Exploring the functional and metabolic effects of adding garra fish meal to a plant-based broiler chicken diet.

The present study evaluated the metabolic and functional effects of adding garra meal to a broiler chicken diet. Three hundred twenty Sasso-breed day-old chicks were randomly assigned to four dietary treatments with either 0, 10, 20 or 30% garra meal added on top of formulated starter and grower basal diets. The experiment lasted for 42 days. Feed intake and body weight gain increased at the starter and grower phases of broilers with garra meal addition (P < 0.05). Broiler chickens fed 30% garra meal were more efficient in converting feed to body weight and yielded the highest carcass weight (P < 0.05). Crude protein ileal digestibility coefficient was higher with 20% (76.2%), and crude fat with 20 (92.1) and 30% (92.6%) garra meal receiving groups (P < 0.05). The increase in individual and total esterified carnitine concentrations in dried blood spots demonstrated the elevated metabolic rate with garra meal addition (P < 0.05). A better supply of glucogenic substrate to the citric acid cycle was seen with garra meal addition due to the increase of propionylcarnitine to acetylcarnitine ratio (P < 0.05) without any apparent effect on ketogenesis in terms of serum 3-hydroxybutyrylcarnitine to acetylcarnitine ratio. Yet, it likely showed that part of the amino acids from garra meal were used as glucogenic substrate (P < 0.05). Histomorphometry data showed 20% garra meal addition elevated villus height, crypt depth and their ratio in the proximal parts of the small intestine (duodenum and jejunum) with the opposite results observed in the more distal part (ileum) with the highest for the control group (P < 0.05). It can be concluded that garra meal improved broiler performance when added to a plant-based diet and only few parameters warranted for caution when using more up to 30% garra meal addition. Beyond growth performance, garra meal generated a shift to a more efficient digestion, absorption and nutrient metabolism.