Horizontal Grooves
click on images for detail

Introduction

Grooves are seen in the claws of many dairy and beef cattle.

Although grooves are common, they vary in appearance and severity.

The more grooves seen in a herd, the greater will be the nutritional problem being experienced by that herd.

A groove grows away from the coronary band at the rate of about 4 mm per month. This allows the date when the groove was formed (time of the insult or nutritional change) to be calculated.

Grooves are an area of weakness around which the claw bends or from which a sandcrack may start.

Description

The claw in the photo to the left is a typical horizontal or "hardship groove."

The groove has grown out to the middle of the claw wall. Here it acts as a fault around which the tip is starting to bend.

Sometimes grooves are so severe that they penetrate right through the wall, in which case they are referred to as "fissures." (click image)

Grooves and fissures are often so common that they are accepted as a part of the normal appearance of a claw. While a few grooves can be tolerated, the widespread appearance of this "acquired abnormality" should be considered as an indicator of a problem that must be investigated.

The photograph on the left shows a "broken toe" (the tip of the claw has broken off square). If many cows in the herd have broken toes, it suggests that a problem has existed for a prolonged period. (click image)

The photograph to the right is of the claws of a young bull weaned onto a very intensive feed. The 3 cm of horn closest to the coronary band are different in appearance from that of the tip. This is one way in which we can observe that an animal is unable to adjust to the "hot" diet. (click image)

The claw of the cow on the left is similar to most of the cows in the same dairy herd. By measuring the distance of the groove from the coronary band and dividing it by 4 (4mm claw growth per month), it was determined that the problem occurred when the cows came in from grass in September. Given this information, the consulting nutritionist concluded that the cows had been given insufficient time to accommodate to the production ration. (click image)

Cause

The groove in its extreme form may be a fissure going right through the claw. This is caused by a moderate-to-severe "short-term" insult. Fissures are particularly prevalent following a sudden drop in the quality of effective fibre.

In dairy cows the appearance of grooves is an extremely important sign that a nutritional event (change) has taken place. The date of the event can be calculated. The events occurring around that date can be studied as possible causes.

Grooves in beef cows at pasture are also probably caused by sudden changes in the quality of the feed. Turning cows out in the spring from forage to lush grass, changes in the pasture due to the sudden onset of ideal growing conditions, and changes from a worn out to a lush pasture are likely causes.

Although the phenomenon of the horizontal groove is not yet fully understood, experience with using the measurement of the position of the groove has proved to be a useful tool. Employing this approach significantly improves a consultant's ability to make recommendations.

Treatment

The nature of this condition is such that it is only possible to use control measures rather than any actual treatment.

Control

Control measures are the same as for Sandcracks. Also consult Pasture and Micronutrients.

For Beef Cattle

• Avoid turning out cows for the first time in the spring when the grass is lush (i.e., between three and six inches high).
• Leave long cover on a pasture in fall and graze first in the spring.
• Avoid including legumes in pasture to be grazed first in the spring.
• Avoid fertilizing pasture to be grazed first in the spring.
• Offer good forage during first ten days after turn out.
• We have found that cows fed Biotin are 2.5 times less likely to develop a sandcrack. This is not a magic bullet. You must also correct management. Heifers in problem herds should be fed this product.
• Test the water supply for iron and sulfates.
• Consider supplementing with zinc methionene. Evaluate the copper levels in the pasture.

For Dairy Cows

• Milking time is an excellent opportunity for observing the quality of the claws. All milking personnel should be trained in the art of reading the signals.
• Test water quality at least every five years for unacceptable levels of iron, sulfate and nitrate.
• We have found that cows fed Biotin are 2.5 times less likely to develop a sandcrack. This is not a magic bullet. You must also correct management. Heifers in problem herds should be fed this product.
• If dry matter intake drops or is low, test for stray voltage.
• If buying forage, have each new batch tested especially for variations in ADF exceeding 5%. If there is a difference of this magnitude, mix the old and new for at least ten days.
• Do not feed silage until it is mature.
• Use pit silos if possible to avoid sudden changes in feed quality between layers as occurs in towers and bags.