Effect of dietary supplementation with full-fat silkworm (Bombyx mori L.) chrysalis meal on growth performance and meat quality of Rhode Island Red × Fayoumi crossbred chickens

Abstract

The objective was to study the effect of the partial substitution of soybean meal and oil with fullfat silkworm (Bombyx mori L.) meal (SWM) in the diet of growing chickens, on their growth and meat quality traits. A total of 195 1-day-old chicks of both sexes were allocated to 15 littered floor pens and assigned to three dietary treatments (5 replicates/treatments) until 8 weeks of age: a commercial diet (Control) and other two diets with an inclusion of either 25% (SWM25) or 50% (SWM50) SWM. At 8 weeks of age, two males/replicates were slaughtered and carcases dissected to compute yields. Pectoralis major muscle was subjected to pH and L à a à b à colour values, proximate composition and fatty acid profile analysis. All chickens showed satisfactory growth performance throughout the trial, with the best growth being observed in the SWM25 group. Carcase traits remained unaffected by the dietary treatment, but SWM25 chickens had a higher breast yield (p < .05) than the Control group. The pH of SWM50 breasts was higher than Control (p < .01). Dietary treatments affected meat protein content, differing between SWM25 and SWM50 (22.2 versus 23.3%, respectively; p < .05). SWM dietary inclusion increased n-3 PUFA and lowered the n-6 PUFA proportions in a level-dependent manner. Consequently, n-6/n-3 ratio diminished, thus improved, with the dietary SWM inclusion. Results showed that it is possible to partly substitute soybean meal/oil with SWM in the diet of chickens, ensuring satisfactory performance and carcase traits, and providing meat with a healthier n-6/n-3 ratio. HIGHLIGHTS Silkworm (Bombyx mori) chrysalis is a possible sustainable feed ingredient for growing chickens, alternative to conventional soybean. The dietary inclusion of silkworm full-fat meal in chicken diets provided satisfactory growth performance, carcase and meat quality traits. The dietary inclusion of full-fat silkworm meal in chicken diets enriched meat lipids with omega-3 fatty acids.

Systematic review and meta‐analysis of production performance of aquaculture species fed dietary insect meals

“…50,52 On the other hand, silkworm contains ecdysteroid, a growth-promoting factor, that improves protein synthesis and tissue formation. 53 This sufficiency could contribute to the significant positive effect of SGR, PER and subsequently reduce FCR of animals fed dietary silkworm meal. The meta-regression indicated an inverse correlation between dietary silkworm and Hedges' g for SGR (Figure 9), which could be attributed to several factors, mainly low feed intake driven by low palatability of silkworm, 48 as well as negative changes in physical properties of extruded silkworm-containing diets.…”

Insect meal as a feed ingredient for poultry

“…Sonali chickens fed on the diet containing 25% SWM as replacement of soybean meal increased the weight gain, feed intake, heart percentage, breast meat yield, and reduced breast meat protein percentage and ash percentage; 50% SWM increased the meat pH, and n-3 PUFAs, and reduced the n-6 PUFAs of breast meat [ 111 ]. In addition, diet containing 75% SWM as replacement of soybean meal fed to Ross 308 broiler chicken resulted in increased body weight, feed intake, gross return/bird and profit/kg meat, and reduced cost/kg meat; 100% SWM has the opposite effect, and 25% SWM in diet reduced the feed intake and increased the cost/kg meat; 50% SWM reduced profit/kg meat [ 112 ] Table 3 lists the typical results of silkworm meal application in broilers.…”

Do insects as feed ingredient affect meat quality?

“…A slight effect has been observed for lipids (3.56 vs 4.48% for leg meat of control and treated, respectively) in the study of [63] and for protein and ash contents (however not coherent with the inclusion level; [71]). Meat pH increased with the silkworm meal inclusion level but it did not impair meat colour [71].…”

“…The best result of the dietary inclusion of silkworm pupa meal in chickens concerns the FA profile of the meat lipids: the PUFA n-3 increased, and the omega-6/omega-3 ratio decreased with the increase of the dietary silkworm meal substitution level (P<0.01). The C18:3 n-3 content in breast meat ranged from 6.75 to 15.0 to 28.4 mg/100 g meat, for control, 25% and 50% silkworm meal inclusion level, respectively (P<0.05; [71]).…”

“…Silkworm pupa meal has been successfully included in chicken broilers diet (Table 7), as it produced no effect neither on colour values and lipids content [71] nor on sensory analysis [63] [67] of the meat. A slight effect has been observed for lipids (3.56 vs 4.48% for leg meat of control and treated, respectively) in the study of [63] and for protein and ash contents (however not coherent with the inclusion level; [71]). Meat pH increased with the silkworm meal inclusion level but it did not impair meat colour [71].…”