KMS Islam
Department of Animal Nutrition, Bangladesh Agricultural University, Mymensingh 2202
MR Debi
Department of Animal Nutrition, Bangladesh Agricultural University, Mymensingh 2202
A Liesegang
Institute of Animal Nutrition, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, CH-057 Zurich
During an experimental period of 28 days, citric acid (CA) was tested as a growth promoter instead of antibiotics with replacement of commercial diet by rice polish (RP). Newly 240 hatched broiler chicks (Cobb 500) distributed into eight dietary groups (3 replicate cages having 10 birds in each), 1=Control (commercial diet), 2=Commercial diet+0.5% CA, 3=5.0% RP, 4=5.0% RP+ 0.5% CA, 5=10.0% RP, 6=10.0% RP+0.5% CA, 7=15.0% RP, 8=15.0% RP+0.5% CA. Diets were supplemented by acid insoluble ash (1.0% Celite) as a marker. At the end, blood sample was collected from all birds. Total ash, mineral content, and density of tibia were determined. Final body weight (g/b) of chicks were 1655, 1733, 1642, 1694, 1618, 1656, 1613 and 1631 g, respectively (P>0.05). Feed intake (g/bird) was 2359, 2419, 2432, 2433, 2524, 2494, 2519 and 2424 g, respectively (P>0.05). FCR varied (P<0.05) among the groups were 1.48, 1.44, 1.54, 1.49, 1.62, 1.55, 1.62, and 1.54, where better FCR was in CA groups comparison to non-CA groups. Retention of Ca, P, and Mg increased in the CA group’s comparison to non-CA groups but replacement of 5.0% commercial diet (with or without CA) caused a higher retention level. Higher dressing percentage observed in CA group (65.4, 65.9 for group 2, 4) comparison to non-CA groups (63.8, 63.9 for groups 1, 3). Bone mineral concentration (total ash, Ca, P and Mg) slightly increased in CA groups (P>0.05). In general, replacement of a commercial diet by RP up to 15.00% would be possible maintaining growth performance of broiler where further supplementation of 0.5% CA showed more advantages by increasing mineral density of bone.
Broiler; Rice polish; Citric acid; Performance; Mineral metabolism
Faculty of Animal Husbandry, Bangladesh Agricultura University, Bangladesh.
Animal Health and Management
Birds, feeding, and management- Two hundred and forty unsexed day-old Cobb- 500 broiler chicks were kept in 24 pens of 16 square fit with 10 birds per pen. Commercial broiler starter diet, but with 1.0 % Celite was added as a tracer considered as the control diet. Birds were divided into 8 dietary groups like 1=Control (commercial diet), 2=Commercial diet+0.5% CA, 3=5.0% rice polish (RP), 4=5.0% RP+0.5% CA, 5=10.0% RP, 6=10.0% RP+0.5% CA, 7=15.0% RP, 8=15.0% RP+0.5% CA. A feeding trial was conducted for a period of28 days. The proximate components of the formulated diets were determined according to the method described by AOAC (1990). The chicks were handled carefully according to the guidelines of the animal welfare committee of the Faculty of Animal Husbandry, Bangladesh Agricultura University. The birds were kept on deep litter. At the beginning, the room temperature was 34°C. This temperature was decreased to 22°C over the first 3 weeks. Feed was supplied and the amount of leftover feed was recorded when the birds were weighed each week. Sampling and analysis of feed and excreta- Feed and excreta samples were collected during the last week of the trial to determine dry matter, total ash, and acid insoluble ash, Ca, P and Mg. The amount of Ca, P, and Mg were determined by auto analyzer (Cobas Mira, Roche, Basel, Switzerland) using standard commercial kits. The digestibility of individual minerals and metabolizable energy was calculated using the following formula. Apparent digestibility (%) = 100 – [(% indicator in feed / % indicator in excreta) × (% nutrient in excreta / % nutrient in feed) ×100]. Determination of blood profiles related to mineral metabolism- Blood samples were drawn from birds during age of 28 days to determine mineral concentration (Ca, P and Mg). Immediately after collection, blood samples centrifuged at 1500 rpm for 10 minutes and serum transferred to a test tube for further analysis. Determination of mineral density of tibia- The tibias from each side of the sacrificed birds were chosen, excised from the fresh carcass, and flesh was removed. The tibia individually sealed in a plastic bag to minimize moisture loss. Forty (10 from each group) tibias from the right side were kept in the refrigerator at 4°C. Mineral content was measured using the peripheral quantitative computed tomography (QCT) method (Stratec XCT 960A, Pforzheim, Germany), scanning at 10, 50, and 90 percent longitudinal location of the tibia for total, trabecular and cortical bone of mineral density. Determination of dry matter, ash, Ca, P, and Mg of the tibia- The tibia dried at 105°C for 48 h and placed in a desiccators and weight recorded. Total ash was determined by placing dried tibia in muffle furnace for 24 hours at 600°C. Percentage of tibia ash calculated according to the procedure of Al- Batshan et al. (1994). Statistical analysis- Initially, the raw data was organized using the computer program Excel (Microsoft Corporation, Renton, WA) and then analyzed using the SPSS11.5 (SPSS Inc., Chicago, IL). All data analyzed by 1-way ANOVA, and Duncan’s multiple range test (Duncan, 1955) conducted to determine the differences among the treatment means (Steel and Torrie, 1980).
Bang. J. Anim. Sci. 2020. 49 (2): 159-165
Journal