October 2020 Monthly Management

Lameness in Cattle

Lameness is a major problem in Irish dairy herds – it has become the second largest dairy cow health challenge after mastitis, affecting animal welfare and productivity of the farm business. Lameness is not a single disease but a symptom associated with a range of conditions. This article will give a brief outline of the factors and common diseases that are associated with lameness on Irish farms.

Factors Affecting Lameness

During the winter period, the environmental conditions at housing are highly significant. In many farms cubicle size, overcrowding and general hygiene are major factors contributing to increased lameness compared to when cows are out at pasture. Typically, cows will spend less time resting and more time standing if environmental conditions are inadequate. Manure management and prevention of prolonged contact between feet and slurry is important as a preventive measure to control lameness. Incidences of lameness at pasture are also quite common. The conditon of farm roadways and walking distance to paddocks are distinct conrtributary factors. Lameness in grazing cattle tends to increase about three weeks after heavy rainfall, prolonged wet weather conditions lead to higher bacterial challenge and a softening of the hoof.

Routine foot trimming and conformation of the foot consistently improves the shape of the foot. Drying off is often a good opportunity to focus on foot trimming as when the cow is dried off, she will usually stay in one place and the risk of injury is less with good management.

Older cows are mainly affected between five and eight years old. Studies have found that the risk for six different foot disease traits increased with age.

Many foot lesions are also related to the early post-calving period. At and around calving, cows have a reduced immune system and may have an increased standing time which may predispose to foot lesions and lameness therefore extra care should be given to freshly calved cows.

Digital Dermatitis

This disorder is present on many dairy farms and besides being very infectious, it is very hard to get rid of. Several different types of bacteria affect the skin in the interdigital space, which is characterized red, hairless and very painful lesions. Due to their appearance, the lesions are often referred to as “strawberry like.” Most frequently they are seen at the back of the foot, in the interdigital space between the two heels. Animals may keep the affected limb off the ground and/or are severely lame, due to the painfulness of the lesions.

Regular foot bathing with a 10% copper sulphate or 20% zinc solution will aid in preventing outbreaks. Individual cows with severe digital dermatitis will require a topical treatment with an antibiotic or a curative alternative with zero meat or milk withdrawal e.g. Intra Repiderma Spray.

Sole Ulcers

A sole ulcer forms when the skin underneath the sole horn is damaged and dies off. This leads to the absence of any horn formation at this location. The underlying fat tissue bulges outwards through this hole, forming the specific “view” of a sole ulcer. Through the sole ulcer, bacteria can enter the underlying tissue and cause infection. A sole ulcer is most often seen at the outside claw of the back feet, just in front of the heel of the foot. Here most pressure is on the underlying tissue due to the attachment of the flexor tendon to the pedal bone (rotational point).

The prevention of sole ulcers should be directed at maintaining correct claw shape through foot trimming. Equal weight distribution on the feet along with proper environmental conditions will reduce sole ulcer incidences.

White Line Disease

White line defects occur when foreign objects (little stones, small metal/wood pieces etc.) penetrate the white line. If they (and dirt) penetrate all the way to the corium, they cause an infection, forming an abscess. This
is very painful, which often causes sudden and extreme lameness. Abscesses, when not detected early on, may search for a way out by pushing upwards into the hoof. Treatment involves hoof paring to remove foreign objects, providing drainage for any infection, and removing of weight from the affected area.

Drying Off Cows

The risk of mastitis infection is 5 – 7 times higher during the early dry period and just prior to calving compared to during lactation. Consequently, it is extremely important to dry off cows correctly to minimize problems. Plan for at least a 6-week dry period (ideally 8) to maximize udder health and allow the udder to prepare for the next lactation.

The objectives of dry cow therapy are to eliminate existing infections at the end of the lactation and to prevent new infections over the dry period.

Preparation and hygiene are essential at drying off

In order to ensure the task is completed properly, you will require the following:

Best Practice Steps for Drying Off Cows:

1. Mark all cows for drying off and milk them last so that they can be dried off at the end of milking.
2. Always wear gloves, keep gloves clean and replace as necessary.
3. Strip out all four quarters.
4. Pre-dip/spray teats. Allow 30 seconds contact time and wipe off with a clean paper towel.
5. Starting with the furthest away teats, scrub the teat end with cotton wool and surgical spirit – this may need to be repeated until teat ends are thoroughly clean.
6. Starting with the closest teats infuse dry cow therapy and massage into the udder. If using a sealer this should be inserted straight after the dry cow tube. When infusing sealer pinch the teat end at the base of the udder to ensure it remains at the base of the teat. Do not massage up into udder.
7. Repeat on remaining teats one at a time.
8. Cover the whole surface of the teat with freshly prepared teat disinfectant
9. Avoid cows lying down on bare ground or areas that are soiled with manure in the two hours directly after you administer dry cow treatment.
10. Separate cows and put into a clean dry paddock for 3-4 days after drying off. If cows will be housed ensure cubicles are clean and dry.

Grass & Grazing

This month’s feature farmer is Kieran Keane, Meenies, Drimoleague.

With the milking platform stocked at 3.5cows/ha all year round, I zero graze from outside silage ground in September to help build a decent cover of grass for the final round of grazing.

The last rotation started on October 1st and there is approx. 46% of the farm closed (16/10/2020). With a high demand for grass next Spring I am aiming to have 75 or 80% of the farm closed by the end of this month.

The land is flat and quite heavy in places so conditions can go from being ok to challenging very quickly. The good weather so far has been a real help in getting the wetter areas grazed and for getting a good clean out on the higher covers. There is no silage in at the moment, I am making the most of the good conditions and pushing on with grazing as when the weather breaks cows will need to be moved to on-off grazing here straight away.

For the next two weeks I will be trying to get the paddocks closest to the yard with good access closed off so that they will be ready for grazing again at turnout next spring.

Selective Dry Cow Therapy:

There were approx. 10 cows dried using sealers only last year. The plan this year is to go through each of the four milk recordings and select out cows that tested under 90 SCC consistently during the year for teat sealers only.