Document Type : Research Paper
Authors
1
Ph.D. Student and, Department of Animal Science, Faculty of Agriculture Science, University of Guilan, PO Box 41635-1314, Tehran, Iran
2
Associatet Professor, Department of Animal Science, Faculty of Agriculture Science, University of Guilan, PO Box 41635-1314, Tehran, Iran
3
Assistant Professor, Department of Poultry Science, Faculty of Agriculture Science, Tarbiat Modares University, PO Box 14115-336, Tehran, Iran
Abstract
This research was conducted to evaluate broiler response to in-ovo feeding of beta-hydroxy beta-methylbutyrate (HMB) and dextrin and the timing of the first feed deprivation using Box-Behnken design and response surface methodology. On day 18 of incubation, 1500 fertile eggs from Ross 308 strain were randomly assigned to experimental treatments of Box-Behnken design, each with 4 replicates, as 3 levels in-ovo injection of HMB (0, 0.5 and 1 %) and dextrin (0, 20 and 40 %), and 3 levels of the first water and feed restriction time (6, 27 and 48 hours). The in-ovo injection of dextrin led to significant lower hatchability (P<0.05), whereas in-ovo injection of HMB had no significant effect on hatchability (P>0.05). In European efficiency factor models, the jejunal villi surface area and glycogen contents of liver and breast muscle at 7 days of age, the linear components showed highest contribution (0.61 to 0.79) of variation in chick responses. The results of this research showed that maximum European efficiency factor at 7 days of age can be achieved by in-ovo administration of HMB and dextrin (0.54 and 39.03 percent, respectively) in amnion fluid till maximum 20.79 hours feed deprivation after hatch.
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