Objectives: Avian lymphatic system plays a very significant role in immunity as well as disease control. This research aimed to investigate the histomorphological changes and involution of the thymus of Sonali chicken at different post-natal stages in Bangladesh as the age-related changes of the thymus of Sonali chicken were not described before. Materials and methods: A gross and microscopic investigation was performed on the thymus of 25 healthy Sonali chickens representing different stages of post-natal life: days 1, 14, 28, 42, and 56. Experimental chickens were sacrificed by cervical subluxation, and the thymus was collected and subjected for both the gross and histological studies. The histological changes were examined with light microscopy after H&E staining. Results: The thymus was located in close association of the jugular vein, having a long chain of thy¬mic lobes, 58 lobes on each side. The statistically significant age-related changes were observed (p < 0.05). All gross parameters (weight, length, width, and thickness) found to be increased up to day 42. On day 56, the growth was found to decline from the previous groups. The microscopic observations revealed the same pattern of changes such as gross parameters, i.e., continuously increased till day 42 and then declined (p < 0.05). At day 56, the involutory signs such as partial loss of interlobular septa and accumulation of adipose tissue in connective tissue septa were found. Conclusion: It is well known that in chicken, after a certain period, the thymus got involuted. In Sonali chicken of Bangladesh, the age of involution was notified at day 56/8th week of the post-natal stage, which was correlated both in macro- and microscopic observations. [J Adv Vet Anim Res 2020; 7(2.000): 324-330]

Objectives: Avian lymphatic system plays a very significant role in immunity as well as disease control. This research aimed to investigate the histomorphological changes and involution of the thymus of Sonali chicken at different post-natal stages in Bangladesh as the age-related changes of the thymus of Sonali chicken were not described before. Materials and methods: A gross and microscopic investigation was performed on the thymus of 25 healthy Sonali chickens representing different stages of post-natal life: days 1, 14, 28, 42, and 56. Experimental chickens were sacrificed by cervical subluxation, and the thymus was collected and subjected for both the gross and histological studies. The histological changes were examined with light microscopy after H&E staining. Results: The thymus was located in close association of the jugular vein, having a long chain of thy­mic lobes, 5–8 lobes on each side. The statistically significant age-related changes were observed (p < 0.05). All gross parameters (weight, length, width, and thickness) found to be increased up to day 42. On day 56, the growth was found to decline from the previous groups. The microscopic observations revealed the same pattern of changes such as gross parameters, i.e., continuously increased till day 42 and then declined (p < 0.05). At day 56, the involutory signs such as partial loss of interlobular septa and accumulation of adipose tissue in connective tissue septa were found. Conclusion: It is well known that in chicken, after a certain period, the thymus got involuted. In Sonali chicken of Bangladesh, the age of involution was notified at day 56/8th week of the post-natal stage, which was correlated both in macro- and microscopic observations. Adv. Vet. Anim. Res., 7(2): 324-330, June 2020

Objective: This study aims for molecular identification of naturally growing Bacillus cereus strain from a unique source, able to survive, and alleviate heavy metals from the nature. Materials and Methods: Pure isolate from Murrah buffalo milk was prepared in B. cereus selec¬tive Polymyxin pyruvate egg-yolk mannitolbromothymol blue agar (PEMBA) medium through a cascade of contamination free subcultures. The morphological and biochemical tests were done prior to 16S rRNA gene sequencing for strain identification and further physiological tests. The test strain was inoculated in both solid and suspension culture medium supplemented individually with Cd, Cu, Ag, and Zn to reveal the qualitative and quantitative heavy metal tolerance proper¬ties, respectively. Finally, the data collected from the in vitro assessment was statistically analyzed Results: Molecular analysis revealed that the test strain was B. cereus BF2, which was motile, catalase positive and Gram positive rod. B. cereus BF2 was found significant at 0.3% bile salt toler¬ance [two-way analysis of variance (ANOVA)p value is < 0.0001] where, t-test p value is < 0.0002 between Control Group (CG) and TGR-1; p < 0.037 between TGR-1 and 2; p < 0.0014 between CG and TGR-2. Similarly, B. cereus BF2 was significant in pH tolerant up to 8.0 with p < 0.0115 (in scale p < 0.05). The heavy metal tolerance test revealed that the test metals could not stop the growth of B. cereus BF2 even after 24 h of incubation but partially suppressed the growth kinetics for let¬ting into stationary phase. Among the four heavy metals, Cd and Zn showed partial antagonism to the growth of B. cereus BF2. The survivability was highly significant in the medium supplemented with Zn (p < 0.0001) and Ag (p < 0.018). Conclusion: Bacillus cereus BF2 can survive in selective heavy metals with metal resistance and biodegradation capacity. [J Adv Vet Anim Res 2020; 7(1.000): 62-68]

Objective: This study aims for molecular identification of naturally growing Bacillus cereus strain from a unique source, able to survive, and alleviate heavy metals from the nature. Materials and Methods: Pure isolate from Murrah buffalo milk was prepared in B. cereus selective Polymyxin pyruvate egg-yolk mannitol–bromothymol blue agar (PEMBA) medium through a cascade of contamination free subcultures. The morphological and biochemical tests were done prior to 16S rRNA gene sequencing for strain identification and further physiological tests. The test strain was inoculated in both solid and suspension culture medium supplemented individually with Cd, Cu, Ag, and Zn to reveal the qualitative and quantitative heavy metal tolerance properties, respectively. Finally, the data collected from the in vitro assessment was statistically analyzed Results: Molecular analysis revealed that the test strain was B. cereus BF2, which was motile, catalase positive and Gram positive rod. B. cereus BF2 was found significant at 0.3% bile salt tolerance [two-way analysis of variance (ANOVA)—p value is < 0.0001] where, t-test p value is < 0.0002 between Control Group (CG) and TGR-1; p < 0.037 between TGR-1 and 2; p < 0.0014 between CG and TGR-2. Similarly, B. cereus BF2 was significant in pH tolerant up to 8.0 with p < 0.0115 (in scale p < 0.05). The heavy metal tolerance test revealed that the test metals could not stop the growth of B. cereus BF2 even after 24 h of incubation but partially suppressed the growth kinetics for letting into stationary phase. Among the four heavy metals, Cd and Zn showed partial antagonism to the growth of B. cereus BF2. The survivability was highly significant in the medium supplemented with Zn (p < 0.0001) and Ag (p < 0.018). Conclusion: Bacillus cereus BF2 can survive in selective heavy metals with metal resistance and biodegradation capacity. J. Adv. Vet. Anim. Res., 7(1): 62-68, March 2020

Objective: This experiment was conducted to assess the effects of the housing system on the welfare and growth performance of the Muscovy duck. Materials and methods: A total number of 48 Muscovy duck aged 3-week old were divided ran¬domly into two groups (24 duck on each): deep litter system and cage system. Each group was subdivided into three replicates (8 birds on each) were identified with wing rings. Results: The study showed that feeding and drinking behaviors significantly increased (p < 0.05) in duck reared at the cage system. While there was no noticeable effect on lying and feather peck¬ing, duck raised in the deep litter had better growth performance with a substantial difference, which achieve a higher feed conversion rate with lower feed efficiency. Physical conditions were significantly better at cage management. The level of stress indicating hormones indicating free Thyroxin was increased with the cage. Therefore, the litter system improves duck welfare and their performance. Conclusion: It is concluded that the duck managed under the litter system has more opportunities that facilitate the expression of more natural behavior, and thus improve their health and perfor¬mance, as a result of improved feed conversion rate and feed efficiency. [J Adv Vet Anim Res 2020; 7(3.000): 407-413]

Objective: This experiment was conducted to assess the effects of the housing system on the welfare and growth performance of the Muscovy duck.  Materials and methods: A total number of 48 Muscovy duck aged 3-week old were divided ran­domly into two groups (24 duck on each): deep litter system and cage system. Each group was subdivided into three replicates (8 birds on each) were identified with wing rings.  Results: The study showed that feeding and drinking behaviors significantly increased (p < 0.05) in duck reared at the cage system. While there was no noticeable effect on lying and feather peck­ing, duck raised in the deep litter had better growth performance with a substantial difference, which achieve a higher feed conversion rate with lower feed efficiency. Physical conditions were significantly better at cage management. The level of stress indicating hormones indicating free Thyroxin was increased with the cage. Therefore, the litter system improves duck welfare and their performance.  Conclusion: It is concluded that the duck managed under the litter system has more opportunities that facilitate the expression of more natural behavior, and thus improve their health and perfor­mance, as a result of improved feed conversion rate and feed efficiency. J. Adv. Vet. Anim. Res., 7(3): 407-413, Sep 2020 http://doi.org/10.5455/javar.2020.g435

Objective: The present study aimed to assess for the first time, in Medina, the prevalence of Mycobacterium avium subsp. paratuberculosis in ruminants due to its potential zoonotic importance. Materials and methods: A total of 823 sera samples and 364 milk samples were used to deter¬mine the incidence of Mycobacterium avium subsp. Paratuberculosis (MAP) using the indirect Enzyme-Linked Immunosorbent Assay. Results: The seroprevalence of MAP was 11.1% in sheep and 13.8% in goats, while no infection was recorded among camels. MAP infection was not influenced by the animals gender, but it was influenced by its locality since the infection rate in local animals was higher than that in imported ones with a significant correlation (p < 0.05). MAP infection had a significant correlation (p < 0.05) with 2 years aged animals. On the other hand, the detection of MAP in milk revealed that 17 (13.8%) goats and 12 (4.9%) sheep were infected. The prevalence of MAP in milk samples was not influenced by either the animals age or locality. Conclusion: Sheep and goats may act as a reservoir for MAP to the Medina community. Since Medina is an active area of mass gatherings as a destination for pilgrims throughout the year, therefore, necessary control measures should be implemented to lower the economic losses, zoonotic infections, and the possibility of a global epidemic. [J Adv Vet Anim Res 2020; 7(1.000): 69-76]

Objective: The present study aimed to assess for the first time, in Medina, the prevalence of Mycobacterium avium subsp. paratuberculosis in ruminants due to its potential zoonotic importance. Materials and methods: A total of 823 sera samples and 364 milk samples were used to deter­mine the incidence of Mycobacterium avium subsp. Paratuberculosis (MAP) using the indirect Enzyme-Linked Immunosorbent Assay. Results: The seroprevalence of MAP was 11.1% in sheep and 13.8% in goats, while no infection was recorded among camels. MAP infection was not influenced by the animal’s gender, but it was influenced by its locality since the infection rate in local animals was higher than that in imported ones with a significant correlation (p < 0.05). MAP infection had a significant correlation (p < 0.05) with 2 years aged animals. On the other hand, the detection of MAP in milk revealed that 17 (13.8%) goats and 12 (4.9%) sheep were infected. The prevalence of MAP in milk samples was not influenced by either the animal’s age or locality. Conclusion: Sheep and goats may act as a reservoir for MAP to the Medina community. Since Medina is an active area of mass gatherings as a destination for pilgrims throughout the year, therefore, necessary control measures should be implemented to lower the economic losses, zoonotic infections, and the possibility of a global epidemic. J. Adv. Vet. Anim. Res., 7(1): 69-76, March 2020