When Your Cow Does Not Get Pregnant, Possible Causes and Suggestions
No matter what, there is almost always a group of cows that don’t conceive on the first attempt. They are inseminated, but within a month or two, they have either required another insemination or unexpectedly turn up open. What is going on?
Why are there so many cows that don’t get pregnant? Even when careful attention is given to reproductive management, success rates can be disappointing.
There are many potential explanations: anovulation, genetic predisposition, improper timing of insemination, problems with semen storage, poor artificial insemination (A.I.) technique, embryonic death, infection, heat stress, metabolic issues. … The list goes on. For this article, let’s focus on four overarching reasons why cows don’t get pregnant.
- Improper timing of insemination–breeding too early or too late.
- Frequently inseminating cattle based on secondary signs of estrus.
- High incidence of uterine infection.
- Improper insemination technique or use of semen damaged during storage or handling.
- Embryonic or fetal mortality.
- Excessive weight loss or poor body condition.
- Improper palpation technique during pregnancy exams.
- Heat stress.
- Inseminating cows too late in relation to ovulation.
- Deficient crude protein or excess degradable protein intake.
- Gross over-conditioning.
- Subclinical uterine infection.
- Vibriosis and trichomoniasis in natural breeding.
- Leptospirosis and haemophilus.
- Viruses (IBR/IPV, BVD) and maybe others.
- Ureaplasma and mycoplasma.
- Toxicity (i.e., ketone bodies, mycotoxins, high blood urea nitrogen (BUN) and endotoxins).
- Imbalance of calcium, phosphorus, vitamins A, D, and E and carotene.
- Hormonal imbalance (i.e., intake of forages high in estrogen).
- Use of low breeding efficiency sires.
- Improper use of drugs or hormones that impact reproductive function.
- Evaluate the heat detection program and timing of service.
- Use Milk Progesterone Testing to evaluate accuracy of heat detection.
- Submit blood samples or reproductive tract swabs for disease testing.
- Have veterinarian examine repeat breeders; treat if infection is present. (See suggestions for uterine infection, page 3).
- Re-evaluate semen handling and insemination techniques. Attend retraining session for artificial insemination technique.
- Analyze milk samples for milk urea nitrogen (MUN). Submit blood samples for CBC (complete blood count), including serum minerals.
- Test forages and the total mixed ration (TMR) for standard analysis, minerals and mycotoxins if suspected.
- Submit feeding program for evaluation and check basic feeding practices (i.e., feed availability).
- Avoid gross overfeeding of grain.
- If possible, provide cows with adequate amounts of fresh forage as pasture or greenchop for at least four to six weeks each year.
- Avoid moldy or apparently high-estrogen forages.
- Purchase semen from reputable sources.
- Review use of drugs and/or hormones administered to breeding stock.
- Evaluate vaccination and biosecurity practices and protocols.