Effect of different levels of fishmeal in the diet on carcass quality of cockerels
SHIV SHANKAR KUMAR, A. PRASAD AND CHANDRAMONI
Department of Animal Nutrition,
BiharVeterinaryCollege, Patna - 14
Carcass quality of cockerels was evaluated after feeding a combination of five vegetable protein sources (soybean meal, mustard oil cake, groundnut cake, sesame cake, and guar meal in the ratio of 4:1:1:1:1) replacing or reducing the levels of fishmeal in the ration. Six dietary treatments were employed in which one served as control with fishmeal 10%. Other five test diets replaced fishmeal of control ration to the extent of 20, 40, 60, 80 and 100%. After feeding for 8 weeks, the birds were slaughtered to evaluate the carcass quality. The dressing percentage and eviscerated percentage of cockerels receiving diet of 20% replacement of fishmeal by prepared vegetable protein mixture were significantly higher than other groups. However, dressing percentage and eviscerated percentage of birds fed up to 80% replacement of fishmeal did not differ significantly from control group. Similar trend was observed in meat to bone ratio.
Chicks fed all vegetable protein diet (100% replacement group) had significantly higher percentage of moisture in thigh and breast muscle in comparison to control and other experimental groups. Significantly lower moisture percent in thigh and breast muscle was observed in 20% replacement group, which was probably due to accrual of more protein in muscle tissues. An inverse relationship was obtained in protein percent of both types of muscles, the group, which had lower moisture percent, reflected higher percentage of protein indicating deposition of nutrients at the cost of moisture. The ether extract percent of thigh muscles in 100% replacement group reflected significantly higher percentage than other groups. However, a reverse trend in ether extract was obtained in breast muscle. Ether extract in breast muscle was the lowest in 100% replacement group. It was concluded that 80% fishmeal may be replaced by the vegetable protein mixture from the cockerel ration without affecting carcass quality.