Omid Afsarian; Mohamad Hosein Shahir; Hoshang Lotpholahian; Abdolah Hoseini; Naser Mousavi; Amir Akhlaghi
Volume 18, Issue 1 , April 2016, , Pages 61-73
Abstract
Two experiments were conducted to evaluate the effects of thyroxin in ovo injection and post hatch arginine feed supplementation on performance and cold tolerance acquisition in broilers. In experiment 1, a total of 2400 hatchings eggs were randomly assigned to four treatments: Positive controls (intact ...
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Two experiments were conducted to evaluate the effects of thyroxin in ovo injection and post hatch arginine feed supplementation on performance and cold tolerance acquisition in broilers. In experiment 1, a total of 2400 hatchings eggs were randomly assigned to four treatments: Positive controls (intact or pricked with a needle), Negative control (intact egg), injected with distilled water and injected with thyroxin. In experiment 2, a total of 240 day old male broiler chicks from the intact and injected with thyroxin treatment groups were assigned in a 2 × 2 factorial trial based on completely randomized design, with two level of injection (non-injection or injected with 65ng of thyroxin) and two type of diet (without Arginine or 5 kg/ton Arginine). In order to induce ascites in chicks, all of the chicks were exposed to 15°C from 14 to 42 d of age. The results showed that the second grade chicks and yolk sac weight were decreased (P<0.05) in thyroxine by in ovo injection. Ascites mortality rate, packed cell volume percent and red blood cell count were decreased (P<0.05) by thyroxine injection and arginine supplementation. In conclusion, these results show that in ovo injection of thyroxin and arginine feed supplementation improves the performance during exposure to cold environments.