Abstract
An experiment was conducted to investigate 5 different thermal manipulation (TM) protocols utilizing eggshell temperature (EST). Group 1 was set at 37.5°C and 60% of relative humidity (RH) from day 1 to 19 of incubation. Treatments in groups 2 to 5 covered days 7 to 16 of incubation, employing different EST and 65% RH (group 2: 39.5°C/6h/day; group 3: 39.5°C/12h/day; group 4: 40.5°C/6h/day; and group 5: 40.5°C/12h/day). A total of 4,300 eggs were distributed across five different setters with a capacity of 860 eggs each. After hatching, 540 male Ross chicks (108 per treatment) were reared with six pens of 18 chicks each. Until 21 days of age, room temperature followed the Ross guidelines, whereafter all groups were subjected to heat stress (8h/32°C) from day 21 to 28 post-hatch. Performance and cloacal temperature were evaluated at 28 days of age. Chicks from group 2 (39.5°C/6h/day) had lower cloacal temperature during heat stress (P<0.05; 41.0°C) compared to the other groups: 42.9 41.5, 41.5, and 41.1oC for groups 1, 3, 4, and 5, respectively. Body weight gain (BWG) at 28 days of age was lower for group 5 (1,425g), and this group also had the worst feed conversion ratio (FCR) (1.47; P<0.05), whereas there was no difference among the other groups (1,574 g and 1.33 respectively on average). Feed intake was not affected (P>0.05). Group 1 chicks had a higher mortality rate (10.7%) between days 21 and 28 (immediately after the onset of heat stress) compared to other groups (P<0.05). Based on cloacal temperature and mortality rate, it can be concluded that the best TM protocol was 39.5oC EST between day 7 and 16 for 6 hours per day.
Original language | English |
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Pages | 39 |
Number of pages | 1 |
Publication status | Published - Oct 2024 |
Event | 49th IFRG Meeting - Limak Limra Hotel & Resort, Antalya, Turkey Duration: 3 Oct 2024 → 4 Oct 2024 |
Conference/symposium
Conference/symposium | 49th IFRG Meeting |
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Country/Territory | Turkey |
City | Antalya |
Period | 3/10/24 → 4/10/24 |
Keywords
- adaptation
- broiler production
- cloacal temperature
- eggshell temperature
- heat stress