| Dissertation note |
To study the effect of different levels of Canola meal on the performance of broiler chicks, an experiment containing 240, day-old broiler chicks was conducted. The chicks were divided into 6 main groups, having 40 chicks each and were further divided in four subgroups of 10 birds each. Each sub-group was reared separately in cages, 6 experimental rations with varying levels of Canola meal having CP 21% and 19% and ME 3000 and 3100 Kcal/kg for starter and finisher respectively were provided to the birds -libitum upto six weeks. Canola meal was added in the rations at 25., 22.5, 20, 15, 10 and 0 percent levels with soybean meal. These rations were designated as A, B, C, D, E and F. Starter rations were fed to the birds for 4 weeks and finisher rations for last 2 weeks of the study. Average live weight gain per chick fed rations A, B, C, D, E and F were 1568, 1685, 1633, 1572 and 1677 grams, respectively. There was a significant (P <0.05) difference among the different levels of canola meal. Maximum weight gain was observed in group "B" fed canola meal 22.5% level. Average feed consumption on rations A, B, C, D, E and F were 3248, 3175, 3153, 3157, 3103 and 2935 grams, respectively. A significant (P<0.05) difference was observed among different groups regarding feeding consumption. In case of feed efficiency a non significant difference was observed. The average dressing percentage were 64.41, 64.00, 63.00, 61.75, 62.5, 63.52 percent for rations A, B, C, D, E and F, respectively. A non significant difference was observed regarding dressing percentage. The average heart weight of chicks fed rations A, B, C, D, E and F showed a non significant difference. Flowever, a significant difference was observed in case of gizzard weight. A decrease in gizzard weight with increasing levels of canola meal was observed. Likewise spleen and pancreas weight also showed a non significant (P<0.05) difference among the treatments. However, the liver and thyroid weights of chicks fed rations A, B, C, D, E and F showed a significant (P <0.05) different among the treatments. There was a proportionate increase in the liver weight with increasing levels of canola meal. Increased liver weight in high canola meal based rations may be due to hydrolytic products of glucosinolates which are hepatoxic in nature and cause hyperplasia of liver. Increased thyroid weight is attributed to goitrogenic effect of ailyl-isothiocynates causing thyroid hypertrophy.
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