Feed intake and laying performance of captive Sardinian partridges (Alectoris barbara Barbara Bonnaterre, 1790) fed whole defrost mealworms (Tenebrio molitor L., 1758) in the diet for environmental enrichment

Introduction. Feeding practice of captive wild birds aims to minimize the effects from feed provision by humans in substitution of the natural diet[1,2], among many other goals. Environmental enrichment through whole mealworms[3] could help in getting the fitness to the environment of captive partridges once released. Material and methods. 24 breeding couples of Sardinian partridges kept in cages during the laying period (Apr-May 2019) were fed diets as follows: a) complete pelleted diet for layers (CON, control diet; CP: 16%; CFat: 2.5%, MJME 11.6/kg, as fed) vs. b) whole defrost (overnight) mealworm enriched diet, at a combination of 5% (ME5, combined as fed; CP: 17%, CFat: 13%, MJME 9.05/kg as fed) with the CON diet. All partridges were not accustomed to mealworms, as a pre-requisite. Daily feed intake (DFI), body weight (BW) and number of laid eggs (LE) were monitored over 5 weeks of experimental feeding. Birds were fed ad libitum and had free access to water. Data were analyzed by one-way ANOVA with significance at P-value<0.05. Results and Discussion. Partridges of each couple enrolled in the trial showed preference for mealworms as feed source, with complete consumption of mealworms before turning to the pelleted feed in the 100% of birds. This led to a decrease in the consumption of the pelleted feed in all the couples fed the ME5 diet, with a decrease DFI (g). All birds appeared healthy and laying activity was not affected (Table). Table. Bird performance in the two feeding groups (CON vs. ME5) Final BW of birds fed ME5 decreased, following the reduction of daily feed intake and energy (Δ= -0.12MJME/d). This is however, expected and in agreement with the live BW of wild birds[2]. Considering the low survival rate of released partridges in the nature (starvation), the environmental enrichment via the diet can serve to express feeding choice and acquire knowledge on potential edible sources. Conclusion. Untrained birds tended to select whole mealworms for first. The preference for mealworms led to reduced feed intake in terms of DFI of pellet proportion, on an as fed basis. Despite the final weight of birds from the ME5 dietary group turned to be lower, the eggs laid per week and the egg weight by each couple did not vary according to the dietary treatment. Feeding whole mealworms to breeding couples of Sardinian partridge appears to be a promising practice, though nutritional value of mealworms and health assessment are in the focus. References. [1] Cappai et al., (2017) JPN, 101: 421-426; [2] Cappai et al., (2018) JPN, 102: e870- e876; [3] Biasato et al., (2016), JPN, 100: 1104-1112.