The maximum speed of a slaughter line (aka evisceration line) is set by the USDA’s Food Safety and Inspection Service (FSIS) in the Code of Federal Regulations. This “maximum slaughter rate” (maximum line speed) is based on the number of animals that FSIS inspectors can effectively inspect for disease in a given time period.[1-3]
The speeds of secondary processing lines are not regulated.
U.S. Government Accountability Office (2017) Workplace Safety and Health: Better Outreach, Collaboration, and Information Needed to Help Protect Workers at Meat and Poultry Plants, GAO-18-12, p. 38. [“The Food Safety and Inspection Service (FSIS) sets maximum evisceration line speed in order to ensure its inspectors can effectively perform their inspection procedures. According to FSIS officials, FSIS does not regulate the speed of other lines, which may run slower than evisceration lines due to complex worker tasks.”]
Livestock – 9 CFR § 310.1 Extent and time of post-mortem inspection; post-mortem inspection staffing standards.
Poultry – 9 CFR § 381.69 Maximum line speed rates under the New Poultry Inspection System.
Yes. The established maximum slaughter rates (line speeds) as set by FSIS regulations differ based on species, as well as some defining characteristics within species. The speeds are also determined by the number of inspectors at each inspection station.[1,2]
Livestock – 9 CFR § 310.1 Extent and time of post-mortem inspection; post-mortem inspection staffing standards.
Poultry – 9 CFR § 381.69 Maximum line speed rates under the New Poultry Inspection System.
The following are the current maximum line speeds set by FSIS regulations (often called traditional line speeds).[1,2] These do not include speeds for plants given line speed waivers.
Poultry – The maximum slaughter line speed for young chicken (broiler) slaughter establishments is 140 birds per minute (bpm). The maximum line speed for turkey slaughter is 55 birds per minute.[3]
Pigs – The maximum slaughter line speed for pigs/hogs cannot exceed 1,106 head per hour. The speed can be slower depending on the number of inspectors at each station and the class of pigs/hogs.[4]
Cattle – The slaughter line speed for cattle cannot exceed 390 head per hour. It can be much lower, as it is based on the number of inspectors, the type of inspection, and the class of cattle (i.e., steers and heifers vs. mature cows and bulls).[5]
USDA FSIS (2014) 79 Fed Reg 49566 Modernization of Poultry Slaughter Inspection.
USDA FSIS (2019) 84 Fed Reg 52300, 52301 Modernization of Swine Slaughter Inspection.
9 CFR § 381.69 (a) (b), USDA FSIS Maximum line speed rates under the New Poultry Inspection System.
9 CFR § 310.1, table 4 to Paragraph (B)(3), USDA FSIS Extent and time of post-mortem inspection; post-mortem inspection staffing standards. https://www.govinfo.gov/content/pkg/CFR-2020-title9-vol2/pdf/CFR-2020-title9-vol2-sec310-1.pdf
9 CFR § 310.1, USDA FSIS Extent and time of post-mortem inspection; post-mortem inspection staffing standards.
In 1997, FSIS began allowing a limited number of poultry and hog slaughter plants to operate line speeds in excess of regulations established at the time.[1] It was part of a pilot program known as HIMP, and it was implemented on the basis that “current slaughter inspection methods, particularly fixed inspector stations on establishment slaughter lines, limits industry innovation.”[2]
Slaughterhouses participating in HIMP were authorized to increase chicken slaughter to 175 birds per minute, and there was no restriction on pig slaughter line speed.[3,4]
The program was designed to make “slaughter process control an industry responsibility subject to FSIS carcass and verification inspection.”[5]
However, the agency was criticized by the Government Accountability Office, which noted that the program’s faster line speeds raised concerns about worker safety.[6] Similarly, the USDA’s Office of Inspector General found that the FSIS did not adequately oversee the program.[7]
Nonetheless, FSIS granted line speed waivers (waiving the existing line speed regulations) to additional chicken slaughterhouses in a revised program called the New Poultry Inspection System (NPIS).[8]
And in a program called the New Swine Slaughter Inspection System (NSIS), the agency permitted all hog slaughter plants complying with NSIS inspection requirements to operate line speeds at any rate chosen by the facility.[9] This program was subsequently restricted by the courts (see question on maximum line speeds for pigs below).
For poultry: These regs included the New Line Inspection System (NELS), Streamlined Inspection System (SIS), and New Turkey Inspection System (NTIS) which permitted a maximum line speed of 140 bpm for chickens and 51 bpm for turkeys. [79 Fed Reg 39566, 49567] For pigs: the existing regulations of 390 head per hour remained the same.
USDA FSIS (1997) 62 Fed Reg 31553, 31557 HACCP-Based Meat and Poultry Inspection Concepts.
Chapman, J.A. et al., (2021) Slaughterhouse Deregulation: A View of the Effects on Animals, Workers, Consumers, and the Environment. American Bar Assoc. Vol 50, Issue 4.
USDA FSIS (2018) 83 Fed Reg 49048, 49048 Petition To Permit Waivers of Maximum Line Speeds for Young Chicken Establishments Operating Under the New Poultry Inspection System; Criteria for Consideration of Waiver Requests for Young Chicken Establishments To Operate at Line Speeds of Up to 175 Birds per Minute.
USDA FSIS (updated 6/27/13) HACCP-Based-Inspection Models Project, History https://www.fsis.usda.gov/inspection/compliance-guidance/haacp/haccp-based-inspection-models-project
U.S. Government Accountability Office (August 2013) Food Safety: More Disclosure and Data Needed to Clarify Impact of Changes to Poultry and Hog Inspections, GAO-13-775. [“GAO identified weaknesses including that training of plant personnel assuming sorting responsibilities on the slaughter line is not required or standardized and that faster line speeds allowed under the pilot projects raise concerns about food safety and worker safety.” See, GAO Highlights]
USDA Office of Inspector General (2013) Food Safety and Inspection Service – Inspection and Enforcement Activities At Swine Slaughter Plants, Audit Report 24601-0001-41 [“We also found FSIS could not determine whether the goals of a pilot program—Hazard Analysis and Critical Control Point (HACCP)- based Inspection Models Project (HIMP)—were met because FSIS did not adequately oversee the program.” See, What OIG Found]
USDA FSIS (2014) 79 Fed Reg 49566, 49570 Modernization of Poultry Slaughter Inspection.
USDA FSIS (2019) 84 Fed Reg 52300 Modernization of Swine Slaughter Inspections.
As of January 2025, there were 44 poultry slaughter plants participating in the USDA’s Modified Line Speed Waiver Program, thereby allowed to run at speeds up to 175 birds per minute.[1] The chicken plants without waivers have a maximum line speed of 140 birds per minute.
Initially under the New Poultry Inspection System, waivers of the existing speed lines were given to many more plants. But in 2020, union workers filed a federal lawsuit against the USDA, arguing that the waivers were unlawful because they failed to consider worker safety at the increased speeds. The court found that FSIS had not properly considered worker safety in enacting the waiver program, pointing to studies, reports, and declarations from workers showing that faster line speeds “increase the number of repetitive motions performed by poultry workers, which in turn substantially increases the risk of injury.”[2,3]
FSIS responded by initiating a worker safety study and requiring plants with waivers to agree to participate in the study. The plants had until September 1, 2022, to agree or their waiver would be terminated. If the plants chose to participate, they could maintain line speeds at 175 bpm with a modified waiver.[4]
In January 2025, the USDA released a study that concluded that higher slaughter line speeds of 175 bpm (compared to lower speeds) are not associated with higher levels of worker MSD (musculoskeletal disorders), nor are they associated with higher levels of airborne peracetic acid (PAA).[5] However, the study also confirmed that high levels of MSD were endemic throughout the studied operations and that for PAA “current risk mitigation efforts are insufficient.”
USDA FSIS (2024) Modernization of Poultry Slaughter Inspection https://www.fsis.usda.gov/inspection/inspection-programs/inspection-poultry-products/modernization-poultry-slaughter (Accessed 1/25/25)
United Food and Commercial Workers vs. USDA, case 1:20-cv-02045, 532 F. Supp. 3d (8/20/21) (D.D.C.), p. 7.
Note: Another suit was filed by several animal welfare organizations arguing that increased line speeds would risk worker safety and guarantee increases in animal cruelty and public health dangers. [HSUS et al vs. Sonny Perdue, No. 3:20-cv-1395 (February 25, 2020, N.D. Cal.)] https://blog.humanesociety.org/wp-content/uploads/2020/02/1-complaint.pdf
USDA FSIS Constituent Update – July 29, 2022, FSIS Announces Study of Effect of Increased Poultry Line Speeds on Worker Safety, https://www.fsis.usda.gov/news-events/news-press-releases/constituent-update-july-29-2022
USDA FSIS (January 9, 2025) Poultry Processing Line Speed Evaluation Study, Harris-Adamson, C. et al., (Researchers, Univ. of California, San Francisco), p. 7. [“Evisceration line speed category (=145 BPM, >145 to <175 BPM, 175 BPM) was not associated with the Peak Force Index -Threshold Limit Value (PFI-TLV score), the primary metric of upper extremity MSD risk.” at p. 6. “Airborne concentrations of PAA did not differ by evisceration line speed category.” at p. 7]
As of November 2024, six hog slaughter plants operated with waivers that allow them to set their own line speed.[1] Plants without waivers have a maximum line speed of 1,106 hogs per hour.
Although the New Swine Inspection System authorized all hog slaughter plants (complying with certain requirements) to set their own line speeds, in March 2021, a federal judge citing worker safety blocked the USDA’s decision to allow faster line speeds.[2] FSIS accepted the court’s ruling and said that establishments operating under the NSIS cannot exceed a maximum line speed of 1,106 head per hour (going back to the traditional inspection maximum speed). The agency then developed a time-limited trial by extending line speed waivers to six hog slaughter plants to “experiment with ergonomics, automation, and crewing to create custom work environments that will protect food and worker safety while maintaining productivity.”[3]
In early 2025, the USDA concluded its time-limited trial evaluation study with mixed results on worker safety.[4] Regarding maximum line speeds, the six establishments with waivers ranged from the regulatory maximum of 1,106 head per hour (HPH) to “up to 350 HPH faster.”[5] An earlier report from an Iowa State researcher also suggested that top rates for the plants with waivers were about 1,450 pigs per hour.[6]
USDA FSIS (November 8, 2024) Modernization of Swine Slaughter Inspection, NSIS Conversion Numbers https://www.fsis.usda.gov/inspection/inspection-programs/inspection-meat-products/modernization-swine-slaughter-inspection
United Food & Commercial Workers Union v. US Dept of Agric., Case No. 19-cv-2660 (JNE/TNL) (D. Minn. Mar. 31, 2021)
USDA FSIS Constituent Update – November 12, 2021, Time-Limited Trial for NSIS Establishments.
USDA FSIS (January 9, 2025) Swine Processing Line Speed Evaluation Study, Harris-Adamson, C. et al., (Researchers, Univ. of California, San Francisco). [For more information, see, Line Speeds Impacts on Slaughter and Processing Workers]
USDA FSIS (January 9, 2025) Swine Processing Line Speed Evaluation Study, p. 17.
Dermot Hayes (2021) Economic Impact of the Recent District Court Ruling Regarding Line Speeds on the U.S. Pork Industry, p. 3. [“These plants operate between approximately 1,225 and 1,450 head per hour… Collectively, these plants harvest one fifth of the approximately 130 million hogs annually harvested nationally.”]
As of March 2024, FSIS granted waivers to five beef slaughter facilities for Tyson Foods, Inc. and Tyson Fresh Meats, Inc. But it appears that those waivers, issued under the Salmonella Initiative Program, deal with the inspection process, rather than making any change to maximum slaughter line speed.[1] Thus, all cattle slaughter plants must still abide by the traditional inspection system with maximum line speed at 390 head per hour.
USDA FSIS Regulatory Waivers and the Salmonella Initiative Program, Current Participant List (updated 12/9/24) https://www.fsis.usda.gov/sites/default/files/media_file/2022-06/SIP-waiver_table.pdf
Not in practice. The agency maintains a position that it has “neither the authority nor the expertise to regulate issues related to establishment worker safety.”[1] However, this hands-off approach has been challenged by two federal court decisions which generally found that if FSIS considered worker safety in its rules, it should have incorporated that consideration in its regulations.[2,3]
FSIS asserts that it collaborates with OSHA on worker safety issues.[4] But in 2023, the Government Accountability Office found those joint efforts entirely inadequate, stating, “we have seen little evidence of direct on-the-ground collaboration to help protect meat and poultry workers. Further, our discussions with OSHA worker safety inspectors and FSIS meat and poultry inspectors indicate little knowledge of the need to collaborate on worker safety.”[5]
In January 2025, the USDA released 2 studies, one evaluating line speed impacts on workers at poultry plants and the other evaluating pig plants.[6,7] Comparing operations with higher slaughter line speeds to those with slower speeds, the reports both concluded that higher slaughter line speeds are not associated with higher levels of worker MSD (musculoskeletal disorders), nor are they associated with higher levels of airborne peracetic acid (PAA).The studies also confirmed that high levels of MSD were endemic at the studied operations and that for PAA levels in poultry plants “current risk mitigation efforts are insufficient.”
USDA FSIS (2019) 84 Fed Reg 52300 Modernization of Swine Slaughter Inspections. [“While FSIS agrees that safe working conditions in swine slaughter establishments are important, the Agency has neither the authority nor the expertise to regulate issues related to establishment worker safety.” at p. 52315]
United Food & Commercial Workers Union v. US Dept of Agric., Case No. 19-cv-2660, 532 F. Supp. 3d 741 (D. Minn. March 31, 2021) [“Crucially in this case, FSIS had identified worker safety as an important factor that it ought to consider when setting line speeds. When it failed to consider worker safety in the Final Rule, it “failed to consider an important aspect of the problem.’” p. 25]
United Food and Commercial Workers vs. USDA, case 1:20-cv-02045, 532 F. Supp. 3d (8/20/21) (D.D.C.) [“If an agency has a plaintiff’s concerns “in mind” when exercising its authority, “[t]his alone is enough to show that [the plaintiff’s] asserted interests at least arguably fall within the zone-of-interests.” p. 12]
USDA FSIS (2014) 79 Fed Reg 49566 (2014) Modernization of Poultry Slaughter Inspection. [“As part of FSIS’s ongoing collaboration with OSHA, FSIS had numerous discussions with OSHA during the development of this final rule on how best to address potential issues related to line speeds and worker safety.” at p. 49597]
U.S. Government Accountability Office (June 2023) Meat and Poultry Worker Safety: OSHA Should Determine How to Address Persistent Hazards Exacerbated by COVID-19, GAO-23-105104, p. 50.
USDA FSIS (January 9, 2025) Poultry Processing Line Speed Evaluation Study, Harris-Adamson, C. et al., (Researchers, Univ. of California, San Francisco), p. 7. [“Evisceration line speed category (=145 BPM, >145 to <175 BPM, 175 BPM) was not associated with the Peak Force Index -Threshold Limit Value (PFI-TLV score), the primary metric of upper extremity MSD risk.” at p. 6. “Airborne concentrations of PAA did not differ by evisceration line speed category.” at p. 7]
USDA FSIS (January 9, 2025) Swine Processing Line Speed Evaluation Study, Harris-Adamson, C. et al., (Researchers, Univ. of California, San Francisco), p. 17.
This is a minor consideration for the agency. For poultry, FSIS reiterates its position that there are minimal animal welfare concerns as long as plants can maintain “good commercial practices” and “process control” as required by the Poultry Products Inspection Act.[1] For hogs, FSIS believes that inspectors will be able to effectively monitor the treatment of animals as required by the Humane Methods of Slaughter Act.[2]
However, common sense suggests that faster line speeds increase animal pain and suffering. There are more transport trucks moving on tighter schedules. Animals in slaughter queues must be moved more quickly in larger groups. Each preparatory slaughter step must occur at a faster pace. Workers on the slaughter line have less time to attend to each animal. Animals improperly stunned will inevitably get less attention.
USDA FSIS (2014) 79 Fed Reg 49566 Modernization of Poultry Slaughter Inspection. [“FSIS regulations require that establishments slaughter poultry in accordance with good commercial practices in a manner that results in thorough bleeding of the poultry carcasses and ensures that breathing has stopped before scalding.” at p. 49609]
USDA FSIS (2019) 84 Fed Reg 52300 Modernization of Swine Slaughter Inspections. [“FSIS disagrees that revoking line speeds will have a negative effect on animal welfare. As the Agency explained in the proposed rule, FSIS was able to conduct more offline humane handling verification tasks under HIMP as compared to traditional inspection. As is the case under HIMP, more inspection resources will be available to verify whether establishments meet humane handling requirements as an offline activity under NSIS.” at p. 52315]