RESPONSE OF GUINEA FOWL TO IN OVO ADMINISTRATION OF VITAMIN B9 (FOLIC ACID) ON DIFFERENT DAYS OF EMBRYONIC DEVELOPMENT

Abstract

ABSTRACT The growing interest in guinea fowl as a hardy and economically valuable poultry specie informed the search for alternatives to enhance its growth performance. This study investigated the effect of in ovo injection of Vitamin B9 at different days (21, 23 and 25) of embryonic development on guinea fowl’s hatching traits, post-hatch growth performance, blood profile, intestinal morphology, and carcass characteristics. A total of 180 hatching eggs of helmeted guinea fowl were incubated for 28 days. After candling on day 12, only 112 eggs were fertileand were randomly allotted to four groups: the control group (non-injected group), in ovo 1 (injected with 0.05ml of folic acid per egg on day 21), in ovo 3 (injected with 0.05ml of folic acid per egg on day 23) and in ovo 5 (injected with 0.05ml of folic acid per egg on day 25). Hatching traits were assessed on day 0. Afterwards, body weight and feed intake were evaluated weekly. Two birds/replicate were slaughtered and assessed for lymphoid organs and intestinal morphometry for blood profile, samples were collected for haematological parameters, serum biochemical indices and anti-oxidant status (Superoxide dismutase-SOD, Malondialdehyde-MDA, Glutathione-GSH and Catalase glutathione-CAT) analysis on day 7 and 70. Data collected were subjected to One-way Analysis of Variance. The control group had the highest hatchability percentage (94.40%) followed by hatching eggs from in ovo 1 group (72.20%). The egg weight, chick weight and chick to egg ratio were not significantly (p>0.05) affected by the days of injection. The Packed Cell Volume (PCV) and Hemoglobin (Hb) level of the guinea fowl were significantly (p<0.05) influenced at day 7 of age. Non-injected group for both PCV (41 %) and Hb (13.70 g/dl) had significantly (p < 0.05) higher values than all injected groups while keets from in ovo 5 had significantly lowest value of PCV (31 %) and Hb (10.67 g/dl).The blood antioxidant status on days 23 and 25 had significantly (p<0.05) highest concentration of MDA while SOD and CAT were significantly (p < 0.05) highest in keets from in ovo 1 eggs. Duodenal histomorphometry at hatch was significantly (p<0.05) influenced by treatment. Villus height was highest in keets from eggs injected on days 21 (1.47 µm) and in ovo 5 eggs (1.45 µm). In addition, the proportions of jejunum and ileum were highest (p<0.05) at day 7 in keets from in ovo 3. The study concluded that for an enhanced growth performance and gut development in guinea fowl, in ovo injection of 0.05ml folic acid (vitamin B9) in their fertile eggs on either day 21 or day 25 of embryonic development showed better effect.