Higher dietary vitamin E and selenium fed during different age periods: Influence on meat stability of broiler chicks
PRAVEEN K. TYAGI, PRAMOD K. TYAGI, A.B. MANDAL,
A.V. ELANGOVAN AND R.P. SINGH
Central Avian Research Institute, Izatnagar - 243 122 (UP)
Two separate basal diets for starting (0-3 wks) and finishing (4-7 wks) phases were formulated as per BIS (1992) recommendations for broiler chickens. To these basal diets, vitamin E and inorganic selenium were added @ 225 IU vitamin E and 0.5 mg Se per kg of diet during various age periods and four dietary schedules (treatments) were adopted as per the following feeding regimen: (D 1)-basal diet without supplemental vitamin E and selenium fed during 0-7 weeks of age (control), (D 2)-basal diet supplemented with 225 IU vitamin E and 0.5 mg Se per kg of diet fed continuously during 0-7 weeks of age, (D 3)-basal diet supplemented with 225 IU vitamin E and 0.5 mg Se per kg of diet fed during 0-3 weeks of age and unsupplemented basal diet fed during 4-7 weeks of age, and (D 4)-unsupplemented basal diet fed during 0-3 weeks of age and basal diet supplemented with 225 IU vitamin E and 0.5 mg Se per kg diet fed during 4-7 weeks of age. Day old, straight run broiler chicks (n=160) were distributed randomly into 16 groups of 10 chicks each. Each of the four dietary regimens were offered as mash ad libitum to four replicated groups of chick for a period of seven weeks (0-7 weeks of age). At the end of the experiment, four birds from each treatment group (one bird / replicate) were randomly picked up and sacrificed and carcass samples were stored at –18 0C until analyzed periodically for meat stability and sensory evaluation. Significantly (P<0.01) highest TBA values were observed from meat samples stored at –18 0C for 1,2 and 3 months in birds fed continuously on diet unsupplemented with vit. E/Se (control) than the birds fed on vit. E/Se supplemented diet during 0-7(D 2), 0-3(D 3) and 4-7(D 4) wks of age. Upon 2 and 3 months storage, the stability of meat samples also deteriorated (P<0.01) in diet 3 wherein vit E/Se was added in diet during starting phase (0-3 wks of age) only. Similarly, drip loss was also significantly (P<0.01) high in control diet than other diets. Sensory attributes done up to 2 months storage also showed deterioration in quality of meat of control diet than the other diets. It is concluded that a concentration of 225 IU vitamin E and 0.5 mg selenium per kg in diet of broiler chicken fed during 4-7 weeks of age before slaughter is sufficient to obtain maximum meat stability.