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Subject: Livestock Production and Management × Author: CHINNI PREETAM, VELUPULA × End date: 2019 × Start date: 2000 × Thesis Type: Ph.D ×
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    PRODUCTION PERFORMANCE AND IMMUNOCOMPETENCE OF COLOUR LAYER BIRDS WITH 25% NATIVE INHERITANCE UNDER BACKYARD AND DIFFERENT SYSTEMS OF MANAGEMENT
    (SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502. (A.P.) INDIA, 2008-11) CHINNI PREETAM, VELUPULA; QUDRATULLAH, S(MAJOR); RAVINDER REDDY, V; RAJASHEKHAR REDDY, A; RAMAKOTI REDDY, M; NAGALAKSHMI, D
    ABSTRACT: A study was conducted to evaluate the growth and production performance, economics of rearing and immune competence of 4-breed backcross layer type coloured female birds with 25% native inheritance, developed at Sri Venkateswara Veterinary University. Five hundred day-old chicks were reared up to 6 weeks of age under intensive system at the Department of Poultry Science, College of Veterinary Science, Rajendranagar, Hyderabad and the data on parameters of economic importance like body weight, feed consumption, FCR, livability and carcass yields, besides immunological parameters were collected. At 7 weeks of age, four hundred female birds were selected and distributed into 5 treatment groups having 4 replicates of 20 birds each with similar body weights. The first group was fed grower mash ad lib. and reared under intensive system to serve as control (T1), while T2 and T3 groups were offered 20 and 40% of ad lib. feed, respectively and maintained under semi intensive system. The remaining two treatment groups were reared under extensive system (scavenging), T4 at farm and T5 in an adopted village of the Krishi Vigana Kendra (KVK), Central Research Institute on Dryland Agriculture (CRIDA), Hyderabad. All parameters of economic importance during grower and layer phases were studied. Males were introduced at 40 weeks of age to study the treatments effect on fertility and hatchability. Economics were worked out for the cost of rearing the test birds up to pullet age and to determine profits during laying phase from 20 – 60 weeks of age. Another experiment was conducted separately to evaluate the immune competence of 4-breed backcross layer bird together with the parent stocks involved in its genesis. The results of chick phase indicated that the mean 6-week body weight of 4-breed backcross layer type birds with 25% native inheritance was 266.9 g, while cumulative feed intake was 863.7 g with an FCR of 3.33. The mean livability was 99.6 %. The dressed, eviscerated and ready to cook yields were 80.2, 68.7 and 67.7%, respectively. During growth phase (7-20 weeks of age), ad lib. fed birds (control) recorded significantly (P < 0.05) the highest body weight (1361.6 g) than 40% ad lib fed birds (1083.7 g), while significantly the least weight was recorded in rest of the treatments, 938.28 g in 20% ad lib group, and 901.6 & 866.6 g under scavenging on farm and in farmers back yard, respectively. The feed intake was significantly (P<0.05) the highest in control (94.0 g) followed by 40% and 20% ad lib groups (21.9 and 35.2 g/bird/d, respectively) with the corresponding FCR of 3.32 and 4.28. The livability was 93.8, 87.5 and 90% in control, 20 and 40% ad lib. groups, respectively. The age at first egg (AFE) was significantly (P< 0.05) better with ad lib. fed group (146.5 d) followed by scavenging groups (176.4 and 171.5 d in T4 and T5, respectively) and 40 and 20% ad lib. groups (188 and 184.5 d, respectively), all values being significantly (P< 0.05) inferior to control. Thus AFE increased with decreasing feed intake and was better under intensive system than semi intensive or scavenger system. Similar trend was observed for age at 50% production. The mean percent hen day production over 10 laying periods of 28 d each differed significantly (P<0.05) from each other, with the best being recorded in ad lib. group (54.1%) and the least in 20 and 40% ad lib groups. Scavenging in farmers’ backyard gave 35.8% hen day production, whereas at farm it was 32.5%. The mean feed intake was significantly higher in ad lib group (94.0 g/b/d) followed by 40% ad lib (45.5 g/b/d) and 70% ad lib (26.7 g/b/d) groups, all values being significantly different from each other. The FCR was significantly better (2.14 and 2.29) with ad lib and 20% ad lib feeding than 40% ad lib feeding (3.09). The mean egg weights ranged between 50.4 and 53.9 g. The egg quality parameters like Haugh Unit score, albumen Index, shell percent and shell thickness were significantly (P < 0.05) influenced by treatment groups, but did not show any specific trend. Yolk index was not influenced, while yolk colour was significantly (P< 0.05) better under both the scavenging systems. Overall livability was significantly better with intensive system (**) and least with scavenging system, especially at farmers backyard, where half of the mortality was due to predators. Fertility ranged between 88.4 and 94.9 %, while the hatchability ranged between 80.9 and 88.9% and 90. 9 and 93.8 % for total eggs set and fertile eggs set, respectively. At 8 weeks of age, humoral immune response to SRBC and ND vaccine were 8.3 and 6.8 log2 titers, respectively, while CMI response to PHA-P was 0.46. During 20 weeks of age, significant differences (P>0.05) were observed in treatment groups for immune response to ND vaccine, which was high to medium (10.1 to 9.3) in all groups maintained at farm, the highest being in control group (10.1) and the values for scavenging at farmers backyard were constantly low at 20 weeks (8.1) and 40 weeks (6.1) of age, but were above protective levels. There were no significant differences in SRBC titers at 20 and 40 weeks of age and CMI response to PHA-P indicating system of management did not effect the immune response to SRBC and PHA-P. The results of the immunity trial on back cross and its parent stock indicated that the immune response to SRBC, PHA-P and ND vaccine were high in NDN bird, whereas the immunity of 4-breed back cross was comparable with all other genotypes. The mass of spleen and bursa was directly proportional to immune competence in chickens. Significant differences were observed in lymphoid organ weight. The relative spleen weight of 4-breed back cross was similar to that of all other genotypes, except DR and 2-breed cross. The relative weight of bursa in 4-breed back cross bird was similar to that of WLH, DR, 3BC and 4BC. (INDICATE THE FULL FORM OF THESE GENOTYPES) MENTION ECONOMICS ALSO