Effect of Dietary Replacement of Fishmeal by Insect Meal on Growth Performance, Blood Profiles and Economics of Growing Pigs in Kenya

Abstract

Pig production is one of the fastest growing livestock sectors. Development of this sector is hampered by rapidly increasing costs of fishmeal (FM), which is a common protein source in animal feeds. Here, we explored the potential of substituting FM with black soldier fly larval meal (BSFLM) on growth and blood parameters of pigs as well as economic aspects. At weaning, 40 hybrid pigs, i.e., crossbreeds of purebred Large White and Landrace were randomly assigned to five iso-nitrogenous and iso-energetic dietary treatments: Control (0% BSFLM and 100% FM (T0)), and FM replaced at 25% (T25), 50% (T50), 75% (T75) and 100% (T100) with BSFLM. Average daily feed intake (ADFI), average daily gain (ADG), body weight gain (BWG) and feed conversion ratio (FCR) were calculated for the whole trial. Hematological and serum biochemical parameters, the cost-benefit ratio (CBR) and return on investment (RoI) were evaluated. No significant effect of diet type was observed on feed intake and daily weight gain. Red or white blood cell indices did not differ among diets. Pigs fed T25, T75 and T100, had lower platelet counts compared to T0 and T50. Dietary inclusion of BSFLM did not affect blood total cholesterol, triglycerides, low-density lipoprotein and high-density lipoprotein. CBR and RoI were similar for the various diets. In conclusion, BSFLM is a suitable and cost-effective alternative to fishmeal in feed for growing pigs.

Keywords: alternative protein; animal feeds; blood parameters; cost benefit analysis; growing pigs; insect larval meal; return on investment.

Figure 1

Mean (±SE) weekly body weight of pigs fed BSFLM-based diets and a control diet. BSFLM = black soldier fly larval meal. T0 = 0% (control), T25 = 25%, T50 = 50%, T75 = 75% and T100 = 100% levels of replacement of fishmeal with BSFLM. For each diet, four males and four females were investigated.

Figure 2

Body weight gain (mean ± SE) of pigs fed BSFLM-based diets and a control diet for the whole trial. Bars followed by the same letter are not significantly different: p < 0.05, general linear model (GLM, least significant difference test (LSD)). BSFLM = black soldier fly larval meal. T0 = 0% (control), T25 = 25%, T50 = 50%, T75 = 75% and T100 = 100% levels of replacement of fishmeal with BSFLM. For each diet, four males and four females were investigated. Data for female and male pigs pooled together because there is no significant effect of sex. n = 8 per bar.

Figure 3

Average daily feed intake (±SE) in pigs fed BSFLM-based diets and a control diet. Bars with the same letters are not significantly different: p < 0.05, general linear model (GLM), BSFLM = black soldier fly larval meal. T0 = 0% (control), T25 = 25%, T50 = 50%, T75 = 75% and T100 = 100% levels of replacement of fishmeal with BSFLM. n = 8 per bar.

Figure 4

Feed conversion ratio (mean ± SE) for pigs fed BSFLM-based diets and a control diet. Bars with different letters are significantly different: p < 0.05; general linear model (GLM), LSD. BSFLM = black soldier fly larval meal. T0 = 0% (control), T25 = 25%, T50 = 50%, T75 = 75% and T100 = 100% levels of replacement of fishmeal with BSFLM. n = 8 per bar.