Effects Of Dietary Antibiotics Research Articles

Effects of Dietary Antibiotics, Actigen<sup>®</sup> Yeast Cell Wall Derivative, or Both on Broiler Chicken Live Performance in a Fifty-Two Day Pen Trial on Built-up Litter

Effects of Dietary Antibiotics, Actigen<sup>®</sup> Yeast Cell Wall Derivative, or Both on Broiler Chicken Live Performance in a Fifty-Two Day Pen Trial on Built-up Litter

Appropriate Chicken Sample Size for Identifying the Composition of Broiler Intestinal Microbiota Affected by Dietary Antibiotics, Using the Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis Technique

The bacterial microbiota in the broiler gastrointestinal tract are crucial for chicken health and growth. Their composition can vary among individual birds. To evaluate the composition of chicken microbiota in response to environmental disruption accurately, 4 different pools made up of 2, 5, 10, and 15 individuals were used to determine how many individuals in each pool were required to assess the degree of variation when using the PCR-denaturing gradient gel electrophoresis (DGGE) profiling technique. The correlation coefficients among 3 replicates within each pool group indicated that the optimal sample size for comparing PCR-DGGE bacterial profiles and downstream applications (such as identifying treatment effects) was 5 birds per pool for cecal microbiota. Subsequently, digesta from 5 birds was pooled to investigate the effects on the microbiota composition of the 2 most commonly used dietary antibiotics (virginiamycin and bacitracin methylene disalicylate) at 2 different doses by using PCR-DGGE, DNA sequencing, and quantitative PCR techniques. Thirteen DGGE DNA bands were identified, representing bacterial groups that had been affected by the antibiotics. Nine of them were validated. The effect of dietary antibiotics on the microbiota composition appeared to be dose and age dependent. These findings provide a working model for elucidating the mechanisms of antibiotic effects on the chicken intestinal microbiota and for developing alternatives to dietary antibiotics.

Histological and ultrastructural characteristics of the periodontal syndrome in the rice rat. IV. The effects of dietary antibiotics on the histological and ultrastructural characteristics of periodontal syndrome susceptible rats.

In this paper on the periodontal syndrome in the rice rat, the effects of dietary penicillin and tetracycline on the progressive inflammatory and degenerative changes (as seen in rice rats fed diet 700 alone) were noted at the light and electron microscopic level. Throughout the observation period (0–14 weeks postweaning), animals fed diet 700 with penicillin or diet 700 with tetracycline showed no evidence of bacterial colonization, a minimal PMN infiltrate restricted to the gingival epithelium and subjacent lamina propria, and no marked degenerative changes within cells that normally inhabited the periodontium (viz. epithelial cells, fibroblasts, osteoblasts). Marked osteoblastic or osteoclastic activity was rarely noted along the alveolar crest in this group of animals.These results give added support to the concept of a single microbial agent or group of microbial agents, as the primary etiology of this disease.

The effect of dietary antibiotics on protein and energy metabolism in rats: Possible significance of the gut microflora

AbstractThe influence of the intestinal microbial activity on protein metabolism was tested in rats with three diets fed without and with antibiotics (Nebacitin). True protein digestibility, biological value, net protein utilisation, true amino acid digestibility and apparent digestible energy were measured. The intestinal microbial activity was on average reduced to one‐fifth by antibiotics. On a diet low in crude fibre (2.5%) but high in crude protein (17.6%), this reduction had only a minor influence on the parameters for protein quality that were measured. However, true digestibilities of histidine and cystine were strongly reduced by the antibiotic treatment. The digestibility of energy was also significantly reduced (5%). For diets higher in crude fibre and lower in protein, the influence of the microbial activity was more pronounced. Digestibility of protein and energy were severely reduced by the dietary antibiotic treatment. In general, antibiotic supplementation decreased the parameters that were measured.

Antibiotic Growth Promotion: Effects of Bacitracin and Oxytetracycline on Intestines and Selected Lymphoid Tissues of New Hampshire Cockerels

INTRODUCTIONTHE biological basis for the use of antibiotics in poultry feeds has been reviewed by Bird (1969). The effects of dietary antibiotics on the growth of various organs in the domestic fowl have been studied widely, cerning the influence of antibiotics on the weight of organs with the largest number of cells of the lymphocytic series.Jankovic and Mitrovic (1967) showed that antibody-producing cells are present in large numbers in the thymus, spleen, and small and large intestines, but not in the bursa of Fabricius. The bursa probably produces immature plasma cells for other lymphoid tissues (Woods and Linna, 1965), or produces hormones that stimulate the proliferation of plasma cells in distant sites in the bird (Isakovic and Jankovic, 1964). Glick (1968) found that feeding a combination of penicillin, oxytetracycline, and tylosin, or penicillin alone, did not interfere wth antibody production. However, feeding tylosin alone significantly reduced precipitin production.

Effect of antibiotics on intestinal absorption in mice.

1. The effects of dietary antibiotics (penicillin, neomycin or terramycin) on the absorption of D-glucose, D-galactose, L-arginine or L-histidine by the mouse were investigated by using sacs of entire everted ileum.2. Compared with the controls, there was generally an increased absorption of all these solutes. Tissue uptake of the solutes remained unaltered. The inward movement of water into the sacs was increased but was generally independent of solute transport.3. The body-weight decreased slightly and caecal weight increased with penicillin only. The weight of the small intestine decreased with the different antibiotics, and the gut wall became thinner. Faecal fat increased slightly, but not significantly, with neomycin only. Water intake decreased with the different antibiotics.

Effects of Dietary Antibiotics and Uric Acid on the Growth of Chicks

One-day-old (Vantress × Arbor Acre) male chicks, fed a diet containing 2% uric acid, showed a significant weight depression after 4 weeks. This growth depression was not observed in chicks that received the same uric acid-containing diet but supplemented with 11 mg/kg of bacitracin and 44 mg/kg of procaine penicillin G. It is proposed that uric acid depresses growth by acting as an irritant and thus interfering with the absorption of nutrients from the intestinal tract; or uric acid inhibits the microbial biosynthesis of known vitamins or other nutrients essential to the host. Chemical analyses of the intestinal contents revealed an increased degradation of uric acid in the tract of the “uric-antibiotic”-fed chicks. No significant reduction or elevation was noted in the level of serum uric acid in any of the chicks. Antibiotic assays showed rapid penicillin inactivation in the tract, but persistence of the bacitracin. Although the beneficial response and increased uricolysis were observed in the “uric-antibiotic”-fed chicks, the level of antibiotic was lower in these birds. A growth response was obtained with diets supplemented with bacitracin only when an “old” environment appeared to have been established.

EFFECT OF DIETARY ANTIBIOTICS UPON COLIFORM BACTERIA AND LACTOBACILLI IN THE INTESTINAL TRACT OF URIC ACID-FED CHICKS.

Bare, L. N. (University of Kentucky, Lexington), R. F. Wiseman, and O. J. Abbott. Effect of dietary antibiotics upon coliform bacteria and lactobacilli in the intestinal tract of uric acid-fed chicks. J. Bacteriol. 87:329-331. 1964.-Male chicks (1-day-old; Vantress X Arbor Acre) were fed a basal glucose-soybean oil meal diet, a 2% uric acid-containing diet with and without 5 mg/lb of zinc bacitracin and 20 mg/lb of procaine penicillin G, and one supplemented with the antibiotics only. After 4 weeks, the chicks receiving the uric acid without antibiotics showed a weight depression. The presence of antibiotics in the ration with the uric acid reversed this growth depression. Bacteriological and chemical analyses of the contents of the small intestine revealed an increase in numbers of uricolytic Aerobacter spp. and an increased degradation of uric acid in the tract of the "uric-antibiotic"-fed chicks. The counts of lactobacilli were always lowest in this group of chicks

The effect of dietary antibiotics upon hepatic and renal xanthine dehydrogenase activity in chicks

Single-comb White Leghorn cockerels were fed a nutritionally adequate, practical-type chick starter diet supplemented with either 15 g. oxytetracycline or 6 g. procaine penicillin per ton in two feeding trials. Fresh liver and kidney homogenates from 4- and 9-week-old chicks were assayed in vitro for xanthine dehydrogenase activity. Oxytetracycline, but not penicillin, significantly inhibited xanthine de-hydrogenase activity per gram of kidney dry matter of 4-week- but not of 9-week-old chicks. Neither antibiotic affected liver xanthine dehydrogenase activity at either age. It is suggested that the growth stimulation observed during the period of rapid growth may be due in part to enhanced nitrogen utilization, resulting from the decrease in renal xanthine dehydrogenase activity.

Effect of Penicillin on Growth and Bone Ash of Chicks Fed Different Levels of Vitamin D and Phosphorus

THE sparing action of antibiotics on water-soluble vitamins has been reported by several investigators (Oleson, Hutchings and Whitehill, 1950; Stokstad and Jukes, 1951; and Biely and March, 1951); however, very little work has been done on the effect of dietary antibiotics on the requirements for fat-soluble vitamins. Burgess et al. (1951) found that penicillin increased the storage of vitamin A in the liver and the level of serum carotenoids, indicating a sparing action of penicillin on vitamin A and its precursors. The work of Burgess et al. suggested the possibility that other fat-soluble vitamins may be spared by antibiotics, and therefore the following study on vitamin D was undertaken.The purpose of this work was to study the effect of penicillin on growth and bone calcification in chicks fed graded levels of vitamin D in the presence of a low and high level of inorganic phosphorus. In addition, the effect …

Effect of Dietary Antibiotics on the Growth of Chicks Receiving Suboptimum Amounts of Thiamine by Mouth or by Injection

Effect of Dietary Antibiotics on the Growth of Chicks Receiving Suboptimum Amounts of Thiamine by Mouth or by Injection

Effect of Dietary Penicillin on Blood Composition and Œstrogen-induced Oviduct Growth in the Folic-Acid Deficient Chick

STUDIES designed to elucidate the processes responsible for the growth-promoting effects of dietary antibiotics have shown that the growth-rate of chicks and rats deficient in individual vitamins is increased by addition of an antibiotic. Growth responses to antibiotics on adequate diets have also been shown to be accompanied by increases in blood and liver concentrations of certain vitamins1. It has been pointed out by Coates et al.2 that such increases may be non-specific to antibiotic treatment and may merely accompany a growth acceleration. Common et al.3 demonstrated an increase in the blood levels of calcium and riboflavin in œstrogen-treated pullets as a result of adding aureomycin to an adequate diet. On the basis of experiments by Hertz et al.4 such an increase could be attributed to an increase in dietary availability of these nutrients. In view of these remarks concerning the difficulty in interpreting such increases in blood- and tissue- levels of a particular metabolite resulting from the inclusion of an antibiotic which also causes a growth stimulation, the two criteria of folic acid availability chosen in the experiment reported here were end-organ response to œstrogen and haemoglobin-level in the blood. A short period of œstrogen treatment affects both blood composition and oviduct growth-rate, and the latter has been shown to be specifically reduced by folic-acid deficiency5.