Ducklings In Groups Research Articles

GROWTH PERFORMANCE, BLOOD PARAMETERS AND INTESTINAL MORPHOLOGY OF MOLAR DUCKLINGS FED DIETS SUPPLEMENTED WITH PROBIOTICS

The present study was conducted to investigate the effect of feeding commercial probiotic preparation (Proact) supplementation on growth performance, carcass traits, blood parameters, intestinal morphological parameters and economical efficiency. A total of 240, one-day old Molar ducklings were individually weighed, wing- banded and randomly assigned to eight equal groups each of 3 replicates (30 birds each). All birds were fed a starter diet until 21- day of age and finisher diet from 22 day until marketing (70 d). Ducklings of group 1 (control) were fed the starter and finisher diets without Proact supplementation. Ducklings of groups 2, 3, 4, 5, 6, 7 and 8 were fed the control diets plus graded levels of Proact (0.25, 0.50, 0.75, 1.00, 1.25, 1.50 and 1.75g/ kg diet, respectively). Results revealed that ducklings of group 4 (0.75) showed significantly (P≤ 0.05) higher body weight, body weight gain, feed intake and performance index. Moreover, feed conversion ratio, European efficiency index and economic efficiency were significantly improved. Carcass and giblets weights and percentage were significantly (P≤ 0.05) increased with the supplementation. Probiotics supplementation (0.75g/ kg diet) significantly increased serum glucose and liver enzymes (AST and ALT), and significantly (P≤ 0.05) decreased createnine, cholesterol, triglyceride and total lipids. However; total protein and albumen were not affected. Moreover, villi height, villi width and villi height: villi width ratio were significantly improved by the addition of probiotics up to 0.75g/ kg diet. Therefore, it may be concluded that supplementation of 0.75g probiotics/ kg diet could be used in diets of Molar ducklings from 0-10 weeks of age to improve growth performance, feed efficiency, and carcass traits.

MORPHOFUNCTIONAL EVALUATION OF THYMUS IN PEKIN DUCK DURING DIETARY INCORPORATION OF ORGANIC SELENIUM FEED ADDITIVE DAFS-25k

The histological study results of the thymus structure of Pekin ducks during administration of DAFS-25k feed additive are presented. It has been established that the thymus is a morphologically mature and actively functioning organ in one-day-old Pekin ducklings. With age an increase in the size of thymus lobules was observed in ducklings in the control and experimental groups but under the influence of selenium the cortical area increased more intensively. 45-day-old ducklings in the experimental group demonstrated a reliable increase in the ventricular-brain ratio mainly due to the expansion of the cortical area. The surface of the cortical substance did not change in intact ducklings, the tendency of extension in the surface of the brain substance was observed, which at that age is a sign of an accidental involution associated with the onset of a plumage change from juvenile down to primary feathers. Under the influence of selenium in the thymus of the ducklings of the experimental group the processes of accidental involution are leveled, the processes of synthesis of thymopoietins and proliferation of thymocytes are more active. Up to age of 75 days there is active proliferation of thymocytes in the thymus of ducklings of both groups; however reliably higher parameters of ventricularbrain ratio under the influence of selenium were observed in the experimental group, there was a clear boundary between them, as well as significantly higher quantity and size parameters of Hassal’s corpuscles were noted. From the age of 90 days signs of age involution in the organ were observed, and in the experimental group these processes were going more physiologically in accordance with the age of the birds. Introduction of the organic and selenium additive DAFS-25k in the diet of ducklings at a dose of 1.3 mg/kg of feed promoted the increase of the functional activity of the thymus that leveled the development of accidental involution and optimization of age involution.

Rescue of a duck circovirus from an infectious DNA clone in ducklings.

BackgroundDuck circovirus may predispose the host to immunosuppression and may serve as an immunological trigger for further complicated disease progression. Due to the lack of a cell culture system for propagating DuCV, little is known regarding the molecular biology and pathogenesis of DuCV. The aim of this study was to describe the construction and initial in vivo characterization of full-length DNA clones of DuCV (pIC-Mu2DuCV) and its infectivity under in vivo conditions.MethodThe constructed pIC-Mu2DuCV contained two copies of the whole DuCV genome and an introduced Xho I restriction enzyme site. Eighty-one 10-day-old conventional ducklings that were free of DuCV were randomly divided equally into three groups (1, 2 and 3). The ducklings in groups 1, 2 and 3 were inoculated intramuscularly with pIC-Mu2DuCV, wild-type virus GH01 and PBS, respectively. Subsequently, all of the ducklings were examined clinically, which were each given a physical condition score, and their rectal temperatures were taken daily during the experimental period. DuCV genomes in serum samples and in various tissues from all of the ducklings at 0, 1, 3, 5, 7, 10, 15, 21 and 28 DPC were detected by PCR and real-time quantitative PCR, respectively.ResultsThe average daily weight gain (ADWG) of group 3 was significantly higher than those of groups 1 and 2, and the temperature of all ducklings was stable between 41.7 °C and 42.2 °C. The clinical values (physical condition scores) of groups 1, 2 and 3 were 12.5, 15.6 and 0, respectively. In addition, viremia occurred at 15 and 10 days post-challenge (DPC) in groups 1 and 2, and antibodies could be detected in these ducklings at 21 and 15 DPC. Proliferation ability analysis showed that the viral titers of group 1 were lower than those of their parental viruses in group 2.ConclusionThis study shows that the rescued viruses are not significantly different but exhibit lower pathogenicity and proliferation ability compared with the parental virus. The results will facilitate future studies on DuCV pathogenesis and biology.

Comparative Efficacy of the Conventional and Experimentally Developed Duck Plague Vaccine

The comparative efficacy between the conventional vaccine (DLS-DPV) and experimentally prepared duck plague vaccine (BAU-DPV) was evaluated in seventy-five 35-day-old Zinding breed ducklings during the period from October/02 to March/03. The ducklings were equally divided into five groups (A, B, C, D and E). Ducklings of group A and B were primarily vaccinated with 0.5 ml and 1.0 ml of DLS-DPV respectively and those of group C and D were primarily vaccinated with 0.5 ml and 1.0 ml of BAU-DPV. The ducklings of group E were kept as unvaccinated control. Five months after primary vaccination all the ducks of vaccinated groups were boosted with 1.0 ml of DLS-DPV and BAU-DPV and 21 days after booster vaccination all the ducks of vaccinated and control groups were challenged with 1ml of 10 EID of virulent 4 50 field isolate of duck plague virus (DPV). The level of immunity developed in different vaccinated groups of ducks was measured by passive hemagglutination (PHA) test. The mean PHA titre of birds of group A, B, C and D after primary vaccination were 38.4 ± 6.4, 28.8 ± 3.2, 51.2 ± 7.84 and 38.4 ± 6.4 and after booster vaccination were 153.6 ± 25.6, 76.8 ± 12.8, 358.4 ± 62.71 and 115.2 ± 12.8 respectively. Results of PHA test indicated that experimentally prepared duck plague (BAU-DPV) vaccine revealed higher immune response compared to that of the conventional (DLS-DPV) vaccine and results of the challenge experiment indicated that the mean PHA titre over 100 after booster vaccination revealed 100% protection.

Auditory basis of maternal attachment in ducklings (Anas platyrhynchos) under simulated naturalistic imprinting conditions.

The presence of broodmates during the imprinting process results in peer imprinting that interrupts a visually mediated maternal attachment. We sought to determine the conditions in which group-trained mallard ducklings (Anas platyrhynchos) acquire a maternal attachment. At 48 hr of age, ducklings were allowed to follow a vocal, stuffed mallard hen individually or in groups of 4. Individual ducklings showed a preference for the silent, familiar mallard over an unfamiliar pintail. Ducklings trained in groups did not show a preference. When the mallard maternal call was present during testing, group-trained ducklings overwhelmingly responded to it regardless of whether it came from the familiar mallard or an unfamiliar pintail. Training ducklings in groups, which simulates the natural social context of imprinting, results in peer imprinting. Thus, early in development the young become visually imprinted to each other, and the maternal call mediates attachment to the mother.

Effect of dose and time of vaccination on immune response of duck plague vaccine in ducks

Effect of dose and time of vaccination on immune response of duck plague vaccine in 90 (45 of 18-day-old and 45 of 35-day-old) Jinding ducklings was studied during the period from October 2002 to March 2003. Each of both age group (18-day-old and 35-day-old) was divided into three groups as A, B, C and D, E, F respectively, consisting of 15 ducklings in each. Each duckling of groups A and B was primarily vaccinated with 0.25 ml and 0.5 ml of duck plague vaccine (LRI, Mohakhali) intramuscularly at 18 days old respectively and could not be boosted due to the death of all the ducklings of both groups within 20 days of primary vaccination. Each duckling of group D and E received 0.5 ml and 1.0 ml of duck plague vaccine (LRI, Mohakhali) intramuscularly at 35 days old respectively and ducks of both the groups boosted with 1.0 ml of vaccine 5 months after primary vaccination. Groups C and F served as unvaccinated control. 14 days after booster vaccination ducks of group D, E and F were challenged with the virulent field isolate of duck plague virus @ 1.0 ml / duck IM (104 EID50 / dose). The ducklings of group D that were vaccinated primarily at 35 days old with 0.5 ml and boosted after 5 months with 1.0 ml of duck plague vaccine had significantly (p< 0.01) higher PHA titres after 2 weeks of primary vaccination (38.4 ± 6.4), booster vaccination (153.6 ± 25.6) and challenge infection (281.6 ± 62.71) in comparison to control group (≤4, ≤4 and 20.0 ± 2.3 respectively) and all the ducks survived (100%) after challenge. The ducklings of group E that were vaccinated primarily at 35 days old and boosted after 5 months of primary vaccination with 1.0 ml of duck plague vaccine had also significantly (p< 0.01) higher PHA titres after two weeks of booster vaccination (76.8 ± 12.8) and challenge infection (153.6 ± 25.6) in comparison to control group, but only 8 (53.3%) ducks could protect the challenge infection with virulent duck plague virus. It may be concluded that ducklings below 30 days of age should not be vaccinated with duck plague vaccine. It also may be proposed that primary vaccination at 35 days old with duck plague vaccine (LRI, Mohakhali) @ 0.5 ml / duckling and booster vaccination after 5 months of primary vaccination @ 1.0 ml could be practiced for better immune response against duck plague.Key words: effect; dose; age; immune response; duck plague vaccine; ducksdoi: 10.3329/bjvm.v2i2.2542Bangl. J. Vet. Med. (2004). 2 (2): 117-119

Standardization of age and route for duck plague vaccine in local ducklings of vaccinated and non- vaccinated parent origin

The study was carried out to determine the appropriate age and route of vaccination with duck plague vaccine (LRI, Mohakhali) in experimentally reared local ducks during the period from September 2006 to May 2007. A total of 90 local ducklings were divided into eight groups namely A, C, D and E for vaccinated parent origin and B, F, G and H for non-vaccinated parent origin. Again Group C, D, E, F, G and H were divided into subgroups C1 & C2; D­1& D­2; E1& E2; F1 & F2; G1 & G2; H1 & H2 respectively and contained 5 ducklings each. Group A and B contained 15 ducklings in each group and were used as unvaccinated control and also for studying persistence of maternally derived antibody level. Highest mean MDA titre in ducklings of Group A was found 53.33 ± 4.03 at the age of day 1 that declined to a negligible level (≤4) at the age of day 21 and highest mean MDA titre in ducklings of Group B was found 29.86 ± 1.45 at the age of day 1 that declined to a negligible level (≤4) at the age of day 16. Ducklings of different sub-groups were vaccinated with duck plague vaccine at day 14, day 21 and day 28 through intramuscular (breast) and subcutaneous route at the dose rate of 1ml per duckling. Sera were collected from vaccinated ducklings on day 7, day 14 and day 21 after vaccination and antibody titre was measured by passive hemagglutination test. Among the vaccinated subgroups, the highest mean PHA titre was found 89.60 ± 15.67 and 83.20 ± 19.20 in subgroups E1 (vaccinated at day 28) and F1 (vaccinated at day 14) respectively. At challenge, ducklings of vaccinated subgroups showed 100% protection except C1 and C2 (showed 80% protection) and control subgroups showed 0% protection. From the results of protection test it may be concluded that both intramuscular (breast) and subcutaneous routes are equally suitable for duck plague virus vaccination in ducklings and the optimum age for vaccination to ducklings originated from vaccinated parent to duck plague vaccine might be at day 21 or 28 and ducklings originated from non-vaccinated parent at day 14 or 21 instead of usual schedule of day 28. Key words: Vaccination, duck plague vaccine, age, route, ducklings DOI = 10.3329/bjvm.v6i1.1335 Bangl. J. Vet. Med. 2008. 6 (1): 27-30