Jayanegara Anuraga, Sholikin Mohammad M, Sabila Della A N, Suharti Sri, Astuti Dewi Apri
Pak J Biol Sci. 2017;20(10):523-529. doi: 10.3923/pjbs.2017.523.529.
Cricket contains high crude protein level but it also contains considerable amount of chitin that may impede nutrient digestion and decrease production performance of animal. This experiment aimed to decrease chitin content of cricket (C) through exoskeleton removal (CER) or by chemical extraction (CCE).
Nutritional evaluation of cricket was performed in two experiments. In experiment 1, three forms of cricket were prepared, i.e., C, CER and CCE. These were subjected to chemical composition determination and in vitro rumen fermentation incubation as individual substrates. In experiment 2, C and CER were included in concentrate rations at different proportions to substitute soybean meal (SBM), i.e., R1 (concentrate containing 30% SBM), R2 (50% SBM was substituted by C), R3 (100% SBM was replaced by C) and R4 (100% SBM was replaced by CER). The concentrates were then evaluated in vitro for their rumen fermentation and digestibility characteristics. Data were analyzed with analysis of variance and Duncan's test.
Cricket was high in crude protein(CP), ether extract (EE) and chitin contents. Removal of exoskeleton decreased CP and chitin contents of cricket. Chemical extraction of cricket increased its CP and completely removed its chitin. Main fatty acids observed in cricket were linoleic acid, palmitic acid, oleic acid and stearic acid and the composition was unaltered due to exoskeleton removal or chemical extraction. Cricket was relatively highly digestible and exoskeleton removal and chemical extraction did not further improve in vitro dry matter digestibility (IVDMD) and in vitro organic matter digestibility (IVOMD) of cricket. The R1 and R2 revealed similar IVDMD and IVOMD, but R3 and R4 resulted in lower values for both parameters than those of R1 and R2 (p<0.05).
Exoskeleton removal or chemical extraction effectively reduced chitin content of cricket and the insect may be used to substitute SBM up to 50% in concentrate for ruminant.
蟋蟀含有高蛋白，但也含有大量几丁质，这可能会阻碍营养物质的消化，并降低动物的生产性能。本实验旨在通过去除外骨骼（CER）或化学提取（CCE）来降低蟋蟀的几丁质含量。
对蟋蟀进行了两项营养评估实验。在实验1中，制备了三种形式的蟋蟀，即C、CER和CCE。将它们作为单独的底物进行化学成分测定和体外瘤胃发酵培养。在实验2中，将C和CER以不同比例添加到精料日粮中以替代豆粕（SBM），即R1（含有30% SBM的精料）、R2（50% SBM被C替代）、R3（100% SBM被C替代）和R4（100% SBM被CER替代）。然后对这些精料进行体外瘤胃发酵和消化率特性评估。数据采用方差分析和邓肯检验进行分析。
蟋蟀的粗蛋白（CP）、乙醚提取物（EE）和几丁质含量较高。去除外骨骼降低了蟋蟀的CP和几丁质含量。对蟋蟀进行化学提取提高了其CP含量并完全去除了几丁质。蟋蟀中观察到的主要脂肪酸为亚油酸、棕榈酸、油酸和硬脂酸，其组成不因外骨骼去除或化学提取而改变。蟋蟀的消化率相对较高，去除外骨骼和化学提取并未进一步提高蟋蟀的体外干物质消化率（IVDMD）和体外有机物消化率（IVOMD）。R1和R2的IVDMD和IVOMD相似，但R3和R4的这两个参数值均低于R1和R2（p<0.05）。
去除外骨骼或化学提取可有效降低蟋蟀的几丁质含量，这种昆虫可在反刍动物精料中替代高达50%的豆粕。
