Influence of in ovo injection of L-Glutamine on pre- and post- hatch growth performance, small intestine morphology and immune responses in broiler chickens

The aim of this study was to evaluate the effect of in ovo injection of L- Glutamine on pre and post hatch growth performance، carcass traits، jejunum morphology and immune responses of broiler chickens. Four hundred eighty fertile Ross 308 broiler breeder eggs in a completely randomized design were used into 6 experimental groups، 4 replicates of 20 eggs each. Treatment groups were: non-injected control، sham control (sterile water)، 10، 20، 30 and 40 mg glutamine were dissolved in 1ml sterile water and then inoculated into amniotic fluid of the 17. 5 d- old embryo through broad end of the egg. After hatch، 10 chicks per each replicate were distributed in pens and reared up to 42 d of age. The results showed that the hatchling weights and overall daily body weight gain were 3. 6% and 3. 8% higher in the group given 40 mg glutamine than noninjected control، respectively (P<0. 05). At day 24، relative weight of breast muscle was influenced by embryo feeding of glutamine (P<0. 05)، but relative weights of liver، gizzard and heart were not affected (P<0. 05). Compared with untreated control، glutamine was enhanced jejunal villi height and crypt depth in 3 and 24 days of post hatch. By 40 mg glutamine injection، the humoral and cell mediated immune responses were improved. The results suggest that in ovo injection of 40 mg L-glutamine into amniotic fluid of growing embryo can improve hatchling weight، average daily gain، morphometric development of the intestinal tract and humoral and cellular immune responses of broiler chickens.