Publikationsdatenbank

Was machen Betriebe mit guter Fruchtbarkeit besser? (2023)

Art

Vortrag

Autor

Borchardt, Stefan (WE 19)

Kongress

1. Tumpejevi dnevi

Ptuj, 02. – 03.02.2023

Quelle

Sprache

Englisch

Kontakt

Tierklinik für Fortpflanzung

Königsweg 65
Haus 27
14163 Berlin
+49 30 838 62618
fortpflanzungsklinik@vetmed.fu-berlin.de

Abstract / Zusammenfassung

How to achieve high pregnancy rates?

Dr. Stefan Borchardt

Reproductive performance has a major effect on dairy farm profitability (Cabrera, 2014). The 21 d Pregnancy Rate is the best metric to determine reproductive efficiency (Overton and Cabrera, 2017). This metric, commonly abbreviated as 21 d PR, reflects the probability of an eligible cow (i.e., past the voluntary waiting period (VWP) and not “Do not breed”) to become pregnant within a stated 21d period. Two main drivers control 21d PR: Service rate (or Heat Detection Rate) and conception rate (or pregnancy per AI; P/AI). In order to achieve high 21d PR one has to focus on 5 things:
1. Healthy transition cows
2. Inseminate cows quickly after the end of the VWP
3. Maximize P/AI at first service
4. Identify nonpregnant cows early and re-inseminate them quickly
5. Maximize P/AI for AI 2+

Management of transition cows
Transition cow health is an important prerequisite for achieving high fertility. Diseases around calving have a negative impact on fertility but they also increase the risk for pregnancy loss (Santos et al., 2010; Ribeiro et al., 2016). Farmers should pay attention to cow comfort and maximizing dry matter intake (e.g., avoid overcrowding, provide adequate bunk space). In addition to that, a prevention strategy for hypocalcemia and ketosis should be implemented. Both farms use a controlled energy diet for the whole dry period and a negative DCAD (dietary cation-anion difference) in close up cows (Cardoso et al., 2020). A key aspect of controlled energy diets is to maximize dry matter intake (13.5 kg/d) without overfeeding energy (80 MJ/d). Therefore, these farms use high quality chopped straw (particle length 1 to 4cm) in large amounts (app. 5kg per cow/d). All cows are tested twice within the first 2 weeks for hyperketonemia using a cowside blood BHBA test. Cows with hyperketonemia (BHBA ≥ 1.2 mmol/L) receive 300ml propylene glycol for 3 to 5 d (McArt et al., 2011).
To prevent hypocalcemia is has been recommended to feed a negative DCAD diet (-50 to -100 meq/kg DM) for the last 3 weeks before calving (Lean et al., 2019). This can be achieved by avoiding feed components with excessive cations (e.g., grass silage) or use specific products (anions) to lower DCAD. The implementation of a negative DCAD diet has to be controlled using urinary pH (goal 6.0) on a weekly base in a subsample of cows. As older cows have a greater risk for hypocalcemia, these cows receive oral calcium supplementation at calving.
Management of the first AI
The 2 farms have a different approach for managing first service. Farm 1 has a VWP of 60 d and they use an automated activity monitoring system for estrus detection. Within the 1st cycle after the VWP 70 % of the cows are bred upon estrus detection. The remaining cows (30%) are enrolled into a modified Ovsynch protocol with 80 DIM. Cows receive 2 injections of prostaglandin at d 7 and 8 (Table 2; Wiltbank et al., 2015). There is almost no difference in P/AI when comparing AI after estrus (primiparous cows 59 %, multiparous cows 45 %) or timed AI (primiparous cows 58 %, multiparous cows 40 %).
The second farm uses a modified Double-Ovsynch protocol with 2 injections of prostaglandin at d 7 and 8 in the second portion of Double-Ovsynch protocol (Fricke and Wiltbank, 2022). All cows receive timed AI. First service conception risk is 59% and 43% for primiparous cows and multiparous cows, respectively.
It has been shown that incomplete luteal regression after one PGF injection reduced P/AI. This can occur in 25% of the cows and is primarily a problem in multiparous cows. Giving two injections of PGF on d 7 and d 8 can improve the percentage of cows with complete luteal regression and increase P/AI by 10% (Borchardt et al., 2021).

Management of subsequent services
Nonpregnant cows need to be identified quickly in order to re-inseminate them. Therefore, a systematic approach has been recommended. There are timed AI protocols available (called Resynch) that can be used to reduce interbreeding intervals (Lopes et al., 2013). The first GnRH injection of these protocols can be given to all cows one week before pregnancy check without any negative effect in cows that are pregnant (Figure 1). This approach is only recommended, if it becomes a weekly farm routine and pregnancy examinations are done on the same day of the week.

Figure 1. Management of nonpregnant cows at pregnancy diagnosis in order to re-inseminate them quickly.
For nonpregnant cows, there are 2 distinct situations (Perez et al., 2020): 1) nonpregnant and an active corpus luteum (>15mm) and 2) nonpregnant without an active corpus luteum. Nonpregnant with a CL (usually 70 to 80% of the cows) have better fertility compared with cows without a CL because the follicle that will ovulate at the end of the protocol develops under a more optimum hormonal environment. However, cows without a CL at pregnancy diagnosis should be enrolled into an Ovsynch protocol again starting at the day of nonpregnancy diagnosis.

Literature
Borchardt, S., C. M. Tippenhauer, P. M. Fricke, and W. Heuwieser. 2021. Economic impact of adding a second prostaglandin F(2alpha) treatment during an Ovsynch protocol using a meta-analytical assessment and a stochastic simulation model. J Dairy Sci 104(11):12153-12163.

Cabrera, V. E. 2014. Economics of fertility in high-yielding dairy cows on confined TMR systems. Animal 8 Suppl 1:211-221.

Cardoso, F. C., K. F. Kalscheur, and J. K. Drackley. 2020. Symposium review: Nutrition strategies for improved health, production, and fertility during the transition period. J Dairy Sci 103(6):5684-5693.

Carvalho, P. D., V. G. Santos, J. O. Giordano, M. C. Wiltbank, and P. M. Fricke. 2018. Development of fertility programs to achieve high 21-day pregnancy rates in high-producing dairy cows. Theriogenology 114:165-172.

Fricke, P. M. and M. C. Wiltbank. 2022. Symposium review: The implications of spontaneous versus synchronized ovulations on the reproductive performance of lactating dairy cows. J Dairy Sci 105(5):4679-4689.

Lean, I. J., J. E. P. Santos, E. Block, and H. M. Golder. 2019. Effects of prepartum dietary cation-anion difference intake on production and health of dairy cows: A meta-analysis. J Dairy Sci 102(3):2103-2133.

Lopes, G., Jr., J. O. Giordano, A. Valenza, M. M. Herlihy, J. N. Guenther, M. C. Wiltbank, and P. M. Fricke. 2013. Effect of timing of initiation of resynchronization and presynchronization with gonadotropin-releasing hormone on fertility of resynchronized inseminations in lactating dairy cows. J Dairy Sci 96(6):3788-3798.

McArt, J. A., D. V. Nydam, P. A. Ospina, and G. R. Oetzel. 2011. A field trial on the effect of propylene glycol on milk yield and resolution of ketosis in fresh cows diagnosed with subclinical ketosis. J Dairy Sci 94(12):6011-6020.

M.W. Overton, M.W. and V.E. Cabrera. 2017. Monitoring and quantifying the value of change in reproductive performance. D. Beede (Ed.), Large Dairy Herd Management, American Dairy Science Association, 549-564

Perez, M. M., R. Wijma, M. Scarbolo, E. Cabrera, F. Sosa, E. M. Sitko, and J. O. Giordano. 2020. Lactating dairy cows managed for second and greater artificial insemination services with the Short-Resynch or Day 25 Resynch program had similar reproductive performance. J Dairy Sci 103(11):10769-10783.

Ribeiro, E. S., G. Gomes, L. F. Greco, R. L. A. Cerri, A. Vieira-Neto, P. L. J. Monteiro, Jr., F. S. Lima, R. S. Bisinotto, W. W. Thatcher, and J. E. P. Santos. 2016. Carryover effect of postpartum inflammatory diseases on developmental biology and fertility in lactating dairy cows. J Dairy Sci 99(3):2201-2220.

Santos, J. E., R. S. Bisinotto, E. S. Ribeiro, F. S. Lima, L. F. Greco, C. R. Staples, and W. W. Thatcher. 2010. Applying nutrition and physiology to improve reproduction in dairy cattle. Soc Reprod Fertil Suppl 67:387-403.

Wiltbank, M. C., G. M. Baez, F. Cochrane, R. V. Barletta, C. R. Trayford, and R. T. Joseph. 2015. Effect of a second treatment with prostaglandin F2alpha during the Ovsynch protocol on luteolysis and pregnancy in dairy cows. J Dairy Sci 98(12):8644-8654.