Progress 10/01/04 to 09/30/11
Outputs
OUTPUTS: A Stochastic Evaluation of Reproductive Management Programs for Dairy Herds. J. O. Giordano, P. M. Fricke, M. C. Wiltbank, and V. E. Cabrera. Department of Dairy Science, University of Wisconsin. A Markov-chain simulation model was developed to compare the net present value (NPV, $/cow/d) generated by different reproductive management programs (RP) in a dairy herd. The daily NPV of a specific RP was calculated by adding the discounted expected monetary values (DEMV) of that proportion of cows that become pregnant at each successive AI service until a maximum predefined DIM plus the DEMV of that proportion of cows not becoming pregnant to the RP. The DEMV for a lactation defined by DIM at pregnancy was calculated based on the value of milk produced, feed cost, expected value of a new born calf, and cost of culling. Economic, productive, and reproductive values were user-defined for each RP evaluated. The model sequentially estimated the percentage of cows eligible for breeding, becoming pregnant, and not becoming pregnant at each AI service based on the service rate (SR) and conception rate (CR) of each RP. Total AI service cost including pregnancy diagnosis (PD) was applied to all cows until pregnancy or culling for reproductive failure. For synchronized AI services, total cost was calculated by adding the individual cost of: treatments, labor, AI, and PD. Total cost for estrous services was calculated by adding the individual cost of heat detection, AI, and PD. A decision tree then compared the NPV for different RPs. A comparison among commonly used programs with typical reproductive values (Table 1) indicated that a Presynch-Ovsynch (PS-Ov) protocol with 100% TAI (A) for 1st service was stochastically dominant over RP (B) and (C). Utilization of this model by commercial dairy herds may facilitate selection of economically-optimal RP based on farm-specific parameters. PARTICIPANTS: I collaborated on this project with two of my colleagues, Dr. Milo Wiltbank and Dr. Victor Cabrera. In addition, Mr. Julio Giordano is the graduate student on this project and these data will be included as part of his Ph.D. thesis. TARGET AUDIENCES: Target audiences for these data include: dairy farmers, veterinarians, county extension agents, and the AI industry. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Development and use of a stochastic model by commercial dairy herds may facilitate selection of economically-optimal reproductive programs based on farm-specific parameters.
Publications
- Giordano, J. O., P. M. Fricke, M. C. Wiltbank, and V. E. Cabrera. 2010. A stochastic evaluation reproductive management programs for dairy herds. J. Dairy Sci. 93(E-Suppl. 1):752.
- Giordano, J. O., P. M. Fricke, M. C. Wiltbank, and V. E. Cabrera. 2010. An economic decision-making model for comparing reproductive management programs in dairy herds. Midwest ADSA.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: A series of experiments was conducted to assess hormonal synchronization protocols for submitting lactating dairy cows for first postpartum or resynchronized breedings. Our first objective was to determine the effect on pregnancies per AI (P/AI) of increasing the dose of the 1st GnRH and PGF2α injections during the Breeding-Ovsynch of Double-Ovsynch (DO; Pre-Ovsynch, GnRH-7d-PGF2 alpha -3d-GnRH; 7d later Breeding-Ovsynch, GnRH-7d-PGF2 alpha-56h-GnRH-16h-TAI) for 1st post-partum TAI. In Exp.1, cows were blocked by parity and randomly assigned to a 2x2 factorial design to receive either low (L) or high (H) doses of GnRH (100 vs. 200 micrograms) and either low (L) or high (H) doses cloprostenol (500 vs. 750 micrograms) resulting in the following treatments: LL (263), HL (277), LH (270), and HH (274). Ovarian ultrasound and serum progesterone (P4) were used to assess ovulation to 1st GnRH and luteal regression after PGF2 alpha (P4 less than or equal to 0.5 ng/ml at 2nd GnRH) of Breeding-Ovsynch in a subgroup of cows. Pregnancy status was assessed 29 and 74 d after TAI. In Exp. 2, cows were blocked by parity and randomly assigned to LL (222) or HH (226) treatments described for Exp. 1. Our second objective was to assess if using Double-Ovsynch (DO, Pre-Resynch, GnRH-7d-PGF2 alpha-3d-GnRH, 7d later Breeding-Resynch, GnRH-7d-PGF2 alpha-56h-GnRH-16h-TAI) to resynchronize ovulation for second and subsequent TAI may increase pregnancies per AI (P/AI) compared to Standard Ovsynch (OV, GnRH-7d-PGF2 alpha-56h-GnRH-16h-TAI). For Exp. 3, cows at various DIM and prior services were blocked by parity and were randomly assigned to either DO or OV for resynchronization of ovulation and TAI. All DO cows received the 1st GnRH injection of Pre-Resynch 22 d after TAI, and cows (962) diagnosed not pregnant using transrectal ultrasonography 29 d after TAI continued the protocol. All OV cows received GnRH 32 d after TAI, and cows (956) diagnosed not pregnant using transrectal palpation 39 d after TAI continued the protocol. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Results have been presented to scientists at the National ADSA meetings and to veterinarians, dairy producers, and county extension faculty at numerous meetings throughout the past year. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
For Exp. 1 and 2, ovulation to the 1st GnRH injection of Breeding-Ovsynch was greater for cows receiving H vs. L GnRH; however, luteal regression after PGF2 alpha did not differ for cows receiving H vs. L dose of PGF2 alpha (93.8 vs. 91.5 percent). For Exp. 2, P/AI at 29 d did not differ between H vs. L treatments, and was not affected by parity. Thus, despite an increase in ovulation to the 1st GnRH injection of Breeding-Ovsynch, there was no detectable effect of increasing the dose of GnRH or PGF2 alpha on fertility to 1st post-partum TAI after Double-Ovsynch. For Exp. 3, Overall, P/AI 29 d after TAI was not affected by parity and was greater for DO compared to OV cows [38.5 (370/962) vs. 30.0 (287/956)]. Pregnancy loss from 29 to 74 d after TAI was not affected by parity and did not differ between treatments [DO, 13.9 (50/359) vs. OV, 17.5 (49/280)]. Proportion of cows with a CL at the 1st GnRH injection of Breeding-Resynch and OV was greater for DO than OV cows [85.4 (373/437) vs. 68.9 (314/456)]. Ovulation to the GnRH injection before TAI was similar between treatments [DO, 90.0 (251/279) vs. OV, 87.5 (238/272)]. We conclude that Double-Ovsynch increased fertility of lactating cows compared to a Standard Ovsynch protocol when used for resynchronization of ovulation. These results were presented to scientists at the National ADSA meetings and to veterinarians, dairy producers, and county extension agents at meetings held throughout the past year.
Publications
- Giordano, J. O., P. M. Fricke, S. Bas, A. P. Cunha, R. Pawlisch, J. N. Guenther, and M. C. Wiltbank. 2009. Effect of increasing GnRH and PGF2α dose during Double-Ovsynch on fertility of lactating dairy cows at first postpartum timed artificial insemination. J. Dairy Sci. 92(E-suppl. 1):264.
- Giordano, J. O., M. C. Wiltbank, S. Bas, A. P. Cunha, R. Pawlisch, J. N. Guenther, and P. M. Fricke. 2009. Fertility after timed artificial insemination in lactating dairy cows resynchronized using Double-Ovsynch or Standard Ovsynch. J. Dairy Sci. 92(E-Suppl. 1):188.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Results from this work have been disseminated through the PI's statewide, national, and international Extension program in Dairy Cattle Reproduction. Methods of dissemination include oral presentation at extension and scientific meetings for dairy producers, veterinarians, and researchers as well as through the PI's web site. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Results from this research have been disseminated through the PI's statewide, national, and international extension program in dairy cattle reproduction. Audiences include: dairy veterinarians, dairy producers, AI technicians, and the allied dairy industry. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The primary objective of this study was to evaluate fertility of anovular dairy cows treated with GnRH 4 d after first postpartum timed AI (TAI). Secondary objectives were to determine ovulatory response to treatment, effect of treatment on circulating P4, and the proportion of cows with a short luteal phase. Anovular cows were identified from an initial 1047 lactating Holstein cows using transrectal ultrasonography based on the absence of a CL at the first GnRH injection of a Presynch + Ovsynch protocol, and anovular cows were randomly assigned to receive no further treatment (Control, n = 85), or 100 ug of GnRH 4 d after TAI (GnRH treated; n = 71). For GnRH treated cows, 51% responded by ovulating a follicle in response to GnRH treatment 4 d after TAI; however, pregnancies per AI (P/AI) did not differ between GnRH treated cows that ovulated (36%) compared to GnRH treated cows that did not ovulate (21%). There was a quadratic effect of P4 at the PGF2 alpha injection of Ovsynch on P/AI, and cows with P4 ≥ 1 ng/mL at the PGF2 alpha injection of Ovsynch had greater P/AI (41%) than cows with P4 < 1 ng/mL (12%); however, no treatment difference was detected. Overall, P/AI did not differ between control (30.1%) and GnRH (29.6%) treatments for synchronized cows. Although treatment of anovular cows with GnRH 4 d after TAI failed to improve fertility, variation among cows in serum P4 at the PGF2 alpha injection of Ovsynch dramatically affected fertility of anovular dairy cows.
Publications
- Sterry, R. A., E. Silva, D. Kolb, and P. M. Fricke. 2008. Strategic treatment of anovular dairy cows with GnRH. Theriogenology (In press).
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: The objectives of this project were threefold: 1) to assess the accuracy of a pregnancy associated glycoprotein assay (PAG) to determine pregnancy status of dairy cows 27 days after insemination; 2) to assess a practical method for identifying anovular lactating dairy cows before first postpartum insemination; and 3) to optimize a strategy for resynchronizing lactating dairy cows failing to conceive to a previous insemination. These results have been disseminated through the PD's international, national, and statewide extension program in dairy cattle reproduction. The PD presented 23 talks for the dairy industry in Wisconsin during 2007 with a total of 721 people in attendance, 23 out of state regional and national talks during 2007 with a total of 936 people in attendance, and 6 meetings to international audiences (two talks in Italy, two talks in Vancouver, two talks in Mexico, five talks in Germany, and one talk in Austria) during 2007 with a total of 562 people in
attendance.
PARTICIPANTS: Individuals: Paul M. Fricke, PI/PD Elena Silva, graduate research assistant Ryan A. Sterry, graduate research assistant Collaborators: Milo C. Wiltbank, Dairy Science Department collaborator David Kolb, veterinarian Joan M. Ballam, statistician, Monsanto Dairy Business Michael F. McGrath, research leader, Monsanto Dairy Business N. Mathialagan, laboratory technician, Monsanto Dairy Business Blue Star Dairy, De Forest, WI, collaborating dairy Partner organization Monsanto Dairy Business
TARGET AUDIENCES: Target audiences include: dairy veterinarians, dairy consultants, dairy producers, county agriculture agents
PROJECT MODIFICATIONS: None.
Impacts
Results from this project has provided key information to the dairy industry including a practical method for identification of noncycling cows before insemination, the accuracy of a new method for pregnancy diagnsosis (PAG) as well as information on use of transrectal ultrasonography as a method for pregnancy diagnosis, and a new practical method for resynchronizing cows failing to conceive to a previous insemination. These findings have been implemented into on-farm reproductive management strategies as a way to improve reproductive performance and profitability of dairy farms.
Publications
- Silva, E., R. A. Sterry, D. Kolb, M. C. Wiltbank, and P. M. Fricke. 2007. Effect of pretreatment with prostaglandin F2α before resynchronization of ovulation on fertility of lactating Holstein cows. J. Dairy Sci. 90:5509-5517.
- Silva, E., R. A. Sterry, D. Kolb, N. Mathialagan, M. F. McGrath, J. M. Ballam, and P. M. Fricke. 2007. Accuracy of a pregnancy-associated glycoprotein (PAG) ELISA to determine pregnancy status of lactating dairy cows twenty-seven days after timed AI. J. Dairy Sci. 90:4612-4622.
- Silva, E. P. B., R. A. Sterry, and P. M. Fricke. 2007. Assessment of a practical method for identifying anovular lactating dairy cows synchronized for first postpartum timed artificial insemination. J. Dairy Sci. 90:3255-3262.
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Progress 01/01/06 to 12/31/06
Outputs
In the first study, lactating Holstein cows (n = 763) were assigned randomly at timed AI (TAI) to receive the first GnRH injection of Ovsynch 26 (D26) or 33 (D33) d after TAI to resynchronize ovulation in cows failing to conceive (Resynch). Cows in the D26 treatment received GnRH 26 d after TAI and continued Resynch only when diagnosed not pregnant 33 d after TAI, whereas D33 cows initiated Resynch only when diagnosed not pregnant 33 d after TAI. Pregnancies per AI (P/AI) was greater for cows assigned to the D33 than the D26 Resynch treatment (39.4 vs. 28.6%). A treatment by parity interaction was detected for P/AI after Resynch for not pregnant cows with a CL in which primiparous cows had a greater PR/AI than multiparous cows when Resynch was initiated 33 d after the initial TAI, and primiparous and multiparous cows when Resynch was initiated 26 d after the initial TAI. We conclude that delaying initiation of Resynch until 33 d after TAI increased P/AI for
primiparous cows. In a second experiment, Lactating Holstein cows were assigned randomly to treatments to improve fertility after first postpartum timed AI (TAI). In Exp. 1, cows received no treatment (C; n = 9), a CIDR insert from 5 to 12 d after TAI (CIDR; n = 9), or 100 μg of GnRH 5 d after TAI (G5; n = 7). Although treatments did not affect circulating progesterone (P4) concentrations from 5 to 19 d after TAI, there was a tendency for CIDR cows to have greater P4 compared with C or G5 cows within 24 h after treatment. In 2 field trials, cows received either C (n = 223), CIDR (n = 218), or G5 (n = 227) treatments (Exp. 2), or C (n = 160), G5 (n = 159), or treatment with 100 μg of GnRH 7 d after TAI (G7; n = 163; Exp. 3). Although treatment did not affect pregnancies per AI (P/AI) in Exp. 2 or 3, when data were combined to compare C (n = 383) and G5 (n = 386) treatments, P/AI tended to be greater for G5 (49.1 %) than C (45.8 %) cows, and this effect resulted from a GnRH
treatment by cyclicity status interaction in which P/AI for noncycling cows receiving G5 was greater than noncycling C cows (45.5 vs. 31.1 %). In conclusion, treatment with CIDR inserts after TAI had no effect on P/AI, whereas treatment with GnRH 5 d after TAI improved P/AI for noncycling, but not for cycling cows.
Impacts
Results from these experiments have provided information to dairy producers, bovine practitioners, and county extension agents to: 1)optimize the timing of resynchronization of ovulation in lacatating dairy cows failing to conceive to a previous breeding, and 2) to improve fertility in anovular cows synchronized for to receive their first postpartum timed artificial insemination. These results will directly impact the more than 14,000 dairy producers and 1.2 million lactating dairy cows in Wisconsin.
Publications
- Sterry, R. A., M. L. Welle, and P. M. Fricke. 2006. Treatment with GnRH after first timed AI improves fertility in noncycling lactating dairy cows. J. Dairy Sci. 89:4237-4245.
- Rivera, H., R. A. Sterry, and P. M. Fricke. 2006. Presynchronization with GnRH does not improve fertility to synchronization of ovulation and timed artificial insemination in Holstein heifers. J. Dairy Sci. 89:3810-3816.
- Stevenson, J. S., J. R. Pursley, P. M. Fricke, H. A. Garverick, D. J. Kesler, J. S. Ottobre, and M. C. Wiltbank. 2006. Treatment of cycling and noncycling lactating dairy cows with progesterone during Ovsynch. J. Dairy Sci. 89:2567-2578.
- Sterry, R. A., M. L. Welle, and P. M. Fricke. 2006. Effect of interval from timed AI to initiation of resynchronization of ovulation on fertility of lactating dairy cows. J. Dairy Sci. 89:2099-2109.
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Progress 01/01/05 to 12/31/05
Outputs
Three experiments have been conducted to manipulate ovarian function in nonlactating dairy heifers and lactating dairy cows to improve reproductive management and reproductive performance. In the first experiment, controlled Internal Drug Releasing (CIDR) inserts were used to suppress estrus in nonlactating Holstein dairy heifers (n=189) during a hormonal protocol for timed AI and to synchronize return to estrus among heifers failing to conceive to first AI service. Inclusion of CIDR inserts suppressed estrus during the TAI protocol with no reduction in fertility, and resynchronization of estrus using CIDR inserts resulted in tighter synchrony of estrus among nonpregnant heifers compared to untreated controls. Overall fertility throughout this experiment was low due to poor performance of two of the three herd inseminators. The protocol tested in this study should minimize the time and duration needed for estrus detection and may increase the proportion of dairy
heifers bred to AI. In a second experiment, lactating Holstein cows (n=763) were assigned randomly to resynchronize ovulation by using Ovsynch (Resynch) either 26 or 33 d after a previous timed AI (TAI). Primiparous cows with a CL at the not-pregnant diagnosis receiving Resynch 33 d after TAI had greater fertility than cows receiving Resynch on d 26. Overall number of pregnancies was greater when Resynch was initiated 33 vs. 26 d after a previous TAI. We conclude that delaying initiation of Resynch until 33 d after TAI increased fertility, particularly for primiparous cows. A third experiment was conducted to test the effect of post-insemination treatments on fertility. Lactating Holstein cows were assigned at first postpartum timed AI (TAI) to receive no treatment, a CIDR insert from 5 to 12 d after TAI, or treatment with GnRH either 5 or 7 d after TAI. Although treatment with CIDR or GnRH d 7 did not affect fertility, overall fertility tended to be greater for cows receiving GnRH 5
d after TAI due to an increase in fertility for anovular cows. Ongoing experiments are being conducted to further understand the mechanism by which GnRH treatment post TAI improves fertility in anovular cows and to continue to optimize timing of nonpregnancy diagnosis and resynchronization of ovulation in lactating dairy cows.
Impacts
Results from these experiments have provided information to dairy producers, bovine practitioners, and county extension agents to: 1) syncrhonize nonlactating dairy heifers to receive a timed artificial insemination, 2) to ooptimize the timing of resynchronization of ovulation in lacatating dairy cows failing to conceive to a previous breeding, and 3) to improve fertility in anovular cows synchronized for to receive their first postpartum timed artificial insemination. These results will directly impact the more that 14,000 dairy producers and 1.2 million lactating dairy cows in Wisconsin.
Publications
- Sterry, R. A., M. L. Welle, and P. M. Fricke. 2006. Effect of interval from timed AI to initiation of resynchronization of ovulation on fertility of lactating dairy cows. J. Dairy Sci. (In press).
- Rivera, H., H. Lopez, and P. M. Fricke. 2005. Use of intravaginal progesterone-releasing inserts in a synchronization protocol before timed AI and for synchronizing return to estrus in Holstein heifers. J. Dairy Sci. 88:957-968.
- Sterry, R. A., M. L. Welle, and P. M. Fricke. 2005. Effect of GnRH or CIDR inserts administered early after first timed insemination on fertility of lactating dairy cows. J. Dairy Sci. 88(Suppl. 1):87. (Abstr.).
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