Hydroxy-selenomethionine secures performance of broilers under heat stress
Dr. Michele De Marco, Global Scientific & Technical Manager at Adisseo, presented our latest research during the Australian Poultry Science Symposium (APSS).
This new study investigated the effect of different selenium dietary sources on heat stress management, in finishing broilers.
The experiment was designed in collaboration with the University of Ghent using a cyclic heat stress model to study the effects of Selisseo® on the FCR of broilers; along with some heat stress-related biomarkers. In the finisher phase of the breeding cycle (day 25 to day 39) the temperature in the experimental poultry house was increased from 22°C to 34°C for six hours per day, with a relative humidity between 50 and 60%. Broilers were reared for 39 days and fed a diet with either 0.3 ppm Se kg/feed from sodium selenite or 0.3 ppm Se kg/feed from Selisseo®.
When the cyclic heat stress was applied, a significant improvement in feed efficiency was observed for the Selisseo® group compared to the sodium selenite group (1.56 vs. 1.62, respectively). Mortality in the finisher period, which increased substantially with cyclic heat stress, was lower of -4.2 points for the Selisseo®-fed birds compared to the birds fed sodium selenite.
The results obtained on performances were furthermore corroborated by different biomarkers. In fact, the selenium levels in plasma was significantly higher in the Selisseo® group than the sodium selenite group – confirming the higher bioavailability of the organic form. On day 39, broilers fed Selisseo® maintained significantly higher serum T3 level than in broiler fed sodium selenite indicating a higher metabolic efficiency. Moreover, broiler fed Selisseo® showed lower plasma heat shock protein 70 (HSP70), an indication of lower oxidative damages in the cells. These results indicate a better adaptation to heat stress of broilers fed Selisseo®.
Dr. Michele De Marco commented: “Maintaining the antioxidant balance, by ensuring an adequate production of selenoproteins, is the key to secure broiler’s performance during heat stress. Feeding broiler with a pure form of organic selenium such as Selisseo® enhance the selenium deposition in tissues creating a sort of “selenium insurance policy”. This selenium insurance policy enables animals to produce enough amounts of antioxidant enzymes during heat stress – when feed intake is reduced resulting an effective way to secure their growth performance and to reduce the mortality rate in this challenging condition.”