In Holland three times as many pigs are kept as needed for national consumption. The rest is exported.
The following table gives some core figures on intensive and biological pig farming in Holland. The first column shows aspects, for instance how much meat the average Dutchman eats. The second column, headed "1999", shows the average meat-consumption in 1999 (88 kg). The third column calculates the required amount of meat in kg for all of Holland. Comments and clarifications are in the last column.
With this table we are trying to make clear what would happen if all intensive cattle farmers would switch to biological farm-management aimed at the national market. Apart from consequences in business economics, it would also imply a greater use of space inside and outside stables. Maximum welfare improvement would amount to 30% higher costs, which is an amount somewhere between 1 and 50 euro per pig (Dr. M. den Ouden, Wageningen).
The table calculates the required number of biological pig farmers, assuming that consumption of pork in Holland would remain the same, despite expected higher meat prices. There are some extra rows that provide information that may not be essential to the calculations, but that may provide interesting information. The arrows in the left column point out essential information.
From this table, you can deduce that the modal Dutchman consumes about half a pig per year, which can be used in turn to calculate how many biological pig farmers would be needed to produce this meat (given the average number of pigs per farm).

Figures from PVE and CBS required in Holland for national consumption of pork
year

1999

total yearly remarks
kg meat per capita available 88 including veal and poultry etc.
  average gross consumption pork p.p. in kg 43 645.000.000
average net consumption meat p.p. in kg 40 600.000.000 excluding fatty rims and bones
meat price paid up front by government (taxpayer) (30% on top of 4 euro per kg) 70 1.800.000.000 this is more than 50k Euro per pig farm
permanently kept no. of meat pigs in Holland (max. 4 months) 6.774.085 stables are cleared (slaughter) 3x per year
no. of meat pigs kept yearly in Holland 20.322.255 7.371.321 one third is consumed in Holland
number of biological pig farms 36 15.751 more small businesses
number of factory meat pig farms 14.662 5.318 after export ban and without switch
average no. of meat pigs per factory pig farm 462 average of a number of large and a lot of small businesses
average no. of pigs per biological pig farm (max 6 months) 234 average of a number of large and a lot of small businesses
max. no. of biological pigs in pasture per hectare 27 10 hectare free roaming space for an average biological farm
outside space for biological pigs in hectares 157.510 approx. the surface of the province of Utrecht
gross production no. of biological meat pigs 23.000 7.371.321 with equal slaughter weight
gross annual production of pigs in factory farming 23.470.000 incl. sows etc.
exported alive 4.423.000 * 0 * Animal Freedom is opposed
imported alive 507.000 * 0 * Animal Freedom is opposed
annual no. of slaughters 19.554.000 * 7.371.321 * two thirds is exported
slaughter weight pigs in kg 110
production in kg 1.711.000.000
quantity of meat per pig in kg 87.5
actual consumable kg per pig 70 without heads and after boning

These figures show that if Holland were to switch from intensive cattle farming to biological pig farms for the purpose of only covering national requirements in pork, the number of businesses can remain almost the same if the following conditions are met: no export of pork, fewer meat pigs per stable, and letting pigs live one and a half times as long as now. The quantity of manure would be halved.
One barrier in this switch is formed by the huge investments factory farmers have made: a debt of 500,000 euro is fairly normal. Also, international agreements on free export make it hard to impose import and export restrictions. Almost none of the factory farmers have their own land to grow fodder or to spread manure on. If they want to switch, they will have to lease, rent or buy extra farmlands.
In view of the seriousness of the consequences of farm-management for animals in exporting countries we think it worthwhile to intervene in the proposed manner: where there's a will, there's a way.
When consumers pay reasonable prices for meat, meat consumption will decrease and fewer meat producers will be necessary. In exchange, consumers will no longer pay through taxes for keeping an unjust branch afloat.