Insect fat touted as effective replacer of soybean oil in turkey bird diets

24-May-2022 - Last updated on 24-May-2022 at 13:02 GMT

A new study from Poland outlines how soybean oil can be partially or fully replaced with cold-extracted black soldier fly larvae (BSFL) fat in turkey diets without no negative effects on growth performance.

Data about the use of BSFL fat in young turkey nutrition is still limited, said the Polish team.

They said their study, published in the journal of Animal Feed Science and Technology, represents the first attempt to evaluate the inclusion of BSFL fat, which has been obtained under industrial-scale conditions by using a cold-extraction technique, in young turkey diets.

Cold extraction is a common method applied in the production of soybean and rapeseed oil, they noted.

“The S-C [super-critical] CO2 extraction method is frequently proposed in the literature as a high-quality and high-yield technique to obtain insect fat (Kiero ́nczyk et al., 2018; Purschke et al., 2017a). However, this process allows extremely pure products to be obtained on a pilot or laboratory scale. From a practical point of view, there is a need to apply methods that allow the scaling up of insect fat production due to the rapid development of this branch of animal production. Cold extraction is a commonly used method in the feed industry that does not require the use of heat and organic solvents and has low initial and operational costs,” stressed the team.

The study

The goal of the study was to evaluate the effects of partial or total replacement of soybean oil (SO) with cold-extracted BSFL fat in young turkey diets on a variety of parameters including growth performance, apparent ileal nutrient digestibility coefficients, microbial community modulation, immune status parameters, among several others.

A total of 216 7-day-old female turkeys were randomly allotted to three different rations, according to the article. Each group contained six replicate pens with 12 birds per pen and the study lasted 28 days.

The birds were fed a soybean-maize basal diet enriched with 50g/kg dietary fat that included soybean oil (SO) in the control group, 50:50 SO BSLF fat in the BSFL50 group, and BSFL fat as the sole energy source in the BSFL100 group.

The BSFL fat used, added the authors, was characterized by high lauric and palmitic acid contents, as well as saturated fatty acids (SFAs), while concentrations of mono- and polyunsaturated fatty acids were higher in the SO group.

The findings

The growth performance parameters were not affected by BSFL fat substitution. No statistically significant differences between the control and experimental diets were noticed in the case of production criteria such as body weight, body weight gain, feed intake, and FCR in each rearing period or in terms of the entire experiment, observed the team.

Partial or total replacement of SO with BSFL fat improved cecal microbiota communities by limiting Bacteroides-Prevotella cluster counts.

BSFL fat modulated the immune system by reducing the level of interleukin-6, added the authors.

They also saw that lipase and amylase activity was enhanced by BSFL fat implementation, while liver health status was increased by reduced cholesterol and triglyceride levels.

The results demonstrated that the cold-pressing extraction method is efficient in terms of obtaining black soldier fly larvae fat at an industrial scale. Generally, insect fat, said the research team, can be efficiently implemented in poultry diets in place of soybean oil without any production issues (Kiero ́nczyk et al., 2020b, 2018). However, further studies are needed, they added.

“In conclusion, it is possible to partially or totally substitute SO in turkey diets with cold-extracted BSFL fat without any negative effect on growth performance, nutrient digestibility, physiological traits, or immunological status trait.”