The 60-70% increase of animal products consumption expected by 2050 has pushed research to investigate new raw materials for animal feeds. In this context, insects are a very interesting and innovative feed for fish and terrestrial animals due to their valuable chemical composition and their claimed sustainability (van Huis et al., 2015). So far, research has mainly been addressed to the protein content of insect larvae meals in fish,poultry and pigs (feeds as conventional protein sources (mainly fishmeal and soybean meals) substitutes (Veldkamp and Bosch, 2015;Bovera et al., 2016; Gasco et al., 2016; Piccolo et al., 2017) and the most insect species investigated were Black soldier fly (BSF - Hermetia illucens) and Yellow mealworm (TM - Tenebrio molitor). Nevertheless, when processing larvae, and in order to increase the protein content and the storability of the meals, some authors underlined the importance of defatting larvae meal (Henry et al., 2015). The extracted lipid could find uses as animal feeds (Li et al., 2016; Schiavone et al., 2017)or biodiesel (Surendra et al., 2016). Using lipid in the rabbit diets has an impact on growth and health of rabbits. In rabbit post-weaning stage, Djakalia et al. (2012) showed that the use of soybean oil (SBO) by its essential FA composition improves growth performance of rabbits compared to the use of the palm oil, which is rich in SFA. As far as rabbit are concerned, to the best of our knowledge only two research have been performed using insect meal (silkworm) replacing soybean meal in diets for growing rabbits (Carregal and Takahashi, 1987; Liu et al., 1987) and no researches were ever been conducted using insect fats or oils. The aim of this research was therefore to assess the effect of BSF fat and TM oil used as partial or total substitute of soybean oil on growth performances and slaughter traitsof growing rabbits. Two hundred Hycol hybridsweaned rabbits (36 days old, initial mean body weight:1050.71±137.85) were randomly divided into five groups of 40. Rabbit were fed ad libitum with a control diet (C) containing 1.5% of SBO tested against four experimental diets developed substituting the control diet SBO with 50 or 100%of BSF fat or TM oil (BSF50, BSF100 ,TM50 and TM100). The effects on growth performance were studied from 36 to 77 days of age. Mortality was controlled and registered daily throughout theexperimental period. During the experiment, live weight and feed intakewere recorded per cage on a fortnightly basis. At the end of the trial, the means of LW,average daily feed intake (ADFI), and average daily weight gain(ADG) were calculated. Feed conversion rate (FCR) was calculatedas the ratio between the ADG and the ADFI. At the end of the trial, 20 rabbits per group were slaughtered and weight recorded (SW).After 24-h of cooling at 3-4 oC, the commercial carcasses with head were dissected according to the procedures described by Dabbou et al. (2017).The chilled carcassweight (CCW)was recorded and the dressing out percentagewas calculatedas the ratio between CCW and SW. The reference carcass weight (RCW) was also calculated.The perirenal fat was recordedand expressed as a percentage of RCW.The statistical analyses were performed using the SPSS softwarepackage (version 21 forWindows, SPSS Inc., Chicago, IL, USA).One-way ANOVAwas used to evaluate the effect of BSF fat and TM oil on growth performances and carcass characteristics.Mortality was calculated by Fisher's exact test and used control group as the reference. Significance was declared at P<0.05. Table 1 reports the effects of experimental diets on growth performance.After 41 days of feeding trial, no difference was observed amongthe control and the groups containing insect oils in terms of performance and mortality. The final rabbit body weight ranged from 2811.42 (TM50) to 2917.30 (TM100).The average ADFI, ADG and FCR were 152.01, 44.46 and 3.44, respectively. As far as slaughtering performances are concerned (Table 2), there were nodifferences among experimental groups for allthe considered parameters(P>0.05). The obtained results showed that BSF fat and TM oil used as partial or total substitute of SBOcan be used as feed ingredient in rabbit diets without impacting growth performance and slaughter traits. Future studies are needed to investigate the effects of dietary BSF fat and TM oil on meat quality traits and fatty acid profile.
Partial or total substitution of soybean oil by Tenebrio molitor oil or Hermetia illucens fat in rabbit diets. Preliminary results: effects on growth and slaughtering performances.
Gai F
2017
Abstract
The 60-70% increase of animal products consumption expected by 2050 has pushed research to investigate new raw materials for animal feeds. In this context, insects are a very interesting and innovative feed for fish and terrestrial animals due to their valuable chemical composition and their claimed sustainability (van Huis et al., 2015). So far, research has mainly been addressed to the protein content of insect larvae meals in fish,poultry and pigs (feeds as conventional protein sources (mainly fishmeal and soybean meals) substitutes (Veldkamp and Bosch, 2015;Bovera et al., 2016; Gasco et al., 2016; Piccolo et al., 2017) and the most insect species investigated were Black soldier fly (BSF - Hermetia illucens) and Yellow mealworm (TM - Tenebrio molitor). Nevertheless, when processing larvae, and in order to increase the protein content and the storability of the meals, some authors underlined the importance of defatting larvae meal (Henry et al., 2015). The extracted lipid could find uses as animal feeds (Li et al., 2016; Schiavone et al., 2017)or biodiesel (Surendra et al., 2016). Using lipid in the rabbit diets has an impact on growth and health of rabbits. In rabbit post-weaning stage, Djakalia et al. (2012) showed that the use of soybean oil (SBO) by its essential FA composition improves growth performance of rabbits compared to the use of the palm oil, which is rich in SFA. As far as rabbit are concerned, to the best of our knowledge only two research have been performed using insect meal (silkworm) replacing soybean meal in diets for growing rabbits (Carregal and Takahashi, 1987; Liu et al., 1987) and no researches were ever been conducted using insect fats or oils. The aim of this research was therefore to assess the effect of BSF fat and TM oil used as partial or total substitute of soybean oil on growth performances and slaughter traitsof growing rabbits. Two hundred Hycol hybridsweaned rabbits (36 days old, initial mean body weight:1050.71±137.85) were randomly divided into five groups of 40. Rabbit were fed ad libitum with a control diet (C) containing 1.5% of SBO tested against four experimental diets developed substituting the control diet SBO with 50 or 100%of BSF fat or TM oil (BSF50, BSF100 ,TM50 and TM100). The effects on growth performance were studied from 36 to 77 days of age. Mortality was controlled and registered daily throughout theexperimental period. During the experiment, live weight and feed intakewere recorded per cage on a fortnightly basis. At the end of the trial, the means of LW,average daily feed intake (ADFI), and average daily weight gain(ADG) were calculated. Feed conversion rate (FCR) was calculatedas the ratio between the ADG and the ADFI. At the end of the trial, 20 rabbits per group were slaughtered and weight recorded (SW).After 24-h of cooling at 3-4 oC, the commercial carcasses with head were dissected according to the procedures described by Dabbou et al. (2017).The chilled carcassweight (CCW)was recorded and the dressing out percentagewas calculatedas the ratio between CCW and SW. The reference carcass weight (RCW) was also calculated.The perirenal fat was recordedand expressed as a percentage of RCW.The statistical analyses were performed using the SPSS softwarepackage (version 21 forWindows, SPSS Inc., Chicago, IL, USA).One-way ANOVAwas used to evaluate the effect of BSF fat and TM oil on growth performances and carcass characteristics.Mortality was calculated by Fisher's exact test and used control group as the reference. Significance was declared at P<0.05. Table 1 reports the effects of experimental diets on growth performance.After 41 days of feeding trial, no difference was observed amongthe control and the groups containing insect oils in terms of performance and mortality. The final rabbit body weight ranged from 2811.42 (TM50) to 2917.30 (TM100).The average ADFI, ADG and FCR were 152.01, 44.46 and 3.44, respectively. As far as slaughtering performances are concerned (Table 2), there were nodifferences among experimental groups for allthe considered parameters(P>0.05). The obtained results showed that BSF fat and TM oil used as partial or total substitute of SBOcan be used as feed ingredient in rabbit diets without impacting growth performance and slaughter traits. Future studies are needed to investigate the effects of dietary BSF fat and TM oil on meat quality traits and fatty acid profile.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
