Volume 13: Industry Processes and Controls
3. Head-boning and brain removal
Processes involved in head-boning in 1986
Condition of head when sent for boning
Transport of heads for boning
Harvesting of head meat
Removal of the brain from the head
Rendering of skulls

Condition of head when sent for boning

3.6 The butchering of carcasses, including the removal of the head, is described in Chapter 2. The head was skinned and dehorned, the nasal passages and throat cleared of any solid material, and the retropharyngeal lymph node slashed and other deep incisions made in order to facilitate inspection of the head. ¹

3.7 Tonsils had to be removed from bovine heads as part of the inspection process in export slaughterhouses, where most cattle were slaughtered. ² The tonsils of cattle slaughtered in other plants may have remained in the head when it was sent for boning, although the Inquiry did hear evidence that tonsils were always removed before the head reached the head-boning plant. ³

3.8 It appears that the tongue was generally removed from heads in the slaughterhouse. ⁴ However, the Inquiry also heard evidence of heads being sent with the tongue both to specialist head boners and to butchers who had requested this. ⁵

3.9 The captive bolt stunning of cattle is described in Chapter 2. This stunning process and the subsequent insertion of the pithing rod into the head of slaughtered cattle was a widespread practice that created a hole in the skull. ⁶

3.10 It is unclear whether heads were occasionally provided for boning with the brain removed before 1986. This did occur on occasions in the period following the introduction of the SBO controls (particularly when heads were sent from slaughterhouses to specialist head-boning plants), and it appears possible that this may have occurred on limited occasions in the period before the emergence of BSE. The manner in which brain removal was performed is addressed below.

Transport of heads for boning

3.11 Those larger slaughterhouses that also boned the heads of cattle had a special section in the same premises but away from the slaughter line.

3.12 The Inquiry heard that heads were often transported together in bulk to the premises where they were to be boned:

. . . the heads were removed off the hooks where they were hung in the slaughterhouse and they were thrown basically in a cold van in which they were removed to the head-boning plant and they only transported heads at the time . . . they still had the head meat that was going to be recovered mechanically at the head-boning plant. ⁷

Harvesting of head meat

3.13 Specialist head-boning plants removed the meat by a labour-intensive process using a circular electrical knife. Ms Hovi, an Official Veterinary Surgeon, had seen several head-boning plants in operation in several countries:

I have never seen a machine removing the meat from the head; it is usually a man who has a circular saw. It is very fast, they do not waste time processing one head. ⁸

Removal of the brain from the head

3.14 The extent to which brains were removed before 1986 is discussed in the Annex to this chapter. Where this happened, it was more likely to have been done after the head meat had been harvested, rather than before. The practices described below are primarily taken from observations made by Mr Stephen Hutchins, a MAFF Senior Veterinary Officer, in a report he prepared in February 1990. ⁹ In the absence of any description of brain removal before 1986, the methods employed are assumed not to have changed.

3.15 The removal of the brain is difficult because of the strength and thickness of the cow's skull. Nonetheless it can be performed in a number of ways, not all of which involve splitting the skull:

(i) Oblique cut through the rear of the skull by an electric or manual saw

3.16 In this method a cut was made from just in front of the captive bolt hole to a line just above the foramen magnum (the cavity at the base of the skull). This cut could be made with either an electric saw or a manual saw. The brain generally retained its structure and was then 'shelled out'. ¹⁰

(ii) Splitting the skull with a band saw

3.17 After removal of the head meat, the skull was fed upside down and back-to-front through a vertical band saw. The skull was split longitudinally in a vertical plane, bisecting the brain along the mid-line. ¹¹

(iii) Splitting the skull with a specialised tool

3.18 According to one veterinarian:

There is a patent tool which will actually split it [the skull], which you can wind down and put pressure on. ¹²

3.19 The Inquiry also heard evidence of the use of a mechanical cleaving machine, which appears to have been a similar device. ¹³ It was suggested as well that a specialised guillotine had been employed to split heads. ¹⁴

(iv) Splitting the skull with a hand-held cleaver

3.20 The practice of splitting heads with cleavers has never been widespread and a number of witnesses told the Inquiry that bovine skulls could not be split in this way. ¹⁵ Other witnesses, however, stated that they had seen this method employed in smaller slaughterhouses:

I think mainly the abattoirs I worked in in Lincolnshire were smaller type beef abattoirs and they would use a cleaver to actually go in an A shape on to the head to chop out the front of the skull to remove that brain. ¹⁶

Brains were removed by use of a cleaver, and being scooped out by hand by the slaughtermen. ¹⁷

(v) Expulsion of the brain by a jet of water or air

3.21 This method did not require the head to be split. Rather, it relied upon the use of a powerful jet of hot water or air to expel the brain tissue through the cavity at the base of the intact skull (the foramen magnum). The jet would be generally introduced first via the captive bolt hole and later through the foramen magnum. ¹⁸

(vi) Suction of the brain through the captive bolt hole

3.22 This method involved removal of the brain by means of suction through the captive bolt hole. ¹⁹ Mr Carrigan told the Inquiry that he did not believe that brain removal was possible by this method. ²⁰

Rendering of skulls

3.23 Once the head meat had been removed, the skulls - including eyes and brains (where the brain had not been removed) - were disposed of to renderers. Renderers collected them from slaughterhouses, boning plants or butchers. Mr Richard Cracknell, representing Anglo Beef Processors, explained to the Agriculture Committee of the House of Commons in June 1990 that, prior to the introduction of the SBO controls, the head would go to the renderers 'with the bones' and that slaughterhouses would usually be paid for such material according to its weight. ²¹