, is currently trending as one of the most-read A.I. and Breeding articles. to jump to the article. Summary: University of Idaho’s K. Scott Jensen explains that every person on the dairy responsible for heat detection should follow the same decision-making process every day with every cow. The key to developing a system for getting cows bred is consistency, he says.
Because this article is so popular, we asked Jensen a follow-up question:
Q. What tips would you suggest to a dairy’s employees to help them become more consistent at evaluating heat detection signs and decisions to inseminate?
My tip would be for the herdsman or breeding manager to outline the criteria for breeding each individual cow. Some of the criteria could include percentage of tail chalk/paint removed, dirty flanks (yes/no – from being ridden), presence and color of mucous from the vulva, swelling of the vulva, color (pink or pale) inside the vulva.
Any one or all of these criteria at right could be used to create a breeding decision chart.
When all breeders make breeding decisions based on the same standards, breeding success rates generally improve.
—K. Scott Jensen, University of Idaho
ARTICLE
Getting cows inseminated and, even more importantly, getting cows pregnant can be very challenging on a dairy. Many different factors such as nutrition, calving and disease problems, and environmental conditions all play a role in getting cows to cycle.
Once cows are cycling normally, the failure to detect cows in heat accurately and in a timely manner is the most common problem. Success in getting cows pregnant can be increased by identifying the critical components of a breeding system and then ensuring that the details of each of those components receive sufficient attention. Let’s look at the role that individuals might play in the process.
One of most important factors of success involves the overall management, whether from the owner and/or herdsman. Nutrition is extremely important. Cows fed a balanced ration are more likely to return to estrus earlier than cows that are not. Ensure that cows are fed consistently.
Cows that receive appropriate assistance at calving also return to estrus earlier. Likewise, cows that receive careful fresh cow treatment (temperatures monitored, needed treatments administered in a timely manner, etc.) generally return to estrus earlier. Putting all of these things together is challenging but essential. Cows must be cycling normally prior to the start of efforts to rebreed them. Any missing pieces will most likely delay the rebreeding process.
Controlling the weather (environmental factors) is impossible; however, it is possible to manage corrals to reduce environmentally related problems. Maintain clean corrals and alleyways. Provide adequate straw or other bedding, especially in wet conditions. Provide windbreaks and shade as needed.
Artificial Insemination (AI) technicians are also a vital part of the process. Typically, the AI technicians also handle the heat detection process. Properly identifying cows when they come into heat is essential. Every individual responsible for heat detection should follow the same decision-making process every single day with every cow. See Table 1 for examples.
For most inseminators, a cow with the tail chalk rubbed off would be inseminated. The more difficult decisions come when only one or two of the other secondary signs of estrus are observed. Should a cow with the hair on her tail head roughened up a little be inseminated? Most likely it will depend on whether or not any of the other signs are also observed. No matter what the decision though, the same observations on other cows should result in the same insemination decision. In other words, be consistent in your decision-making process.
Now, a word about the timing of insemination. Timing can be best determined by reviewing factors including sperm viability, occurrence of ovulation following the onset of estrus and ova viability (see Figure 1 ).
Insemination is best 12 hours following the onset of estrus. The problem for most inseminators is that they don’t know exactly when that occurs. Generally speaking, due to the length of time required for sperm transport and the limited time of ova viability, it is better to inseminate earlier rather than later. This means that cows should be inseminated when signs of estrus are observed. This is especially true on dairies where cows are inseminated only once daily.
Careful attention to detail and consistency in feeding, fresh cow management, corral management and heat detection and breeding can improve reproductive success. If reproductive efficiency on your operation is less than desirable, I encourage you to carefully review each of these components to determine areas where specific improvement might be warranted. PD
K. Scott Jensen
University of Idaho
Owyhee County Extension scottj@uidaho.edu
