In a comment, Fabian said, "A good answer should provide the laws and regulations involve, but also provide some evidence if those laws are not enforced properly."
In summary:
There are no Federal laws at all regarding "animal abuse" on farms
State-level cruelty laws usually exempt "normal" farm practices
There is one Federal law which should regulate "abuse" at slaughter-houses, but which:
- Isn't thoroughly enforced by the USDA
- Doesn't apply to chickens
Laws on the farm
There are no Federal laws regarding animal cruelty on farms. Here are two relevant quotes:
From the Humane Society of the United States:
Q. Aren't there laws that protect farm animals from abuse?
From life on a factory farm to death at a slaughter plant, animals raised for meat, eggs, and milk suffer immensely. And, as shocking as it may be, much of the abuse these animals endure is often perfectly legal. There are no federal animal welfare laws regulating the treatment of the billions of "food animals" while they're on the farm. Further, while all 50 states have cruelty statutes, most explicitly exempt common farming practices, no matter how abusive.
From USDA's Animal Welfare web site:
Farm Animals are regulated under the Animal Welfare Act (AWA) only when used in biomedical research, testing, teaching and exhibition. Farm animals used for food and fiber or for food and fiber research are not regulated under the AWA.
Although there are no federal laws, Wikipedia says that,
Several states have enacted or considered laws in support of humane farming.
The five laws (from five States) listed in this section of Wikipedia all pertain (only) to use of gestation crates.
There's a compendium of all State laws listed here (which I haven't read, but which you could if you want details about any specific State).
The sidebar of this USDA Animal Welfare page lists the Federal laws, which are:
Reading this list, assuming it's complete, shows that it's true that there are no Federal laws which condemn cruelty to farm animals before they are taken for slaughter: which includes all animals which will not enter the human food chain (e.g. because they are too sick).
Laws on slaughter
There is a Humane Methods of Slaughter Act:
Originally passed in 1958, the law that is enforced today by the USDA Food Safety and Inspection Service (FSIS) was passed as the Humane Slaughter Act of 1978. This Act requires the proper treatment and humane handling of all food animals slaughtered in USDA inspected slaughter plants. It does not apply to chickens or other birds.
Contact the USDA Humane Handling Ombudsman if you have a humane handling related comment or concern or wish to file a complaint.
The USDA sometimes "suspends" a slaughterhouse, after an "undercover investigator" from an animal welfare group captures video and sends it to the USDA: for example, USDA suspends slaughterhouse after video appears to show animal cruelty says,
The USDA suspended inspections at the Hanford-based company, effectively halting slaughter operations there.
Company officials have not seen the video, Brian Coelho, president of the Central Valley Meat Co., said Tuesday. He said he was "extremely disturbed" to learn that inspections were suspended.
"Our company seeks to not just meet federal humane handling regulations, but to exceed them," Coelho said in a statement.
Effectiveness of USDA inspections
USDA inspectors do not detect or prevent all instances of cruelty: at least one animal welfare group claims to have discovered (and has corresponding video of) several instances of 'cruelty' over the years.
This document shows that in 2008 and 2009, there were 80 or 90 "suspensions" per year, issued to federally inspected
plants for violations of humane handling and humane
slaughter regulations.
It does seem true to say that USDA inspectors do or have "condoned" cruelty:
- Ibid says, on its first page,
In early 2008, multiple incidents of egregious cruelty
to cattle at the Westland-Hallmark Meat Packing
Co. in Chino, California, caught on videotape by
animal protection advocates, resulted in widespread
public outrage and eventually led to the largest
beef recall in the history of the U.S. These incidents happened despite the continual on-site presence of USDA inspection personnel and the performance of periodic third-party humane slaughter audits at the plant.
The Humane Slaughter Act simply requires that animals be rendered insensible to pain before they are harvested. However, apparently this law is not being enforced in some instances. For example, the Washington Post article reported that "enforcement records, interviews, videos and worker affidavits describe repeated violations of the Humane Slaughter Act" and "the government took no action against a Texas beef company that was cited 22 times in 1998 for violations that include chopping hooves off live cattle".
There are allegations (which may be so self-evident as to need no proof) that the USDA is more concerned with "food safety" than with "humane killing".
The US Government Accountability Office (which reports to Congress) wrote a document in 2010 titled HUMANE METHODS OF SLAUGHTER ACT:
Actions Are Needed to Strengthen Enforcement. The GAO report things like:
- Only 23% of inspectors would suspend operations on seeing multiple failures to stun an animal
- Inspectors at half of the
plants did not correctly answer basic facts about signs of sensibility [i.e., determine whether stunning was successful]
The GAO made four "Recommendations for Executive Action", only one of which (which was to review the paperwork) now has a status of "Closed - implemented".
Reporting violations to the USDA
The USDA is more concerned with "food safety" than "humane killing".
On the subject of "food safety", the problem at the Canadian XL Foods meat packing (slaughterhouse) was that the workers were too hurried: for example The Globe and Mail's XL Foods workers feared raising food safety concerns, union says article wrote,
Mr. O’Halloran also called for whistleblower protection for workers like those at XL who saw safety standards lapse as a result of what the union describes as an impossibly fast pace of work coupled with inadequate training.
“The line speeds, when they get up high, you don’t have time to clean your knife properly,” he said. “If the line speed is too great, you cheat. You don’t have enough time to do it. And, consequently, you are not doing all the things [required for] cleanliness.”
Apparently it's not easy to be a whistleblower:
Canadian meat industry workers are in the same boat as American meat industry workers in that they lack whistleblower protections – key legal safeguards that would enable problems to be made known (and hopefully addressed) without punishing the messenger.
The allegation that cruelty happens, and is not reported by the workers involved, finds some support in articles like this one.
However Anti-Whistleblower Bills Hide Factory-Farming Abuses from the Public suggests that anti-whistleblower ("ag-gag") bills have been introduced but not passed; so apparently it is still legal (per the First Amendment which allows journalists to report) to produce videos like the one you cited in the OP.
Conclusion
This story from today's news (from Canada) seems to me typical of other articles I read while researching this answer: 'Horrific' conditions seen in egg industry are 'unacceptable': Egg Farmers of Canada.
In my opinion, the following is a summary of what's happening:
- Apparently "cruel" treatment on the farm is not illegal
- Some methods of killing such as "thumping" (aka 'blunt trauma') are said to be normal industry practice (for unwanted animals, i.e. except at the slaughter-house)
- Undercover animal rights activists take video (on private property)
- The intent of the activists is not to get the law enforced (there is no law), but to coerce companies (e.g. McDonald's) and other suppliers/consumers via the threat of bad publicity
- News such as this is not popular with the general public
- The factory farming industry tries to downplay and deny such news, tries to villify animal rights activists, and tries to prevent such news (video) from being obtained.