Poultry Foods . . . Their Digestion

Sun (Auckland), Volume I, Issue 276, 11 February 1928, Page 26

Poultry Foods . . . T heir Digestion

Sidelights on the Digestive Organs and Their Working

Scientific feeding of poultry is becoming generally realised as being essential to secure the best results in all branches of the industry. Articles are constantly being written explaining the necessity of giving fowls wholesome food, and statements are made that, in feeding them on inferior foodstuffs, their digestive organs are overworked, thus robbing them of energy that might be utilised in a more remunerative way. To fully grasp how it produces a better return to give birds food that is easily digested and full of nourishment, it is necessary to understand something about their digestive organs. Every poultry-keeper knows that when food . is swallowed it is passed by muscular action into the crop. What happens to the food after it leaves the crop is merely a matter of guess-work to the majority. Fowls have no teeth, therefore we must give them a substitute. Sharp grit, flint if obtainable, is almost universally accepted as being the best means to employ, to break the outer husks of the grain, and to reduce the food swallowed to a more soluble form. This is done by the muscular action of the gizzard, into which the food passes after leaving the crop, expanding and contracting in such a manner as to cause the food and grit to move about, presumably in all directions. The gizzard is simply a muscularly controlled grinding and churning machine. When the food is reduced to a state of soft pulp the first process of digestion commences, and it is aided by the natural flow of saliva, which contains an important digestive ferment, its action being to convert the starch (carbohydrate) into sugar (maltose). The other substances found in saliva moisten the food, and cover it with a slimy substance which helps the birds to swallow food easily. The gastric juice (a digestive secretion of the glands of the stomach) also aids the digestion, the ferments contained therein split up the proteins and the fats. The food is now reduced to a milky looking substance called chyme. This acid chyme is passed into the small intestines, and is neutralised by coming in contact with the pancreatic juice, a 6olourless alkaline fluid, containing three more digestive ferments. The pancreatic juice comes from the pancreas which lie between the folds of the small intestines. These ferments carry on the process of splitting up the carbohydrates, proteins and fats. The gall tbladder also contains a fat-splitting ferment. This fluid is called bile, and is carried to the small intestines intermittently. The bile plays a more important part than the majority of poultry-keepers realise, and fowls with liver disease cannot digest food so easily as healthy ones. Liver diseases are often caused by improper feeding, viz., too liberal an amount of fats and insufficient exercise. Food is also further digested by the intestinal juice. To put it in simple language food, or chyme, in the small intestines is acted upon or digested by the three digestive ferments already named:—(l) The pancreatic juice; (2) the bile; (3) the intestinal juice. By means of the above juices the chyme is converted into substances which are digested ready for absorption, and it is the work of the small intestines, by means of the numerous cells which line its walls, to absorb the digestive products of the chyme. Food and other substances which escape the action of the digestive ferments pass into the large intestines to the rectum, the muscular action of which expels the droppings. In the large intestines water is absorbed into the bird’s system. Having described the actions of the digestive organs and juices, the next step is the assortment of foodstuffs. The main objects of food are to build up the body, to supply heat and to provide energy to enable the bird to move about. Foods may be divided into three main classes: (1) Carbohydrates. (2) Fats. (3) Proteins. Carbohydrates are compound® containing carbon, hydrogen, and oxygen. Fats are a combination of alcohol, and acids. Proteins contain carbon oxygen, hydrogen, nitrogen. Sulphur and phosphorous are also found in some proteins. Proteins are the most important food; they replace worn out tissue, and also build up new tissue. Fowls could live on proteins alone, but if fed on starches (carbohydrates) and fats, would in time die. Proteins, beside building up and replacing tissue, give heat and promote ] energy, but in, the last two respects I carbohydrates and fats are the , best

food .to give, to promote energy and heat. Carbohydrates and fats play an important part in protecting the proteins of the fowl’s body from being used, and they also prevent consumption (going light). Every poultry-keeper has a chart showing the composition of the various grains, etc., and when he has learnt the parts that proteins, carbohydrates and fats play in maintaining life, energy and heat, it will soon be very easy for him to select a wellbalance ration. Water is as important as food. Give your birds a plentiful clean 'supply. It is advisable to remember, that a variety of food stimulates the appetite, and birds fed on the same foods day after day, will in time lose their desire to eat much, and feeding will become a habit instead of a pleasure. Fowls need a change of diet as much as human beings. See that they get it, but endeavour to give it in such a form that they get a well-balanced ration each day. By looking at your birds constantly and handling them occasionally you can soon learn to judge from appearance the food they require. This last statement may be doubted by some people, but before they criticise let them experiment for themselves. Just on more remark: Even if your birds have free range over pasture land, give them cabbages; they are the best natural tonic. MOULTING TIME We are now having some hot weather. This will greatly assist those who want to get some of the birds through the moult. During that season many birds show signs of debility, so that here is the need for care and watchfulness on the part of the breeder. As soon as such cases are detected they should be removed to a cool place by themselves, then fed on the most nourishing diet, and given a tonic to raise the system. The blood must be kept in good order, otherwise the bird will go wrong. There are many good tonics, but none better than the well-known “Douglas” mixture. Cod liver oil is also a good tonic for the moulting season, particularly if mixed with a little iron, as the oil greatly assists the growth of feathers. If the bird is taken in time the treatment will not be long, but in some cases the debility has a firm hold before detection, and the patient must be treated frequently and persistently. In the ordinary way of feeding use a little meat, well boiled, plenty of oatmeal porridge and milk, and the birds can have a little hemp--seed witfi advantage. This seed contains a deal of oil, and has a tendency to produce fat, both of which are good for a bird suffering in the moult. All the cocks taken out of the breedingpens edn be put in small houses and encouraged to moult now as soon as possible.