Management Tips

Management Tips

Information on how dairies incorporate BioPRYN® into their routines

Is BioPRYN Right for Your Dairy?
For most dairy producers, identifying non-pregnant, open cows is a critical part of streamlining their herd reproductive program. Once cows have been identified as open, they can be rebred or re-entered into a synchronization program. Every day that pregnancy detection is delayed also delays the speed at which a cow can be bred back.

Using BioPRYN assures accuracy, quality control, and is easy and convenient to administer. Using BioPRYN in conjunction with an aggressive reproductive program can also improve pregnancy rate of a dairy herd.

Dairy producers that live in locations not consistently served by a veterinarian also have found tremendous value in the test.


BioPRYN and dairy synchronization protocols
A Wisconsin dairy producer has used BioPRYN as part of the reproductive protocol on his 540-cow dairy since August, 2004. Prior to using BioPRYN, he was using ultrasound to detect pregnancy in his dairy herd.

This producer utilizes a full synchronization program beginning at 51 to 57 days in milk and includes the BioPRYN test at 30 – 36 days after breeding. Once detected pregnant, subsequent blood tests are performed at 60 – 66 days and 120 – 126 days bred to confirm the pregnancy is carried full-term. The description of a sample farm breeding protocol follows:


Sample Farm Breeding Protocol
Ovsynch: On Monday, all cows between 51-57 days in milk are started on the Ovsynch program. Additionally, cows that were found to be open on the previous week’s pregnancy report are restarted on the Ovsynch program. They are given 2cc of GnRH Monday morning between 8-9 a.m.
The following Monday morning, all cows given GnRH the previous week are given a shot of 5 cc Prostaglandin. Before starting injections, staff at the Farm review their list to make sure cows haven’t been bred in the past week off of standing heat. If a cow has been bred, she is removed from the Prostaglandin list.
Two days later, on Wednesday morning (48 hours) cows receive 2nd 2 cc GnRH dose and are inseminated.

CIDR: Heifers that are of breeding age (13 months) and are of proper size (750 lbs) are placed on the breeding program. On Monday morning a CIDR is placed in the heifer. The following Monday morning the CIDR is pulled out and a 5cc shot of Prostaglandin is given. On Wednesday afternoon heifers are inseminated.
The CIDRs are also used on the lactating herd if after two inseminations the cow hasn’t settled or displayed a heat. A CIDR is administered instead of a 2cc shot of GnRH.

Blood Drawing
Blood is drawn on Wednesday morning at the same time cows are being inseminated. Blood is drawn on cows 30-36 days bred. All cows that are pregnant are again rechecked at 60-66 days pregnant to find early embryonic death loss. Pregnant cows are rechecked again at 120-126 days post-breeding. All open cows are restarted on the Ovsynch program.


BioPRYN and G6G
Streamline dairy reproductive efficiency
Combining a G6G Ovsynch protocol with BioPRYN maximizes reproductive performance on dairies.

G6G is a set of two hormonal injections prior to the initiation of the Ovsynch protocol. These injections are designed to initiate a new estrous cycle and maximize the number of animals bred by timed AI. The protocol is initiated with an injection of prostaglandin (PGF2α, PreP) which induces luteolysis of a mid- to late-cycle corpora lutea, 2 days later an injection of gonadotrophin releasing hormone (GnRH, PreG) is administered toinduce ovulation of the growing follicle on the ovary. Six days later, the first shot of GnRH in the Ovsych Protocol, is given to cause ovulation and prepare the animal for the successive shots if GNRH and PGF2α. Dr. Pursley’s research data indicates that Ovsynch works best when started on day six or seven of the estrous cycle. Figure 1 illustrates the differences between the traditional Ovsynch program and the G6G protocol.

Research is showing how effective the new G6G protocol can be to increase ovulation after the first dose of GnRH. A recent on-farm study found that 85 percent of the cows enrolled in the G6G program ovulated in response to the first injection of GnRH in the Ovsynch protocol, while only 54 percent showed a response in the traditional program without the set-up shots.


Integrating pregnancy detection
One of the strongest aspects of BioPRYN is its accuracy in identifying non-pregnant cows. Research has shown that the test is 99 percent accurate when cows are identified as open. Figure 2 illustrates the choices a producer can consider after receiving a BioPRYN pregnancy report. The report has four categories: open, pregnant, open repeat, pregnant repeat. If open, the veterinarian recommends re-synching the cow for subsequent rebreeding using G6G or Ovsynch, depending on where she is in her cycle. If the cow is pregnant, the producer just needs to reconfirm 60-70 days post-breeding.

BioPRYN pregnancy testing fits well within a weekly schedule for synchronization that can quickly be integrated into the farm’s normal cowflow. Figure 3 is the program recommended for incorporating BioPRYN into a Resynch protocol utilizing either G6G or Ovsynch.