Alternatives For Antibiotic Growth Promoters Research Articles

Identification and characterization of probiotics isolated from indigenous chicken (Gallus domesticus) of Nepal.

Excessive and irrational use of antibiotics as growth promoters in poultry has been one of key factors contributing to increased emergence of antibiotics resistant bacteria. Several alternatives for antibiotic growth promoters are being sought, and the search for effective probiotics to be used as feed additives is amongst the promising ones. Our study aimed to isolate and test potential probiotics bacteria from cloacal swabs of various indigenous chicken (Gallus domesticus) breeds from rural outskirts of the Kathmandu valley (Nepal). Selective isolation of probiotics was conducted by micro-aerophilic enrichment of sample in MRS Broth at 37°C, followed by culturing on MRS agar supplemented with 5 g/L of CaCO3. Isolated bacterial colonies producing transparent halo were selected as potential lactic acid bacteria (LAB), and tested for their antibacterial activity, phenotypic and biochemical characteristics, acidic yield, and tolerance to acid and bile. A total of 90 potential LAB were isolated from cloacal samples collected from 41 free-ranging chickens of indigenous breeds. Of these, 52 LAB isolates (57%) showed variable antibacterial activity to at least one bacterial pathogen. Of 52 LAB, 46 isolates fulfilled phenotypic and biochemical criteria of Lactobacillus spp. Of these, 37 isolates produced varying percentage yields of lactic acid, 27 isolates showed survival at pH 3.0, and 17 isolates showed survival tolerances in the presence of 0.3% and 0.5% bile salts for 24 hours. Phylogenetic analysis of 16S rDNA sequencing of LAB isolates fulfilling in vitro probiotics properties showed that 3 isolates had genetic identity of 99.38% with Lactobacillus plantarum, while one isolate was genetically similar (99.85%) with the clade of L. reuteri, L. antri and L. panis. Our study identified four Lactobacillus spp. strains having potential probiotics properties. Further investigations are needed to evaluate these isolates to be used as poultry probiotics feed supplement.

Organic Acids as Alternatives for Antibiotic Growth Promoters Alter the Intestinal Structure and Microbiota and Improve the Growth Performance in Broilers.

The present study aimed to investigate the effects of organic acids (OA) as alternatives for antibiotic growth promoters (AGP) on growth performance, intestinal structure, as well as intestinal microbial composition and short-chain fatty acids (SCFAs) profiles in broilers. A total of 336 newly hatched male Arbor Acres broiler chicks were randomly allocated into 3 dietary treatments including the basal diet [negative control (NC)], the basal diet supplemented with 5 mg/kg flavomycin, and the basal diet supplemented with OA feed additives. Each treatment had eight replicates with 14 birds each. The results showed that AGP and OA promoted growth during day 22–42 compared with the NC group (P < 0.05). OA significantly increased the jejunal goblet cell density and ileal villus height on day 42 compared with the NC group (P < 0.05). Meanwhile, OA up-regulated the mRNA expression of jejunal barrier genes (Claudin-3 and ZO-1) relative to the NC group (P < 0.05). Significant changes of microbiota induced by the OA were also found on day 42 (P < 0.05). Several SCFAs-producing bacteria like Ruminococcaceae, Christensenellaceae, and Peptococcaceae affiliated to the order Clostridiales were identified as biomarkers of the OA group. Higher concentrations of SCFAs including formic acid and butyric acid were observed in the cecum of OA group (P < 0.05). Simultaneously, the abundance of family Ruminococcaceae showed highly positive correlations with the body weight and mRNA level of ZO-1 on day 42 (P < 0.05). However, AGP supplementation had the higher mRNA expression of Claudin-2, lower goblet cell density of jejunum, and decreased Firmicutes to Bacteroidetes ratio, suggesting that AGP might have a negative impact on intestinal immune and microbiota homeostasis. In conclusion, the OA improved growth performance, intestinal morphology and barrier function in broilers, which might be attributed to the changes of intestinal microbiota, particularly the enrichment of SCFAs-producing bacteria, providing a more homeostatic and healthy intestinal microecology.

Препараты для замены кормовых антибиотиков

Препараты для замены кормовых антибиотиков

In vivo effect of Andrographis panniculata nees and Morinda citrifolia on expression of toll-like receptors in indigenous Nicobari fowl

A study on the effect of feeding of Nicobari fowl breeders with Andrographis panniculata (Kalmegh) and Morinda citrifolia (Noni) and its subsequent effect on TLR (Toll like receptors) expression in post-hatch chicks was carried out. Two hundred seventy breeding Nicobari fowls were assigned to each of three dietary treatments namely, T1: Control groups; T2: Kalmegh @ 3g per bird per day; T3: Noni @ 10ml per bird per day. Chicks were hatched out from experimental groups and at 15 days of age, spleen samples were collected from chicks through slaughter. Expression of TLR was quantified with Real-Time PCR (QPCR) and fold difference in expression of different TLRs was analysed. Supplementation Kalmegh significantly improved the expression levels of TLR3, TLR4, TLR5, by 5.4, 9.7 and 1.6 times, respectively as compared to control; while noni supplementation up regulated the expression levels of respective TLRs by 2.9, 5.0 and 0.48 times. We concluded that in vivo exposure to bioactive components present in herbal plants up regulated the expression of TLR4 and TLR5 in chicks that is responsive for their antiviral inducing property at gene level. Thereby kalmegh and noni might be promising alternatives for antibiotic growth promoters.

Immunomodulatory effect of Morinda citrifolia and Andrographis paniculata on expression of toll-like receptors in Nicobari fowl

This study was conducted to observe the effects of dietary noni and kalmegh supplementation on production performance, immunity and gene expression of toll-like receptors in Nicobari fowl. Supplementation of noni and kalmegh significantly influenced the gene expression levels of TLR-2, TLR-3, TLR-4, TLR-5, TLR-15 and TLR-21 as compared to control. The selectively increased TLR-3, TLR- 4 and TLR-5 and decreased expression of TLR-7 indicated that supplementing noni fruit and kalmegh (@ 10 ml + 200 mg / day / bird) induces antiviral and antibacterial responses in chicken. In conclusion, noni and kalmegh might be promising alternatives for antibiotic growth promoters and commercial immune boosters to improve the production of safety poultry produce.

인진쑥 및 녹차 추출물을 이용한 무항생제 닭고기 생산 연구

Two experiments were conducted to determine whether water extracts from Artemisia capillaries (A. capillaries) and Camellia sinensis (C. sinensis) could be used as alternatives to antibiotic growth promoters in broiler feed. The experiment 1 was verified their chemical composition, extracts yields, total phenolic compounds concentration, antioxidant activity, antimicrobial activity, and chicken splenocytes proliferation through in vitro test. The extract yields of A. capillaries and C. sinensis were 26.5 and 16.8%, respectively. Total phenolic compounds concentrations of them expressed as gallic acid equivalent were 15.28 and 26.74 mg/mL, respectively. Electron donating abilities of them expressed as SC showing 50% DPPH radical scavenging were 0.30 and 0.06 mg, respectively. Bacterial inhibitory rates of them against Escherichia coli, Staphylococcus aureus, and Salmonella Typhimurium were ranged from 42.1 to 52.3% and from 21.6 to 33.7%, respectively. And, these extracts increased proliferation of chicken splenocytes. Especially, A. capillaris was more excellent than Echinacea and Concanavalin A known as T-cell stimulator. The experiment 2 was investigated their effects on growth performance, relative organ weight, cecal microflora, blood biochemical parameters, and splenic cytokines mRNA expression in broiler chicks. Four hundred eighty 1-day-old male broiler chicks (Ross 308) were divided in to 4 treatment groups with 4 replicates of 30 birds in each group: NC (control, no antibiotics), PC (avilamycin, 10 ppm; salinomycin, 60 ppm), AC (A. capillaries, 100 ppm), and CS (C. sinensis, 100 ppm); treatments were administered through water supplementation. Final body weight was significantly higher in all treated groups than in NC (p<0.05). Cecal Salmonella numbers were significantly or somewhat decreased in all treated groups than in NC (p <0.05). The relative weights and lengths of the small intestine were more significantly decreased in the PC and AC groups than in the other groups. Cecal Salmonella numbers were significantly or somewhat decreased in all treated groups than in the NC group (p<0.05). The contents of total cholesterol, aspatate aminotransferase, and alanine aminotransferase in blood serum were more significantly decreased in all treated groups than in NC (p<0.05). In conclusion, these results suggested the possibility that these extracts could serve as alternatives for antibiotic growth promoters.

Use of organic acids mixture as an option to replace antibiotic growth promoters in poultry diets

Antibiotic growth promotion in agricultural animal production has been practiced for about 50 year in the United States and other countries. Early indications were for a beneficial effect on production efficiency in poultry and swine. There were early concerns about the development of antibiotic resistance in human pathogens resulting in recommendations to ban sub therapeutic use in animal feeds. One of the best alternatives for antibiotic growth promoters are organic acids. Organic acids mixtures have been shown to be an effective alternative to eliminate salmonellas in feeds and chickens. Various organic acid combinations were tested to prevent Salmonella contamination through the ration in day-old chicks, and it was observed that a mixture of formic (70%) and propionic acid (30%), was efficient to eliminate S. enteritidis and S. thyphimurium, both of great importance in human health and increase growth rate in broiler.

Effects of mushroom and herb polysaccharides, as alternatives for an antibiotic, on growth performance of broilers

1. This in vivo trial was conducted to study the effects of polysaccharide extracts of two mushrooms, Lentinus edodes (LenE) and Tremella fuciformis (TreE), and a herb, Astragalus membranaceus (AstE) on growth performance, and the weights of organs and the gastrointestinal tract (GIT) of broiler chickens. 2. Three extracts (LenE, TreE and AstE) were supplemented at inclusion rates of 0·5, 1, 2, 3 and 4 g/kg from 7 to 14 d of age and compared with an antibiotic treatment group (20 mg/kg, virginiamycin (VRG) as well as a group of non-supplemented birds. 3. Body weight (BW) gain, feed intake and feed conversion ratio (FCR) of the extract-supplemented groups were not significantly different from those of the antibiotic group. Significant effects of type of extract and concentration on growth performance were found from 7 to 28 d of age. Generally, birds fed with LenE showed higher BW gain and lower FCR from 7 to 28 d of age than those fed with TreE and AstE and 2 g/kg LenE was considered the optimal inclusion rate for enhanced broiler growth. However, the extracts had no significant effect on the relative weights of organs and GIT compared with the antibiotic group. 4. The birds fed the extracts showed better growth performance than the non-supplemented birds, but were not significantly different from those fed VRG. Of the three extracts, LenE appeared to be a potential growth promoter. Future studies are needed to investigate whether the extracts can be used as alternatives for antibiotic growth promoters in challenged birds, and to elucidate the mechanisms for potentially enhanced growth performance in poultry.