Fattening, Killing, and Plucking Table Poultry

New Zealand Journal of Agriculture, Volume 84, Issue 4, 15 April 1952, Page 285

Fattening, Killing, and Plucking Table Poultry

FATTENING, the last stage in the production of table poultry before the birds are killed and processed, is discussed in this article, the third of a series by F. C. Bobby, Superintendent, Poultry Industry, Department of Agriculture, Wellington. Methods of .killing and plucking are described, and emphasis is placed on the need to carry out these processes correctly if the birds are to be marketed in an attractive and appetising condition. Trussing will be the subject of another article to be published later. GOOD FEEDING and sound management are essential for birds intended for the table, because the frame is formed and fleshed during the rearing and growing period. Fattening, on the other hand, is the final stage before killing and covers a comparatively short period. Until this final stage is reached no special method of feeding is called for. A good chick mash forms a suitable diet during the, brooding period, and a growers’ mash can be fed up to the time for fattening provided it is not unduly bulky because of the use of large proportions of bran and pollard. In previous years only an excess of bran need have been guarded against, but the carbohydrate content of pollard is now so low that this meal too must be used in moderation.

A table bird must be well fleshed by the time it reaches the fattening stage. Fattening will not necessarily put breast meat on a bird, its real objects being to put fat on the bird and to improve the quality of the flesh. A well-fattened bird has increased fat under the skin on the breast and around the pelvic bones which melts during cooking and permeates the flesh, making it more succulent and tender. Two methods of fattening poultry are commonly recognised trough feeding straight off the run or after the growing period and trough feeding followed by cramming. As it is doubtful whether trough . feeding and cramming (a system of mechanical forced feeding) would be economical in New Zealand, only the trough feeding method will be described. Cramming table birds with a cramming machine in common use in England requires particular skill. The mechanical operation of cramming is not' unduly difficult, but skill is required in mixing the correct type of food and in judging how long a bird is to be crammed. Essentials of Fattening Fattening by trough feeding has four important aspectswhen to start fattening, limiting the birds’ activity, the class of food to use, and the length of the fattening period. The primary object in table-bird production is to obtain quantity with quality, and not quantity at the expense of quality. After the growing stage quality slowly deteriorates both in cockerels and, more slowly, in pullets. The extreme case is the fully-developed breeding male after the breeding season; such a bird, often referred to as a “stag”, has little or no value as a table bird. In both cockerels and pullets to be reared

for the table the end of the breast bone should be soft and pliable; that is, it is still gristle and has not become bone, which is hard and rigid. Cockerels should show no development of the spurs. With heavy-breed birds (light breeds are not recommended for fattening) and first crosses of which one parent at least is a heavy breed fattening may start between 16 and 18 weeks. The exact age will depend on the breed and how well the birds have been reared and grown. During the period of fattening birds should be strictly confined; cages or fattening crates similar to an average broody coop for, say, 6 birds are best for this purpose. Birds may be fattened on the floor in an intensive house, but it is strongly recommended that they be in units not exceeding 20 to 30 if this method is adopted. Cages or coops are preferable to a pen for fattening. Rations for Fattening Feeding is restricted to a semi-fluid mash given twice daily. Water is not necessary. The change from ordinary feeding is made after the birds have been starved for 24 hours, which brings them to the new method of feeding with a keen appetite. The essentials of a fattening ration are milk and a finely ground meal containing a high percentage of carbohydrate or starch. The milk may be buttermilk, skimmed milk, or dried skimmed-milk powder. Maize, oats, and barley all provide valuable meals for fattening, but oat or barley meal must be of high bushel weight and finely ground. Two mashes suitable for fattening are: 501 b. of maize meal, 251 b. of oatmeal, 201 b. of barley meal, and 51b. of dried skimmed-milk powder; or 501 b. of maize meal, 301 b. of oatmeal, and 201 b. of barley meal mixed with buttermilk or liquid skimmed milk at the rate of 101 b. (1 gallon) to 1001 b. of mash. The mash should be sufficiently liquid to permit its being poured slowly from a bucket or watering can. The first ration should be mixed with water to this consistency and water added to the second, after the liquid milk has been mixed in, until the correct consistency is attained.

The birds should be given as much as they will eat at each of the two daily meals, but any that is left should be removed as soon as the birds turn away from the troughs. Cleanliness of the troughs is important, particularly if liquid buttermilk or skimmed-milk is used. Sour troughs with an objectionable smell quickly reduce the birds’ appetites. . If good samples of oats or barley cannot be procured, maize meal and wheat meal may be used with a milk product. Length of Fattening Period Trough feeding should last for 14 to 18 days. How long the birds will feed readily will depend largely on the palatability of the ration, the consistency of the mash, and the 'health of the birds. As soon as their appetites are seen to be falling off appreciably -the birds should be killed, for when appetites fail body weight can be lost rapidly. With the rations recommended heavy-breed birds should gain about Jib. during the fattening period and improve considerably in quality of flesh. Milk products are particularly valuable for improving quality. Before the birds are killed they should be starved for 12 hours to empty the intestines. At one time 24 hours’ starvation was considered desirable, but recent studies of this aspect of fattening indicate that this results in an unnecessary loss of weight. On the other hand, birds killed soon after being fed are more likely to turn green round the vent while being held before being processed, particularly during hot weather. Methods of Killing A bird may be killed by dislocating the neck or by severing the jugular vein and allowing the bird to bleed. The old-fashioned method of cutting off the head is unpleasant and messy. Whether the bird is to be plucked dry or wet, dislocation of the neck is satisfactory, provided that a definite break is made and a gap of up to 2in. is formed in the spinal column into which the blood may drain and clot when the bird is hung up by the feet or held head down in a metal funnel. Draining of the blood from the body into the neck is essential to prevent

discoloration of the flesh on the breast. Unless all the blood is drained from a bird after it has been killed the appearance is depreciated considerably. Severing of the jugular vein can be accomplished by inserting a pointed, narrow-bladed knife into the throat. The bird becomes unconscious, after which all the blood is drained from the body. If properly carried out, this method leaves the bird with flesh of a better colour than if the neck had been dislocated. Dry plucking after severance of the jugular vein is accelerated considerably by insertion of the knife through the slit in the top of the mouth toward the back of the skull. A small twist of the knife destroys the nerves where the brain connects with the spinal column in the neck, causing the feathers on the body to loosen immediately. Care should be taken not to damage the brain in the front and centre of the skull, as the effect is to tighten- the feathers and to make plucking more difficult. This operation is not necessary where wet plucking is used. Dry and Wet Plucking Dry plucking has been practised for centuries. A reasonably quick process in the hands of the skilled operator, particularly with discarded pullets or hens, it can be slow, tedious, and not particularly successful in the hands of a novice, particularly with a chicken, which tears easily on the feather tracts on the lower part of the neck and front of the breast. The trend now is toward wet plucking because it is easier, and quicker. Either of two methods may be used hard scalding or semi-scalding. Hardscalded birds may be stripped of feathers while lying on a hardwood or metal table; semi-scalded birds are often plucked . while hanging up. Hard Scalding The bird is plunged into and swirled around in water between 180 and 190 degrees F. for just long enough to loosen the feathers by cooking the

muscles in the feather follicles. The feathers are then released and can be removed very easily. If the colour of c .° m H an „ , le , g ® ls V? retained, . e head and legs should not be immersed. . . Thls n l? thod of scalding can easily damage the protective skin, with the result that discoloured hlotchv areas result mat discoloured, oiorcny areas appear as the bird dries. These areas become most nronoimced if the bird P ecorae most pronounced it the bird ls subsequently placed in cold store, the annearance of the bird being affected seriously. It is also claimed that hard scalding is detrimental to the keeping quality of a bird because it damages the outer protective skin. Because of these disadvantages the trend is toward the second method for commercial purposes.

Semi-scalding The water used is lower in temperature and immersion is for a definite period, according to the class of bird. This method has the advantage that the • protective skin is not damaged readily during the removal of the feathers, resulting in a bird in as good a condition as one that has been dry plucked. Plucking after semi-scalding is more rapid than dry plucking, but not quite as easy as with hard scalding. The water temperature recommended is 128 to 130 degrees F. with an immersion period of 30 seconds or 122 to 127 degrees for 90 seconds. Adult birds will stand 130 degrees for longer than 30 seconds, but birds younger than 16 weeks should be given the lower temperature for not longer than 30 seconds. Temperature and immersion time should be carefully controlled for best appearance of the final products. Birds plucked by this, method may be cold stored with less rapid deterioration in keeping quality than in hard-scalded birds. Cooling To prevent bacteria causing decomposition, particularly in the region of the vent, a bird must be cooled as quickly as possible after being plucked. Cooling is desirable even if the bird is to be trussed soon after being killed, as a cleaner job can be made of trussing when the fat has set. With a bird killed by dislocation of the neck this is more important still, as it is desirable for the blood to clot fully if trussing is to be clean. During cold weather birds can be cooled on racks in fan-circulated air, but cooling is most effective and rapid in a cool room with a temperature of 32 to 34 degrees F. If a special room is not available in summer, birds may be cooled by immersion in cold water for 6 to 10 hours, depending on the temperature of the water. Proper cooling is essential for birds to be packed for market. Photographs on this page by Photo News; Ltd.