Many issues can impact an animal’s ability to show heat. If you feel you are not finding cows in heat, it might be time to take a closer look at the issue.
First, you need to determine if the problem exists throughout the entire herd or within a specific subgroup. To do this, analyze your dairy's computer record system. Look at records for reproduction and events that have happened by lactation or lactation group. Once the group in which the problem exists is determined, you will be better able to find possible causes and solutions.
Here are some potential causes to consider:
Slippery floors can be a deterrent to cows exhibiting heat and can also cause injury to animals. Generally concrete is the most common flooring surface in dairy facilities. To make concrete flooring more cow-friendly, one could groove or scabble slippery floors. Caution must be used when using grooving or scabbling floor options, as not to make the surfaces too abrasive on hooves. Another option is to use grooved rubber belting or similar rubber products.
Lameness causes stress on an animal. Lameness also tends to cause animals to lie down and eat less. Obviously, if an animal lies down more, it becomes more difficult to observe signs of heat. And, if an animal eats less, lameness can cause a cow to lose body condition.
A one-point loss in body condition can inhibit an animal's ability to exhibit heat. Keeping the ration adequate to prevent body condition loss is critical. Remember a cow is a mother; she needs enough energy to produce milk (feed her calf) before she will want to reproduce again.
The higher the number of pregnant cows in a pen the lower the amount of estrus that is shown; pregnant cows and cows in mid-cycle are much less likely to mount cows in or near heat. A possible solution for this issue is to maintain a higher percentage of open cows within the breeding group.
The more metabolic problems an animal has when freshening, the greater probability of anestrus. According to research, clinical ketosis, dystocia and retained placentas are associated with more days to first service and a lower conception rate at first service. Overcrowding of transition groups may also lead to more metabolic problems at or after calving.
Some estimates place undetected heats on farms in the USA at 50%. One solution for the issue of failure to properly observe estrus may be to adequately train employees in heat detection technique. In regard to specific timeframes for observing animals for heats, the proper time to observe animals is not while they are eating; instead, for best results, it should be every employee's job to make sure they observe animals at all times and properly identify the animals in heat. If herds are housed in stanchion barns, they need to be turned out daily, to conduct proper heat detection.
It is harder to detect heats during times of extreme high temperatures, and if you are able to catch them in heat, many have a hard time staying pregnant. A solution is to engage in heat abatement strategies, which may include sprinklers, fans, tunnel-ventilated barns, or multiple water sources for cows on pasture.
In conclusion, there are many different factors that could cause you to say, "My cows are not showing heat and conceiving the way they should." To overcome the obstacles, drill down through all layers to find the source of the problem - problems that could relate to the cows not showing heat or people not heat detecting correctly. Several products are also available to aid in heat detection such as Reveal™ Livestock Markers, Allflex® Livestock Intelligence cow monitoring systems, heat detection training and more. Work with your local resources (veterinarian, GENEX representative, etc.) to determine your challenges and the right fix for your operation.
Fourichon, C., H. Seegers, and X. Malher. “Effects of Disease on Reproduction in Dairy Cows.”
Theriogenology 53.9 (2002). 1729-59.Stevenson, Jeffrey S. “The question would be are their cows really not showing heat or are we not heat detecting correctly.” 1997.
Varner, M. A. “Stress and Reproduction.” Dairy Integrated Reproductive Management.
Historically, semen fertility has been evaluated by a trained veterinarian or lab technician who checks the semen with a microscope for percent live sperm cells, motility and morphology. In fact, every collection of semen produced by GENEX is evaluated multiple times in the lab before it's approved for use on your operation.
Lab analysis is very effective in ensuring semen has been properly processed, frozen and handled; however, lab analysis only tells part of the story. Semen from two different bulls may look very similar under the microscope yet perform very differently in cows. A better method is to let the cows tell which bull's semen is most fertile, and that's what PregCheck™ sire fertility rankings do.
Beef PregCheck™ fertility rankings use the fertility model the dairy industry has used for many years, except it is set to a beef base. This means beef sires are compared to other beef sires, not dairy sires. Many variables are statistically accounted for in the model, including technician, herd effect, age of cow, number of previous breedings and many others. This sophisticated evaluation model, along with accurate on-farm data, results in beef bull fertility data that is sound and reliable. Note that PregCheck™ rankings are not an EPD but can be read and utilized like an EPD or performance ratio.
PregCheck is set to a 100-base system, meaning a value of 100 is average. Every one point difference is equivalent to a 1% difference in conception rate. For example, if Bull A has a 104 PregCheck™ ranking and Bull B has a 100 PregCheck™ ranking, Bull A is predicted to be 4% higher in conception rate than Sire B.
PregCheck™ rankings are the result of real breedings which have shown differences between bulls.
Each bull’s ranking has an associated reliability level. Consider if Bull A has the 104 PregCheck™ ranking with 93% reliability and Bull B has the 100 PregCheck™ ranking with a 75% reliability. Bull A can be used with confidence; he routinely performs 4% above the average of his contemporaries for conception rate. At only 75% reliability, there is still some uncertainty in how Bull B will perform until he is bred to more females. However, Bull B is trending average for conception rate.
As more pregnancy data becomes available, reliability increases and the amount of change in the ranking will decrease. For a reliable evaluation, which is about 70%, a bull must have approximately 400 breedings in the database.
The true advantage is the ability to eliminate inferior fertility sires from your breeding program. When utilizing bulls with higher PregCheck™ rankings, you can expect increased conception rates resulting in more A.I. pregnancies and pounds of calf per year.
While all GENEX sires are procured with producer profitability in mind, PregCheck™ fertility rankings offer you another option to improve your bottom line.
The rankings are published in the Beef Genetic Management Guide and on individual bull pages on the website. You can also ask your local GENEX representative for a list of bulls with high PregCheck™ fertility rankings.
Today, you have more sexed semen product options than ever before and that means determining the most appropriate sexed semen product to use has become more difficult with their differing fertility and price. So, how can you be sure you’ve chosen the sexed semen that will earn you the largest return on investment? Use the Prospective℠ program, a semen profit comparison tool.
The Prospective℠ program is a free, value-added tool aimed at helping you develop the most effective strategic breeding program. The unbiased, Microsoft Excel-based program uses your dairy's basic inputs to calculate how a semen product choice may impact your profits. It shows the return on investment for sexed semen products in comparison to conventional semen.
The program is applicable whether you want to use sexed semen on cows or heifers; the Excel file contains one tab with appropriate calculations for sexed semen use in cows and a separate tab for calculations relating to sexed semen use in heifers.
» For cows, return on investment is calculated as: Difference in Asset (Calf) Value + Difference in Semen Cost + Cost of Added Days Open = Total Profit/Loss of Using the Sexed Product Versus Conventional Semen.
» The same formula is used for heifers, but it also includes a value for additional milk income associated with heifers birthing heifer calves.
Furthermore, the Prospective℠ program calculates the estimated cost of days open based on different breeding strategies (i.e., if you plan to use the sexed semen product on the first service, first two services or all services).
Both the cow and heifer reports are broken into three sections: 1) conventional semen, 2) GenChoice™ sexed semen and 3) GenChoice™ 4M sexed semen. The screenshots shown below walk you through the three sections in the heifer report. In all sections, you are able to edit the cells shaded light gray. The white cells are calculated values. The values shown in red indicate a financial expense or loss.
In the first section (pictured below), you will enter your # of units, price/unit, conception rate, heifer ratio and values per calf for heifers and bulls in the light gray boxes. The additional light gray cells contain values based on industry research, but these values can be altered if you have data specific to your dairy.
In the second section of the heifer report (Figure 2), GenChoice™ sexed semen is being compared to conventional semen based on your farm-specific inputs. In this section, you would again enter your farm-specific data - price/unit, conception and heifer ratio for 501 stud code semen – in the light gray cells in the upper left.
In this example, the bottom box shows GenChoice™ sexed semen is a profitable choice for this dairy when used on the first service to heifers ($8.02/unit profit) or first two services ($1.99/unit profit) compared to conventional semen. If GenChoice™ sexed semen was used on all services, it would lead to an expected loss of $4.44 per unit compared to conventional semen.
The third section of the Prospective℠ program compares GenChoice™ 4M sexed semen use to conventional semen based on farm-specific inputs. Again, you would enter your price/unit, conception rate and heifer ratio for 601 stud code semen in the light gray cells in the upper left.
In this example, the price per unit and expected conception rates have increased in comparison to the values used in Figure 2. Furthermore, in this example GenChoice™ 4M sexed semen is profitable, compared to conventional semen, when used on any number of services. Interestingly, the profit gained per unit of GenChoice™ 4M sexed semen is also greater than profit gained per unit of the traditional GenChoice™ sexed semen when compared on any number of services. If your on-farm conception rates for GenChoice™ 4M sexed semen are significantly greater, then you could expect a greater return on investment even with a higher price per unit.
Conception rates impact the return on investment from different sexed semen products. The increase in sexed semen conception rates in recent years has mostly been attributed to technology improvements.1,2 Among the improvements is sexed semen processed with SexedULTRA™, which GENEX and other A.I. organizations have been marketing for several years. However, sexed semen conception rates still trail conventional semen. Furthermore, there’s a significance variance in fertility levels among individual sires. (learn more about PregCheck+™ fertility rankings for GenChoice™ and GenChoice™ 4M sexed semen). It is not uncommon for conception rates to vary between individual sires by 10 points or more.
Ultimately, conception rates from sexed semen will continue to improve and its use in the dairy industry will continue to increase. By using the Prospective℠ program to compare sexed semen products you will be able to better utilize the products now and in the future.
There’s been a significant increase in the number of new dairy traits developed industrywide over the past couple years, and new traits will continue to be developed. With all this change and progress, it may be difficult to determine which traits hold the most value for your dairy and how you can best utilize the information that is available. It may even become information overload. For this reason, you might consider using genetic sub‑indexes.
One benefit of the Ideal Commercial Cow™ (ICC$™) indexes for Holsteins and Jerseys is that they are comprised of sub-indexes, enabling you to narrow genetic emphasis to better achieve your breeding goals. Said another way, it is easier to select genetics through a sub‑index than to individually select for all traits that contribute to a specific breeding objective.
The table below lists the top 25% of the GENEX Jersey lineup (April 2018 data) ranked by the ICC$™ index. You have decided to choose the top five bulls from this group that meet your breeding program goals. If production is your main emphasis, you would choose the top bulls for the Cheese Maximizer (ChMAX$) sub-index. See the values highlighted in yellow.
If you choose to concentrate on Sustainability (SUST$) or Fertility (FERT$), the same logic would apply. The top five SUST$ sub-index values are highlighted in teal and the top FERT$ values are highlighted in dark blue. Note the top five bulls for each sub‑index varies. This demonstrates how sires typically perform better in certain sub-indexes compared to others.
The table’s bottom row shows the ICC$™ index average of the top five bulls for each sub-index. As you can see, the averages for the top five ChMAX$ and SUST$ sub-index bulls are very similar (+775 and +767 respectively). The ICC$™ index average for the FERT$ sub‑index list, however, is slightly lower (+733). In this instance, you may decide the decline in overall ICC$™ index values does not meet your overall needs when selecting for ideal commercial cows, and you may instead choose to exclude bulls that do not meet a minimum threshold for the FERT$ sub-index.
The second FERT$ column shows which sires may be the best option when choosing high ICC$™ index sires with positive FERT$ values; these values are highlighted in purple. The overall ICC$™ index average of these five bulls (+771) is comparable to those selected based on ChMAX$ or SUST$. This demonstrates the relative ease in which sub-indexes may be used for achieving specific breeding goals.
In the future, sub-indexes are likely to become even more prevalent. Even now, the Dairy Wellness Profit (DWP$) index published by Zoetis includes two economic-based sub-indexes in Calf Wellness dollars (CW$) and Wellness Trait dollars (WT$). One could speculate that Net Merit $ and Cheese Merit $ indexes published by the Council on Dairy Cattle Breeding (CDCB) may transition to economic-based sub-indexes eventually as well.
As more and more genetic traits are developed, sub-indexes become a logical way to eliminate the oversaturation of traits and to focus on specific breeding objectives. It is much easier to select on a single sub-index that emphasizes the desired area of farm management than to select on the many traits that may be associated with it.
For more information on using the ICC$™ index and its sub-indexes to achieve your breeding objectives, contact your local GENEX representative or contact customer service.
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