Mealworm works well as an alternative protein for slow-growing chickens, but shouldn’t be seen as a full replacement for the protein content provided by soybean meal, after a study in Spain found the change was linked to reduced feed intake and weight gain.
As a result, the insect-based feed should be considered only as a partial replacement for soybean products during the first weeks of such birds’ lives, the researchers said.
The study tracked 128 chickens from their first day of life. Divided into two groups, the control was fed a conventional diet using soybean meal as a protein source, while the experimental group was fed meal made from mealworm (Tenebrio molitor), the larvae of darkling beetles.
Aside from one group consuming no T. molitor and the other no soya, the exact composition of the birds’ diets changed in accordance with three different growth periods, up to 95 days. The other components were corn, wheat, barley, sunflower, oats and a vitamin-mineral premix.
Diet composition at start of life crucial
Over the full course of the study, they observed no difference in the average live weight or food conversion ratio (FCR) of the birds. However, body weight gain was different to a high degree of significance, with the soybean meal group higher, while a highly-significant difference was seen in water intake, and a significant difference in food intake. On both of the latter parameters, the soybean group again saw higher numbers.
The birds fed mealworm fell furthest behind their control counterparts in the first phase of the experiment, leading the scientists to warn that a high percentage of mealworm should not be included in the first 29 days of their lives.
“A partial substitution would be more appropriate during this first period, since after it, the chickens improved notably their development and performance, reaching at the end of the cycle values similar to those of chickens fed soybean meal, despite starting from animals with less development during the first month,” they explained.
“Under these conditions, T. molitor larval meal can be an alternative protein source to include in the diets of slow-growing chickens.”
You can read the full study report in the journal Veterinary Sciences.
