The Importance of Animal Welfare in Poultry Processing Industry

Poultry Processing Plant is a building complex with a certain design that is used as a place for slaughtering poultry properly for public consumption and must meet certain technical requirements. With proper ante-mortem and post-mortem examinations, it is hoped that carcasses, meat and internal organs can meet the requirements of being safe and fit for human consumption. To meet the increasing demand for poultry meat and its processed products, Poultry Processing Plant plays an important role as an important means needed to improve public services as well as break the chain of transmission of zoonotic diseases (from animals to humans), so that the carcass/poultry meat and internal organs are healthy, safe and fit for consumption and does not harm the health of the human body.

Quality is the composite of those characteristics that differentiate individual units of a product and which have significance in determining the degree of acceptability of that unit to the user. However, for meat industry, meat quality is a term used to describe the overall meat characteristics including its physical, chemical, morphological, biochemical, microbial, sensory, technological, hygienic, nutritional and culinary properties. It is a well-known fact that poultry production at mass level has already been achieved and now emphasis is laid on increasing meat quality by altering the said characteristics of poultry meat. The appearance, texture, juiciness, wateriness, firmness, tenderness, odor and flavor are the most important and perceptible meat features that influence the initial and final quality judgment by consumers before and after purchasing a poultry meat product

Furthermore, for processors, manufacturing value added meat products, quantifiable properties of meat such as water holding capacity, shear force, drip loss, cook loss, pH, shelf life, collagen content, protein solubility, cohesiveness, and fat binding capacity are indispensable to acquire excellent functional properties that will ensure a final product of exceptional quality and profitability. However, poultry grading system used worldwide continues to be based on aesthetic attributes such as conformation, presence or absence of carcass defects, bruises, missing parts, and skin tears without taking into account the functional properties of meat which has thwarted the rise of further processing industry.

To produce a quality poultry meat product from a live bird involves a series of efficiently-performed, specific tasks in a sanitary manner. Before poultry can be processed, they must be caught, cooped, transported and held, then unloaded at the processing plant. Inside the processing plant, broilers are hung on shackles, stunned, slaughtered, bled, defeathered, eviscerated, inspected, chilled, graded, packaged and shipped. Because of the complexity of production and processing procedures, several factors may reduce carcass yield, carcass grade and the company’s overall profit margin.

Defects resulting in carcass downgrading and product losses are strongly influenced by conditions at the farm and processing plant and also indirectly affected by the animal welfare. How animals are handled during harvest in the farm and pre-slaughter affects the appearance of meat products such as: severe bruising or hematoma and broken bones. The application of electrical stimulation and how the carcass is chilled influence the rate of rigor mortis and subsequent meat quality. The application of stunning and exsanguination methods that ensure reduced animal stress are important to meat quality. Stress factors and poor welfare can lead to increased susceptibility to disease among animals. This can pose risks to consumers, for example through common food-borne infections like Salmonella, Campylobacter and Escherichia coli.

The Indonesian government through the Law of the Republic of Indonesia Number 41 of 2014 which regulates animal husbandry and animal health defines Animal Welfare as: All matters relating to the physical and mental state of animals according to the size of the natural behavior of animals that need to be implemented and enforced to protect animals from inappropriate behavior by everyone towards animals used for human needs. An animal is in a good state of welfare if (as indicated by scientific evidence) it is healthy, comfortable, well nourished, safe, able to express innate behavior, and if it is not suffering from unpleasant states such as pain, fear, and distress. ?It is the purpose of this regulation to protect and promote the welfare of all animals in the Indonesia by supervising and regulating the establishment and operations of all facilities utilized for breeding, maintaining, keeping, treating or training of all animals either as objects of trade or as household pets.

There are few steps must be continuously monitored and precisely controlled to ensure the implementation of animal welfare in poultry processing industry.

Catching, Cooping and Transporting Live Birds

At the grow-out house, market-age live birds are caught by the live haul catch crew (harvester crew), loaded into coops and transported to the processing plant. During catching, minimize bruising because it results in carcass downgrading and yield loss. Ninety percent of bruising occurs within 12 to 24 hours before processing. Areas most frequently bruised are the breast (42%), wings (33%) and legs (25%). Good animal welfare procedures can reduce bruising and the number of birds that are dead-on-arrival (DOA’s) at the processing plant. During loading live birds into coops considering the numbers of live birds per coop. The right amount of live birds must fit into the coops based on average live weight (ALW) of live birds and the size of coops. Too many live birds per coop can lead to live birds stress and increase dead-on-arrival (DOA’s) at the processing plant. The distance that broilers are transported before processing affects carcass contamination and yield. Broilers that are transported long distances (6 hours) have fewer bruises due to confinement and the fatigue from traveling makes them less active during slaughter. However, the stress associated with transporting slows digestive tract clearance and increases the live shrink (live weight loss).

Receiving, Holding and Unloading Live Broilers

When birds arrive at the plant, they need adequate ventilation in the holding area to minimize mortality and excessive live shrink. Live birds should arrive at the plant and be scheduled for processing 8 to 12 hours after their last feeding. This decreases the amount of material that could potentially contaminate the carcass during processing by allowing adequate time for the bird’s gastrointestinal tract to become empty (avoid full crop). Live birds that go without feed for long periods of time (greater than 13 to 14 hours) begin to lose the mucosal lining of their intestines and will have lower carcass yields at slaughter. When the intestinal lining is lost, fecal material in the bottom of the coops will have a reddish-orange appearance to it and the resulting intestine will be much weaker and more easily broken during evisceration. Be careful during the unloading and hanging steps to minimize carcass bruising, broken legs, broken wings, and red wing tips. If the doors (hinged front flap) to the coops (modules) are not positioned correctly during unloading, they will cause leg and wing damage. Bruising is minimal when coops are tilted in a smooth motion as opposed to bouncing the coop back and forth. Clean empty coops properly before reloading to minimize cross contamination among broilers. In the hanging area, use low levels of light to minimize the live birds’ excitement once they are placed in the shackles. Blue light seems to be most effective at calming broilers.

Stunning, Slaughtering and Bleeding

Based on Indonesian National Standard which regulate halal poultry slaughtering (SNI-99002-2016), stunning of live birds is done in the range of 15 – 80 V per bird of electrical voltage and 0.1 to 0.5 A per bird of electrical current for a duration of 3 to 22 seconds. This practice is important, not only because it renders the bird unconscious, but also because it affects bleeding, feather release and overall meat quality. When the stunning voltage is high, wing hemorrhages, red skin condition, poor feather removal, broken bones and blood splashes in the meat may result. The main concern with stunning, slaughtering and bleeding is to minimize the number of birds that are improperly bled and to limit those that have not expired before they enter the scalder machine. The halal slaughtering method based on SNI-99002-2016 required to cut the windpipe (trachea), gullet (oesophagus), jugular vein and carotid artery. The position of the bird’s head during the slaughter operation is critical for proper bleeding and depends upon the alignment of the toe and head guide bars. If the live bird’s head is not in the correct position for neck cutting, the trachea and esophagus will also be severed. When the trachea and esophagus are severed, it is difficult to remove the head and lungs. The recommendation of a bleeding time in the range of 3 to 4 minutes.

Scalding and Defeathering

After bleeding, birds are scalded by immersion in a scald water tank with temperature 57°C to 59°C for 1.5 to 3.5 minutes, depending upon the bird’s average live weight (ALW). Scalding facilitates feather removal, but only if a uniform temperature is maintained throughout the scalder. When the scald temperature is too high, carcasses become discolored due to uneven moisture loss. If the bird is alive when it enters the scald tank, the trachea, esophagus, lungs, crop, gizzard and air sacs may become contaminated with scald water. The resulting carcass will be red in appearance. Moreover, the lungs may collapse and be difficult to remove, or they may drip as the viscera is transported through the plant. Carcasses leave the scalder and go through a series of pluckers designed to remove feathers from the body, wing, hock and neck. Feather removal is most successful when the pluckers are placed close to the scalder so that the bird’s body temperature remains high during picking. The pluckers can be a major source of carcass bruising, wing breakage and broken hocks, especially if rubber fingers are worn or not positioned correctly.

Eviscerating

During the evisceration process, carcasses can easily become contaminated with fecal material, especially if the vent opener and draw hand are misaligned or the intestines are unusually weak. If the body cavity of the bird appears convex, then the length of the feed withdrawal before processing was too short and the bird’s intestines are full of fecal material. Full intestines are more easily cut or torn during evisceration and the contents may leak on to the carcass during extraction. On the other hand, when birds go without feed for too long before processing (greater than 14 hours), then the intestinal lining is lost and intestines may break during extraction. Carcass, gizzard and liver contamination with bile are also related to an extended feed withdrawal time. Contaminated surfaces on the carcass have to be washed, trimmed or vacuumed at a reprocessing station and this process is expensive and time consuming.

Chilling and Packaging

The chilling operation decreases the carcass temperature to maximum 4°C within 1 hours of slaughter and inhibits microbial spoilage. Rapid chilling limits the growth of pathogenic bacteria on the carcass and increases the products’ shelf-life, especially when an appropriate amount of free chlorine (1 to 4 ppm) is used in the chiller water. Depending upon the extent of their attachment, bacteria present on the carcass as it enters the chiller are frequently removed during the chilling operation. After chilling, carcasses are hung on a drip line generally for 2.5 to 4 minutes to control the amount of moisture pickup. Although most of the moisture from chilling is retained in the skin, the amount of cutting during evisceration will have a significant effect on carcass water retention. Carcass internal temperature on exit from the chiller must be 4°C or less. In the packaging area, whole carcasses or parts must have an internal product temperature of 4°C or less. This temperatures should be maintained throughout storage and shipment. Also place emphasis on minimizing recontamination of the product with proper equipment sanitation and good manufacturing practices.

Summary

Poultry processing plant is important sector to convert the live bird’s muscles into meat/carcass, to remove the unwanted components of the live bird (blood, feathers, viscera, feet, and head) and to keep microbiological contamination at a minimum. The ultimate quality of the final product depends not only on the condition of the birds when they arrive at the plant, but also on how the bird is handled during processing. Bruising, broken bones, missing parts and high carcass reprocessing numbers can cause significant economic losses. Unloading, stunning, slaughter, scalding, picking, eviscerating, chilling and packaging poultry are some of the processing steps that can result in product defects. Thus, these steps must be continuously monitored and precisely controlled to ensure the implementation of animal welfare in poultry processing industry.