Formic and propionic acids' effectiveness on laying hens' productivity and egg quality, utilization of nutrients and some blood profiles during the early production phase

The use of organic acids as growth promoters in poultry diets continues to pique the researchers' curiosity. So, this study aims to investigate the effect of feeding formic acid, propionic acid, or both in their pure form on laying hens' productivity, egg quality, nutrient utilization, and some blood profiles during the early production phase using eighty ISA Brown laying hens aged 28-42 weeks. The hens were randomly assigned into four groups, each consisting of 10 replicates with 2 hens/replicate. The treatments were C (control), F (1 ml formic acid/kg diet), P (1 ml propionic acid/kg), and M (0.5 ml formic acid and 0.5 ml propionic acid/kg). The percentage of egg production, egg mass (P < 0.05), albumen crude protein percent, and estradiol hormone (P < 0.001) were significantly increased upon acids' mixture treatment, whereas the percentages of albumen fat (P < 0.05) and yolk fat (P = 0.0006) were significantly decreased. Formic acid significantly increased the percentages of shell calcium (P = 0.0001) and yolk (P < 0.01) and decreased albumen percent (P < 0.01). The acids' mixture produced the lowest plasma cholesterol value (P = 0.0001), which was followed by formic acid treatment. Unlike the control, the experimental treatments significantly increased Haugh unit, albumen index (P < 0.05), crude protein retention percent (P < 0.01), and decreased plasma triglycerides (P = 0.0007). According to the findings, early-phase laying hens' diets supplemented with a pure blend of propionic and formic acids produced more eggs and had higher egg quality.