BREAD MADE WITH MILK

Northern Advocate, 10 August 1934, Page 10

BREAD MADE WITH MILK

NUTRITIONAL VALUES.

METHODS’OF MODERN RESEARCH

THE'.USEFUL ALBINO RAT

(By “Cadinal Point.”)

(No. 10.)

Exhaustive experiments with white, or albino,, rats, have been carried out in Europe, the United States of 'America, New Zealand and elsewhere to lind out the nutritional and other Values of bread made with milk, but before going into details it is necessary to‘explain just why this type of animal was selected -and a few facts about a fascinating study. To many not versed in the subject, experimentation with rats is associated’with. cruelty and ill-treatment of the rodents, but the reverse Is the case — the rats are cared for and treated better than many humans.

For numerous reason's the albino rat has been selected for the purposes of experiments. To insure accurate results'in investigations it is necessary to

select, as an experimental animal, a type which, under uniform environment, nutritive, and psychological conditions, might be expected to follow with a minimum of variation certain predetermined standards of behaviour during its span of life. The animal chosen for this purpose has to be of the greatest possible uniformity in vitality, weight, structure of its organs and parts, at given ages, and in transmitting power, in other words, a standardised animal is needed for tho most accurate results in biological research. It is on account of its numerous virtues fitting in with these conditions that the albino rat has come into favour for research purposes. It is easily kept in fairly small quarters, and lives and grows on almost all food used for human consumption. It is not expensive to maintain. Its omnivorous habits make it an exceptionally valuable animal for nutritional investigations, since the effects of an exclusively vegelablo diet or those of a strictly animal diet may be observed. Comparisons Possible. A rat of three years is equivalent in ago to a man of 90 years. Both are at

the close of the life span. The rate of growth in Iho rat is thus MO times as rapid as in man. 'Developments in tho two forms is in the same stage when equal fractions of their life span arc compared. Tims it is possible to verify or apply directly to man experimental data obtained on the albino rat. No ether form is at present sufficiently well known to be utilised iu this manner. As a domesticated animal which may be readily gentled the albino rat is responsive to care and attention and thrives under the conditions of comfort and contentment which is provided for it in research laboratories. To illustrate the care and attention given to rats in modern' laboratories one may quote from “Breeding and Care of the Albino Rat for Research Purposes, ’’ by (ireeninan' and Duhring, who state: —“Clean, healthy, albino rats are essential for accurate research work and their production is a serious, difficult, and worth while task. Individual attention, shown by handling and petting, is essential for their best

growth and for securing uniform reactions when used as research animal-'. They should have’ample opportunity to know their caretakers.” It is pointed out that a change of caretakers during research work causes serious chocks to the experiments and retards growth “Rats,” the authors state, “seem to know instinctively those who are fond of them. They learn to distinguish kindness and attention readily. The worth-while caretaker is the person who will talk to them while working, and occasionally open a cage door, smooth the rats, induce them to romp and play and caress them. Under favourable conditions all rats are playful.” Rats Susceptible to Music. The rats are most susceptible to music. In certain' conditions of health rats may become nervous and attempt to bite. In such cases talking quietly to it for a few moments, or softly humming a I line without attempting to touch it, will sometimes completely change its attitude, so that it will come to the front of the cage clicking its

tooth, as ah expression of confidence and happiness, and permit one to handle it without objection. Stringed instrument music will quieten rats, even at feeding times.

An exhaustive scries of tests into the food value of bread made with skim milk powder lias been carried out over a prolonged period by one of the principal New Zealand dairy companies. Although not concluded the experiments arc far enough advanced to enable definite conclusions to be reached. These fully bear out the results achieved in Europe and the United States, and prove beyond a shadow of doubt the food value superiority of skim milk powder bread as against the ordinary water loaf.

The experiments commenced with an equal number of albino rats, six in each series. The tests were started when the animals were from 21 to 2d days old, when they were taken direct from their mothers, and lasted over PC days. The rats selected were as even in weight, constitution, etc., as it was

possible to secure. As bucks grow

faster than does, their numbers on either side was evened up. One lot of six was fed on ordinary bread made with water and no milk added, the other six with similar bread to which skim milk powder had been added. The skim milk powder wns added in an amount equivalent to half the water used in mixing the dough being replaced by skim milk. Conclusive Proof. In' keeping with the most modern research methods the rats were provided with special cages, water bottles, submitted to lighting effects, and treated with the utmost care. They were handled by one person only, and no strangers were allowed near them. After several weeks.the two series of rats began to show marked differences. The ones fed on ordinary water broad started to fail rapidly. Their coals a lid bodies became thin, the former lacking healthy lustre and remained dead white in colour. On the other hand those fed with the additional skim milk powder remained

physically perfectly fit. They kept up weight and were full of vitality. Their coats were a healthy, .irony colour. None died.

In the water bread fed group when placed on the. additional skim milk diet plus butter, at once they began to regain weight and health., Several dual groups were experimented with, the results in all cases being the same. Experiments carried out by Mr A, E, Aldridge, the well known Npw Zealand analytical chemist, resulted in the same conclusions. He found that rats fed on bread made from the cheapest formulae, i.e., water, showed, evidence of starvation at the end of the .third week; of the. tost. Those 1 fed on.bread made with milk remained healthy. •Speaking of the. experiments, Mr Aldridge says: “ . . . the modern baker can, by the inclusion of,; such relatively cheap' ingredients ’ as‘ milk, and slight increase in yeast,;produce a real food that fully merits the support of the public.” , .....