Process description

Meat processing is a significant industry in New Zealand contributing almost 20% of the country's export receipts, with approximately 20,000 people directly employed in meat

processing and packing plants in 1 998 The predominant

species processed in the New Zealand meat industry is sheep, with significantly fewer

cattle, while other species such as pigs, deer, goats and horses are processed in only small

numbers in specialised abattoirs. Total slaughter numbers by species in New Zealand in 1 998 are shown in Table 3 . 1 below:

Table 3.1 _{Total numbers of stock slaughtered in New Zealand in 1 998}

Lambs Adult sheep Calves and vealers Adult cattle Pigs Deer Goats Horses Total Total number 27,062,560 (7 1 ) 5,865,686 ( 1 5) 1 ,402,689 (4) 2,465,658 (7) 776,856 (2) 4 1 2,059 ( 1 ) 144,647 « 1 ) 4,246 38, 1 34,40 1

All stock processed in New Zealand freezing works has been reared on pastoral farms.

Once transported to the freezing works, the stock received for slaughter is held

temporarily in holding paddocks before transfer to roofed stockyards attached to the main freezing works. The process that follows is essentially the same for sheep and cattle,

although where there are any differences these are noted in the following process outline. From the stockyards animals are driven along a race that leads up to the entry to the slaughterhouse.

The first process undertaken within the slaughterhouse is the stunning of the animal with an electrical stunner, or in the case of cattle with a bolt stunner gun that drives a pin into the animal' s head. Most meat produced in New Zealand is killed in accordance with the requirements of the Muslim religion, by a "Ralal Sticker" who bleeds the animal by sticking the jugular arteries in the neck prior to the throat being cut. The animal is then inverted and hung by its rear hocks to the moving overhead chain conveyor that

transports it through the remainder of the process, and the draining blood is collected in stainless steel drip trays for further processing.

As the animal moves along the overhead conveyor system butchers and slaughterhouse labourers or assistants make a series of cuts to facilitate placement of a clip on the intestines to prevent discharge of gut contents, and to facilitate the removal of the pelt by an automatic pelt remover. In modern works an automatic decapitator removes the head, and the front hocks are severed in an automatic hock remover. Gut contents and edible organs are removed for further processing in the "gut and bung" section, with the viscera remaining intact provided the clip remains in place.

At several stages during the slaughter and evisceration process the carcass is rinsed with hot water and/or steam for hygiene purposes, and slaughter floor personnel wash knives

and their hands in a hot water and detergent solution between carcasses to prevent the transfer of microbial contamination. The overhead conveyor system transports the carcasses along the chain past trimmers and graders who cut off diseased, bruised or otherwise defective tissue, and mark carcasses according to quality criteria. Government meat inspectors check both meat and offal for evidence of transmissible disease and of faecal or other types of contamination. Ovine carcasses remain intact to this stage, while bovine carcasses are split in half vertically along the spinal column before further processmg.

Carcasses are then transferred on the overhead conveyor to the cooling floor or chillers where they are conditioned for at least 1 2 hours prior to either transfer to freezing chambers or to the boning or cutting room for further processing. Where further processing is carried out, the carcass is broken down using power saws into front and hindquarters, and individual parts are deboned and divided into prime cuts by hand. The product is then wrapped, chilled, frozen or otherwise prepared for despatch.

Edible offal (otherwise known as small goods or fancy meats), which includes kidneys, livers, brains, hearts and tongues are processed in a separate department. For example tongues may be processed by either boiling or tinning, or preserving in brine solutions. Some inedible offal is also recovered, for example the casings (or intestines) are passed through rollers or 'runners' to remove faecal material and then cured in salt. Unwanted by-products are digested or rendered in a separate operation to produce meat and bone meal.

Animal hides and pelts are partially processed in separate departments in freezing works by treating them to remove wool or hair in the fellmongery, and then partially preserving them prior to their transport to separate tanneries that are stand-alone operations.

Depilation, or separation of wool or hair from the skin, occurs on the paint table where a solution of sodium sulphide containing calcium hydroxide is applied to the inside of the skin. This solution penetrates through the skins, dissolves the roots, and the hair or wool may then be removed. Wool removed in this way is referred to as 'slipe wool' . The skins are then immersed for a further period in a solution of lime and sodium sulphide, known as the 'liming' process, to remove any unpulled wool or hair and also the epidermal layer of the skin. The pH of the treating solution is then lowered and protein enzymes are added to soften the pelt in the 'bating' process. The addition of salt and sulphuric acid to the solution, i.e. the pickling process, preserves the pelt during storage prior to tanning. The use of preservative chemicals such as trichlorophenate and �-naphthol was common; however these have been replaced by substitutes containing alternative fungicides such as sodium mercaptobenzothiazole (MTB), 2-( thiocyanomethylthio) benzothiazole

(TCMTB), boric acid and carbendazim.

As in any large industrial operation there are a number of both skilled and unskilled maintenance staff employed to repair and maintain the plant. A number of trades are represented, including boiler attendants, carpenters, electricians, engineering fitters, painters and plumbers, as well as workers engaged in cleaning, laundry and stores. These workers perform the tasks routinely associated with their trades in any industrial plant,

although their work in this industry does entail significant contact with biological wastes, ammonia used as a refrigerant and emissions from welding and gas cutting of the

stainless steel that is used extensively in these plants for hygiene reasons.