July 2016

For our first newsletter for this season I am mainly focusing on coccidiosis disease. When a farmer has calves affected by coccidiosis, it’s often the last disease suspected and the health effects to the calves can be very severe, causing long term damage.

In 2011, we increased the level of Bovatec® in the calf meal by 50%. This was after feedback from some customers that they were getting calves affected by coccidiosis. Now even though the lasalocid sodium (active ingredient of Bovatec) is included at 135ppm, as opposed to the standard rate of 90ppm, we still get about 1 report per season of a farm being affected with coccidiosis. While this is less than 1% of our customers, this certainly causes a lot of problems for the farm that is affected.

Coccidiosis is a protozoan disease and all cows carry coccidial oocysts in the small and large intestines. Most cattle develop some immunity to it while continuing to shed a few oocysts in their faeces. Introducing new animals to the herd can introduce new variants of coccidial oocysts to which there is limited herd
immunity. Calves can handle a few oocysts, but a heavy load is another story. They are vulnerable because they have little immunity, particularly if they ingest a high number of immature protozoa in their environment that overwhelm their immune system.

Calves may carry the oocysts without affect until one of the following triggers sets it off; the presence of other pathogens, a change in diet, inadequate colostrum as a newborn calf, environmental factors including the use of small pastures year after year, crowding, poor hygiene, adverse weather (cold, wet or hot), transport, frequent regrouping of calves and bringing in new animals.

Preventive measures include minimising fecal contamination of the environment as when a calf lies in manure and licks itself, it ingests oocysts. When feeding straw or hay, ensure it doesn’t become contaminated with fecal matter. When the calves are no longer inside the sheds, clean the sheds out before summer as this allows dry hot weather to sterilize the pen.

Ionophores such as lasalocid (Bovatec®) and monensin (Rumensin®) and are included in calf meals because they increase feed efficiency and also act as a coccidiostat, hindering multiplication of coccidial oocysts. However according to one American website they should be considered as one of the preventive measures rather than for treatment and control.

You can see from this graph that as Aoraki Calf Meal has Bovatec® included at higher inclusion rates, protection is gained earlier. However, note the calf could be 5 weeks old before it gains sufficient protection. If it is has ingested oocysts during the period of non-protection and then suffers from one of the triggers already listed, then there is a high risk of coccidiosis occurring.

One of our customers who have previously had coccidiosis in their calves now dose their calves with Baycox® C at day 14 which gives the calf protection from day 21. They have found this to be very effective, but it is an additional cost.

Another customer, Phillipa Gillies, had calves affected by coccidiosis about 6 years ago. Phillipa reared 850 calves on their dairy farm last season using the same calf pens multiple times without any issues. Here is her recipe for successful calf rearing.

One dose per calf of ImmuStart® on day 1 before they get any colostrum. This helps to provide protection against Rotavirus, E coli, Salmonella, Cryptosporidia, Coronavirus and also contains probiotic bacteria. Phillipa no longer vaccinates her cows for Rotavirus. She also uses Dancalf® plus in the milk from Day 5 through until weaning at 80kg to prevent coccidiosis. She also feeds 1.5 litres of milk twice a day for 5 days, then the calves go outside and receive 3 litres once a day until weaning. Straw is used in the calf pens and between each batch of calves the pen is sprayed with disinfectant and a generous new layer of straw is added. Phillipa has not had to treat any calves for coccidiosis since adopting this regime and has a very low mortality rate in her calves. ImmuStart® and Dancalf Plus® are both Nutritech products and can be purchased from most farm merchandise outlets.

For more information regarding these products visit www.nutritech.co.nz or email me.

2016 Pricing

Not all of the pricing for the raw materials has been finalised yet, however we will be dropping the price from July 1 by $26 per tonne for the High Octane and $30 per tonne for the Low Protein, as per past seasons the price will be a floating price rather than fixed. More details of pricing will be in the August newsletter.