Abstract
Background:
Heat stress (HS) significantly affects tropical broiler farming by impairing growth, physiology, meat quality, survival, and profitability. Since feed constitutes a major production cost, adopting feeding management approaches may reduce costs while enhancing bird resilience under HS without compromising productivity.

Aim:
This study aimed to evaluate the effectiveness of different feeding management approaches on growth, rectal temperature, water intake, serum biochemistry, meat quality, gut histomorphology, and profitability in heat-stressed broilers.

Methods:
A total of 750 broiler day-old chicks were reared in an open-sided house for 6 weeks and allocated to five feeding approaches: T1 = ad libitum feeding (AdLF); T2 = quantitative feed restriction (6, 9, and 12% restrictions during the 4, 5, and 6th weeks, respectively, QuantFR); T3 = fixed-period feed withdrawal (8 h restriction, 8hFW); T4 = different periods of feed withdrawal (5, 7, and 9 h restrictions during the 4, 5, and 6th weeks, respectively, DPFW); and T5 = intermittent feed withdrawal (2 h of feeding and 2 h of fasting, InterFW), with 5 replications of 30 chicks each. All groups were fed ad libitum for the first 3 weeks; thereafter, feed restriction protocols were applied. Data on growth, water intake, rectal temperature, serum biochemistry, carcass yields, meat quality, and gut histomorphology were analyzed.

Results:
The 8hFW group showed significantly (P<0.05) improved FCR, survivability, and production efficiency compared with the AdLF group. The InterFW group exhibited the highest weight gain and feed intake. The 8hFW group also exhibited significantly (P<0.05) reduced rectal temperature and water intake and improved serum glucose, lipid profile, and liver enzyme levels, with similar trends observed in the QuantFR and DPFW groups. Feeding approaches markedly (P<0.05) influenced dressing, breast, liver, and abdominal fat, while enhancing various meat quality parameters compared with the AdLF group. Similarly, intestinal histomorphometry improved significantly (P<0.05) in all feed-restricted groups compared with the AdLF group. Economically, 8hFW yielded the highest benefit-cost ratio (P<0.05), while AdLF had the lowest.

Conclusion:
Fixed-period feed withdrawal (8hFW) was the most effective approach in mitigating HS effects, improving growth performance, meat quality, gut morphology, and profitability. Therefore, this approach is a practical and cost-effective solution for broiler production under extreme HS.

Key words: Feed restriction; Growth performance; Gut histomorphology; Heat stress; Survivability.