Over the years, the growing concerns about the negative impact of anti-microbial growth promoters has triggered researches into the use of phytogenic feed additives in poultry production in order to ascertain better performance of birds as well as safety in the food chain. Phytogenic feed additives are compound derived from varieties of plants, its parts, extracts and essential oils which possess active substances that are of significant importance. Some of its functions include anti-microbial and anti-oxidative effects on the poultry feeds and carcass as well as enhancement of flavour of feeds. Despite the beneficial influences of PFAs, numerous controversial issues have emerged on the appropriate dosage to be used in poultry production. This may be due to the differences in edaphic and climatic actions on plants available in various part of the world and stage of harvesting of plants which makes standardizing inclusion levels of phytogenic feed additives in poultry diet seemingly difficult. However, it is crystal clear that phytogenic feed additives qualify as a better substitute to anti-microbial growth promoters as it is safe and ecologically friendly.

The objective of this study was to evaluate the effect of monosodium glutamate (MSG) inclusion in broiler diet on meat quality of broiler chickens for 8 weeks. A total of 300 day old mixed sexed Abor-acre chicks were randomly allocated to six treatments with five replicates per treatment and ten birds per replicate in a completely randomized experimental design. Six administration levels of monosodium glutamate (0.00, 0.25, 0.50, 0.75, 1.00 and 1.25 g MSG/kg diet) were added as taste enhancing additive in the diet at both starter and finisher phases. Four birds (unsexed) per replicate were slaughtered at the end of the trial period for meat quality evaluation. The result revealed fat and crude protein contents of the meat and palatability of the thigh muscle were significantly influenced by MSG, but the oxidative stability, moisture, thawing and cooking loss were not significantly influenced by the dietary treatments. In summary, the palatability of chicken meat from broilers fed diet with MSG inclusion up to 0.75 g MSG/kg diet was enhanced, and fat content was reduced with dietary inclusion of MSG.

The study was carried out to examine the effect of varied levels of dietary monosodium glutamate on acetylcholinesterase, specific acetylcholinesterase and total protein concentrations in the brain regions of broiler chickens. Three hundred (300) day – old unsexed Abor – acre chickens were randomly assigned to diets: A, B, C, D, E and F containing 0.00, 0.25, 0.50, 0.75, 1.00 and 1.25 g/kg MSG respectively. Each treatment was replicated 5 times with 10 birds per replicate. The birds were fed ad – libitum and provided with clean water for 8 weeks (56 days) after which 2 birds per replicates were slaughtered. The brains were removed, dissected into different regions comprising of the olfactory lobe, pineal body, optic lobe, cerebellum and the medulla oblongata. The different parts of the brain were homogenized to determine the acetylcholinesterase and total protein which were also used in the assessment of the specific acetylcholinesterase of the brain. No significant differences were observed in the acetylcholinesterase activity of the olfactory lobe, pineal body, optic lobe, cerebellum except for the medulla. Likewise, the dietary monosodium glutamate did not influence the activities of the total protein and specific acetylcholinesterase of the olfactory lobe portion of the brain. The dietary monosodium glutamate exerted significant effects on the total protein of other brain parts studied and which invariably resulted in significant changes in the specific acetylcholinesterase of the optic lobe, cerebellum and medulla except for the optic lobe. This study revealed that monosodium glutamate added to broilers diet above 0.75 g/kg significantly altered the concentration of the brain acetylcholinesterase, total protein and specific acetylcholinesterase thereby impaired brain functions.