Grass – Frequently Asked Questions  

After dosing calves how long would you recommend leaving them in the original paddock? We don’t want to be bringing any bugs with them onto the fresh grass

With all dosing routines, it is best to consult your vet as every farm and worm burden varies. In all cases, it is extremely beneficial to do a faecal egg count (take dung samples to the vets to test the worm burden in the group). See our guide on best way to take a sample here for the most accurate results. This will guide you to the most appropriate dosing for you. It will indicate worms present to be shed and you can make an informed decision with your vet. In any case, if you have the ability to strip graze any paddocks with back fences, this is ideal. Moving fences in 24 hours and back fencing them is great, you don’t need to worry about calves taking in bugs that they are just after ridding themselves of. In a lot of cases however, back-fencing is not possible. If it is not, keeping new grass in front of them by strip grazing will lower the risk of taking in the bugs again and dosing soon before moving to a new field. You can move them approximately 48 hrs post-dosing. Remember, it is always best to consult your vet.

Is strip grazing a good practice with calves or is it unnecessary?

Strip grazing is great practice. It gets calves to clean out paddocks, forcing them to eat all grass. This is good as they will get a better balance in nutrients, particularly as the blades of grass will be varied stages of growth and therefore have structural differences. Furthermore, cleaning out paddocks keeps the grass fresh and reduces souring of the grass. If calves are left to graze a full field without strip grazing it, they will walk over it many times, first selecting the tastiest grass and working their way to the poorer tasting grass. This results in a more varied diet and inconsistent daily liveweight gains.

Is 12- 14% CP meal enough for calves at grass.

Yes, this makes sense as high CP (crude protein) meal is lower in fibre and luscious leafy grass is also low in fibre. Feeding 14 -16% with good digestible fibre ingredients will keep the balance good, helping to satisfy the need for fibre. Furthermore, don’t go too heavy on N in fertiliser. High nitrogen can be difficult for calves to contend with leading to scouring and subclinical or even clinical acidosis.

Would leaving calves in and out to a paddock by the shed preweaning help with grass digestion post weaning?

Leaving calves in and out to a paddock by the shed preweaning can have its benefits and pitfalls. The benefits include helping calves adjust to future grass-based diet and it can help them become accustomed to being outdoors which will help them during their transition to a fully outdoors environment. A major pitfall, which is becoming a concern on more farms every year is the risk of coccidiosis. This system is a haven for coccidiosis which, if contracted, will counteract all benefits of the system. However, if the paddock can be subdivided to allow rotation of calves, giving rest to parts of it at times, you will lower the risk of coccidiosis. As coccidiosis is very difficult to eliminate due to its resilience, prevention is most certainly key. It can be good to chat to your vet about your own personal situation to discuss options on prevention of coccidiosis through management.

How much meal should calves be eating at grass? When can they be off meal fully or should they be left on meal?

Initially it would be good to feed ad-lib meal to calves, if possible. Often this is not the case, predominantly due to bird activity. If calves will consume 2-3kg meal/day then feed that. It can be difficult to get calves to take that much meal, particularly if the grass is very sweet. Normally calves will tell us what they need or want but, in this case, grass is very like ice-cream. They will fill themselves up on it but not be able to get the required nutrients from it. Sometimes it takes feeding meal twice daily. However, this is not always possible on a farm so feeding a minimum of 1 kg is very important. Not feeding meal when they go out to grass could be detrimental to their health as it takes time for them to build up the ability to access the nutrients I the grass. Keeping small amounts of grass into them (new grass daily or every couple of days) and getting them to clean it out will help intakes of meal as well as promote daily liveweight gains.

When calves are taken off meal can depend somewhat on the year in question. If the grazing season is very unpredictable and weather is changeable it is bet to leave calves on a buffer of concentrates to counteract the stress of the changing consistency in grass. If the year is dry with very consistent weather concentrates may be removed from the diet in later summer. This can only be done if calves are receiving grass frequently, keeping this diet as consistent as possible.

When should calves be first dosed?

Bucket reared calves are very vulnerable to worms. Ideally faecal egg counts should be carried out. This will give you a much better idea of the worms and level of burden you are fighting. Knowing this can provide you with a more informed choice on which dose to get and when to give it. It can also aid the reduction of anthelmintic resistance. The way in which you collect faeces for testing is important to give you a more accurate result as every calf can be different in the worm burden. If testing faeces is not an option on your farm bear in mind that the worms we are most concerned about in calves have a life cycle of three weeks. The weather can have an impact as more humid conditions favour the growth of these worms. Dosing at approximately 3-4 weeks can be a good guide but it is always best to consult your vet to discuss the exact circumstances you are faced with eat time you are preparing to dose your calves.

What is the best type of grass to turn calves out in?

There is not a lot of research in the area of grass variety and covers which are best for calves. Anecdotal evidence however suggests that older, heavier covers are best for calves. This is to provide calves with sufficient levels of fibre for their transition to grass. This does not compromise their protein needs and they can have excellent daily liveweight gains in these conditions. Leaving calves in a leafy luscious paddock will deprive them of their need for fibre but will taste so good it will be hard to encourage them to consume concentrates. Heavier covers will provide a more gradual transition to grass.

How often should calves be moved when at grass?

Ideally calves should get fresh grass every day and no longer than every three days. This will encourage them to clean out all parts of the grass – leaf and stem (if stem is present). It is important for them to eat the components with more fibre as well as protein. This will give them a balance to help them to transition to a grass diet. Moving them often will help improve intakes and therefore daily liveweight gains as well as maintaining access to clean grass thus reducing the risk of coccidiosis.

Should I feed meal at grass?

Yes, calves should have access to meal at grass, most importantly during their introduction and adjustment to the grass diet. This will ease the effects of the change allowing them stability for continued growth. Maintaining meal in the diet will help stabilise the diet in times of changes in consistency due to weather or transitioning to fields with different grass. A low level of meal is often sufficient, particularly when the year is dry. It also allows a quicker reintroduction to a higher level of meal when it becomes necessary again.

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