EFFECTS OF DIFFERENT FEEDING REGIMES ON TONIC IMMOBILITY, RECTAL TEMPERATURE AND CARCASS CHARACTERISTICS OF COBB BROILERS

In commercial poultry production, profit could be maximized by reducing cost of feeding through feed restriction, which could also reduce abdominal fat accumulation without detrimental effects on the birds’ performance. Unfortunately, there are little or no information on performance characteristics of Cobb broilers that is gradually gaining popularity for its dual purpose capability in Nigeria. Hence, the present trial monitored tonic immobility, rectal temperature and carcass characteristics of Cobb broilers placed on different feeding regimes. Results showed that tonic immobility induction was similar across the treatments with values ranging from 1.13 sec (T3) to 1.50 sec (T2). Similar trend was observed in tonic immobility duration that varied between 159.1 and 266.3 sec. Statistical variations (P= .05) were observed in rectal temperature at 3 weeks old, with the lowest value (41.14°C) in control (T1) and highest (41.6°C) in T3. At 6 weeks old, the rectal temperature was similar and ranged from 41.46 – 41.61°C in T2, T3 and T4, respectively, which were significantly higher (P= .05) than 41.34°C recorded in control. At the end of the study, body weight was not statistically different (P= .05) across the treatments but, varied between 860.2 g (T4) and 916 g (T3). Dressing percentage was best (64.97%) in T4, followed by 64.59%, 62.69% and 62.2% in T1, T3 and T2, accordingly. While the abnormal fat was as high as 1.23% in control birds, it was between 0.63 and 0.94% in the treated birds. This probably suggested normal physiological status hence, Cobb broilers may thrive well on feed restriction.