DEAR SIR: I have read the article on the effect of different flooring types on the performance of cattle, published in the Northern edition of the Irish Farmers Journal, 7 January 2017.

The information reported in the article is based on a trial carried out by a PhD student in the AFBI Hillsborough on the effect of slats, slats with rubber and straw on the performance of 80 Friesian bulls regarding average daily gain, carcase weight and cleanliness. The results of the trial are as presented in your paper and I wish to comment only on what is presented therein at face value as I do not have access to the raw data on the trial.

I wish to make the following comments and observations.

Your article states “Carcase weight on rubber was marginally better for bulls on rubber.” According to the data given, bulls finished on rubber slats had a heavier carcase weight of 6.1kg. With beef at €3.70/kg, this is €22.57. Surely this is significant to farmers given the present climate.

Also, in terms of payback and in a beef finishing situation, using your 204-day cycle, a farmer will get 1.8 rounds of cattle through his facility. With rubber trading at €55/sq m and a stocking density of 2.2m per animal, a farmer’s outlay will be €121, with a payback of €40.62 (24 by 1.8).

The farmer will have his cost recouped in three years. This, by any yardstick, is quick payback and I haven’t even factored in reduced associated costs with lameness, like vet bills and labour.

Also if those were continental-type cattle, grading better than Friesian bulls, payback would be shorter. The carcase weights as presented comparing concrete and straw versus rubber also shows a 9.2kg, €34 increase in favour of rubber.

The finished carcase weights ranging from 279.1kg and 282.1kg were” light” by cattle finishing standards. Had they been heavier at between 300kg and 350kg then the pressure on limbs, hocks, claws and with 12 animals per pen then I believe the negative impact of raw slats on lameness and reduced average daily gain would have been picked up.

Likewise, the positive effects of rubber in this situation would have been gathered and would have reflected what is happening in finishing yards in Ireland for the past 12 years.

There were 80 animals in the trial and in order to get sufficient replications I presume they were divided into 20 groups of four. While this model facilitated trial research and probability, it does not mirror or replicate what happens on farm where there are between 10 and 20 animals per pen.

My point here is that with just four animals per pen there is reduced incidence of lameness, tramped tails, riding activity with bulls and resultant injuries. On a farm with at least 12 animals per pen, you have a higher level of injuries and lameness.

In the trial this was not picked up and I believe could not have been picked up. Likewise the benefit of the rubber in this situation would not and could not be picked up.

Interestingly, in the trial there was no information presented on lameness, injuries, lying and ruminating bouts or standing bouts.

Your reference to cleanliness is also interesting. As every farmer knows, dirt score is very much related to diet and very subjective while measuring. I note that the void/slot area in the slat was reduced from 4cm to 3cm, which could be significant. Not all rubbers are the same of course and the rubber we use is flush with the edge of the slat.

Your mention of many enquiries for rubber with the upcoming grant is correct and not surprising. For grant schemes in the North to date and in the south some years ago, slat rubber was and will be the most sought-after product on the list of eligible items.

Finally, I am not sure what the writer means when he says that previous research studies done by Teagasc and the AFBI supports the findings of the present trial.

Continental bulls in the Grange Teagasc trial in 2006/2007 gained 14kg of carcase weight on rubber compared to raw slats. This is worth €51.8 to the farmer @ €3.70/kg. Perhaps it is performances like this being achieved by cattle farmers throughout the world that make slat rubber such a key element in profitable and welfare-friendly animal production.

Final thought. If we exclude rubber from the trial, is this study seriously suggesting to farmers that there is no difference from a performance and welfare point of view in using straw bedding versus bare concrete slats?