avoparcin and Weight-Gain

Antibiotics, prebiotics and probiotics are widely used as growth promoters in agriculture. In the 1940s, use of Streptomyces aureofaciens probiotics resulted in weight gain in animals, which led to the discovery of chlortetracycline. Tetracyclines, macrolides, avoparcin and penicillins have been commonly used in livestock agriculture to promote growth through increased food intake, weight gain, and improved herd health. Prebiotic supplements including oligosaccharides, fructooligosaccharides, and galactosyl-lactose improve the growth performance of animals. Probiotics used in animal feed are mainly bacterial strains of Gram-positive bacteria and have been effectively used for weight gain in chickens, pigs, ruminants and in aquaculture. Antibiotics, prebiotics and probiotics all modify the gut microbiota and the effect of a probiotic species on the digestive flora is probably determined by bacteriocin production. Regulations governing the introduction of novel probiotics and prebiotics vary by geographical region and bias is very common in industry-funded studies. Probiotic and prebiotic foods have been consumed for centuries, either as natural components of food, or as fermented foods and it is possible to cause the same weight gain effects in humans as in animals. This review presents the use of growth promoters in food-producing animals to influence food intake and weight gain.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Aquaculture; Chickens; Eating; Fermentation; Food Microbiology; Gastrointestinal Microbiome; Glycopeptides; Gram-Positive Bacteria; Growth Substances; History, 20th Century; History, 21st Century; Humans; Lactobacillus; Macrolides; Obesity; Oligosaccharides; Penicillins; Poultry; Prebiotics; Probiotics; Ruminants; Streptomyces aureofaciens; Swine; Tetracyclines; Weight Gain

1. The aim of the experiment was to test the possible interactions of an enzyme complex and a food antibiotic on the growth and metabolism, carcase yield, whole body composition and nutrient deposition in broilers. The basal diet contained 400 g/kg barley. The four treatments were as follows: O--without supplements (control), E--enzyme complex Roxazyme G, 200 mg/kg, A--antibiotic avoparcin, 10 mg/kg, EA--Roxazyme G, 200 mg/kg plus avoparcin, 10 mg/kg. 2. Roxazyme G positively influenced weight gain, food conversion efficiency, energy metabolisability, fat and nitrogen utilisation and the dry matter content of droppings. Fat and energy deposition in the whole body were also increased, whereas protein deposition and carcase yield were not influenced. 3. Avoparcin increased energy metabolisability and fat utilisation, but had no influence on nitrogen utilisation. No significant improvements from avoparcin were seen in growth or in nutrient deposition in the body. The fibre degradability (NDF and ADF fraction) was significantly depressed by antibiotic supplementation. 4. The inclusion of both supplements to the diet did not have a fully additive effect on growth, energy metabolisability, or fat and nitrogen utilisation. The interaction between enzyme and antibiotic for food conversion efficiency during the first experimental period (7 to 21 d) was nearly significant (P = 0.053). Except for fibre degradability (P < or = 0.01), no other significant interactions between enzyme and antibiotic were found.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Body Composition; Body Weight; Chickens; Enzymes; Glycopeptides; Glycoside Hydrolases; Multienzyme Complexes; Weight Gain

1. An experiment was carried out with male broiler chicks to evaluate the combined effect of monensin (150 mg/kg) and the growth promoters (GPs) Zn bacitracin (BAC, 50 mg/kg), virginiamycin (VIR, 25 mg/kg) and avoparcin (AVO, 20 mg/kg) fed from 7 to 28 d of age on performance, utilisation of dietary nutrients, yield of defeathered eviscerated carcases (DEC) and size of various organs. The effect of the GPs in the monensin-unsupplemented diets fed up to 49 d of age on performance and carcase was also determined. 2. Monensin significantly (P < 0.05) depressed food intake, weight gain and food efficiency from 7 to 28 d of age. None of the GPs was able to counteract these effects. However, AVO slightly ameliorated them. AVO also significantly increased food intake and improved gain and food efficiency during 7 to 28, but not 28 to 49 or 7 to 49 d of age. VIR and BAC did not affect performance in either age period. 3. Monensin did not affect the utilisation of dietary dry matter, fat or energy, but it significantly decreased nitrogen utilisation. AVO improved nitrogen and fat utilisation and increased dietary AME(n) content. AME(n) was also increased by VIR. The utilisation of these nutrients was not affected by the interactions between monensin and the GPs. 4. Monensin did not affect yield of the DEC or the relative liver size at 31 d of age. It significantly increased the relative length of the small intestine (SI) and decreased its specific weight. AVO significantly increased yield at 31, but not at 53 d of age. BAC and VIR did not affect this variable. AVO and VIR, but not BAC, at both age periods reduced, at times significantly, the size, length and specific weight of the SI. 5. Our conclusions: BAC, VIR and AVO do not counteract the toxic effect of monensin. The effect of GPs in improving performance decreases and even disappears with age, while their effect in reducing the size of the SI is still evident in 49-d-old birds.

Topics: Animal Nutritional Physiological Phenomena; Animals; Anti-Bacterial Agents; Bacitracin; Chickens; Drug Interactions; Eating; Glycopeptides; Male; Monensin; Virginiamycin; Weight Gain

Diets based on barley or corn without avoparcin supplementation were associated with high counts of Clostridium perfringens in the contents of the small intestine of the birds at the age of 2 to 4 wk. The weight gain of birds younger than 2 wk and the body weight of 4-wk-old birds were significantly lower, and the feed conversion ratio at slaughter was significantly higher, in birds on barley diets than in birds on corn diets. The frequency of birds with sticky droppings on Day 21 was significantly higher for barley diets. The number of C. perfringens, and the feed conversion ratio at slaughter were significantly lower but the number of coliform bacteria, weight gain during the 3rd wk, and body weight of 4-wk-old chickens were significantly higher when the diets were supplemented with 7.5 mg avoparcin/kg feed. The effect of avoparcin on the feed conversion ratio was statistically significant only on a barley diet.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Chickens; Clostridium perfringens; Colon; Enterobacteriaceae; Female; Glycopeptides; Hordeum; Intestine, Small; Lactobacillus; Male; Streptococcus; Weight Gain; Zea mays

The clinical, pathological, and bacteriological findings of a mild form of necrotic enteritis (NE) in broiler chickens are presented. The term subclinical NE (SNE) is proposed for this condition. A diagnosis of SNE was based on the detection of macroscopically visible, focal necrotic lesions in the small intestinal mucosa. The ileal gut contents from SNE birds yielded increased numbers of Clostridium perfringens and reduced numbers of coliform bacteria. Reduced numbers of lactobacilli and streptococci were detected in birds from SNE pens and coccidial oocysts were not found in the rectal contents of SNE birds. Statistical analyses showed strong correlations between SNE and increased feed conversion ratio and retarded growth rate. An increased occurrence of SNE was observed in birds on a diet containing a large amount of barley.

Topics: Animal Feed; Animals; Anti-Bacterial Agents; Chickens; Clostridium perfringens; Colony Count, Microbial; Enteritis; Enterobacteriaceae; Glycopeptides; Hordeum; Intestinal Mucosa; Intestine, Small; Lactobacillus; Necrosis; Poultry Diseases; Random Allocation; Streptococcus; Weight Gain

3 group feeding experiments were carried out with the glycopeptide antibiotic avoparcin. Avoparcin was added to salt licks (2.5 g per kg lick stone) and offered to 30 (experiment I), 80 (experiment II), or 20 (experiment III) growing cattle ad libitum over 210, 122, or 281 days. Control animals consumed unsupplemented lick stones. The avoparcin intake amounted to 60 (experiment I), 145 (experiment II), and 100 mg (experiment III) per cattle per day. The daily weight gain increased from 750 to 808 (experiment I), 553 to 649 (experiment II), and from 812 to 822 g per animal per day (experiment III) when avoparcin was added. Avoparcin is a safe feed additive and should be supplemented to various lick stones to improve ruminant performances under tropical rangeland conditions. 15 to 30 mg avoparcin per kg dry matter intake are recommended.

Topics: Animals; Anti-Bacterial Agents; Cattle; Glycopeptides; Male; Sodium Chloride; Weight Gain

Four digestion experiments with 5 wethers each (0, 15, 30 or 60 mg avoparcin per animal and day), three individual feeding experiments (28, 18 or 56 bulls per experiment; 0 and 150/200; 0, 250 and 500 or 0 and 200 mg avoparcin per animal and day in the experiments 1, 2 or 3) and two group feeding experiments (60 bulls and 161 heifers per experiment; salt lick stones without or with 2.5 g avoparcin per kg) were carried out in order to investigate the influence of avoparcin on apparent digestibility, figures of rumen fermentation, fattening and slaughtering results as well as protein, fat and energy retention. Avoparcin supplementation did not significantly influence the apparent digestibility of organic matter and crude nutrients. Concentration of acetate of rumen liquid was decreased (16 or 36) and that of propionate was increased (25 or 50 mmoles per mol) when 200 or 500 mg avoparcin per animal and day were added. Acetate:propionate ratio decreased from 4.2 to 3.5 and 3.1:1. Avoparcin did not influence feed intake, enhanced daily weight gain (37 to 174 g per animal and day) and improved feed efficiency (5 to 26%). Salt lick stones with avoparcin increased weight gain (58 and 96 g per animal and day). Slaughtering results and body composition of bulls were not influenced by avoparcin. Daily retention of protein, fat and energy was significantly increased (16 to 18%; P less than 0.05) when avoparcin was supplemented.

Topics: Animals; Anti-Bacterial Agents; Body Composition; Cattle; Digestion; Eating; Female; Fermentation; Glycopeptides; Male; Molecular Structure; Rumen; Sheep; Weight Gain