What question did this study set out to answer?

To evaluate the effect of bovine somatotropin initiation timing on pregnancy rates in lactating dairy cows receiving timed artificial insemination and to assess a subsequent resynchronization protocol.

June 1, 2000Journal of Dairy ScienceOpen Access

Use of Bovine Somatotropin in Lactating Dairy Cows Receiving Timed Artificial Insemination

View Full Paper

Ask AI

Bookmark

Authors

FMF MoreiraInstituto Nacional do Câncer CRC.A. RiscoOklahoma State University MPMaria de Fátima Ávila PiresBrazilian Agricultural Research Corporation

Discussion

Member takes

Implication

Comparative trial reveals early bovine somatotropin initiation increases pregnancy rates in dairy cows receiving timed insemination, suggesting hormonal timing alters reproductive success.

Key Points

To evaluate the effect of bovine somatotropin initiation timing on pregnancy rates in lactating dairy cows receiving timed artificial insemination and to assess a subsequent resynchronization protocol.
Assigned 403 lactating Holstein cows to initiate 500 mg bovine somatotropin (bST) either at 63 ± 3 days postpartum (concurrent with timed artificial insemination) or delayed at 105 ± 3 days postpartum.
Synchronized all cows using GnRH, PGF2alpha 7 days later, and a second GnRH dose 48 hours post-PGF2alpha before insemination, followed by pregnancy diagnosis at day 27 and day 45 with optional day-20 resynchronization.
In non-resynchronized cows, initiating bST at 63 ± 3 days postpartum increased first-service pregnancy rates at day 45 compared to initiation at 105 ± 3 days postpartum (37.7 ± 5.8% vs. 22.1 ± 4.2%).
In cows receiving the resynchronization protocol, day-45 pregnancy rates were 25.6 ± 4.3% in the early-bST group and 25.8 ± 5.5% in the delayed-bST group, showing no treatment effect.

Cite This Study

Moreira et al. (2000) studied this question.

synapsesocial.com/papers/6a922bf98356c7bfaac7ffc7 https://doi.org/10.3168/jds.s0022-0302(00)74990-3

View Full Paper

Ask AI

Bookmark

Implication

Comparative trial reveals early bovine somatotropin initiation increases pregnancy rates in dairy cows receiving timed insemination, suggesting hormonal timing alters reproductive success.

Use of Bovine Somatotropin in Lactating Dairy Cows Receiving Timed Artificial Insemination

Discussion

Member takes

Implication

Key Points

Cite This Study

Use of Bovine Somatotropin in Lactating Dairy Cows Receiving Timed Artificial Insemination

Discussion

Member takes

Implication

Key Points

Cite This Study

Also Consider

Also Consider