M.A. Hossain
Department of Dairy & Poultry Science, Chittagong Veterinary and Animal Sciences University, Khulshi, Chittagong-4225, Bangladesh
S. Dev
Department of Dairy & Poultry Science, Chittagong Veterinary and Animal Sciences University, Khulshi, Chittagong-4225, Bangladesh
I. Jahan
Department of Botany, University of Chittagong, Chittagong-4331, Bangladesh
M.M. Hossain
Department of Livestock Services, OTI, Savar, Dhaka, Bangladesh
Growth, Microflora, Carcass trait, Probiotics, Viability, Profitability, Broiler chicken
Department of Dairy & Poultry Science, Chittagong Veterinary and Animal Sciences University, Khulshi, Chittagong-4225, Bangladesh
Animal Health and Management
A total of 192 (Ross 308) day-old broiler chicks was procured from a local commercial hatchery to conduct this experiment from d1 to 28 days. The chicks (46.33±0.01 g/b) were weighed on receipt, and then randomly assigned into four treatment groups, i.e D1, D2, D3 and D4. Each treatment had six replicates with eight birds per replicate in a completely randomized design . All the chicks were allotted into 24 similar pens in a battery cage housing condition. Each pen was furnished with hanging feeder and automatic drinker to get an easy access of feed and water for the birds during the trial period. The chicks were brooded with electric bulb (100 watt) placed hanging at the middle of the each pen. For the first two days, the chicks were provided with a temperature of 33°C. The temperature was then gradually reduced by 1 or 2°C every 1 or 2 days until the chicks were 19 days old at which point the temperature was maintained at 24°C for the rest of the trial period. Eighteen hours of lighting and six hours darkness per day were provided throughout the trial period except for first week only, and at this period continuous lighting (23 h light: 1h darkness) program was maintained for the chicks. The ready-made (crumble-pellet; C.P. Bangladesh Co. Ltd.) broiler diets (starter and grower) were procured from the local market of Chittagong, and fed the birds entire the trial period (d1-28). The broiler chicks were fed with starter diets up to 14 days, after that, grower diets were used for the remaining period (d15-28d). The probiotics i.e. Starsol, Avilac Plus, and Avibac etc. were collected from the nearby market of Chittagong. The manufacturing companies of these probiotics are Renata Ltd. (Starsol), Orion Pharma Ltd. (Avilac Plus) and Opsonin Pharma Ltd. (Avibac), respectively. The probiotics were mixed with water at the particular doses and this treated water was used for drinking the broilers for entire the trial period. Prior to feeding, chicks were weighed and recorded at the first day of starting trial. Live weight, feed consumption and feed conversions ratio were calculated weekly. Mortality was recorded when it occurred. Data on carcass yield traits (breast weight, thigh weight, dressing yield, drumstick weight and blood weight) and cost benefit analyses were also assessed on the last day of trial. Apart from these, feed samples were collected and analyzed in the laboratory. Besides, total viable count (TVC) and total lactobacillus count (TLC) were also determined in the laboratory from the faecal samples collected on the last day by slaughtering birds. Feed sample- The collected feed samples were prepared by grinding with pestle and mortar in the laboratory. After that, the samples were sent to the laboratory for proximate analyses. The procedure for the estimation of dry matter (DM), crude protein (CP), crude fibre (CF), ether extract (EE), ash, nitrogen free extract (NFE) etc., were those of AOAC. True metabolizable energy (TME) content of the taken samples was determined indirectly by using the values of CF, EE, and ash contents (%) fitted to a formula suggested by Wiseman. Metabolizable energy (ME) was determined indirectly on the basis of TME contents of the feed samples, assuming that TME was 8% higher than the ME, as it is reported that TME is 5-10% higher than ME (Wiseman,1987). The formula of TME is: 3951 +54.4 EE - 88.7 CF - 40.8 Ash. Calcium and phosphorus content of the feed samples were determined by atomic absorption and spectrophotometry, respectively. Preparation of samples for bacteriological studies- Portion of cecum with their contents were obtained aseptically with a sterile scalpel and forceps. These portions were homogenized uniformly using a mortar and pestle. From the homogenized mass, one-gram portion was transferred to a sterile tube containing 9 ml of 0.1 % peptone water. Thus, 1: 10 dilution of the sample was obtained. Later on serial dilutions of each sample in 0.1% peptone water were made as per recommendation of International Organization for Standardization (ISO, 1995). Enumeration of total viable count (TVC)- For the determination of total bacterial counts, 0.1 ml of each ten-fold dilution was transferred and spread on triplicate PCA or NA agar using a sterile pipette for each dilution. The diluted samples were spread as quickly as possible on the surface of the plate with a sterile glass spreader. One sterile spreader was used for each plate. The plates were then kept in an incubator at 35°C for 24-48 hours. Following incubation, plates exhibiting 30-300 colonies were counted. The average number of colonies in a particular dilution was multiplied by the dilution factor to obtain the total viable count. The total viable count was calculated according to ISO (1995). The results of the total bacterial count were expressed as the number of organism of colony forming units per gram (CFU g-1) of crop and caecum samples. Enumeration of total lactobacillus count (TLC) For the determination of total lactobacillus count and the procedures of sampling, dilution and Streaking was similar to those followed in the total bacterial count. Only in case of lactobacillus count MRS agar was used. To perform MPN technique 1.0 ml of each tenfold dilution was transferred to 9.0 ml MacConkey broth. For each dilution five test tube, containing 9.0 ml MacConkey broth were used. All the test tubes were incubated at 30°C temperature for 48 hours. Growth of the organism was confirmed by the appearance of turbidity. Statistical analyses- All collected data were statistically analyzed using Minitab software (Minitab Version 16, 2000). The data were analyzed using one-way ANOVA with diet as factor. The significance of differences between means was determined by Fisher’s least significant difference at P≤0.05.
Int. J. Agril. Res. Innov. Tech. 10(1): 28-34, June 2020
Journal