In highly simplified terms muscle comes in two types.
‘White’ muscle contracts very fast and generates a lot of power quickly, but it is essentially restricted to its own internal energy supply. Once that energy supply is used up the muscle becomes fatuigued and stops working. In humans ‘white’ muscle would be expected in the legs of sprinters, in birds it is found in the flight muscles of ground birds like chickens and turkeys. In both cases the muscle is used to generate a lot of movement for a few seconds at a time, which is fortunate becuase more than a few seconds and it runs out of steam.
In contrast ‘red’ muscle contracts somewhat slower but it is ‘hooked up’ to the blood supply and so is able to regenreate energy as rapidly as it is used. That ability to use the blood to recharge is what makes ‘red’ muscle red. Red muscle contains myoglobin, a protein very similar to the haemogloboin that gives blood its red colour. The basic function of the myoglobon is to allow the muscle to strip oxygen out of the blood and allow it to be used by the muscle. As a result red muscle can be used for extended periods without tiring. In humans we might expect to find red muscles in the legs of distance runners, in birds we find it in the legs of turkeys. In both cases the legs are being used to carry the animal over considerable distances without resting.
Most animals have the capacity to produce a combination of red and white fibres in any single muscle. If a muscle is continuouly fatigued it will build more red muscle fibres to cope with the stress. If it continually subjected to intense burst activity it will recruit white muscle. As a result the excat colour of a muscle can vary a lot amongst individual of the same species depending on lifestyle.
So now we’ve covered the background…
“Why is veal white like poultry”
Because veal is largely ‘white’ muscle. e-logic nailed the reaon why. Quite simply veal calves are restrained to prevent them walking long distances. As a result the only red muscle they produce are a tiny bit in the postural muscles. The vast majority of the muscle, because it is never being fatigued by sustained use, remains white.
" Are baby cows anemic?"
No. Anemia is a condition of the blood. The colour oof muscle is almost entirely unrelated to the condition of the blood.
“If you kept a cow on a milk diet for its whole life would its flesh stay white?”
No. The colour of the muscle is largely determined by how much sustained work is expected of it. If a muscle is used for nothing but short burst activity like standing up then it will tend to be mainly white muscle. If it is used for endurance work like walking then it will gradually recruit mor and more red muscle fibres to cope with the fatigue.
“I assume its got something to do with iron, but why do cows need more iron then pigs?”
It does have something to do with iron, but only in the sense that myoglobin in red muscle contains iron.
“Pigs run around and do stuff, and cows just stand there and chew cud (assuming that more iron = more hemoglobin = more oxygen in the blood = more aerobic stamina, which I wouldn’t bet the bank on).”
Well you got it pretty much right that more iron inthe muscle is equivalent to more aerobic stamina. What you have to realise is that pigs don’t behave like cows. Cattle will be standing in excess fo 22 hours a day and walking and grazing in excess of 8 hours a day. That’s pretty typical for large grazing animals.
In contrast pigs are opportunistic omnivores. While they will resort to grazing if nothing else affords itself they would much rather pig out (heh) on some high energy food and then spend the next 16 hours sleeping, just like a cat or a dog. Particlularly in captivity this is precisley what pigs do, if only out of boredom. In essence if they aren’t eating, pigs in captivity will be just lying around. Nothing to fatigue the muscles, hence no need for red muscle production. Wild pigs tend to have noticably darker meat than domestic animals because wild pigs do travel long distances.
“but free range veal still doesn’t look like steak, although it is a bit darker in color”
Once again, this is largely down to the lifetsyle of the animal. Depending on excatly what the term “free range veal” refers to the animal may not have had much prolonged exercise. Young calves tend to be lft either hidden oin some long grassof the corner of a paddock or in the care of a nursemaid while the cows go off and graze. As a result they spend much of their day simply lying around. More exercise than a penned claf will egt, but still nothjing life the 16+ hours a day of exercise that the adult animal gets.