Why do farmers produce new breeds of animals?

Answer 1

Most of the criteria that farmers select for in breeding stock is according to one of two things: what the market is looking for, or the qualities that make a particular breed or cultivar meet breed or cultivar standards be it for a breeding program that involves breeding livestock according to their heritage, or for the modern showring.

Starting with plants, the farmers themselves are not sole responsible for the breeding programs of plants. Crop specialists are trained to do this instead of the farmers. Crop specialists choose and select a plant or plants from a particular cultivar that does well in a particular climate, and cross-pollinate or breed that cultivar to another superior cultivar to obtain seeds that would grow well in the fields of the farmers that buy the resulting seed from the resulting cross. This example is especially associated with corn. Most corn plants that you see growing in the feilds are bred so that the seed that is sowed in the fields is not able to produce as good offspring as its parents where able to produce. Thus, all corn has to be harvested AND sold, and more seed bought from the seed supplier all over again. The corn sold is not grown in any fields, but used for food and other things. For crop specialists, they look for in corn is uniformity, high-yeilding plants, and ability to grow well in generally good soil with enough sunlight, warmth, and (hopefully) enough moisture. High yeilds is the primary goal when breeding different crops, from corn to wheat, barley, oats, soybeans, and other major crops.

Now animals are much more complicated, since we are dealing with several different species here. Selecting which stallions to breed which mares deals with a little more complexities than finding which beef bull to breed with your herd of beef cows. With horses, you are not breeding for meat, but more for recreational purposes such as rodeo, show-jumping, racing, working cattle, or draft work. Breeding for racing means selecting for different qualities such as speed, a "hot" temperament, and specific muscling characteristics that enable the offspring of a winning stallion to be faster. Breeding for trail-riding or cowpunching or drafting requires totally different selection of genetics or characteristics than selecting for racing horses or broncs. But since we are dealing with farmers here, lets stick with the four common type of animals that are found on farms: beef cattle, dairy cattle, pigs, and poultry.

With pigs or hogs, whatever you want to call them, farmers select for faster growth, better muscling, and more leanness. Farmers select these traits in their pigs because the market, hence the consumers, demand this kind of pork. No consumer wants to eat a piece of bacon or ham that is just dripping with fat, or where they have to cut off all that fat off; nor do any of the meat plant employees want to have to cut off an excess of 3" of fat off a single pig. That's just wrong! So breeding has evolved from an overly fat pig in the '50's that could hardly walk, to what I like to call "gutless wonders" where there seems to be a big air space underneath those four tippy-toes. So, for breeding sows and boars, both must have some form of those three important traits above to produce offspring that meet the market requirements.

For poultry, the same things apply with hogs. Turkeys and broiler chickens have become so large that by the time they are ready for slaughter the meat on their breasts impedes any sort of movement. But the market calls for leanness, faster growth, and good muscling, and that's what the farmers supply. However, breeding broilers and turkeys are like what the crop specialists have been doing when breeding corn: breed one type of rooster to another type of hen to obtain offspring superior to them but is only "designed" for consumption, and only consumption. Broilers are able to breed naturally, only the roosters have been selected so far that they are now overly aggressive with the hens, and instead of being nice like the heritage-type roosters that the Cornish breed originally was derived from, they are nasty and rape the hens instead. But that's what happens when artificial selection is played around with. Turkeys, on the other hand, are so big that they cannot breed naturally and must be artificially inseminated (AI): semen is taken from the male, and inserted into the hen.

Dairy and beef cattle have been separated genetically for generations to serve two different purposes: milk and meat. Dairy cattle, or cows are bred to produce a calf which allows them to produce milk. Dairy cows are selected for good milk production, docility, femininity, and fertility. Feminine, fertile cows produce good calves and subsequently good milk. Mothering ability is not selected for since the calves are taken away a day or two after they are born and bottle-fed. Fertility has more to do with what condition the cows are in than genetics, but genetics do play a significant role too. Milking ability is the most important quality as well as docility, since the more milk a cow can give, the better. Subsequently dairy bulls are also selected for the same qualities, although docility in a dairy bull is more hard to come by because of their heightened ability to be more aggressive. Dairy bulls, as a result of selecting for more femininity in the cows and heifers, have become more masculine and thus way more aggressive than beef bulls. This is why a lot of bull calves born are castrated and sent to market either as veal, or grown as feeder steers. Few bulls make it to maturity to have their semen used to breed other dairy cows, since natural breeding in dairy operations is not recommended due to the intensified danger these bulls possess. Dairy cattle are able to breed naturally, for sure, but it's more for the safety of the farmer that dairy bulls are not used on their cows and AI is instead.

Beef cattle are bred for: beef. Now there are two types of breeding operations: seedstock or purebred and commercial. Purebred operations breed for bulls that are to be used in commercial operations to sire calves that meet market specifications: good meat quality, uniformity, and good gaining ability. Purebred operations select for many different characteristics according to the management they are under, unlike the three types of livestock operations above. For their cows, they are looking for: mothering ability, calving ease, fertility, milking ability, docility, forage convertability, freedom from genetic defects, calf hardiness, longevity in the cow, femininity, good conformation, and other things that are typical of the breed, be it Angus, Hereford, Simmental, Shorthorn, Charolais, etc. For bulls, seedstock producers are really picky. They often look for: docility, fertility, good conformation, forage convertability, hardiness under minimal management, calving ease, good scrotal circumference, masculinity, freedom from genetic defects, ribeye area, good carcass characteristics, etc. These traits, both on the sire and dam's side are what commercial producers look for when finding bulls and heifers/cows for their ranch. Producers like to buy bulls that won't "melt" under more rougher conditions than they were "tested" in; in other words, bulls won't wear out and not breed cows under rougher conditions than they were in in a bull testing facility involving bulls being fattened on grain and pampered lots. The breeds of their cows doesn't matter, because hybrid vigour which I touched on a couple times previously in corn and broiler chickens is what makes great calves for the feedlot, and what the markets like to call for. Cows can be one breed or a whole mix, so long as they do well in a ranch environment and don't cull themselves out too quickly.

Basically, when selecting breeding animals for the show-ring or for heritage breeds, producers need to select animals that met those characteristics typical of that breed historically. For the show-ring, the most important winning characteristics are all what I mentioned for the purebred producer selecting for for cattle; characteristics may be a bit different for different livestock of course.

Answer 2

selective breeding is used because...lets say that you want a baby black hamster, and you currently have one black hamster and a brown one. the gene for black is dominant and therefore represented by B. the gene for brown is recessive and is therefore represented by b. so if the black hamster had two dominant color genes, therefore being labled as dominant homozygous, he would have BB if the brown hamster had 2 brown genes he would be recessive homozygous, or bb. if they had kids the tree would look like this.

BB--------------------bb

l

l

---------------------------------------

l l l l

Bb Bb Bb Bb

this says that all the hamster will be black, because they all contain one dominant gene, and that is the oe that is shown.

farmers use this so that there animals produce the best of what the farmers need theme for. so if you breed two fat cows, you will end up with another fat cow, and therefore more meat, and more profit for the farmer.

Answer 3

Selective Breeding gives people money. It helps the scientific world to progress and improve our lives. Selective Breeding is the way to do this. Scientists find that when creating animals with more mass for meat or resistant to disease, there will be more production. Farm animals have been bred to increase productivity. Productivity is the amount of saleable product, for example meat, eggs, milk or wool that the farmer gets from an animals for the cost of keeping it and feeding it. Scientists breed animals with the best characteristics as they believe that it would improve human lifestyle. Selective Breeding is always carried out in the intention that it would benefit humans in some way.

Answer 4

because they can!

Answer 5

Characteristics!