TITLE:
Effects of the Partial Replacement of Soybean Meal by Insect or Algae Meal in Chicken Diets with Graded Amino Acid Supply on Parameters of Gut Microbiology and Dietary Protein Quality
AUTHORS:
Susanne Velten, Carmen Neumann, Jenny Schäfer, Frank Liebert
KEYWORDS:
Growing Chickens, N Utilization Model, Body Analyses, Feed Protein Quality, Gut Microbiology, Precaecal Digestibility, Spirulina platensis, Hermetia illucens
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.8 No.3,
July
13,
2018
ABSTRACT: Insects or algae are considered future solutions to
substitute imported feed proteins like soybean meal (SBM) in animal nutrition.
The objective of this research, as part of the multidisciplinary project
“Sustainability transitions”, focused on replacing 50% SBM by partly defatted
larvae meal from black soldier flies (Hermetia
illucens) or the blue-green algae Spirulina
platensis in meat type chicken diets. The current study aimed to evaluate
the effects on body composition, protein quality, apparent precaecal
digestibility (apcD) and parameters of intestinal microbiota. In total, 288
one-day-old male growing chickens (Ross 308) from a commercial hatchery were
randomly allotted to 48 pens (6 birds per pen) across five diets, which were
fed at a free choice level. The control diet utilized SBM, wheat and corn as
main ingredients, and experimental diets replaced 50% of SBM by the alternative
proteins under study. Amino acid (AA) supplementation of the final diets was
conducted both at a basic level (diets HM, SM; Lys and Met added equal to the
control diet) and an extended level of AA fortification (diets HM+, SM+;
extended supplementation of Lys, Met, Thr, Arg). After finishing the growth
study, 4 individual birds per diet were slaughtered for whole body analyses to
derive nutrient utilization and dietary protein quality parameters.
Additionally, pooled chyme samples from 16 birds per diet (control, HM and SM)
were analyzed to assess apcD and microbial parameters. Diets HM and SM with a
basic level of AA fortification led to significant depressions in nutrient
deposition and dietary protein quality. However, HM+ and SM+ diets with an extended
level of AA supplementation led to significantly improved responses; however
these were still generally not on par with the control diet. The HM+ diet
provided superior CP deposition and dietary protein quality, as compared to the
SM+ diet, but equal to the control diet. Results of gut microbiology yielded no
significant effects due to feeding the alternative protein sources under study.