Nutritional value of black soldier fly larvae oil in calf milk replacers

Sustainable alternatives to high-environmental-input feed ingredients are important to reducing the environmental impact of animal agriculture. Protein and oil extracted from cultivation of black soldier fly (Hermetia illucens) larvae (BSFL) on waste feedstocks such as manure, food waste, and plant residues could be a suitable source of nutrients. The oil from BFSL contains large amounts of saturated fatty acids, particularly lauric acid, and may be a more sustainable alternative to palm and coconut oils that are currently used in calf milk replacers in many parts of the world. The objective of this study was to evaluate animal performance in neonatal calves fed calf milk replacers (CMR) containing oil from BSFL. Holstein heifer calves (n = 100) were assigned randomly at birth to receive one of 4 experimental CMR containing 24% CP and 18% fat from a blend of 80/20 palm/coconut oil (B0), 80/20 palm/BSFL oil (B20), 70/30 palm/BSFL oil (B30), or 60/40 palm/BSFL oil (B40). Calves were fed up to 900 g/d of CMR powder reconstituted to 15% solids daily to d 55, then 600 g/d to d 63 and 300 g/d to the end of the trial at d 70. Commercial calf starter, wheat straw, and water were available for ad libitum consumption. Intake, growth, fecal scores, and feed efficiency were monitored and reported weekly. There were no effects of experimental treatments on growth or feed efficiency. Consumption of CMR during the first 2 wk of the study was lower when calves were fed B20 (wk 1 and 2) or B30 (wk 2). Calves were generally healthy and there were no indications of feed refusal or maldigestion. Probability of a non-normal fecal event (fecal score >0) was lower when calves were fed B20 during the first 3 wk of the study. Oil from BSFL may be an attractive alternative to palm and coconut oil in CMR.