Kamdev Sethy

Cognitive performance for 2 strains of broiler birds in homogenous and mixed grouping system

ABSTRACT Sixty‐day‐old chicks from the commercial broiler strain, Vencobb, and 60‐day‐old backyard Vanaraja chickens, were selected as experimental birds for assessing learning and cognitive performance. Learning and cognitive ability were assessed on the basis of maze trial performance, self‐recognition trial (SRT), detour trial (DT), tonic immobility (TI) trial, serum leptin concentration, and encephalization quotient (EQ). The mazes were prepared by using locally available cardboard, papers, and bamboo strips. Three maze trials—T maze trial, Y maze trial, and radial maze trial—were performed. Birds were trained from the second to 10th day for maze tests. The maze test schedules started from 11th day, and data were taken 11th‐17th day, 25th‐31st day, and 39th‐45th day in trial I, trial II, and trial III schedules, respectively. The response of birds to different maze tests and performance in different cognitive trials were assessed on the basis of latency in time to acquire the food and complete the tasks. At the end of the trials, serum leptin concentration was assayed. EQ was calculated by Jerisons formula and Cuviers formula. Vencobb birds showed a better response to different cognitive and learning trials. In T maze trials, the Vencobb variety performed significantly better (P < 0.05) than Vanaraja birds (trial I, P = 0.001; trial II, P = 0.001; and trial III, P = 0.01). Vencobb birds, when housed in group with Vanaraja birds, performed significantly (P < 0.05) worse in trial I (P = 0.012), trial II (P = 0.020), and trial III (P = 0.045). In the Y maze trial, homogeneously housed Vencobb birds performed significantly better (P < 0.05) than did Vanaraja birds (trial I, P = 0.04; trial II, P = 0.01). Vanaraja birds performed significantly (P < 0.05) better when they were homogeneously housed than mixed housed (trial I, P = 0.10; trial II, P = 0.001; and trial III, P = 0.008). There was significant improvement (P < 0.05) in the performance of Vencobb birds with advancement of age from trial I to trial II in all cases (homogenous group, P = 0.012; mixed group, P = 0.010). Similarly, significant (P < 0.05) improvement in performance was observed in homogeneously housed Vanaraja birds (trial I‐II, P = 0.012; trial II‐III, P = 0.040) and mixed housed Vanaraja birds (trial I‐II, P = 0.042; trial II‐III, P = 0.021). In the case of the R maze trial, Vencobb birds (homogenous) performed significantly (P < 0.05) better as compared with Vanaraja birds (homogenous) in all 3 trials (trial I, P = 0.01; trial II, P = 0.001; and trial III, P = 0.03). In homogeneous housing system, the performance of Vencobb birds was significantly better (P < 0.05) than Vanaraja birds in SRT (trial I, P = 0.01; trial II, P = 0.001; and trial III, P = 0.001), whereas Vanaraja birds performed significantly better (P < 0.05) than Vencobb birds in the DT (trial I, P = 0.05; trial II, P = 0.05; and trial III, P = 0.07) and TI trial (trial I, P = 0.02; trial II, P = 0.05; and trial III, P = 0.04). In the SRT test, Vanaraja birds performed significantly better (P < 0.05) in mixed housing than in homogeneous groups (trial II, P = 0.01; trial III, P = 0.01). Vencobb birds showed a significant improvement (P < 0.05) from trial I to trial II in homogeneous and mixed housing (P = 0.04 and P = 0.02). In mixed housing, significant improvement (P < 0.05) in the performance of Vanaraja birds was seen from trial I to trial II (P = 0.001). In DT, homogeneous Vencobb birds (trial I) performed significantly worse (P < 0.05) as compared with mixed grouped birds (P = 0.05). In case of Vanaraja birds, mixed housed birds showed significantly (P < 0.05) better performance than did homogeneous birds (P = 0.001) in trial I. In the TI trial, there was significant improvement (P < 0.05) in the performance from trial I to trial II in homogeneous Vencobb (P = 0.04) and mixed Vanaraja birds (P = 0.05). The EQ maximum was 2.31 in intelligent or superior birds and 1.85 in dull birds. The cognitively superior Vencobb birds showed a significantly higher level of serum leptin concentration than did the dull birds (0.78 ± 0.12 vs. 0.42 ± 0.08 ng/mL, P = 0.02), a result similar to that in Vanaraja birds (1.03 ± 0.13 vs. 0.62 ± 0.06 ng/mL, P = 0.01). It may be concluded that the genetics of the birds affects cognitive and learning ability. Mixed group housing negatively affects the cognitive abilities of birds. Jerisons formula is more highly correlated with brain weight than the traditional Cuviers equation. With the advancement of age, spatial memory involved in gathering and processing improves.

Sex-related differences in hemato-biochemical indices of adult Vanaraja chickens during summer and winter seasons

Aim: The objective of this study was to evaluate the changes in hemato-biochemical indices in male and female Vanaraja chickens under tropical environment during summer and winter season. Materials and Methods: A total of 120 day-old sexed Vanaraja chicks were selected as experimental chickens and distributed equally in two groups having 60 female and 60 male chickens in each group, respectively. The experiment was continued for 8 weeks (56 days) and both male and female chickens were slaughtered by cervical dislocation method. All parameters were estimated at the end of the experiment in both seasons. Results: Male had higher blood glucose, Ca and P level. Blood glucose level significantly (p<0.05) reduced in summer. Female had higher total protein, albumin, globulin, and albumin/globulin ratio. Alanine aminotransferase and aspartate aminotransferase enzyme concentration were significantly (p<0.05) higher in summer. Total erythrocyte count, total leukocyte count, hemoglobin (Hb), Hb/lymphocyte ratio, and packed cell volume were significantly (p<0.05) higher in males. Mean corpuscular volume and mean corpuscular Hb were significantly (p<0.05) higher in females. Conclusion: Sex of chickens had a significant (p<0.05) effect on different parameters whereas season had nonsignificant (p>0.05) effect in most of the observed parameters. Hence, Vanaraja chickens are adaptable to local tropical climate and can be reared efficiently as backyard poultry.

Studies of the macroscopic and microscopic morphology (hippocampus) of brain in Vencobb broiler

Aim: The aim of this study was to study the anatomy of different parts of brain and histology of hippocampus of Vencobb broiler chicken. Materials and Methods: A 12 adult experimental birds were sacrificed by cervical dislocation. After separation of the brain, gross anatomy features were studied. Brain tissue was fixed in 10% buffered neutral formalin for 2-3 days, and then routine dehydration process in ascending grades of ethyl alcohol was done. After xylene cleaning, paraffin impregnation was prepared. Paraffin blocks were cut, and slides were stained by Harris hematoxylin and eosin. Photography was carried out both under lower (×10) and higher (×40) magnifications. Results: The brain structure (dorsal view) of Vencobb bird resembled the outline of a playing card symbol of a “spade.” The brain subdivisions are cerebrum, cerebellum, and medulla oblongata. Cerebrum was devoid of usual convolutions (elevations), gyri, depressions (grooves), and sulci. The cerebral hemispheres were tightly apposed along a median sulcus called interhemispheric fissure and cerebrum and cerebellum were separated by a small transverse fissure. The olfactory bulb was small structures, and the pineal body was clearly visible. The optic lobes were partially hidden under cerebral hemispheres, but laterally, it was large, prominent rounded or spherical bodies of the midbrain. The hippocampal area appeared as dorso-medial protrusion. Different types of neurons were distinguished in the hippocampus were pyramidal neurons, pyramidal-like neurons, and multipolar neurons, etc. There was rich vascularization in the form of blood capillaries throughout the hippocampus. Conclusion: Cerebrum was pear shaped and largest part of the brain. Cerebrum hemisphere was smooth devoid of convolutions, gyri, and depressions, but in the surface of cerebellum, there was the presence of a number of transverse depression (grooves) and sulci subdividing into many folds. Olfactory bulb was poorly developed, whereas optic lobes were rounded and large. The exact boundary line of the hippocampus was not discernable. In hippocampus histology, two categories of neuron local circuit neurons and projection neurons, high vascularization and epididymal lining of lateral ventricle were observed. Hippocampal neurons were comparatively larger without any distinct layers. The afferent neurons projected to the medium septum.