Prevalence of Antimicrobial Resistance in Escherichia coli and Salmonella Species Isolates from Chickens in Live Bird Markets and Boot Swabs from Layer Farms in Timor-Leste

The rapid emergence of antimicrobial resistance is a global concern, and high levels of resistance have been detected in chicken populations worldwide. The purpose of this study was to determine the prevalence of antimicrobial resistance in Escherichia coli and Salmonella spp. isolated from healthy chickens in Timor-Leste. Through a cross-sectional study, cloacal swabs and boot swabs were collected from 25 live bird markets and two layer farms respectively. E. coli and Salmonella spp. from these samples were tested for susceptibility to six antimicrobials using a disk diffusion test, and a subset was tested for susceptibility to 27 antimicrobials using broth-based microdilution. E. coli and Salmonella spp. isolates showed the highest resistance towards either tetracycline or ampicillin on the disk diffusion test. E. coli from layer farms (odds ratio:5.2; 95%CI 2.0-13.1) and broilers (odds ratio:18.1; 95%CI 5.3-61.2) were more likely to be multi-drug resistant than those from local chickens. Based on the broth-based microdilution test, resistance to antimicrobials in the Timor-Leste Antimicrobial Guidelines for humans were low, except for resistance to ciprofloxacin in Salmonella spp. (47.1%). Colistin resistance in E. coli was 6.6%. Although this study shows that antimicrobial resistance in chickens was generally low in Timor-Leste, there should be ongoing monitoring in commercial chickens as industry growth might be accompanied with increased antimicrobial use.

Meat Quality Parameters of Boschveld Indigenous Chickens as Influenced by Dietary Yellow Mealworm Meal

An experiment was conducted to examine the effects of yellow mealworm larvae (Tenebrio molitor) meal inclusion in diets of indigenous chickens. A total of 160 mixed-sex indigenous Boschveld chickens were randomly divided into four categories: control soybean meal (SBM) and yellow mealworm with percentage levels of 5, 10 and 15 (TM5, TM10 and TM15, respectively). Five replicate pens per treatment were used, with eight birds per pen/replicate. On day 60, two birds from each replicate were slaughtered and eviscerated. Meat quality parameters were measured out on raw carcass and cooked breast meat. The carcass weight, breast weight and gizzard weight of the control group was higher (p < 0.05) than the treatment group (TM15). The cooking loss was lower (p < 0.05) in the SBM control group but higher in the TM15 group. Colour characteristics of breast meat before cooking was lighter in the TM10 and TM15 group, ranged from 61.7 to 69.3 for L* and was significant (p < 0.05). The TM10 and TM15 groups showed a lighter colour than the SBM and TM5 groups. The breast meat pH taken after slaughter was different (p < 0.05) in TM5 and TM15, with the highest reading (pH 6.0) in the TM5 group. In conclusion, our experiment indicated that dietary Tenebrio molitor in growing Boschveld indigenous chickens’ diets could be considered a promising protein source for Boschveld indigenous chickens.

High Genetic Diversity but Absence of Population Structure in Local Chickens of Sri Lanka Inferred by Microsatellite Markers

Local chicken populations belonging to five villages in two geographically separated provinces of Sri Lanka were analyzed using 20 microsatellite markers to determine the genetic diversity of local chickens. Population genetic parameters were estimated separately for five populations based on geographic locations and for eight populations based on phenotypes, such as naked neck, long legged, crested or crown, frizzle feathered, Giriraj, commercial layer, crossbreds, and non-descript chicken. The analysis revealed that there was a high genetic diversity among local chickens with high number of unique alleles, mean number of alleles per locus (MNA), and total number of alleles per locus per population. A total of 185 microsatellite alleles were detected in 192 samples, indicating a high allelic diversity. The MNA ranged from 8.10 (non-descript village chicken) to 3.50 (Giriraj) among phenotypes and from 7.30 (Tabbowa) to 6.50 (Labunoruwa) among village populations. In phenotypic groups, positive inbreeding coefficient (F IS) values indicated the existence of population substructure with evidence of inbreeding. In commercial layers, a high expected heterozygosity He = 0.640 ± 0.042) and a negative F IS were observed. The positive F IS and high He estimates observed in village populations were due to the heterogeneity of samples, owing to free mating facilitated by communal feeding patterns. Highly admixed nature of phenotypes was explained as a result of rearing many phenotypes by households (58%) and interactions of chickens among neighboring households (53%). A weak substructure was evident due to the mating system, which disregarded the phenotypes. Based on genetic distances, crown chickens had the highest distance to other phenotypes, while the highest similarity was observed between non-descript village chickens and naked neck birds. The finding confirms the genetic wealth conserved within the populations as a result of the breeding system commonly practiced by chicken owners. Thus, the existing local chicken populations should be considered as a harbor of gene pool, which can be readily utilized in developing locally adapted and improved chicken breeds in the future.

The effect of different types of in ovo selenium injection on the immunity, villi surface area, and growth performance of local chickens

Background and Aim

The presence of free radicals may lower chicken's performance. Thus, the antioxidant defense is needed and can be made through a nutritional approach such as selenium supplementation before hatches. This study aimed to investigate the type of selenium that, as an in ovo feeding (IOF) material, can provide the most enhancement of immunity, villi surface area, and early growth performance of local chickens.

Materials and Methods

This study, with a completely randomized design, used 480 fertile Kampung Unggul Balitbangtan (KUB, a selected local breed) chicken eggs, with 120 eggs per treatment for four treatments. The four treatments of IOF material included the treatment with organic selenium yeast (SY), organic hydroxy-selenomethionine (HSM), inorganic sodium selenite (SS), and uninjected selenium (control). A solution containing 0.15 ppm of different selenium was injected into the egg amnion after 18 days of incubation. Once hatched, the chicks were placed in three individual cages for each treatment (capacity of eight birds per cage). The parameters observed were the villi surface area, antibody titer, the number of total and differentiated leucocytes, glutathione peroxidase (GSH-Px) activity levels, and growth and feed efficiency of the early growth performance.

Results

All the in ovo selenium feeding, except SS, significantly affected the villi surface area, antibody titer, and lymphocyte and heterophil percentages; however, the feedings were still not optimal for enhancing antibody titers and total and differentiated leukocytes. All types of selenium were demonstrated to increase the activity of GSH-Px significantly compared to the control treatment (p<0.05). Furthermore, the daily gain and feed conversion ratio of the groups treated with SY and HSM was significantly improved compared to that of the control group.

Conclusion

In ovo SY and HSM improve immunity significantly, villi surface areas and performance. Therefore, both types are the best nutrient ingredients of IOF for building immunity and producing good performance in chickens.

Effect of feed supplementation of Dacryodes edulis parts' powder as prebiotic on the growth traits, ceca microbiota and blood parameters of local chickens

This study aimed at testing the efficacy and safety of Dacryodes edulis plant parts in diets fed to chicken. The plant has potential for use as a natural prebiotic to substitute the conventionally used antibiotic growth promoters in poultry production. Phytochemical analyses of the plant leaves, stem, and bark combination (stembark) and seed powders from the D. edulis were carried out. The powder from the three D. edulis plant parts were used as supplement in formulating six experimental diets tested in this study. The diets were TL_0Ed (0.5% leaves powder), TL_1Ed (1.0% leaves powder), TB_0Ed (0.5% stembark powder), TB_1Ed (1.0% stembark powder), TS_0Ed (0.5% seeds powder), and TS_1Ed (1.0% seeds powder). Besides, a positive (T₊ positive control; 0.5-g oxytetracycline as recommended by the manufacturer) and a negative (T_- negative control; having no commercial antibiotic and no plant supplement) diets were prepared for comparison purposes. The diets were fed to a total of 288 dual-purpose chicken for a period of 14 weeks. The chicken growth and body composition characteristics, blood chemistry, and microbiota count were collected and used as indicators of the plant parts efficacy and safety. The analysis of the D. edulis plant parts significantly differed (P ≤ 0.05) in their phytochemical contents. The initial body weight and feed conversion efficiency ratios were not significantly different (P ≥ 0.05) between and among treatment groups. However, significant differences (P ≤ 0.05) were detected in the feed intake and body weight gain at eighth week. Live weight at eighth week was significantly different (P ≤ 0.05) with its values ranging between 503.32 and 614.93 g for treatments TL_1Ed and T_Neg-, respectively. The dietary treatment of D. edulis leaves, stembark, and seed powder at the two inclusion levels significantly (P ≤ 0.05) decreased the colonies forming unit of Escherichia coli and Salmonella sp. as compared with negative control treatment in the eighth week phase. The level of glucose, total cholesterol, triglycerides, aspartate aminotransferase, alanine amino transferase, alkaline phosphatase, and the packed cell volume did not differ significantly (P ≥ 0.05) between and among dietary D. edulis treatments. The findings from this research provide crucial information on the efficacy and safety of D. edulis plant parts. This is an important step in testing the potential of the plant in use as a prebiotic in chicken feeds production.