. H. Keisler, J. G. Berardinelli. 2009. Biostimulatory effect of bulls on temporal patterns of leptin concentrations and resumption of luteal activity in primiparous, postpartum, anestrous, beef cows. Biol. Repro. 81[Suppl.]:106, Abstr. 261.
  • Olsen, J. R., S. A. Tauck, J. R. C. Wilkinson, D. H. Keisler, J. G. Berardinelli. 2009. Effect of daily bull exposure on leptin concentrations in primiparous, postpartum, anestrous, beef cows. . Montana Acad. Sci. Annual Meeting, Program and Abstracts. Page 10.


Progress 12/01/09 to 11/30/10

Outputs
OUTPUTS: Exposing anovular, suckled, beef cows to bulls for at least 6 h daily or to excreta of bull for 12 daily significantly reduces the interval to resumption of ovulatory activity. This "biostimulatory effect" of bulls appears to be mediated by a pheromone(s) excreted by bulls into the environment. The objective of this experiment was to determine if daily exposure to bull urine alters resumption of luteal activity and artificial insemination pregnancy rates of primiparous, postpartum, anovular, suckled, beef cows. The null hypotheses were that: 1) interval from exposure to urine to resumption of luteal activity; 2) proportions of cows cycling at the end of the exposure period; and 3) artificial insemination pregnancy rates do not differ between cows exposed for 12 h daily to mature bull urine or saline. Anovular cows were stratified by calving date, BW, calf BW, calf sex, dystocia score, and BCS approximately 44 d after calving and exposed to bull urine (n=20) or physiologic saline (n=21). Each cow was evaluated for the presence of a corpus luteum (CL) once weekly by transrectal ultrasonography, and jugular blood samples were collected every 3 d beginning on the day of exposure for assay of progesterone. A rise in progesterone concentrations of >1.0 ng/mL in 2 consecutive samples confirmed by the presence of a CL was used to determine resumption of luteal activity. Cows were exposed to freshly-collected urine or saline dripped at a rate of 2 L/h over a 12-h period daily (2200 to 0800 h) for 52 d before initiation of an estrous synchronized protocol that included a 7-d controlled internal drug release device (CIDR), PGF 2a, and fixed-time artificial insemination. Cows were exposed to urine or saline during the 7 d that CIDRs were in place and were discontinued at CIDR removal; 72 h before fixed-time artificial insemination Interval from the start of urine or saline exposure to resumption of luteal activity by 52 d did not differ between bull urine- and saline-exposed cows. Likewise, there was no difference in the proportions of cows that resumed luteal activity by the end of the 52-d exposure period. Although artificial insemination pregnancy rates 35 d after insemination of bull urine- and saline-exposed cows did not differ significantly, there appeared to be a benefit to exposing cows to bull urine (65 and 48% for bull urine- and saline-exposed cows, respectively). PARTICIPANTS: J.G. Berardinelli, Principal Director; K. C. Davis, Research Assocaite; Graduate Student; J. R. Olsen, M. S. Graduate Student; J. R. W. Wilkinson, M. S. Graduate Student; R. McCosh, M. S. Graduate Student; M. Borgreen, M. S. Graduate Student; T. Gibbs, Undergraduate Research Intern; Eli Berry, Undergraduate Research Intern; P. Crampton, Undergraduate Research Intern; K. Phillips, Undergraduate Lab Assistant TARGET AUDIENCES: Research Scientists, Academics, Extension and Outreach Specialists, Beef Cattle Producers PROJECT MODIFICATIONS: None

Impacts
Exposing primiparous, postpartum, anovular, suckled, beef cows to mature bull urine for 12 h daily does accelerate resumption of ovulatory activity but it does appear to improve artificial insemination pregnancy rates. Furthermore, bull urine per se may not be the medium that carries the biostimulatory pheromone(s) that accelerates resumption of ovulatory activity in the bovine. More importantly, bull urine may carry an additional pheromone(s) that is associated with fertility in the bovine.

Publications

  • Tauck, S.A., Olsen, J.R., Wilkinson, J.R.C., Davis, K., Wedlake, R., and Berardinelli, J.G. 2010. Characteristics of temporal patterns of cortisol and luteinizing hormone in primiparous, postpartum, suckled, beef cows exposed acutely to bulls. Reprod. Biol. and Endocrinol. 8:89.
  • Berardinelli, J.G., Olsen, J.R., Wilkinson, J.R.C., and Tauck, S.A. 2010. Influence of daily bull urine exposure on resumption of luteal activity in postpartum, anovular, suckled cows. Biol. Repro. 81[Suppl.]:106, Abstr. 544.


Progress 12/01/08 to 11/30/09

Outputs
OUTPUTS: The objective of this experiment was to determine if duration of daily bull exposure influences length of postpartum anestrus in primiparous, anovular, suckled, beef cows. The null hypotheses were that intervals from calving or the start of bull exposure (D 0) to resumption of ovulatory activity (OA), and proportions of cows that resumed OA during the experiment does not differ among cows exposed to bulls for 0, 6, or 12-h daily; and, that there is no relationship between the duration of bull exposure and interval to resumption of OA in cows exposed to bulls for 0, 6, or 12 h daily. At 51.5 d after calving, cows were assigned randomly to be exposed for 12 (BE12; n = 15) or 6 h daily (BE6; n = 14) to mature bulls, or not exposed to bulls (NE; n = 10) for 45 d. The cow to bull ratios for BE12 and BE6 cows were 7.5:1 and 7:1, respectively. Blood samples were collected from each cow by jugular venepuncture at 2-d intervals from D 0 for assay of progesterone. Likewise, ovaries of each cow were examined ultrasonographically for the presence of a corpus luteum. Interval from calving or from D 0 to resumption of OA was shorter (P < 0.05) and the proportion of cows that resumed OA during the experiment was greater (P < 0.05) for BE12 cows than for NE cows. Interval from D 0 to resumption of OA did not differ between BE6 cows and either BE12 or NE cows. However, interval from calving to resumption of OA was shorter (P < 0.05) for BE6 than NE cows. The proportion of cows that resumed OA did not differ between BE6 cows and BE12 cows; however, the proportion of cows that resumed OA during the experiment tended (P = 0.08) to be greater for BE6 cows than for NE cows. There was a linear relationship between intervals from calving (b1 = -7.64 d/h; P < 0.05) and D 0 (b1 = -3.3 d/h; P < 0.05) to resumption of OA and duration of daily bull exposure. These results indicate that the duration of daily bull exposure perceived by primiparous, anovular, suckled cows each day is an integral component of the mechanism whereby cows respond to this stimulus and undergo physiological changes necessary for resumption of ovulatory activity. PARTICIPANTS: J.G. Berardinelli, Principal Investigator; Graduate Student; J. R. Olsen, M. S. Graduate Student; J. R. W. Wilkinson, M. S. Graduate Student; R. McCosh, M. S. Graduate Student; M. Borgreen, M. S. Graduate Student; T. Gibbs, Undergraduate Research Intern; Chris Sundquist, Undergraduate Research Intern; Eli Berry, Undergraduate Research Intern; P. Crampton, Undergraduate Research Intern; K. Hendry, Undergraduate Research Intern; K. Phillips, Undergraduate Lab Assistant; E. Richards, Undergraduate Lab Assistant. TARGET AUDIENCES: Research Scientists, Academics, Extension and Outreach Specialists, Beef Cattle Producers PROJECT MODIFICATIONS: None

Impacts
The biostimulatory effect of bulls accelerates ovulatory cyclicity in primiparous, postpartum, anestrous, suckled cows. We now have shown that the variation associated with this action involves a minimum length of time during any day that cows must be in close proximity to bulls to respond to the stimulatory effect of bulls. This result changes fundamental knowledge regarding the physiological mechanism whereby the biostimulatory effect of bulls accelerates resumption of ovarian cycling activity and increase reproductive efficiency in beef cattle and can be used by producers to more effectively take advantage of the bull effect.

Publications

  • Tauck, S. A., J.R. Olsen, J.R.C. Wilkinson, and J.G. Berardinelli. 2009. Duration of daily bull exposure on resumption of ovulatory activity in postpartum, primiparous, suckled, beef cows. Anim. Repro. Sci. doi:10.1016/j.anireprosci.2009.06.010.
  • Tauck, S. A., J. R. Olsen, J. R. C. Wilkinson, and J. G. Berardinelli. 2009. Duration of daily bull exposure on resumption of ovulatory activity in postpartum, primiparous, anovular, suckled, beef cows. Proc. West. Sec. Amer. Soc. Anim. Sci. 60:259-262.
  • Tauck, S. A., J. R. Olsen, J. R. C. Wilkinson, and J. G. Berardinelli. 2009. Duration of daily bull exposure on resumption of ovulatory activity in postpartum, primiparous, anovular, suckled, beef cows. J. Anim. Sci. 87,[E-Suppl. 3]:150, Abstr. 43.
  • Berardinelli, J. G., J. R. C. Wilkinson, S. A. Tauck, J. R. Olsen, and R. Wedlake. 2009. Duration of daily bull exposure on follicular wave dynamics of postpartum, anovular, suckled cows. Biol. Repro. 81[Suppl.]:106, Abstr. 544.
  • Gibbs, T., and J. G. Berardinelli. 2009. Daily bull exposure duration on resumption of ovulatory activity in primiparous, postpartum, anovular, suckled, beef cows. MSU Student Research Celebration. Montana State University, Conference Program, p. 36(Abstr.): Poster 28.
  • Wilkinson, J. R. C. 2009. The biostimulatory effect of bulls on postpartum follicular wave development in, postpartum, anestrous, suckled beef cows. M. S. Thesis, Montana State University-Bozeman.


Progress 12/01/07 to 11/30/08

Outputs
OUTPUTS: The objective was to determine if bulls alter temporal patterns of cortisol concentrations in postpartum beef cows before resumption of ovulatory activity (ROA). The null hypotheses were that interval to ROA and characteristics of cortisol patterns do not differ between cows exposed or not exposed to bulls. At 72 +/-3.5 d ( +/- SE) postpartum, anovular cows were assigned randomly to be exposed (BE; n=8) or not exposed (NE; n=5) to bulls for 33 d in separate pen areas. Day 0 was designated as the start of bull exposure. Blood samples were collected daily via an indwelling jugular catheter from each cow at 15-min intervals between 1000 to 1400 h over a 9-d interval (D7 to 16) for assay of cortisol. Interval from D 0 to ROA, mean cortisol, and pulse frequency, amplitude, and duration, and inter-pulse interval were analyzed by ANOVA. Interval to ROA was shorter (P<0.05) for BE (11.4 d) than NE (21 d) cows. Mean cortisol and characteristics of cortisol patterns did not differ (P>0.10) between BE and NE cows from D 7 to 16. However, standardizing cortisol patterns relative to cows that ROA indicated that frequency of cortisol pulses was lower (P<0.05), mean cortisol was greater (P<0.05), pulse frequency was lower (P<0.05), and pulse duration was greater (P<0.05) in those BE cows that ROA. Whereas, pulse duration only was shorter (P< .05) in those NE cows that ROA. During the intensive sampling period mean cortisol and cortisol pulse duration were correlated positively (P< .05) with interval to ROA in BE cows, while only mean cortisol was correlated positively (P<0.05) with interval to ROA in NE cows. In conclusion, bull exposure decreased cortisol pulse frequency and lengthened cortisol pulse duration before ROA. The results indicate that changes in characteristics of cortisol concentrations patterns precede the biostimulatory effect of bulls to induce resumption of ovulatory activity in postpartum,anovular, suckled beef cows. PARTICIPANTS: J.G. Berardinelli, Principal Investigator; S. A. Tauck, Ph.D. Graduate Student; J. R. Olsen, M. S. Graduate Student; J. R. W. Wilkinson, M. S. Graduate Student; R. Wedlake, Undergraduate Research Intern; K. Phillips, Undergraduate Research Intern; L. Runnion, Undergraduate Lab Assistant; L. Tauck, Undergraduate Lab Assistant; T. Gibbs, Undergraduate Lab Assistant; E. Richards, Undergraduate Lab Assistant. TARGET AUDIENCES: Research Scientists, Academics PROJECT MODIFICATIONS: None

Impacts
The biostimulatory effect of bulls appears to initally involve a change in cortisol concentrations patterns that have an immediate effect on activity of the hypothalamic-pituitary-ovarian axis. The effect of bulls decreases pulse rhythm of cortisol which facilitates and increase in LH frequency that, in turn, accelerates ovulatory cyclicity in primiparous, postpartum, anestrous, suckled cows. This a change in fundamental knoledge of the physiological mechanism whereby the biostimulatory effect of bulls accelerates resumption of ovarian cycling activity and increase reproductive effciency in beef cattle.

Publications

  • Tauck, S. A., Olsen, J. R., J. R. C. Wilkinson, and J. G. Berardinelli. 2008. The biostimulatory effect of bulls in postpartum, anestrous, suckled beef cows alters cortisol concentrations and characteristic of cortisol concentration patterns before resumption of ovulatory activity. J. Anim. Sci. 86(E-Suppl. 2): Abstr. 479.
  • Tauck, S. A. 2008. The biostimulatory effect of bulls on hypothalamic-pituitary-adrenal and ovarian axes and on temporal aspects of resumption of ovarian cycling activity in primiparous, postpartum, suckled, beef cows. Ph.D. Dissertation, Montana State University-Bozeman.
  • Wilkinson, J. R. C., S. A. Tauck, J. R. Olsen, R. J. Wedlake, and J. G. Berardinelli. 2008. Effects of oro-nasal administration of androstadienone on characteristics of cortisol concentrations in postpartum, suckled beef cows. J. Anim. Sci. 86(E-Suppl. 2): (Abstr. 480).
  • Berardinelli, J. G., and S. A. Tauck. 2007. Intensity of the biostimulatory effect of bulls on resumption of ovulatory activity in primiparous, suckled, beef cows. Anim. Reprod. Sci. Anim. Reprod. Sci. 99:24:33.
  • Tauck, S. A., J. R. Olsen, J. R. C. Wilkinson, and J. G. Berardinelli. 2009. Duration of daily bull exposure on resumption of ovulatory activity in primiparous, postpartum, suckled, beef cows. Anim. Repro. Sci. (Accepted Mar. 2009).
  • Tauck, S. A., J. R. Olsen, J. R. C. Wilkinson, K. Davis, R. Wedlake, and J. G. Berardinelli. 2009. Characteristics of temporal patterns of cortisol and luteinizing hormone in primiparous, postpartum, suckled, beef cows exposed acutely to bulls. Reprod. Biol. and Endocrinol. (Pending).


Progress 12/01/06 to 11/30/07

Outputs
OUTPUTS: The objective of this experiment was to determine if the presence of bulls acutely alters the temporal cortisol concentrations in postpartum, anestrous, suckled beef cows. We tested the hypotheses that mean cortisol concentrations and characteristics of cortisol concentration patterns do not differ between cows exposed to bulls or steers. Primiparous, crossbred (Angus X Hereford) cows were 67 d (SE = 3.5 d) postpartum at the start of the experiment. Cows were stratified by body weight, BCS, calf birth weight, calving date, sex of calf and dystocia score and assigned randomly to be exposed to either bulls (BE, n = 8) or steers (SE, n = 8) 5 h daily for 9 d (D 0 to 8). On D 0 cows in each treatment (TRT) were halter-restrained in individual adjacent stalls housed in similar but separate open-air sheds. Bulls and steers were contained in the immediate vicinity in front of cows, unrestrained and allowed free access to and contact with the frontal aspects of cows. Cows were fitted with indwelling jugular catheters 2 d before the start of the experiment. Blood samples were collected daily from each cow at 15-min intervals for 6 h from 1000 to 1600 h each day. The 5-h exposure period began 1 h after the start of the intensive bleeding period. Serum was assayed for cortisol concentrations using solid-phase RIA. Mean cortisol concentrations and characteristics of cortisol concentration patterns (baseline, pulse frequency, amplitude, duration, and area under pulses) were analyzed by ANOVA for a completely randomized design. There was a significant (P<0.05) TRT by time by day interaction for mean cortisol concentrations from D 0 to 8. The day component of this interaction was likely caused by higher (P<0.05) cortisol concentrations on d 0 (10 ng/mL) and d 1 (4.7 ng/mL), than throughout the remainder of the experiment (2.5 ng/mL). There were no day or TRT effects (P>0.10) for cortisol concentrations from D 2 through 8; indicating cows in both treatments acclimated to the blood sampling procedure within 2 d. The TRT by time interaction might be explained by differences in the characteristics of cortisol concentration patterns. Baseline, pulses/d, pulse amplitude, and area under pulses did not differ (P>0.10) between BE and SE cows from D 2 through 8. However, pulse duration was longer (P<0.05) on d 2 through 8 in BE cows than in SE cows. Furthermore, pulse frequency was decreased (P<0.05) and pulse duration was longer (P<0.05) in BE cows compared to SE cows during the daily exposure period from d 2 through 8. Peak fit analyses indicated that the timing at which pulses occurred appeared to be temporally synchronized in BE cows, whereas the timing at which pulses occurred in SE seemed to be random. In conclusion, bull exposure did not alter mean concentrations of cortisol; however, bull exposure changed temporal patterns of cortisol concentrations by decreasing the frequency, increasing the duration of pulses and synchronizing the pulsatile rhythm of cortisol in anestrous, suckled beef cows. PARTICIPANTS: J. G. Berardinelli, Principal Investigator; S. A. Tauck, Ph.D. Graduate Student; J. R. Olsen, M. S. Graduate Student; J. R. W. Wilkinson, M. S. Graduate Student; R. Wedlake, Undergraduate Research Intern; R. Goodfriend, Undergraduate Research Intern; T. Morris, Undergraduate Research Intern; M. Hove, Undergraduate Research Intern; L. Tauck, Undergraduate Lab Assistant; T. Gibbs, Undergraduate Lab Assistant; E. Richards, Undergraduate Lab Assistant TARGET AUDIENCES: Research Scientists, Academics PROJECT MODIFICATIONS: None

Impacts
Bull exposure did not alter mean concentrations of cortisol; however, bull exposure changed temporal patterns of cortisol concentrations by decreasing the frequency, increasing the duration of pulses and synchronizing the pulsatile rhythm of cortisol in anestrous, suckled beef cows. These data suport the hypothesis that adrenal activity may be involved with the Biostimulatory effect of bulls in postpartum, anovular cows.

Publications

  • Tauck, S. A., J. R. Olsen, and J. G. Berardinelli. 2007. Adrenal involvement in the biostimulatory effect of bulls. Reprod. Biol. and Endocrinol. 5:33-39.
  • Wilkinson, J. R. C., S. A. Tauck, J. R. Olsen, and J. G. Berardinelli. 2007. Concentrations of glucose, NEFA, thyroxine, and triiodothyronine in primiparous, anestrous, suckled beef cows exposed to bulls. Proc. West. Sect. Amer. Soc. Anim. Sci. 58:262-265.
  • Wilkinson, J. R. C., S. A. Tauck, J. R. Olsen, and J. G. Berardinelli. 2007. Concentrations of glucose, NEFA, thyroxine, and triiodothyronine in primiparous, anestrous, suckled beef cows exposed to bulls. J. Anim. Sci. 85(Suppl. 2):169 (Abstr. 63).
  • Wilkinson, J. R. C., S. A. Tauck, J. R. Olsen, and J. G. Berardinelli. 2007. Effect of bull exposure on glucose, NEFA, thyroxine, and triiodothyronine in primiparous, anestrous, suckled beef cows. Montana Acad. Sci. Annual Meeting, Program and Abstracts. Page 3.