NO ONE BREEDS FOR A SLAUGHTER MARKET!!!
HORSES DO NOT GO TO SLAUGHTER BECAUSE OF 'OVER-BREEDING'!!!
Horses go to slaughter simply because of their lack of value and a lack of a better market for that particular horse at that particular time. They are called 'unwanted horses' because most go through auctions and no one wants them, so the low bid of a 'killer buyer' gets them. Everyone else has a chance to buy them, but if no one else wants them, the KB gets them.
When the economy is good, the demand and market prices are high and horses are bred and raised to fill that demand. The problem is that horses take 3 or 4 years from the time a mare is bred by a stallion until the resulting foal is ready to ride and train. Then, some 15 years later, that horse is STILL needing to be fed and cared for whether it has any useful purpose or not. No breeder knows what the economy or market condition is going to be in 5 years, much less 20 years down the road.
In 2005, the market was great. People could not breed saddle horse stock fast enough. The 'Foundationbred Quarter Horse market was so good that entire ranches from Texas to Montana sold their cattle and started raising horses. Auctions were held every fall for weanlings and some averaged over $5000.00 at auction. In 2008 and 2009, many of those same big ranches went bankrupt and hundreds of thousands of horses suddenly had no market at all.
Horse breeding has always gone in cycles. There was an even bigger sell-off of horses back in the early to mid 90s. At that time, over 300,000 horses went to slaughter each year for several years. No one has a crystal ball and no one knows when the next cycle will go up or down. Horses and horse breeders are just along for the ride. It is not fair to vilify breeders because they do the best them can with the market at hand. Their cyrstal ball is no better than yours.
Prices are now coming back up. The breeding herd shrank to a fraction of what it was, but the economy is improving and people are once again looking for good young horses to ride and train. Prices are up significantly in the last few months.
When the market is strong and people are looking for young prospects to train (the horses we call 'project horses'), very few young horses go to slaughter that are not crippled, ugly or ill-tempered. I KNOW! I used to buy a lot of project horses for customers. I always had 2 or 3 people wanting 1 or 2 of them. In 2005, I could not find a decent looking and decent bred AQHA project gelding for less than $2500.00 In 2009, most of them were going to the killer buyers because I and anyone else like me had no one wanting to take a chance on one of them. You cannot blame breeders for this. It is just part of the 'supply and demand' cycle. The supply always dries up several years after the demand dries up and visa-verse.
As for double deck trucks -- I have not seen one haul horses for several years. As a matter of fact, all of the slaughter-bound horses leaving the big local sales in Texas and Oklahoma for more than 10 or 15 years have all been hauled on 53' floor trucks. The ONLY double-deckers I have personally seen were hired by the BLM to haul mustangs into Pauls Valley, OK from Nevada.
Rodeo stock and slaughter horses are about all that are hauled in semis (other than BLM horses). Everyone that hauls them is trying to keep horses from being injured or hauling badly. No one shipping these horses neglects them because pounds and injuries equals dollars. All of the neglect comes at the hands of owners that try to hang on to their horses when they cannot afford them and try to keep from selling them.