Bhuminand Devkota

Synbiotics, a combination of probiotics and prebiotics, are increasingly being explored as alternatives to antibiotics in poultry nutrition due to rising consumer demand for antibiotic-free products and concerns about antibiotic resistance. With these issues, and the ban on antibiotics as growth promoters, the poultry industry is shifting toward natural feed additives. Synbiotics have gained attention for their potential as an effective growth promoter. Broiler growth performance, a critical factor for profitability, can be enhanced using synbiotics, which improve gut health, increase feed efficiency, and boost overall growth. The effectiveness of synbiotics, however, is influenced by the method, timing, and duration of administration. This study focuses on determining the optimal duration of synbiotic supplementation to maximize weight gain, feed conversion ratio (FCR), and gut health, aiming for more efficient and sustainable poultry production. To evaluate the impact of varying supplementation durations, a trial was conducted with day-old Cobb-500 chicks (420 in number), divided into seven treatment groups with six replicates of 10 chicks each. The study was carried out at Fewa Group of Poultry Industries Pvt. Ltd., Pokhara, Nepal, over six weeks, with weekly treatments lasting from the 1st to the 6th week, including a control group without synbiotic supplementation. Weekly performance parameters such as feed consumption, weight gain, and FCR were recorded. The results demonstrated that continuous synbiotic supplementation in feed throughout the rearing period of 6 weeks at the recommended levels significantly improved growth performance. Feed consumption increased notably in the fifth and sixth weeks, while weight gain was positively influenced from the third week onward. Additionally, cumulative feed intake, average weight, and FCR at 42 days showed substantial improvement, indicating that synbiotics are a viable alternative to antibiotics for promoting growth when used throughout the rearing periods of 6 weeks in broiler production.

Background and Aim: To combat enteric infections and antibiotic resistance in the poultry industry, researchers seek alternatives such as probiotics, prebiotics, and synbiotics as growth promoters. Synbiotics support probiotic growth through the supply of essential nutrients. The study’s objectives were to assess the most effective delivery methods for synbiotics and evaluate their growth, histomorphometric, and hematological impacts on Cobb-500 broilers. Materials and Methods: Two studies, independently conducted, employed a completely randomized design. One hundred and eighty viable eggs in the first trial were assigned to three groups: Control (T1), sterile water (T2), and synbiotic in sterile water (T3). On the 21st day of hatching, hatchability, day-old body weights, and ileum samples for histomorphometric analysis were recorded. In the second trial, out of 500 viable eggs, 200 eggs were fed in ovo with synbiotics (PoultryStar® sol, Biomin Singapore Pte Ltd, Singapore) on 17.5 days and 300 were set aside without in ovo injection. The treatments were control (T1), in water synbiotic (T2), in ovo synbiotic (T3), combination of in ovo synbiotic and synbiotic in feed (T4), and synbiotic in feed only (T5). On 21 and 42 days, blood, ileum, and visceral organ samples were collected for laboratory analysis. Data on weight gain, daily feed intake, and water consumption were recorded for 42 days. Results: The initial experiment’s results revealed a decrease in hatchability, slight weight increase, and significant intestinal morphological changes with the use of an in ovo synbiotic. Applying synbiotic through various methods in the second trial yielded better growth results, lower blood cholesterol, and significantly longer (p < 0.05) villi on 21 days. Conclusion: Using the in ovo method to administer synbiotics lowered hatchability. Use of synbiotics with any method or in combination enhances growth, ileum structure, dressing yield, feed efficiency, and cholesterol levels in blood. Synbiotics enhance gut health and overall performance in broilers when used through diverse approaches. Keywords: growth performance, gut health, histomorphometry, in ovo, synbiotic.

Background and Aim: Antimicrobials are extensively used in poultry production for growth promotion as well as for the treatment and control of diseases, including avian pathogenic Escherichia coli (APEC). Poor selection, overuse, and misuse of antimicrobial agents may promote the emergence and dissemination of antimicrobial resistance (AMR) in APEC. This study aimed to assess antimicrobial susceptibility patterns and detect antibiotic resistance genes (ARGs) in APEC isolated from clinical cases of colibacillosis in commercial broiler, layer, and breeder chickens. Materials and Methods: A total of 487 APEC were isolated from 539 across 300 poultry farms in various regions of Nepal. antimicrobial susceptibility patterns was determined using the Kirby-Bauer disk diffusion and broth microdilution methods. The index of AMR, such as multiple antibiotic resistance (MAR) index, resistance score (R-score), and multidrug resistance (MDR) profile, were determined. Polymerase chain reaction was employed to detect multiple ARGs and correlations between phenotypic and genotypic resistance were analyzed. Results: The prevalence of APEC was 91% (487/539). All of these isolates were found resistant to at least one antimicrobial agent, and 41.7% of the isolates were resistant against 8–9 different antimicrobials. The antibiogram of APEC isolates overall showed the highest resistance against ampicillin (99.4%), whereas the highest intermediate resistance was observed in enrofloxacin (92%). The MAR index and R-score showed significant differences between broiler and layers, as well as between broiler breeder and layers. The number of isolates that were R to at least one agent in three or more antimicrobial categories tested was 446 (91.6%) and were classified as MDR-positive isolates. The ARGs were identified in 439 (90.1%) APEC isolates, including the most detected mobilized colistin resistance (mcr1) which was detected in the highest (52.6%) isolates. Overall, resistance gene of beta-lactam (blaTEM), mcr1, resistance gene of sulphonamide (sul1) and resistance gene of tetracycline (tetB) (in broiler), were detected in significantly higher than other tested genes (p < 0.001). When examining the pair-wise correlations, a significant phenotype-phenotype correlation (p < 0.001) was observed between levofloxacin and ciprofloxacin, chloramphenicol and tetracycline with doxycycline. Similarly, a significant phenotype-genotype correlation (p < 0.001) was observed between chloramphenicol and the tetB, and colistin with blaTEM and resistance gene of quinolone (qnrA). Conclusion: In this study, the current state of APEC AMR in commercial chickens is revealed for the first time. This information is useful for the clinical management of disease as well as the creation of policies and guidelines to lower AMR in Nepal’s commercial chicken production. Keywords: antibiotic resistance gene, multiplex PCR, colibacillosis, multiple antibiotic resistance index, mcr1, commercial chicken.

Water buffalo (Bubalus bubalis) in Nepal contributes 57% of the total milk and 36% of the total meat production in the country. Even though the buffalo farming systems range from large-scale and semi-intensive, with herd sizes of more than 50 animals, to small-scale, intensive systems in which farmers keep 1 to 5 animals, while large-scale farms are very few, and medium and small-scale farms predominate in the country. The productive efficiency of Nepalese buffaloes is relatively low, due mainly to subfertility and infertility. Delayed puberty and prolonged inter-calving intervals, attributed mainly to anestrus due to silent cyclicity and ovarian acyclicity, are the major forms of infertility in Nepalese buffaloes. Moreover, buffaloes in Nepal show a distinct seasonal breeding pattern, with July to December as the active breeding season and April to June and January to March as the low and transitional breeding seasons, respectively. It is understood that acyclicity with inactive ovaries is a major problem during the transition and low breeding season; however, silent cyclicity is expected during the good seasons. Among several factors compromising the treatment response of anestrus buffaloes in terms of pregnancy outcome, poor body condition score, sub-normal levels of some blood metabolic parameters, and gastrointestinal parasitic infection are more common. Putting together all those information, we developed an integrated technique of buffalo fertility management that includes anthelmintic treatment at least one month prior to the initiation of specific timed artificial insemination (TAI) protocol and nutritional management by means of providing vitamin–mineral supplementation in addition to improving the roughage supply and energy-protein content in the ration soon after anthelmintic treatment until two weeks after AI. Specific TAI protocol includes Ovsynch during the good season and CIDR co-synch during the transition and low seasons, as silent ovulation during the good season and acyclicity during the other two seasons are the major causes of anestrus. The TAI is important in medium and small-scale farms as the owner is responsible for heat detection, which is challenging in buffaloes. The integrated technique has succeeded in anestrus buffaloes, particularly during the low breeding season. The broader adoption of this technique as a package of practices could be a key to improving the reproductive efficiency of buffaloes in Nepal and other countries with similar farming systems.

Water buffalo (Bubalus bubalis) in Nepal contributes 57% of the total milk and 36% of the total meat production in the country. The productive efficiency of Nepalese buffaloes is quite low, due mainly to subfertility and infertility. Delayed puberty and prolonged inter-calving intervals, attributed mainly by anestrus due to silent cyclicity and ovarian acyclicity, are the major forms of infertility in Nepalese buffaloes. Moreover, buffaloes in Nepal show a distinct seasonal breeding pattern, with July to December as the active breeding season, and with April to June and January to March as the low and transitional breeding seasons, respectively. Endoparasitic infection and poor nutritional status, which are more severe during the low season, are found to be the major factors causing anestrus and compromising its treatment response in buffaloes. Various hormonal protocols for timed artificial insemination (TAI) have been attempted, with a varying pregnancy outcome. Recently, an integrated technique including anthelmintic treatment, nutritional supplementation and hormone-based fertility management programs for TAI has been developed and implemented successfully. A wider adoption of this technique as a package of practices could be key to improving the reproductive efficiency of buffaloes in Nepal.

Objectives: This study aimed to determine the seroprevalence of brucellosis among pigs of commercial farms in Chitwan district of Nepal. Methods: This cross sectional prospective study was conducted among 100 pigs of commercial farms located in western region of Chitwan district of Nepal. Blood sample was collected from each pig by the trained veterinarians and serum was extracted. Each serum sample was processed for Rose Bengal plate test (RBPT) and ELISA for the detection of Brucella spp. Data was analyzed using SPSS software version 21.0 and a p-value of less than 0.05 was considered as significant. Results: Prevalence of brucellosis in pigs was found to be 15% (15/100) by RBPT and 10% (10/100) by ELISA. There was statistically insignificant difference (p=0.98) in gender wise prevalence of brucellosis among pigs. Younger pigs below one year of age were more susceptible to brucellosis than the older pigs. Landrace breed showed more positive test results compared to other breeds. Conclusion: Pigs can be the potential source of transmission of brucellosis to humans. Considering the high economic loss on livestock sector and possible transmission to humans, awareness program and appropriate control strategies is warranted. Breed and age factors should be considered while adopting the control measures of brucellosis among pigs.

Paratuberculosis caused by Mycobacterium avium subspecies paratuberculosis (MAP), is an economically important, endemic in many parts of the globe, and regarded as high prevalent disease of domestic and wild animals, especially ruminants, which is manifest as chronic granulomatous enteritis with decreased milk production, with serious cases resulting in progressive emaciation and death. Understanding the genetic variability of MAP, strains are important in diagnosis, epidemiological investigation, and therefore the formation of strategies for prevention and control of the disease. Thus, this study was designed to grasp the molecular characterization of MAP isolates of Nepal, as pioneer research of this area. Total of 46 MAP isolates obtained from cattle population of three different locations of dairy pocket areas of Chitwan, Nepal were typed using IS1311 polymerase chain reaction-restriction endonuclease analysis (PCR-REA) to research the MAP genotype of Nepal. The extracted DNA samples (n=46) were analyzed for the presence of MAP specific sequences (IS900) using PCR and DNA samples were further subjected to genotype differentiation using IS1311 PCR-REA and IS1311 L2 PCR-REA methods. All the DNA samples were positive for the entire three MAP specific sequences based PCRs. This study revealed that ‘Bison type’ strain is the single most prevalent MAP genotype circulating within the domestic cattle population of Nepal. IS1311 PCR-REA showed that MAP DNA samples of Nepal origin belonged to ‘Bison type’, whereas, IS1311 L2 PCR-REA method showed similarity with "Indian Bison type" and different restriction profiles of ‘Bison type’ genotype as compared to non-Indian strains. The study concludes that in Nepal, "Bison type" MAP stains was prevalent in all the MAP samples obtained from dairy cattle. These results have important epidemiological implications regarding control and prevention of paratuberculosis in Nepal.