Summary: The Animal Experimental Procedure

Materials and Methods
The animal experimental procedure was approved by Ethical committee of ICAR-National Institute of Animal Nutrition and Physiology, Bangalore, India.
Incubation and in ovo treatment
A total of 200 uniform sized eggs (Cobb broiler) were procured from commercial hatchery and incubated with the dry bulb temperature ranging from 99 - 100°F and wet bulb temperature of 85-87°F from day 1 to 18. On day 18, all infertile eggs were removed and the fertile eggs were divided into 3 equal groups (n=69). The treatments included Group I, Control (no administration); Group II, Zinc sulphate (36% zinc); 80 g zinc/0.5ml per egg and Group III, Zinc methionine (20% zinc); 80 g zinc/0.5ml per egg. The post-hatch chicks were further

Each group comprised of 6 replicates with 9 chicks per replicate. The total experimental duration was 5 weeks. The diet was prepared using maize and soybean as major ingredients for pre-starter (0-1 wk), starter (2-3 wk) and finisher (4-5wk) periods (Table 1) and offered ad libitum with access to clean drinking water.
Growth Performance
Body weight changes were recorded every week to ascertain the weekly and overall body weight gain. The experimental diets were given ad lib and the residue was weighed at weekly interval in order to arrive at feed intake. Based on the data pertaining to the feed intake and body weight gain, the weekly and period wise cumulative feed conversion ratio (FCR) was calculated.
Gut development
On day 7, one chick from each replicate and on day 35, two birds from each replicate were sacrificed by cervical dislocation for gut development studies. Gut development was measured by recording the weights of gizzard, proventriculus, liver, as well as weight and length of duodenum jejunum ileum and caecum. Functional development of gut was measured by histological examination of duodenal villi at day 7 and 35 post hatch. Two to three cm long duodenal samples were collected in 10% formal saline after washing the contents with normal saline and were processed for histological