Influence of lipid fraction of Black Soldier fly larvae on productivity, resistance and metabolic processes in milk-fed period calves

Abstract

Relevance. There is evidence of increased immunity in animals when they are fed components from insect larvae. The research objectives are to study some aspects of the composition and bactericidal properties of the lipid fraction obtained from the biomass of Black Lion larvae (LCL-lf); to establish the effectiveness of using LCL-lf as an additive to the diet of calves of the dairy growing period.Methodology. Scientific and economic experience in studying the effect of various levels of use of the lipid fraction obtained from the biomass of Black Lion larvae in the diets of dairy calves (from the 59th to the 123rd day) of the growing period was carried out in JSC «Molodi» of the Moscow region. The animals of the control group were fed a balanced diet in terms of energy and nutrients, the 1st experimental in addition to the main diet daily (individually) in the morning feeding was fed 5 g of LCHL-lf, the 2nd experimental – 10 g of LCHL-lf.Results. Fatty acid composition of LCHL-lf: the sum of saturated LC – 85.9%, lauric acid – 55.6%. The antimicrobial properties of the extract from LCL-lf are largely noted in relation to gram-positive bacteria. It was noted that feeding larvae in the diets of young animals improved the bactericidal properties of the blood serum of experimental animals – from 31.4 to 42.9–48.6% (p < 0.05). The content of erythrocytes (11.6% vs. 10.3 × 1012/l in the control, p = 0.08) and hematocrit (40.9 vs. 37.1% in the control, p = 0.02) was higher in the blood of group 2 animals, which indicates an increase in the redox capacity of the blood of experimental animals. In the blood of animals of the experimental groups, the content of free water–soluble antioxidants increased – from 14.8 mg/l in the control to 17.8 mg/l (p = 0.08) and to 15.7 mg/l (p = 0.39) in the blood of animals of the experimental groups, 1st and 2nd, respectively. In general, over the two-month period of the experiment, the increase in SSP was: in group 1 – 8.4%, in group 2 – 18.7% compared with the control (703.1–769.5 g vs. 648.4 g, p < 0.05).