Yellow mealworm larvae (Tenebrio molitor L.) inclusion in diets for female broiler chickens: effects on meat quality and fatty acid profile

Introduction. Recently, insects are receiving great attention as a potential poultry feed ingredient due to the high costs and limited future availability of conventional feed resources, such as soybean meal (SBM, crude protein (CP) content 54%) [1]. The yellow mealworm (Tenebrio molitor, L.; TM) seems to be particularly suitable as protein sources for this purpose (CP, 52%) [2,3,4]. This study aims to investigate the effects of the dietary utilization of a full-fat TM larvae meal as a partial replacement of SBM, corn gluten meal and soybean oil in broiler chicken diets. Animals, material and methods. A total of 160 female broiler chicks (Ross 708) at one day of age were randomly allotted to 4 isonitrogenous and isoenergetic dietary treatments control feed (C) and 5, 10 and 15% full-fat TM larvae meal inclusion,with 5 pens as replicates and 8 chicks per pen. The fatty acid (FA) composition of the TM larvae meal and experimental diets was determined. Oleic (C18:1 c9), linoleic (C18:2 n6), palmitic (C16:0) and myristic (C14:0) acids were the most represented FA in TM meal. These FA were also the most represented in the experimental diets and their concentration increased with the increase of TM meal inclusion. The broilers were slaughtered at 40 days of age. The carcasses were weighed, and the breast muscles were excised from 10 birds per treatment (2 birds/pen). Meat quality parameters (pH, colour and drip losses) and FA profile of breast muscle were evaluated. All data were tested by means of one-way ANOVA, and the effect of dietary TM larvae meal inclusion was evaluated by means of polynomial contrasts. Results and discussion. Meat pH, colour and drip losses were not affected by dietary TM larvae meal utilization. In breast samples, myristic acid (C14:0) increased linearly with increasing TM meal levels in the diets (p<0.001). The higher level of C14:0 detected in the breast of broilers fed TM larvae meal reflected the amount of this specific FA in the diets. Similar findings were obtained by Loponte et al. [5] who observed an increase in C14:0 in broiler chickens fed a diet containing corn and full- fat TM meal when compared to a corn-soybean based diet. Long-chain n-6 FA also showed a linear increasing response to increasing TM larvae meal levels in the diets. No differences were observed in breast meat for the main FA groups (total saturated, total monounsaturated and total polyunsaturated FA) among the considered dietary treatments. Conclusion. The obtained results showed that the inclusion of full-fat TM larvae meal in the diet of female broiler chickens did not affect meat quality traits and induced very few modifications in the FA profile of breast, confirming the potential of TM meal use in broiler chickens feed. References: [1] Gasco et al. (2019) Animals 9(4): 170; [2] Biasato et al. (2017) Anim. Feed Sci. Technol. 234: 253-263; [3] Biasato et al. (2018) Poult. Sci. 97:540-548; [4] De Marco et al. (2015) Anim. Feed Sci. Technol. 209: 211-218; [5] Loponte et al. (2019) Ital. J. Anim. Sci. 18(1): 168-173.