Effects of aqua agar as water replacement for posthatch chicks during transportation on residual yolk-sac and growth performance of young broiler chickens

Water is one of the most essential nutrients for the maintenance of chicks' function, and delayed access to feed and water post hatch has been reported to dehydrate chicks. Aqua agar (AA) was formulated to contain more than 95% water and an experiment was conducted to evaluate the effects of AA as water replacement for posthatch chicks during transportation. During the simulated transport, chicks were held for 24 h with (AA group) or without (NO-AA group) aqua agar in chick boxes. During the holding period, chicks in the AA group lost less body weight, compared with the NO-AA group. However, the weight of residual yolk tended to be lower in the AA-treated birds. There were no significant differences in the weight of gizzard, proventriculus, and liver, nor in the weights and lengths of the duodenum, jejunum and ileum. A higher body weight was also observed in the AA group at 7 days of age. At 21 days of age, weight gain and feed intake were higher (P < 0.05) in the AA group, when compared to that of the NO-AA group. No significant differences were observed in the feed conversion rate (FCR) between the two groups. In conclusion, the data suggests that the use of AA as a water replacement could reduce the negative impact of water deficiency in posthatch period during transportation, resulting in greatly improved growth performance of young broilers at 21 days of age.