Pine Needle Abortion in Cattle – What You Need to Know

When you think of pine trees, you may picture a picturesque forest or a cozy winter scene. However, pine needles can be a disaster for homesteaders and hobby farm owners who raise cattle. Ponderosa pines grow in the western United States and Canada.   They are often growing near paddocks and pastures. It is important to know the serious correlation between Ponderosa pine needles and cattle abortions.

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When we first had pregnant cattle, our veterinarian noticed that we had a lot of Ponderosa pines in our pastures.  She mentioned the potential danger of our pregnant cattle eating Ponderosa pine needles.  A cow’s gestation is around 9 months (279 to 292 days) and can vary a little depending on the sex of the calf and the breed. Our veterinarian informed us that it could cause pine needle abortion (PNA).  I was shocked; I had never heard of PNA, and the thought of losing a calf because of this was unnerving.

Whether you have a large cow/calf operation or a very small ranch like ours, losing calves to PNA has a huge impact.  

This loss affects the growth of your herd and overall profit.   The estimated loss to the US cattle industry is over $20 million annually.  To us, losing even one out of 4 calves has a big impact.

We have a wide variety of pine trees on our land, and Ponderosa pines are one of them.   I have never been a fan of the Ponderosa pines and their long needles. The thought of this serious potential problem had me taking down trees immediately with my favorite piece of equipment – our skid steer.   Most of our cattle pastures had been cleared of these pine trees, but this gave me good reason to remove the remaining Ponderosas in the pastures containing our mamas.   The Ponderosa pine trees left on our property are fenced outside of reach from our cattle.

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According to the USDA Agricultural Research Service, these pines contain a toxin called isocupressic acid, which causes pine needle-induced abortion.  

In this blog post, we’ll explore why this happens and what you can do to protect your pregnant cows.

Why do cattle eat pine needles?

As homesteaders and hobby farm owners, we know how important it is to understand our animals’ diets. One phenomenon is why cattle seem to be attracted to ponderosa pine needles.   It’s actually not unusual for cows to seek out and enjoy these needles. Here are some reasons:

1. Nutritional value

Ponderosa pine needles are highly nutritious, containing a healthy amount of protein and vitamins. Pine needles are packed with vitamin C, which is especially beneficial during winter when other grasses are not available. Also, they have minerals such as iron, potassium, calcium, magnesium, and phosphorus, which are essential to cows’ health and growth. Eating these needles helps fill nutritional needs that may be lacking in their diet.

2. Flavor

Believe it or not, some cows like the taste of these needles. There are farmers who have personal accounts of cows breaking into their pine tree groves to get to the needles. While there’s no clear answer as to why some cattle develop a taste for them and others don’t, scientists speculate that the flavor of the needles varies from region to region, and some may prefer certain types of pine needles over others.

3. Medicinal Properties

Over the centuries, pine needles have been used in traditional medicine as a natural remedy. Ponderosa pine is known for its antibacterial, anti-inflammatory, and antifungal properties. These properties may help boost the immunity of cows, keeping them healthy against common infections and diseases.

4. Digestive Health

Cows have four stomachs, and each stomach helps break down and digest different types of food. The ingestion of pine needles serves as a natural roughage, which is needed for proper rumen function. By breaking down the needles and fermenting them inside the rumen, the cows’ stomachs can produce valuable nutrients and minerals their digestive system absorbs.

5. Environmental

Cattle living in areas where pine trees are abundant may become accustomed to the needles. Dry needles and green needles may serve as an alternative food source, particularly when there is a lack of feed during drought or cold weather winter months. Consuming them also may help with hydration, as the needles contain moisture, helping the cows to survive periods of drought.

Understanding why your cows may seek out and eat ponderosa pine needles can aid in caring for and managing your livestock, particularly during drought or when dietary supplements may be needed. As always, monitoring your cattle’s diet and health and consulting with a veterinarian if needed is essential.

For non-pregnant cattle, the consumption of pine needles from the Pondersona pine is no issue.

According to the USDA Agricultural Research Service , these Ponderosa pines (Pinus ponderosa) contain a toxin called isocupressic acid, which causes pine needle-induced abortion.

From my research, isocupressic acid affects the corpus luteum in the cow, which produces progesterone, a hormone that helps maintain pregnancy. This is a stage of egg development in the cow’s ovary. When the corpus luteum is damaged by the toxin, it cannot produce enough progesterone, and the pregnant cattle will abort her fetus.  These are some big terms for someone like me who does not have a medical background, but it is important to understand the concept.

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It’s important to note that not all pine trees contain isocupressic acid.

Only certain species, like the Ponderosa pine, are problematic. Additionally, the toxicity of the needles can vary depending on factors like location and time of year. For example, needles that have fallen from the tree in the spring are more toxic than those that fall in the fall. In addition to ponderosa pines, the following also contain significant levels of isocupressic acid:

• Lodgepole pine (P. contorta)
• Common juniper (Juniperus communis)
• Monterey cypress (Cupressus macrocarpa)

If you have Ponderosa pine-infested pastures or a lot of them growing near your pasture or paddock, it’s important to take steps to protect your cattle. The easiest solution is to remove the trees entirely, although this may not be practical or desirable. If removal is not an option, consider fencing the area around the trees to keep your pregnant cattle from grazing on the needles. You can also rake up fallen needles regularly to minimize the risk of ingestion.

Another way to reduce the risk of pine needle abortion is to supplement your cattle’s diet with hay or other forage if they are only pasture-fed. This will help to dilute any toxins they may consume from grazing on contaminated needles. Additionally, if you have cows that are pregnant, consider putting them in a different pasture that does not have Ponderosa pines. This will prevent any accidental ingestion of Ponderosa pine needles.

It’s also important to keep an eye on your cattle for any signs of illness or abortion. According to the USDA Agricultural Research Services watch for the following signs:

• Abortion characterized by weak parturition contractions, excessive uterine hemorrhage, and incomplete dilation of the cervix
• Calves may be weak and may survive if abortion is near term
• Persistently retained placenta
• There may be indications of the impending abortion
• Following the abortion, cows may develop lesions consistent with endometritis and septicemia accompanied by a marked increase in body temperature; cow may die if treatment is not immediately provided

If you notice anything out of the ordinary, contact your veterinarian right away. Pine needle abortion is a serious condition that can be fatal to your animals if left untreated.

In Conclusion:

Pine needle abortion can have deadly consequences for your cattle, but by understanding the link between Ponderosa pine needles and this condition, you can take steps to protect your cows and their offspring. Whether you remove the trees, fence them off, or supplement your cattle’s diet including plenty of available water, it’s important to be proactive in preventing pine needle abortions. Keep an eye on your herd, and if you notice any signs of illness or abortion, seek veterinary help immediately. By taking these steps, you can keep your cattle healthy and thriving.

Fortunately, our veterinarian educated us about PNA before we had to learn this lesson the hard way. By informing other homesteaders or hobby farmers who are new to cattle, we hope this information will prevent a heartbreaking event.

If you have any experience with this problem, please comment below and let me know what you have learned.

Yvonne ♥

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