With reference to Mr Seal's claims for the milk yields of dairy cows (Mailbox, June 22) , I think he should check his arithmetic.

At calving, a good cow will yield five to six gallons of milk per day, that is 40 to 48 pints, not 120 as he claims. After about 30 days this begins to decline and does so throughout the lactation, which is usually about 310 days

Approximately 90 to 100 days after she has calved she will be put to the bull or inseminated.

After her lactation is finished the cow is dried off to await her next calf which will be due about a year after her last one. She is fed carefully balanced feed that keeps her in tip-top condition, both for the milk she gives and the calf she is carrying.

So much is now known about her physical requirements, in terms of vitamins, minerals, trace elements, protein and starch, that dairy cows are better and more appropriately fed than ever before.

The milk from a cow with mastitis has to be thrown away, so no farmer keeps cows that are "riddled with mastitis" and again, because of improved husbandry and hygiene, there is less now than in the past. These cows may work hard but they are cared-for and cosseted.

I think Mr Seal mistakes the very bony frame of the modern Holstein-Friesian cow for one that is half-starved and I admit to the untrained eye they look emaciated, but that view is wrong as they are naturally very lean. However much you feed them they won't get any fatter.

On badger-culling Mr Seal says that TB wasn't known in badgers before the 1950s. Testing for TB in cattle was only started in 1950 when an eradication scheme was implemented.

From the start, farmers were asked about badger setts on their land and were directed to inform the Ministry of Agriculture, Fisheries and Food (MAFF), Defra's predecessor, of any dead badger.

This included road-kill which, because the animals were far less numerous, was a comparatively rare occurrence.

These dead badgers were collected and tested for TB and MAFF wouldn't have wasted their time if they hadn't known of the presence of the disease in the badger population. I think we can assume that these animals have always suffered from TB and that it has always passed back and forth between badgers and cows.

If badger populations were reduced to their 1950s levels everywhere, TB in cattle would be far less of a problem.

Wendy Warren, South Kilworth.