Effect of Fasting Prior to Slaughter on Yield of Broilers

Effects of Feed Withdrawal Periods on Carcass Yield and Breast Meat Quality of Chickens Reared Using an Alternative System

“…A 1.5% yield difference between 6 and 14 h has been reported [29], whereas in other work, 5, 3.1, 1.5, and 1.25% differences were observed between yields on turkey carcasses at 0 and 12, 14, 16, and 24 h, respectively [24]. In the current study, yield differences of up to 1.8, 2.4, and 2.8% were [30] previously stated that smaller carcasses from more dehydrated live broilers absorbed proportionately more water than did heavier carcasses during chilling, which was confirmed by Smith et al [25]. In the current study, the broilers had live weights greater than 2.5 kg and were submitted to water withdrawal only 3 h before slaughter; that is, the live broilers were not dehydrated and therefore the carcasses did not absorb much water during chilling, resulting in lower CCY.…”

“…The higher SFW values at the 12-, 15-, and 18-h FW periods might be due to broiler dehydration and to the metabolism of body tissues to obtain energy for maintenance, as hypothesized by Salmon [24] for turkeys submitted to FW periods of longer than 24 h. These results are of the same magnitude as those reported by Lyon et al [6], with values of 2.94, 4.32, and 5.61% for chicken FW periods of 8, 16, and 24 h. Bilgili [4] reported that SFW is usually linear with time, in the range of 0.18 to 0.42% of live BW per hour. Smidt et al [25] also observed a gradual decrease in the percentage of full feed weight broilers for FW periods increasing from 2 to 40 h. Wabeck [2], Chen et al [26], and Buhr and Northcutt [27] reported significant in- Different letters in the same column indicate a statistical difference (P < 0.05). creases in the weight loss of broilers with prolonged FW times.…”

Lack of interrelationship between the effects of dietary factors and food withdrawal on carcase quality of broiler chickens

“…The data of the present study, however, demonstrated that FW for 24 h resulted in a considerable decrease in the weight of the ready-to-cook carcase, in agreement with Veerkamp (1978) and Bartov (1992). FW, which resulted in a reduction in the weight at slaughter (mainly the result of the emptying of the digestive system) consistently increased carcase yield (percentage of body weight at slaughter) (Tables 3, 6, 7 and 8), in agreement with the well documented data on this subject (Smidt et al, 1964;Wabeck, 1972;Rasmussen and Mast, 1989;Bartov, 1992). The data of this study, in which the combinations of FW with various nutritional and management factors which affect carcase quality differently were evaluated, indicate that 24 h of FW has no effect on the various variables of carcase quality such as relative size of the abdominal fat pad (Tables 4 and 8), fat content of the meat (Table 4) and composition of fat in meat and of abdominal fat pad (data of experiment 1).…”

“…Moreover, there were no signi cant interactions between either of these factors and FW, between the sex of the birds and FW, or between the age at slaughter and FW, in their effect on the various variables of carcase quality. The shrinkage rate after 24 h of FW in the 4 experiments averaged 5·6%, in agreement with Smidt et al (1964) and Wabeck (1972) but lower than the value reported by Veerkamp (1978). Such a shrinkage resulted also in a reduction in the weights of carcase and breast meat in experiments 1, 2 and 3 (Tables 3, 6 and 7, respectively).…”

“…The preslaughter and eviscerated weights were found to decrease as the length of the FW period increased (Smidt et al, 1964;Wabeck, 1972;Veerkamp, 1978;Bartov, 1992). FW periods of up to 24 h did not signi cantly affect the fat content in meat (Ang and Hamm, 1985;Bartov, 1992), the relative size of the abdominal fat pad or the composition of the fatty acids in their meat (Bartov, 1992).…”