Effects of <I>in ovo</I> injection of inorganic salts of Zn, Cu and Mn on hatching traits and post-hatch performance of broiler chickens in the tropics

Abstract

This study determined the effects of in ovo injection of inorganic salts of Zn, Cu and Mn on hatching traits and post-hatch performance of Arbor acre broiler chickens. A total of four hundred hatching eggs of Arbor acre strain of broiler chickens were sorted to give three hundred and twenty hatching eggs. On the 14th day of incubation, the eggs set were candled and 250 eggs (78.13% fertility) were fertile. The fertile eggs were redistributed into 4 treatments: Control (un-injected eggs), in ovo administration of 80 μg.egg-1 inorganic Zn, in ovo administration of 16 μg.egg-1 inorganic Cu and 0.3 μg.egg-1 inorganic Mn) each consisting of 62 eggs. The in ovo injection was carried out on the 18th day of incubation. After hatching, the birds were managed intensively for a period of 6 weeks in a deep litter housing. Data were subjected to Completely Randomized Design. Results revealed hatchability (p<0.05) percentage of 74.71% in the Control (un-injected eggs), followed by similar value of 63.00% each in birds from Zn and Cu-injected eggs. The chick weight was significantly (p<0.05) highest (68.03 g) in birds from the Control (un-injected eggs), followed by (66.15 and 67.90 g) in birds from Zn and Cu-injected eggs, respectively and lowest (60.90%) in birds from Mn-injected eggs. On day 7 of age, birds from Mn-injected eggs had significantly (p<0.05) highest proportion of heart (0.80%) while 0.78 and 0.75% were obtained in birds from the Control (un-injected eggs) and Zn-injected eggs, respectively with the lowest proportion of 0.61% in birds from Cu-injected eggs. Birds from Cu-injected eggs at day 42 of age had highest (11.90x109/L) White blood cell count. The mid-shaft width of birds from Zn-injected eggs recorded significantly (p<0.05) highest value (10.23 mm). The study concluded that in ovo injection of inorganic salts of Zn and Cu improved hatchability comparably to the control treatment. In ovo injection of Zn salt improved growth of the heart (at 7 days of age), duodenum percent (at 42 days of age) as well as tibia mid-shaft width.

Keywords: In-ovo injection, Zinc, Copper, Manganese, performance, Arbor acre broiler chicken, gut morphology