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Present study predicted 6th week body weight of Caribro-Dhanraja broilers (n=75) with different plumage colour through backward elimination regression from 2nd week growth traits (weight, weight gain, chick length, weight: length2 , shank length, toe length, breast length, breast girth, thigh length and wing length).
Int.J.Curr.Microbiol.App.Sci (2018) 7(9): 1147-1155 International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume Number 09 (2018) Journal homepage: http://www.ijcmas.com Original Research Article https://doi.org/10.20546/ijcmas.2018.709.136 Prediction of Market Weight in Caribro-Dhanraja Broilers with Different Plumage Colour Using Growth Traits T.K Patbandha1*, D.D Garg1, D.G Vaghamashi1, S Marandi1, K Ravikala1, S.S Patil2 and S.K Dash3 College of Veterinary Science and A.H., Junagadh Agricultural University, Junagadh-362001, Gujarat, India College of Veterinary Science and A.H., SDAU, Sardarkrushi nagar -385506, Gujarat, India College of Veterinary Science, GADVASU, Ludhiana-141004, Punjab, India *Corresponding author ABSTRACT Keywords Caribro-Dhanraja, Coloured broiler, Growth traits Article Info Accepted: 08 August 2018 Available Online: 10 September 2018 Present study predicted 6th week body weight of Caribro-Dhanraja broilers (n=75) with different plumage colour through backward elimination regression from nd week growth traits (weight, weight gain, chick length, weight: length2, shank length, toe length, breast length, breast girth, thigh length and wing length) Day old chicks were grouped into yellow, black and stripped colour groups based on plumage colour (25 chicks in each group) and traits were measured biweekly upto th week Plumage colour significantly influenced shank, toe and thigh length, and breast girth at nd week; whereas, wing length at 4th week (P0.05) In yellow plumage group, weight, daily gain, weight: length 2, shank, breast and thigh length at 2nd week were positively associated with 6th week body weight (P0.05) In black plumage group, weight, daily gain and weight: length2 of 2nd week were positively association with 6th week body weight, but thigh length was negatively associated (P0.05) Weight, daily gain and weight: length2 at 2nd week were positively associated with 6th week body weight in stripped plumage group (P0.05) Backward elimination regression model for prediction of th week body weight from 2nd week variables revealed higher R2 value (59.6%) in black plumage (predictor variables were weight, breast girth and thigh length) However, R2 value was 36% for stripped colour (predictor variables were weight and breast girth), 25.3% for yellow plumage (predictor variable was wing length) and 41% for pooled data (predictor variables were growth and breast girth) The results indicated lower accuracy for prediction of th week body weight based on variables from 2nd week Introduction Poultry meat is well accepted by people of all religions throughout the world In the present scenario, poultry meat production of the world is dominated by white-feathered broilers because of their fast growth rate along with better feed efficiency (Yang and Jiang, 2005) Slow growing coloured broilers have great consumers‟ demand owing to better quality meat in terms of appearance, less fat and taste as well as better performance in tropical 1147 Int.J.Curr.Microbiol.App.Sci (2018) 7(9): 1147-1155 climate than fast growing white feathered broilers (Yang and Jiang, 2005, Padhi, 2016) Further, coloured chickens fetch more price than the white feathered fast growing broilers (Bett et al., 2011) Identification of broilers with better growth potential at an early age is most essential for better economic return as inferior birds can be culled early Chick quality traits, particularly weight of chick has been commonly used to assess growth performance at later age, but such effect is inconsistent and diminished well in advance before the market age (Jiang et al., 2007; Molenaar et al., 2008; Patbandha et al., 2017) Moreover, others reported positive effect of body linear traits like chick body length on growth performance up to market age (Molenaar et al., 2008; Mukhtar et al., 2013; Patbandha et al., 2017) Association of shank and toe length at early age with future growth performance was observed to be inconsistent up to market age in different studies (Wolanski et al., 2006; Willemsen et al., 2008; Patbandha et al., 2017) However, information regarding association of traits like daily gain, body mass index (weight: length2), toe length, breast length, breast girth, thigh length and wing length with market weight is scanty Further, significant effect of plumage colour on growth traits of chicks within a particular strain has been well established (Azahan, 1994; Rizzi et al., 2013; Rizzi, 2017) Additionally, variable selection for regression model using backward elimination (where initially model includes all variables and later deleted one by one based on F-statistics) has been reported to be best among the all stepwise procedures (Sauerbrei et al., 2007) Hence, the present study was designed to predict the market weight of Caribro-Dhanraja broiler chicken with different plumage colour using backward elimination regression model of different early growth traits Materials and Methods Experimental management birds and general The experiment was conducted on CaribroDhanraja coloured broiler strain during June to August, 2017 at Instructional Livestock Farm Complex, Junagadh Agricultural University, Junagadh (Gujarat) Junagadh is located with a latitude of 21o 31‟ N and an altitude of 70o 36‟ E under South Saurashtra Agroclimatic zone Day old, physically healthy straight run chicks (n=75 with 25 chicks from each yellow, black and stripped colour) were included for this study The chicks were numbered individually using wing band at the start of the experiment The chicks were reared under deep litter system of housing with uniform managemental conditions as per the farm standards Lighting facilities were switched on before few hours of arrival of chicks to provide the required temperature for brooding and provided continuously during the study period for 24 hours Experimental birds were vaccinated for poultry diseases (Marek‟s disease and New castle disease) as per the guidelines for commercial broilers Birds were provided with commercial starter mash (23% CP and 2800 Kcal ME per kg) and finisher mash (20% CP and 2900 Kcal ME per kg diets) with ad libitum access to feed and water Measurement of growth traits Growth traits of individual birds such as body weight, length of chick, shank, toe, breast, thigh, wing and girth of breast were measured at weeks interval up to weeks All the traits were measured during morning before feeding and watering Daily gain and body mass index (weight: length2) were calculated Chick length was defined as length from tip of beak to length of longest toe excluding its nail and measured by keeping the chick on a 1148 Int.J.Curr.Microbiol.App.Sci (2018) 7(9): 1147-1155 platform on its ventral aspect in such a position by extending neck and toe to their maximum extent gently Length from hock joint to bottom of foot pad was considered as shank length; whereas, length of longest toe upto insertion of nail was defined as toe length Breast length and girth were defined as length between both vertices of the sternum and circumference of the breast region, respectively Wing length was measured from scapula joints to the last digit of the wing and thigh length was measured from shinbonefemur joint to shinbone-tarsus joint Statistical analysis The data of growth traits were collected and presented as mean with standard error estimates The growth traits of broilers among the different plumage groups were compared by one-way analysis of variance and Duncan‟s multiple range tests was used as post hoc test to compare the pair wise mean differences Correlation of different growth traits at 2nd, 4th and 6th week with body weight at 6th week was estimated by Pearson correlation Backward elimination regression model (Chatterjee et al., 2000) was used for prediction of 6th week body weight from variables recorded at 2nd week of age The variables were removed one by one from the model when probability of „F‟ > 0.1 The statistical analysis was carried out using SPSS software package (Version 16.0, USA) and considered as significant when „P‟ 0.05 Results and Discussion Growth traits Body weight and conformation traits of coloured broiler chicken are presented in table The body weight of coloured broilers was observed to be 1717.75g at 6th week with feed conversion ratio (0-6 weeks) of 2.16 Plumage colour did not affect body weight, daily body gain, chick length, weight: length2 and breast length of broilers during the study period There was significant effect of plumage colour on shank length (P