Search

The amino acid composition of wild and cultivated buckwheat and No. 1 wheat feed screenings are compared. Proteins of cultivated species contain more lysine than do proteins of wild buckwheat. Both have better amino acid balance than cereal grains. Proteins in wild and cultivated cereal buckwheat contain comparable amounts of glutamic acid plus proline, the main amino acids of storage proteins (prolamines and glutelins) in cereals and the S-containing amino acids cystine plus methionine. The high percentage (29.9 ± 2.37) of wild buckwheat in No. 1 commercial wheat feed screenings enriches its essential amino acid profile.

The botanical, chemical, and amino acid content of wheat feed screenings was determined. The botanical composition showed that wheat screenings contained broken or shrunken particles of wheat, wild buckwheat, wild oats, rapeseed, and a variety of weed seeds. The average protein content of the screenings (13.9%) was higher than that of wheat (12.2%). The amino acid content of five samples of wheat screenings were remarkably uniform. The ash content (2.2%) of wheat screenings was nearly double that of wheat (1.2%). The fiber of wheat screenings varied from 2.56 to 4.18%, but, generally, as the fiber level increased, so did the fat content. In the first experiment, wheat screenings replaced wheat in broiler rations on a weight for weight basis. Experiment 2 was similar to Experiment 1 except that all rations were adjusted to contain the same amount of fat. Experiment 3 compared wheat to wheat screeenings in two types of rations, experimental and two commercially designed rations, in which the grain portion of the ration was substituted with wheat screenings. The results of the three experiments indicate that wheat feed screenings may substitute for wheat in balanced broiler rations without affecting chick growth or feed utilization.

White Leghorn pullets of two strains were fed soybean or rapeseed meal during either or both the growing period and laying period in two separate experiments. Rapeseed meal may be fed to growing pullets at levels up to 17% of the diet without adversely affecting the subsequent rate of egg production or egg size. Birds fed laying diets containing 19% of rapeseed meal produced a greater egg mass per hen-day and gained more weight during the laying period when the growing diet contained rapeseed meal instead of soybean meal. Birds shifted at sexual maturity from soybean to rapeseed meal as dietary protein supplement undergo metabolic adjustment which retards the attainment of maximum rate of production and induces cannibalism. Both rate of production and egg size were lower when rapeseed meal constituted 19% of the laying diet in replacement of soybean meal as protein supplement. Mortality, exclusive of that resulting from cannibalism, was 4.1% and 4.6% respectively in the two experiments. Death from liver haemorrhage occurred only in birds of one strain which were fed rapeseed meal during the laying period and principally in birds which had been fed rapeseed meal during the growing period as well.

Dried poultry waste (DPW) from chicks fed a basal diet was collected, analyzed and used as a feed ingredient in diets of equivalent nutrient composition. Chicks fed rations containing 20% recycled DPW weighed, at 4 wk of age, on the average, 10% lower than the controls. The weights of chicks decreased slightly with each of five successive recycles. The feed efficiency of chicks fed the 20% protein basal was 2.05, while that of the DPW-fed chicks was 2.30. Feed efficiency decreased as DPW was recycled. The addition of 0.20% lysine and 0.20% methionine increased the weights of chicks and improved feed efficiency 6% when added to DPW and control rations. The chemical analyses of DPW recycled five times showed no major changes in the composition except that the fat level increased from 3.04 to 9.6% and the calcium and phosphorus levels decreased from 1.94 and 1.88% to 0.88 and 1.10%, respectively. The five recycles of DPW were identical in amino acid composition. Plasma uric acid levels were raised to 6.0 mg% by feeding 20% DPW, compared to 3.4 mg% in control chicks. However, there was no correlation between plasma uric acid levels and the weight of chicks. The mineral composition of the tibia was not affected by the DPW content of the rations. Mortality in all experiments was less than 1%.

THE hatchability of turkey eggs, as a general rule, declines after the 9th to the 12th week of the breeding season (Dickens et al., 1941; Atkinson et al., 1955; Jensen et al., 1956). This is particularly true of the hatchability of eggs from broad-breasted stock, and it has been suggested that the hens may become depleted of some nutrient or nutrients. In recent years the importance of vitamin E, niacin, pantothenic acid and folacin has been established in the maintenance of hatchability (Jensen, 1953; Scott and Nelson, 1955; Atkinson et al., 1955; Kratzer et al., 1955, 1956; Ferguson et al., 1956). Declining hatchability of fertile eggs is usually accompanied by a decline in fertility. Atkinson et al. (1955) reported that supplementation of diets with dehydrated alfalfa meal and condensed fish solubles resulted in maintaining fertility at a high level throughout a 17-week breeding period. The object of the present experiment …

Breed and sex differences were observed in erythrocyte counts in the chicken. A difference in osmotic fragility of erythrocytes was found between chickens of the New Hampshire and White Leghorn breeds. Erythrocytes from mature males were more susceptible to osmotic hemolysis than were erythrocytes from mature females. Lipids extracted from ghosts of erythrocytes from mature females or from males treated with diethylstilbestrol contained a higher proportion of oleic to stearic acid than did those from male birds. Incubation of erythrocytes in plasma derived from birds of the opposite sex increased the osmotic stability of ceils from males and decreased the stability of cells from females in comparison with the stability of erythrocytes incubated in autologous plasma.

THE FOLLOWING experiment was conducted to study the effects of introducing fat into the ration of mature laying birds previously fed starting, growing and laying diets not supplemented with fat. Data on body weight, mortality, egg production rate, egg size, albumen quality, egg shell thickness and feed consumption are presented. EXPERIMENTAL The birds used were 300 White Leghorn pullets which were already in lay (11 months old) when they were fed the rations supplemented with different levels of fat. Five and 10 percent of tallow† were fed to the birds in the rations shown in Table 1. The control ration and rations 2 and 3 were formulated to supply 1270 Cal. metabolizable energy per lb. (based on average energy values given by Potter et al., 1961). Ration 4 contained 10 percent tallow, but no attempt was made to have the ration isocaloric with the other rations, and its calculated metabolizable …

THE generally recommended level of protein for laying rations is 15 percent. Reports continually appear, however, to indicate that higher levels of protein are of advantage, and, conversely, that satisfactory performance may be achieved with lower levels of protein. The variability in the level of protein found to be optimal suggests that differences in the amino acid composition of the rations fed may be responsible for the discrepancies in the protein levels recommended by different investigators. Depending upon the grain used in formulating laying rations of a certain protein content, the proportion of supplementary protein to cereal protein may vary considerably. As a consequence wide differences in amino acid balance may be encountered even in rations of similar protein content. The following experiment was designed to determine if a laying ration containing 70 percent of wheat and supplying a total of 14 percent protein from plant sources is adequate for…

FOLLOWING discovery of the growth-stimulating properties of dietarily administered antibiotics for the chick, it was reported that the growth response may be due, in some instances, to a sparing effect on the dietary requirement for vitamins of the B-complex (Biely and March, 1951). There are numerous reports in this regard pertaining to other animals as well as the chick. Combs (1955) has tabulated the results obtained with chicks published by different investigators. Although the concept that antibiotics may have a sparing effect on dietary vitamin requirement has been generally upheld, the findings are not consistent as to which vitamins are spared and which are not. The following experiments were conducted in an attempt to determine the reason or reasons for the discrepancies in the response to antibiotics of chicks fed diets deficient in different vitamins of the B-complex. The experiments were carried out over a period of four years to …

(1960). The Chick in Nutritional Research. World's Poultry Science Journal: Vol. 16, No. 2, pp. 110-125.

Following the technique recommended by Shaw in which the erythrocytes and leucocytes are counted in the same chamber, the authors made total erythrocyte and leucocyte counts of 100 apparently healthy and vigorous single-comb White Leghorn hens. Following the counts, post-mortem examinations did not reveal any striking abnormalities. With few exceptions the birds were singularly free from intestinal parasites.The range of the erythrocyte counts was found to be 1,805,000 to 3,845,000, and of leucocyte counts 18,330 to 49,000. The data are analyzed statistically.In respect to the erythrocyte counts, the authors' data are in complete agreement with the recent studies by Cook and Dearstyne of 75 female birds. There is, however, a marked difference in the range (3,000–47,000) and the mean of the leucocyte counts, which may be due to the different technique employed by Cooke and Dearstyne.Total erythrocyte and leucocyte counts were also made of 47 one- to two-day-old chicks. The range of the erythrocyte counts was found to be 1,800,000 to 3,180,000 and of the leucocyte counts 15,000 to 28,330. A statistical analysis of the data is presented. In the case of the baby chicks, since the environmental conditions are relatively uniform, it would appear that factors other than environment affect the total erythrocyte and leucocyte counts of individual chicks.

KUMMEROW, Weaver and Honstead (1949) found that the addition of high levels of fat to the diet increased the requirement of the chick for choline. Siedler and Schweigert (1953), on the other hand, observed no gain from choline supplementation of diets containing from 2 to 8 percent of added fat. Frazer (1946) and Tidwell (1950) reported that choline accelerated absorption of fat in the rat. The data in the literature indicate that choline requirement is not always raised by increasing the dietary fat level; nevertheless, there is often an effect in this direction. Because of the recognized interrelationship among choline, folacin, vitamin B12 and methionine, it seemed possible that contradictory evidence regarding the effect of dietary fat on choline requirement may be the result of differences in the composition of the experimental diets. Schaefer, Salmon, Strength and Copeland (1950) and Strength, Schaefer and Salmon (1951) demonstrated an interrelationship between the …

STANDARDIZATION of techniques for measuring protein quality is difficult because of many interacting factors. The choice of breed or strain of bird may have a bearing upon the response to a given source of protein since there are genetic differences in the amino acid requirements of the chick. For example, breed and strain differences have been demonstrated in the requirement for methionine and cystine (MacDonald, 1958; Miller et al., 1960); arginine (Hegsted et al., 1941; Nesheim and Hutt, 1962); and lysine (Griminger and Fisher, 1962). In a collaborative study March et al. (1965) compared the relative rates of growth of chicks fed diets composed of different grains and protein concentrates at different locations and with chicks of different genetic background. It was found that when the differences in amino acid balance of the diets tested were marked the differences in growth response were consistent. When, however, differences in amino acid…

THE mechanisms whereby hypo-or hypercholesterolemia is induced by the dietary fats fed in cholesterol-free diets are not completely understood. The effects of fats on blood cholesterol level may be related to differences in the rates of bile acid excretion induced by the fats. Gordon et al. (1957); Byers and Friedman (1958); Haust and Beveridge (1958); Srikantia and Gopalan (1960); Goldsmith et al. (1960); Moore et al. (1962); have all shown that unsaturated fats which reduce blood cholesterol levels also increase excretion of bile acids. On the other hand, Avigan and Steinberg (1965); Lindestedt et al. (1965); Grundy et al. (1965); Ali et al. (1966); found no significant differences in bile acid excretion when fats of different degrees of saturation were fed. The above reports pertained to studies with human subjects, rats or rabbits. Comparatively few studies have been made of bile acid excretion in the chicken despite the considerable use…

Thirty-three samples of wheat (Triticum aestivum L.) were assessed on the basis of physical and chemical analysis, protein quality and quantity, and metabolizable energy. None of the values, or combination of values, from the physical and chemical analyses showed significant correlation with metabolizable energy values. Biological tests demonstrated variations in the nutritive quality of the protein in the different wheats. The diets in which the samples of wheat were incorporated were formulated to contain different levels of protein and different proportions of wheat protein and soybean protein to stress in a variety of ways the pattern of available amino acids provided by the wheat protein. A significant response was obtained from lysine supplementation to different cultivars of wheat. Nevertheless, lysine was not always the primary limiting amino acid for growth, despite a consistent improvement in feed efficiency from lysine supplementation. No consistent difference was found in the nutritional quality of protein from wheats containing different levels of protein. Further tests of protein digestibility and amino acid analyses of various cultivars of wheat may explain the varietal differences in biological response.

WITH the modifications that have been made in the energy content of chick starter and broiler rations the requirements for some of the nutrients may be different than those determined on the basis of diets commonly formulated some years ago. For example, the inclusion of fat in poultry rations has been shown by Biely and March (1954, 1957), Sunde (1956), and Davidson (1956) to be practicable only when the level of protein is increased to maintain a proportion between the energy level and the protein level in the diet. The relation of dietary fat and energy level to requirements of other nutrients is not so clear. Although from our present knowledge of calcium, phosphorus, and vitamin D interrelationships, it should be possible to define calcium requirements within fairly close limits, the calcium requirement has been reported within recent years to be as low as 0.5 percent (Simco and Stephenson, 1961) …

Dehydrated poultry waste, with less than 10% moisture content, was fed at a level of 5 to 30% to replacement White Leghorn chicks (4 weeks), broiler stock (8 weeks) and White Leghorn laying pullets (100 days). When the D.P.W. was included in well-balanced rations no detrimental effects were observed on the health of the birds. Growth and feed efficiency were progressively decreased as the level of D.P.W. was increased beyond the 10% level. The economic aspect of producing D.P.W. and its inclusion in poultry rations require a great deal of study. The recycling of poultry manure in the form of D.P.W. may provide a means of operating a fairly odour-free poultry enterprise and at the same time prevent contamination of the environment.

DATA on the hydrogen ion concentration in the intestine of the chick have been reported by Farner (1942), McLaughlin (1931), Mayhew (1935). It is difficult to compare results obtained by different investigators because of differences in the methods used. There is also the possibility that differences in the diets fed may have been responsible for some of the differences observed. Mussehl, Blish and Ackerson (1935) and Olson and Mann (1935) found that variations in the diet did not appreciably change intestinal pH. Heller and Penquite (1936) showed that although basic salts may raise pH in the crop, gizzard and proventriculus, the intestinal pH was not appreciably affected. Beach (1925) showed that cecal pH was rapidly reduced by feeding lactose or milk. Ashcraft (1933) found that pH in the duodenum and ileum was increased while pH of the cecal contents was decreased when milk products were fed. Wiseman, Bushnell and Rosenberg . . .

THE object of the present study was to determine if the vitamin K requirement of growing chicks was altered when the diets were supplemented with different fats and oils. In the case of some of the vitamins it has been found that when fats or oils are added to the diets, special attention has to be paid to the quality of supplementary fat and to the levels of the vitamins supplied to avoid deficiencies in chicks fed the diets. Considerable evidence has been obtained in studies with other species to suggest a relationship between alimentary lipemia and coagulation. The only report in this regard with reference to the fowl is that of Boulanger (1952) who reported that in turkeys there was no change in coagulability of the blood when the blood lipid level was high. EXPERIMENTAL AND RESULTS In all of the following experiments day-old New Hampshire chicks were wingbanded . . .

THE general problem of genotype × environment interaction has been the subject of several investigations over the past two decades. The status of research in this area as it is related to poultry was reviewed by Gowe and Wakely (1954) and more recently by Lerner (1958). These authors pointed out that it has been adequately demonstrated that interaction exists for specific factors such as nutritional deficiencies, resistance to diseases and parasites, and for heat resistance. Both the presence and absence of interactions have been reported for economically important traits in poultry. When controllable environmental conditions are standardized between locations, genotype × location interaction is generally not detected (Gowe and Wakely, 1954). However, when conditions at the different locations are not standardized then genotype × location interactions are observed. Hill and Nordskog (1956) observed such an interaction for hen housed mortality, but not for hen-day egg production. Nordskog and Kempthorne (1960) …

NUTRITION has been shown to influence susceptibility to virus infection and also to affect tumor genesis and development. Rous (1911) observed that young, healthy, well-nourished birds were more susceptible to transmissable chicken sarcoma than unthrifty birds. Since that time there has been considerable evidence of nutritional effects on the course of various virus infections. Clark et al. (1949) summarized the available information at that time regarding the influence of nutrition in experimental infection. Additional information has since been obtained but, because of the complexity of nutritional interrelationships, no general conclusions are possible. Although in many instances infection would seem to be less severe when the diet fed is deficient in some nutrient, the reverse situation also obtains. Tannenbaum and Silverstone have extensively investigated nutritional effects on tumor induction and growth. They have reviewed (1953) their own findings as well as those of other investigators in the field. Generally speaking, vitamin …

AS PART of an investigation into the general problem of fat metabolism in poultry nutrition, an experiment was carried out to determine whether it would be feasible to incorporate herring oil into laying rations. In an experiment to determine the effect of feeding varying amounts of fat to laying birds, Heywang (1943) fed White Leghorn pullets all-mash rations containing 0.8, 2.8, 4.8, and 8.8 percent of fat respectively. Corn oil was used to vary the fat content of the rations. There was no significant difference in the egg production of the hens fed the different levels of fat. The pullets receiving supplementary corn oil in the diet maintained a greater average weight than those receiving the low fat basal diet. Lillie et al. (1952) studied the effect of high fat diets on the performance of Rhode Island Red pullets. In these experiments a normal corn-soya ration was fed, with and …

Erythrocyte and leucocyte counts were made of 65 S.C White Leghorn females and 50 S.C. White Leghorn males which were raised in confinement from the age of one day until sexual maturity.The mean erythrocyte count of the males was significantly higher than the mean of the females. There was no significant difference between the mean leucocyte counts of the males and the females. The erythrocyte counts of the confined birds were significantly lower than those of normal birds kept under natural conditions and those of one- to two-day-old chicks, while the leucocyte counts were significantly higher.

Fowl paralysis is generally considered to be a disease of birds over three months of age. In the present paper data are presented on 45 out of 244 chicks (18.4%), which developed clinical symptoms of fowl paralysis before 90 days of age. Of these, 20 were inoculated and 25 were not inoculated. Forty-two of the 45 chicks (93.3%) showed lesions in the nervous system. Nine chicks (20%) showed lymphomatous tumors.Seventeen of the 45 cases (37.7%) occurred in chicks less than 60 days of age; the same number of cases occurred between 60 and 74 days of age; and 11 cases (24.4%) occurred between 75 and 89 days of age. The mean age of all chicks that developed paralysis was 64.4 days.The fact that typical fowl paralysis occurred in one chick at 37 days, and in several from 40 to 44 days of age, would indicate that the disease may develop at a very rapid rate.

THE Department of Poultry Science is one of eight major departments constituting the Faculty of Agriculture. While each department is more or less autonomous, each must subscribe to a general philosophy. A student in Agriculture must first of all meet certain basic requirements in the freshman and sophomore years. In addition, in his junior and senior years he must meet certain specific requirements of the department in which he is majoring. The courses offered in each department and the over-all curriculum of students in Agriculture are subject to approval by the heads of departments and the Dean of Agriculture. Curricula recommended by the various faculties of the University are subject to approval by the Senate of the University. The Senate is that administrative body which controls the academic structure of the University; thus it will be seen that the approved curriculum of any one department reflects not only the thinking . . .

ANTIBIOTICS appear to exert their greatest effect with chicks reared in an “old” environment according to data reported by Coates et al. (1951), Hill et al. (1953), Lillie et al. (1953), Morrison et al. (1954) and others. Nevertheless Waibel et al. (1954) and Libby and Schaible (1955) noted that, with the continued feeding of antibiotics in a given environment, the response obtained gradually decreased. This would indicate that, in an “old” environment, chicks do not grow at a maximum rate (1) because of the presence of bacteria detrimental to the well-being of the chick or (2) because bacteria which might be beneficial to the chick are suppressed in a highly infected environment. It has been noted that the response to antibiotics in our laboratory was variable. At first it was surmised that the differences in response to antibiotics reflected small variations in the vitamin content of the diets fed. In …

With the particular strains used, Black Australorps exposed to natural infection had a higher incidence of Marek’s disease than did White Leghorns. Females showed a higher incidence of Marek’s disease than did males. Tumour incidence and development were similar in males and females inoculated with Rous sarcoma virus. Mortality from Marek’s disease tended to be higher in birds fed higher levels of vitamin A but the effect was not consistent. When birds from flocks infected with Marek’s disease were killed at 7½ to 10 weeks of age, birds fed higher levels of vitamin A had a higher incidence of tumours. The incidence of tumours in samples of the populations killed at 8 or 10 weeks of age did not accurately predict the rate of mortality or the incidence of tumours in the surviving population for the subsequent 13 weeks. In 3 of the 4 groups of birds studied, comparison of the actual incidence of tumours, i.e., birds which died plus survivors with tumours, was appreciably less than the incidence predicted on the basis of the sample which was killed. It is concluded that regression of tumours in Marek’s disease occurs frequently. Of chickens inoculated with Rous sarcoma virus into the wing-web, 76% of those fed 2,200 I.U. vitamin A per kg. of diet developed tumours and 72% of those fed 22,000 I.U. per kg. of diet. Of the total number of birds inoculated the percentages of persistent or progressive tumours were 40 and 41% on the respective levels of vitamin A. Of tumours which reached a size of 10 mm.3 or more, 28 and 22% regressed on the respective levels of vitamin A.

THE nutritive value of fish meal may decline following storage because of oxidative changes affecting the lipid fraction and changes which are little understood affecting the availability of some of the amino acids in the protein fraction. The literature in this connection has been reviewed elsewhere (March, 1962). It has been found that treatment of fish meal with antioxidant retards oxidative changes (Meade, 1956; Aure, 1957; Lea et al., 1958; Flanzy et al., 1962) and protects against loss of nutritive value of the lipids during storage (Potter et al., 1961; March et al., 1962). March et al. (1961) found that whereas butylated hydroxytoluene (BELT) stabilized the lipids in herring meal against oxidation, the protein nutritive value of the treated and untreated meals after storage was similar. Further investigation of the problem seemed warranted and in the following experiments the effects of treating herring meals with BHT or with 1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline (EQ * )…

The results obtained with the rapid whole blood agglutination test for pullorum disease, applied in the field, agree closely with the results secured with the rapid serum agglutination test, applied in the laboratory.The accuracy of the diagnosis was found to depend upon the training and experience of the technician. When the whole blood agglutination test was applied by inexperienced persons, the results obtained differed from the laboratory test by 12% as compared with a difference of 1.3% when the whole blood agglutination test was applied by an experienced technician.The rapid whole blood agglutination test was found to lend itself very readily to practical application in the field. The extremely low cost makes feasible the application and repetition of the test on a large scale.Since it is known from previous work that one agglutination test will not eliminate all carriers of pullorum disease, the rapid whole blood agglutination test should be applied several times a year until at least two successive negative tests are obtained on each bird of the flock.

Data are presented on two groups of thirty chicks each, hatched from a susceptible and an apparently resistant flock. There was a significant difference in the incidence of fowl paralysis and lymphomatous tumors in these two groups. This is interpreted to mean that there is an inherent difference in susceptibility and resistance to fowl paralysis and lymphomatous tumors.

IN CONNECTION with studies on the nutritive value of herring meal, it was noted that when herring oil was added to chick starting rations deficient in folic acid, growth was depressed (Biely, March and Tarr, 1951; Biely, March and Tarr, 1952). Slinger, Pepper and Hill (1952) found that the depressing effect of a high level of dietary fat on the growth rate of turkeys was lessened by supplementation of the diet with an antibiotic and suggested “that the inhibiting effect of the high level of corn oil was caused by depression of intestinal synthesis by microorganisms and that the antibiotic tended to overcome this influence.” In the present study the effects of folic acid and aureomycin on the tolerance of the chick for fat have been tested. EXPERIMENTAL A series of four experiments has been carried out on the effect of feeding fat to chicks. Light pressed herring oil was …

INVESTIGATIONS carried out by Kraybill and Wilder (1947) indicate that some samples of meat scrap may be deficient in methionine and tryptophane, and that meat scrap in general is rich in lysine. Furthermore, it was reported that some samples of meat scrap could be improved by adding either methionine or choline. Increases in chick growth as high as 21 or 15 percent were obtained with the use of methionine and choline chloride respectively. March, Stupich and Biely (1949) showed that, on the basis of the protein quality index, amino acid assays, and chick biological tests, meat meals and fish meals varied considerably. They found that meat scrap protein showed lower nutritive value than fish meal protein. The relatively low nutritive value of the meat meal protein was considered to be partly the result of deficiencies of tryptophane or methionine or a combination of these amino acids. The following experiments were . . .

THE response of chicks to unidentified factors is affected by the breeder diet according to data reported by Menge et al. (1952); Patterson and McGinnis (1954); March, Biely and Touchburn (1955); and Waibel, Morrison and Norris (1955). In addition to the carryover of an unidentified factor through the egg to the chick, Denton, Lillie and Sizemore (1954), Arscott (1956) and Hopper, Scott and Johnson (1956) present evidence that egg yolk fed to chicks may stimulate growth. Recent findings by several groups of investigators (Camp, Reid and Couch, 1956; Dannenburg et al., 1955; Morrison, Scott and Norris, 1955; Menge et al., 1956), show that part of the response to sources of unidentified factors is due to the inorganic fraction. The following experiments were conducted to determine if whole egg, the ash of whole egg or the shell portion of egg from hens fed different diets would elicit a growth response in . . .

1. The apparent cleanliness of the premises in which chicks are reared has little bearing on the growth rate of chicks within a given environment.2. Bacterial counts of faeces from chicks reared under clean or extremely contaminated conditions showed no difference between the two sets of conditions.3. Delaying feeding until 72 hr. after hatching retarded growth to at least 7 weeks of age. If the age of the chicks was calculated from the time at which the chicks were fed rather than the date of hatch, the weights of the chicks fed 72 hr. after hatching corresponded with those of the chicks fed immediately.4. The contents of the duodenum and mesenteric intestine showed higher bacterial counts when feeding was delayed for 72 hr. than when feed was given shortly after hatching. This effect was no longer evident after the chicks were 1 week old.5. Administration of penicillin in the water did not reduce the difference in growth rates between the chicks given feed immediately and those from which feed was withheld.6. Antibiotics may decrease the thickness of the intestinal wall without stimulating growth.

CEREALS and protein concentrates account for the major part of the cost of laying rations. The mineral and vitamin supplements represent a relatively small amount of the total cost and fluctuations in their price do not greatly alter the cost of the ration as a whole. The present experiment was designed to compare the performance of laying birds fed rations which differed in the following respects: (1) the cereal component, wheat vs. No. 1 feed screening † and (2) the protein supplement, all vegetable (soybean oil meal) vs. mixed protein (soybean oil meal, fish meal and meat meal). Screenings was tested because of its availability and relatively low cost in British Columbia. It had been shown previously that pelleted screenings could be used as a substitute for scratch grain (Biely, Cooper and March, 1951). Availability and cost of protein supplements fluctuate considerably. In order to ascertain the importance of including animal …

ALTHOUGH the advantages of fat supplementation of broiler rations have been amply demonstrated, the value of thus increasing the energy level of laying rations is questionable. It has been reported by Weiss and Fisher (1957) and Donaldson and Gordon (1960) that rations containing high levels of fat fed to laying birds may result in obesity and fatty livers leading to a high rate of mortality. The present paper summarizes the data on mortality obtained in an experiment in which birds were kept in cages and fed diets supplemented with different levels of fat from day-old to 3 years of age. EXPERIMENTAL Starting, growing and laying rations were formulated according to Table 1. The rations were calculated to contain 20, 16.5 and 15 percent protein respectively. Each type of ration was adjusted to contain 2.5, 7.5 and 12.5 percent of fat. The two higher levels of fat were attained by the …

THE early studies on the animal protein factor(s) were made with chicks hatched from breeder stock fed all-vegetable rations, and later with chicks from depleted breeders kept on wire screen floors. In addition, the rations fed to the chicks themselves were often extremely high in soybean oil meal in order to induce differences in the rates of growth between A.P.F. supplemented and unsupplemented rations. The following tests were conducted to determine the need for animal protein factor in the diet of chicks obtained from flocks fed commercial breeder rations containing variable amounts of animal protein concentrates. EXPERIMENTAL Test 1 was conducted with New Hampshire cockerel chicks obtained from a commercial breeding flock. They were fed all-vegetable rations containing 16, 18, and 20 percent protein respectively, soybean oil meal being used as the protein supplement. In addition, chicks were fed rations of similar protein content containing 3 per cent fish meal. . . .

IN THE “Connecticut Broiler Ration” and its various modifications (Scott et al., 1947), as developed at the Connecticut Agricultural Experiment Station, the only grain used in the ration was yellow corn (70%). Comparatively little experimental work has been done with the Connecticut broiler ration using other grains. The comparative nutritive value of corn with other grains has been previously discussed by Almquist et al. (1943) and Biely et al. (1946). Since the T.D.N, content of wheat compares favorably with corn, its available energy being 121 Cal./pound lower than that of corn, and since wheat, moreover, is cheaper and more readily available in Canada than corn, it seemed worth while to determine the replacement value of wheat for corn, either in whole or in part. Preliminary experiments with wheat as a substitute for corn were carried out by Bearse (1948), who reported satisfactory growth with broilers when half of the corn . . .

In experiments conducted to determine the requirements of chicks for vitamin A up to eight weeks of age, vitamin A was supplied, in addition to the basal ration, by oral administration of Reference Cod Liver Oil at the rate of 25, 50, 75 and 100 International units per day. It was found that chicks receiving 75 units of vitamin A per day grew at a normal rate and did not show any signs of vitamin A deficiency. The chicks that received the basal ration only, showed symptoms of avitaminosis A at three weeks of age, while the group receiving 25 international units per day at eight weeks clearly had not received a sufficient supply of the growth factor.

SINGH and Shaffner (1950) found that increasing the calorie content of the diet appeared to raise metabolic rate in the chick. Mellen, Hill and Dukes (1954) reported that the fasting oxygen consumption of male chickens reared on a diet containing 975 Calories per pound was higher than that of similar chicks fed a diet containing only 505 Calories per pound. In the above experiments the diets at the lower energy level were suboptimal in energy and consequently may be considered to represent a low plane of nutrition. There do not, however, appear to be data regarding the effect of high energy levels on the basal metabolic rate of chickens. There have been studies on rats in which the effects of different levels of fat were investigated. Panos and Finerty (1953 Panos and Finerty (1954) found a relative decrease in the weight of the thyroid glands in rats fed fat-deficient diets, and other investigators . . .

THE rate at which feed passes through the digestive tract of the chick may influence the nutrition of the chick by (1) determining the length of time during which nutrients may be absorbed, (2) determining the microbial population of the intestine and (3) limiting the daily feed intake. Studies on the rate of food passage have been made by Browne (1922), Kaupp and Ivey (1923), Keith, Card and Mitchell (1927), Heuser (1945), Hillerman, Kratzer and Wilson (1953) and others. Some of these studies, however, have been concerned only with the time elapsing before feed disappears from the crop. There has not been a great deal of study of the effect which different types of diets may have on the passage rate through the entire length of the digestive tract. Monson, Dietrich and Elvehjem (1950) reported that the excretion time of chickens fed different carbohydrates varied in the following decreasing order: . . .

IT IS generally recognized that under normal conditions the chick does not have a dietary requirement for ascorbic acid. It has been found, however, that ascorbic acid may have a slight stimulatory effect on the rate of growth of chicks fed purified diets. Dietrich et al. (1949) reported that the effect of vitamin B12 on growth of chicks was enhanced by ascorbic acid and the amount of folic acid stored in the liver was higher when vitamin B12 and ascorbic acid were given together than with vitamin B12 alone. Briggs et al. (1944) suggested that, when chicks are fed a highly purified diet, they are not able to synthesize sufficient ascorbic acid to permit maximum growth. They also suggested that the action of ascorbic acid may be indirect involving utilization of other nutrients or stimulating microbial synthesis of vitamins in the intestine of the chick. Support for this latter view …

Rapeseed meal was fed to 25-week old White Leghorn pullets and cockerels at levels of 10.5 and 19.6 percent of the diet. Control diets contained 7.0 and 12.5 percent of soybean meal respectively. The total protein supplied by the diets was 15.0 and 17.0 percent with the respective levels of rapeseed and soybean meal. The responses to the diets were studied over a 64-week period. Body weight gain, egg production and egg size were lower with the rapeseed meal diets than with the soybean meal diets. Fertility, hatchability and growth rate of progeny were similar with the two protein supplements. The rate of mortality was higher in the birds fed the rapeseed diet. Thyroid glands of the birds fed rapeseed meal were markedly hypertrophied. Thyroid glands of progeny from dams fed rapeseed meal were also hypertrophied but the condition showed remission with age.

Data on the incidence of paralysis and lymphomatous tumors in a flock of 542 pullets of six different breeds indicate the presence of both in 14 out of 52 paralyzed pullets, while an additional 22 had tumors but were not paralyzed. The association of paralysis and tumors may have been due to chance. The evidence presented, while not conclusive, points to the inheritance of resistance to paralysis. This is indicated particularly by (1) differences in the proportion of paralyzed pullets in different breeds, and (2) absence of paralysis among the progeny of certain males and in certain large families. The data obtained point to a simple mode of inheritance.

THE usual system of feeding poultry in North America is essentially to supply feed ad libitum. There are, of course, various methods of feeding, but the principle of supplying an unrestricted amount of feed to birds is followed by practically all commercial poultrymen on this continent. In England this so-called “American” system of feeding is looked upon with some disfavor by many experienced poultrymen. The English feeder, as a general rule, prefers to restrict the supply of mash, dry or wet, believing that the birds should be kept on the hungry side before whole grains are fed in the late afternoon or early evening. Under this system the birds are allowed to forage whenever possible on grass range. It is claimed that this system of feeding increases the hardiness of birds and their resistance to disease. In Australia many commercial poultrymen and poultry experts favor the feeding of soaked grains . . .

EIMERIA acervulina infections in the chicken are not usually associated with mortality or severe pathological symptoms. Tyzzer et al. (1932) did not consider this species very pathogenic, and Dickinson and Scofield (1939) demonstrated only a decrease in food consumption and a transitory drop in body weight in birds infected with 35–50 million oocysts of E. acervulina. Hein (1968), investigating the pathogenicity of E. acervulina, concluded that mortality was not a feature of the disease and that anorexia and morbidity were seen only after heavy doses of oocysts (5 M and 20 M per bird). However, under field conditions, E. acervulina infections often cause economically disastrous results in a flock and the disease can be associated with high mortality and morbidity. Suboptimal vitamin A levels in the diet may be one factor responsible for the discrepancy between field and experimental observations of the pathogenicity of E. acervulina. Taylor and Russell…

VARIOUS attempts have been made to utilize dogfish (Squalus suckleyi) for meal production but to date there has been no successful industry in this regard. Tarr (1958) has reviewed the difficulties associated with reduction of dogfish to meal. In the 1940s, when most of the research on the nutritive quality of dogfish meals for poultry was carried out, Rhian et al. (1942) made a comprehensive study of dogfish meal. They reported a marked difference in the protein quality of wet- and dry-processed dogfish meals. The wet-processed meals, which had the higher nutritive values, had considerable amounts of water-soluble materials removed during the wet process. The authors suggested at that time that perhaps some water-soluble substance, which was either toxic to chicks or which adversely affected the protein of the meal, was retained in the dry process meal. With the basal diet then used to test protein quality of the meals,…