Autumn Beef Series in association with Teagasc
The wet and mild summer this year has resulted in higher levels of parasites present in dairy beef animals and with winter housing underway in many parts of the country, it is important these burdens are eliminated to ensure animals remain healthy and performance is maintained during the winter period.
Stomach and gut worms
Worms are generally more of an issue in younger stock in dairy calf-to-beef systems. Stomach and gut worm levels can be monitored using dung sampling and if detected, dosing is recommended.
Likewise, dung sampling a few weeks after treatment is good practice to ensure the product used gave an effective treatment.
When choosing a product for winter control it is important that all stages of stomach worms are treated. If larvae are not treated they can become dormant over the winter and then reappear as type two ostertagiosis in the spring – and these can cause severe disease in animals.
Yellow drenches derived from the active ingredient levamisole are not effective in treating these larvae where clear drenches (macrocyclic lactone) and certain white drenches (benzimidazoles) will provide effective treatment.
Lungworms
This year in particular higher incidences of lung worm have been reported. Monitoring for clinical signs such as a husky cough or difficult breathing is the best way to identify if there is an issue.
Heavy infestations can lead to respiratory disease, therefore a pre-housing treatment is recommended to ensure animals are clean of any burden before housing.
As regards treatment and control, most available anthelminthics are effective against larval and adult lungworms.
Levamisole and white drenches will take out the parasites present on the day of treatment and will have no residual affect. Macrocyclic Lactones such as ivermectins will give longer protection.
Liver fluke
The high levels of rainfall and mild temperatures experienced since turn out have provided the ideal conditions for fluke to thrive in. Farmers across the country need to assess their own farm situation and take action to deal with any potential issue.
Lack of thrive, poor appetite and reduced weight gain are all ill effects of liver fluke, therefore early intervention is necessary.
Once eaten, fluke start to feed and grow. It takes approximately 12 weeks for the flukes to grow to adult stage when they start to lay eggs.
These eggs pass out in the faeces of the animal and when conditions are suitable they hatch and use the mud snail to continue the life cycle.
During this 12-week period the fluke are classified according to their stage of development:
- First 5/6 weeks – early immature fluke;
- Weeks 6 -10/11 – immature fluke;
- Week 11 + – adult fluke.
There are a number of different flukicides on the markets but certain products are only effective against certain stages. Some of the flukicides on the market are only effective against the adult stage, therefore careful thought needs to be given when deciding what product to use and the timing of the treatment.
If using a product that only treats adult fluke stock need to be in at least 11 weeks to ensure an effective treatment.
In areas where burdens are high and farmers need to intervene quickly. Triclabendazole-based products which cover all three stages can be given a few weeks post-housing; there is some known resistance to this product in certain parts of the county so precaution is advised.
In other cases there are a number of products that are also effective against mature and immature fluke and these will give an effective treatment if administered six weeks after housing. When selecting a product check the label to check the stages treated.
The table below outlines the active ingredients used in control of liver fluke in cattle and the stages treated.
Rumen fluke
Rumen fluke is generally not as severe an issue in dairy-beef systems. In faecal tests the majority of animals may show low levels of rumen fluke present, but treatment is not required unless clinical signs such as scouring and weight loss are evident.
Oxyclozanide-based products are the only drug effective in the treatment of rumen fluke, therefore correct use is required to prevent resistance issues.
Pneumonia
Where previous issues were encountered with pneumonia a pre-housing a vaccination plan should be explored in conjunction with local veterinary advice. Currently, there are a range of vaccines available which cover the most common pneumonia-causing viruses and bacteria.
Vaccines are available in intranasal form to cover the two most common viral forms – Respiratory Syncytial Virus (RSV) and Parainfluenza type 3 (PI3) – and can be administered to animals pre-housing with protection from viruses from five days after administering and with cover lasting up to three months.
Other vaccines are available in injectable form to cover these two viruses as well as a major bacterial pneumonia form –Mannheimia haemolytica.
This vaccination programme is two shots four-weeks apart with the initial shot to be administered at least six weeks pre-housing and a booster to be given at least two week pre-housing so full protection is available before turn in.
Where calves were administered this two-shot programme the previous spring a single-shot two weeks pre-housing will provide full protection.
IBR
Infectious bovine rhinotracheitis (IBR) is another viral disease farmers should be mindful of with outbreaks causing acute inflammation of the upper respiratory tract.
Outbreaks can significantly reduce animal performance, resulting in economic losses. The virus can lie dormant in the animal’s system and flare up at times of increased stress such as housing.
There are a number of intranasal and injectable vaccines that are available for IBR and can be administered at the same time as the pneumonia vaccines outlined above.
Good management practices
While vaccines do assist in challenges to animal health, at the same time, no amount of vaccination will overcome a lack of good practices.
Factors such as poor ventilation, overcrowding and inadequate parasite control need to be addressed along with a vaccination programme to ensure animal performance is not reduced due to pneumonia outbreaks.