Transfer of Lauric and Myristic Acid from Black Soldier Fly Larval Lipids to Egg Yolk Lipids of Hens Is Low

Abstract

Implementing insects, such as the black soldier fly larvae (BSFL), as animal feed commonly includes the previous removal of substantial amounts of fat. This fat may represent an as yet underutilized energy source for livestock. However, transfer of lauric and myristic acid, prevalent in BSFL fat and undesired in human nutrition, into animal-source foods like eggs may limit its implementation. To quantify this, a laying hen experiment was performed comprising five different diets (10 hens/diet). These were a control diet with soybean oil and meal and a second diet with soybean oil but with partially defatted BSFL meal as protein source. The other three diets were based on different combinations of partially defatted BSFL meal and fat obtained by two different production methods. Lauric acid made up half of the BSFL fat from both origins. Both BSFL fats also contained substantial amounts of myristic and palmitic acid. However, in the insect-based diets, the net transfer from diet to egg yolk was less than 1% for lauric acid, whereas the net transfer for myristic and palmitic acid was about 30% and 100%, respectively. The net transfer did not vary between BSFL originating from production on different larval feeding substrates. The results illustrate that hens are able to metabolize or elongate very large proportions of ingested lauric acid and myristic acid, which are predominant in the BSFL lipids (together accounting for as much as 37 mol%), such that they collectively account for less than 3.5 mol% of egg yolk fatty acids.

Effect of Black Soldier Fly (Hermetia illucens L.) Fat on Health and Productivity Performance of Dairy Cows

“…Therefore, while the use of insect larval fat is predetermined by its composition and properties, its full targeted use is still hampered by the lack of a complete understanding of its possible utilization. Studies on the applicability of insect fat have been conducted on broilers [ 57 , 71 , 72 ], laying hens [ 73 ], turkeys [ 62 ], rabbits [ 74 ] and fish [ 75 ]. Although BSFLF is rich primarily in lauric acid, the effect of lauric acid, as well as BSFLF on rumen bacteria is less well known [ 76 ].…”

Feeding value of black soldier fly larvae compared to soybean in methionine- and lysine-deficient laying hen diets

“…Al-Qazzaz et al (2016) were even able to show that feeding diets based on BSFL may positively influence sensory palatability and texture of the eggs, traits which could not be sensorily investigated in the present study due to the legal reasons outlined above. One aspect, not specifically looked at in the present study but in the previous experiment (Heuel et al, 2021b), is the degree to which the large amounts of lauric, myristic and palmitic acid present in the BSFL fat are accumulating in the egg lipids. These fatty acids are considered unfavourable for human health (Calder, 2015).…”

Egg quality and laying performance of Julia laying hens fed with black soldier fly (Hermetia illucens) larvae meal as a long-term substitute for fish meal

“…, 2019 ). Previously, it has been reported that the high level of fatty acids in BSFL meal, such as myristic and palmitic acid, could be transferred to the yolk, but they did not affect yolk weight ( Heuel et al . , 2021b ).…”