A. Nizza

Yellow mealworm larvae (Tenebrio molitor, L.) as a possible alternative to soybean meal in broiler diets

Abstract The aim of the study was to evaluate the feasibility of replacing soybean meal (SBM) with Tenebrio molitor larvae (TML) meal in broiler diets. A total of 80 30-d-old male Shaver brown broilers were divided into two groups fed on two isoproteic and isoenergetic diets differing for protein source (SBM vs. TML). Up to 62 d of age, body weight and feed intake were recorded weekly and body weight gain, feed conversion ratio (FCR), protein efficiency ratio (PER) and European efficiency factor (EEF) were calculated. At 62 d, blood samples were collected from 16 birds/group for evaluation of blood profiles. Feed intake was not different between groups considering the entire period of the trial. The FCR was more favourable in the TML than SBM group from 46 d of age and in the entire period of the trial (4.13 vs. 3.62). The PER was higher in the SBM than in the TML group (1.92 vs. 1.37) while the EEF was higher in broilers fed on the TML diet (132.6 vs. 156.2). Albumin-to-globulin ratio was higher in broilers fed on SBM than in the other group (0.44 vs. 0.30). aspartate aminotransferase and alanine aminotransferase were higher in TML than SBM (195.1 vs. 178.6 U/l and 82.07 vs. 46.71 U/l, respectively). Uric acid was higher in broilers fed on SBM than TML (5.40 vs. 4.16 mg/dl). TML did not affect feed intake and growth rate of broilers from 30 to 62 d of age when compared to an isoproteic and isoenergetic SBM diet, but FCR of the TML group was more favourable than that of the SBM group. The lowest albumin-to-globulin ratio in broilers fed on TML suggests a higher immune response, probably due to the prebiotic effects of chitin.

Use of Tenebrio molitor larvae meal as protein source in broiler diet: Effect on growth performance, nutrient digestibility, and carcass and meat traits

The aim of this research was to study the effect of insect meal from larvae ( larvae meal [TML]) as complete replacement of soybean meal (SBM) on growth performance, nutrient digestibility, and carcass and meat traits of broilers. A total of eighty 30-d-old male Shaver brown broilers were homogenously divided into 2 groups (each consisting of 8 replicates of 5 birds). Up to 62 d of age, the groups were fed 2 isoproteic and isoenergetic diets differing for the ingredient used as the main protein source: the control group was fed a corn-SBM-based diet, whereas in the TML group, the SBM was completely replaced by TML. Broiler growth performance was measured during the trial. At 62 d of age, 2 broilers per replicate (16 per group) were slaughtered and apparent ileal digestibility coefficients and carcass and meat traits were determined. The use of TML as the main protein source in the broiler diet had no significant effect on most growth performance and carcass traits and chemical and physical properties of meat, the latter being important for marketing purposes. The feed conversion ratio in the entire experimental period (from 30 to 62 d) was improved in the TML group compared with the SBM group ( < 0.05). The apparent ileal digestibility coefficients of DM, OM, and CP in broilers fed the SBM diet were greater ( < 0.01) than the other group. The full digestive system in broilers fed SBM had a lower ( < 0.05) absolute and relative weight than that of broilers fed TML. Also, the weight and the percentage of the spleen in the SBM group were lower ( < 0.05) than those in the TML group. The length of the entire intestine in the group fed TML was greater ( < 0.05) than the other group and the same happened when intestinal length was expressed as percentage of broiler BW ( < 0.05). Among the different intestinal tracts, the ileum and ceca of broilers fed TML had a greater ( < 0.05) length than that of broilers fed SBM. Also, ceca weight (as an absolute value or percentage on live weight) in broilers fed TML was greater ( < 0.05) than that of broilers fed SBM. Breast pH and cooking losses in broilers fed TML were greater ( < 0.05) than those of broilers fed SBM. Chemical characteristic of meat obtained from right breast of slaughtered broilers were unaffected by dietary treatments. larvae meal can be a suitable alternative protein source for growing broilers and also when used as principal protein contributor to the diet.

In vitro crude protein digestibility of Tenebrio molitor and Hermetia illucens insect meals and its correlation with chemical composition traits

The aims of this study were to evaluate the correlation between in vitro crude protein digestibility coefficients of insect meals from Tenebrio molitor (TI) and Hermetia illucens (HI) and their chemical composition traits as well as to develop regression equations able to estimate the in vitro crude protein digestibility (CPd) from proximate analysis of insect meals. Twelve samples of insect meals (6 from TM larvae, TM 1-6 and 6 from HI larvae, HI 1-6) were obtained from different producers and analysed for chemical composition and in vitro crude protein digestibility by a two-step enzymatic method (digestion with pepsin and trypsin-enriched pancreatin). For both insect meal samples, CPd was negatively correlated to ADF and chitin contents, while just for HI there was a positive correlation (P<0.01) between CP percentage of the samples and CPd. For both insect meals the former variable chosen in the stepwise analysis was the chitin, explaining the 79.45% of CPd variability for Tenebrio molitor samples and the 98.30% for Hermetia illucens. In the second step, the amount of protein linked to ADF was added in the model for T. molitor and CP for H. illucens samples. The coefficients chitin is the main constituent of insect body able to affect the crude protein digestibility of Tenebrio molitor and Hermetia illucens larvae meals estimated by an in vitro enzymatic method.

Use of dietary mannanoligosaccharides during rabbit fattening period: Effects on growth performance, feed nutrient digestibility, carcass traits, and meat quality

This study was conducted to compare the effects of mannanoligosaccharides (MOS) and antibiotics as a dietary supplement on ADG, ADFI, G:F, and feed nutrient digestibility of rabbits during the fattening period, as well as on carcass traits and meat quality. A total of 512, sixty-day-old hybrid Hyla rabbits were randomly divided into 4 treatment groups based on BW and sex. The 4 treatment groups consisted of a control group and 3 MOS groups. The control group was fed a diet that contained apramycin (50 mg/kg), but diets for the 3 MOS groups contained 0.5, 1.0, or 1.5 g/kg of MOS instead of apramycin. The rabbits were fed experimental diets for 22 d and all rabbits were slaughtered at the end of the experiment when they were 82 d old. Individual BW and feed intake per cage were recorded weekly for 32 cages randomly chosen per group (64 rabbits) to calculate ADG, ADFI, and G:F. The apparent digestibility values of OM, CP, ether extract, crude fiber, NDF, ADF, cellulose, and hemicellulose were measured using AIA as an inert marker. Carcass data were collected from 16 randomly chosen rabbits (8 males and 8 females) per group. The control group had less G:F (P < 0.001) than the MOS groups and a linear increase (P < 0.001) in G:F was observed as the concentration of MOS increased from 0.5 to 1.0 and 1.5 g/kg. The apparent digestibility of DM, OM, crude fiber, NDF, ADF, cellulose, and hemicellulose increased (quadratic, P < 0.05) as the concentration of MOS in the diets increased. The apparent digestibility of DM, OM, CP, crude fiber, NDF, ADF, cellulose, and hemicellulose was also greater (P < 0.05) in the diets containing MOS than in the control diet and the digestibility of these nutrients was greater (P < 0.05) in the diet containing 1.5 g/kg of MOS compared with the control diet. The concentration of palmitic acid, stearic acid, and SFA was greater (P < 0.05) in the meat from rabbits fed the control diet than rabbits fed the MOS diets. The concentration of stearic acid decreased (quadratic, P < 0.05) in the meat of rabbits as the concentration of MOS in the diet increased. Meat from rabbits fed diets containing MOS also had greater contents of oleic acid (P < 0.05) and MUFA (P < 0.001) than those rabbits fed the diet containing apramycin. The thrombogenic index was greater (P < 0.05) in the meat from the control group rabbits than the MOS group rabbits. In conclusion, the inclusion of MOS in diets fed to rabbits during the fattening period may improve G:F and modify the fatty acid profile of meat.

Effect of feed restriction on performance and feed digestibility in rabbits

Abstract Two hundred and fifty-six Hyla rabbits were equally divided into two groups fed the same commercial concentrates supplied ad libitum (group AL) or restricted to 90 % of ad libitum (group RES) from weaning (35 d) to slaughter (85 d). Mortality was recorded daily. On 20 rabbits per group feed intake and live weight were recorded, respectively, on a daily and weekly basis. Samples of concentrates and faeces were collected and chemical composition and acid insoluble ashes were determined, the latter to estimate nutrient digestibility. The moderate feed restriction did not induce differences in slaughter weight (2755.3 vs 2732.2g, respectively for groups AL and RES) or in the average daily weight gains of the rabbits (40.02 vs 39.54 g/d, respectively for groups AL and RES) while the feed conversion ratios were more favourable for group RES (3.88 vs 3.40, respectively for AL and RES groups, P<0.05). The same rabbits showed significantly higher apparent digestibility for almost all the nutrients (except crude protein and ether extract) in particular for the crude fibre, NDF and ADF, confirming a higher residence time of the feeds in the digestive system.

Physical and chemical quality of ostrich eggs during the laying season.

1. Fifteen ostrich females were monitored for a full breeding season. At 30, 70, 110, 150 and 210 d from the beginning of laying, one egg per female was taken to the laboratory to assess its physical and nutritive characteristics. 2. The average length was 15·4 cm, while the width was 12·9 cm. Average shell thickness ranged from 2·20 mm at the equator to 2·24 mm at the small pole. The three principal components of the egg (albumen, yolk and shell) amounted to 57·1, 23·3 and 19·6%, respectively. None of the above variables, despite showing some significant differences between sampling periods, showed a clear trend linked to the laying season. 3. In contrast, the dry matter of the albumen showed a correlation with the sampling period, increasing from 11·1% in the first period to 12·0% in the last. The crude protein content ranged from 47·7 to 48·2%, the fat from 43·8 to 44·2% and the ash between 5·2 and 5·5% of dry matter. 4. The fatty acid composition of the yolk showed the presence of C18:1 (from 122·0 to 136·4 mg/g), followed by C16:0 (from 40·8 to 46·0 mg/g), C18:0 (from 19·2 to 21·2 mg/g) and C18:2 (from 17·1 to 19·6 mg/g). The content of cholesterol/g of yolk was between 10·6 and 10·9 mg. 5. In conclusion, compared with the hens egg, the ostrich egg has similar chemical and nutritive characteristics, but a higher unsaturated/saturated fatty acid ratio and lower cholesterol content.

Effect of mannanoligosaccharides supplementation on caecal microbial activity of rabbits

A total of 200 weaned (35 days) hybrid Hyla rabbits were randomly divided among five groups housed in bicellular cages (20 cages per group). Between 35 and 60 days of age, the groups were submitted to the following treatments: group ANT (positive control) fed a basal diet supplemented with antibiotics (colistin sulphate, 144 mg/kg; tylosin, 100 mg/kg; and oxytetracyclin, 1000 mg/kg); groups MOS_0.5, MOS_1.0 and MOS_1.5 fed the basal diet supplemented with 0.5, 1.0 and 1.5 g/kg mannanoligosaccharides (MOS), respectively; another group fed the basal diet without antibiotics or mannanoligosaccarides supplementation (negative control). Along the trial, an episode of epizootyc rabbit enteropathy occurs so that in the control group mortality rate was very high (78%) and survivor rabbits showed severe symptoms of disease (diarrhoea). Thus, the control group was discarded from the trial. At 60 days of age, samples of caecal content were collected from 10 rabbits per group and used as inocula for an in vitro gas production trial. At the end of fermentation (120 h of incubation), organic matter digestibility (OMd), cumulative gas production, fermentation kinetics, pH, volatile fatty acid (VFA) and NH3 productions were measured. Inoculum from MOS_1.0 rabbits showed the significant higher values of OMd (64.21%, P < 0.05), gas production (262.32 ml/g, P < 0.05), acetate (96.99 mmol/g OM, P < 0.05) and butyrate (26.21 mmol/g OM, P < 0.05) than the other groups. Slight differences were recorded among the groups ANT, MOS_0.5 and MOS_1.5. In addition, branched chain acids, in proportion to total VFAs, were significantly higher in MOS_1.0 inoculum (0.04, P < 0.05). MOS are able to affect fermentation activity of caecal micro-organism, but their activities seem not proportional to their level in the diet.

Effects of Mannan Oligosaccharide and Inulin on Sharpsnout Seabream (Diplodus Puntazzo) in the Context of Partial Fish Meal Substitution by Soybean Meal

One hundred forty-four sharpsnout seabream of about 100 g initial body weight were randomly stocked in 12 experiment tanks (180 L). Testing conditions included 12 fish per tank, with triplicate tanks for treatment. The experimental period lasted 150 days. Average water temperature was 21.9±1.6°C, salinity was 30.0‰ and pH ranged from 7 to 8, throughout the experiment. A control diet (FM) was made from fish meal. One similar diet (SBM) was made with approximately 40% of the protein supplied by soybean meal. The remaining two diets (SBM-MOS and SBM-INU) were formulated adding 8 g of mannanoligosaccharide (MOS) and inulin (INU) per kg of the SBM diet, respectively. The results showed that mean final weight (average values 234.4 g), specific growth rate (average values 0.585), feed conversion rate (average values 2.05) and protein efficiency ratio (average values 1.01) were unaffected by MOS or INU supplementation to SBM diet. Body proximate composition was affected by MOS and INU supplementation. Fish fed SBMMOS and SBM-INU diets showed the highest moisture level and the lowest lipid content. Also the total polyunsaturated fatty of the lipids was reduced by MOS and INU in comparison to SBM diet alone.

Effect of phytase with or without multienzyme supplementation on performance and nutrient digestibility of young broiler chicks fed mash or crumble diets

A total of 210 unsexed 1-day old Arbor Acres broiler chicks were wing banded and randomly distributed among 30 cages of 7 birds per cage keeping equal initial BW during days 1–20 of age. A factorial design (2×3) was used in which there were two feed forms (mash vs crumble diet) and three enzyme treatments (unsupplemented, phytase, phytase plus multienzyme). Each treatment was replicated 5 times with 7 chicks per replicate. Body weight (BW), body weight gain (BWG) and feed conversion ratio (FCR) of fed chicks were significantly improved when the crumble diet was administered. However, feed intake of chicks fed on the crumble feeds was significantly lower than those fed the mash diet. Digestibility of ether extract and crude fiber was significantly greater in groups fed the crumble diet than those fed the mash diet. Enzyme supplementation significantly and similarly increased growth and production index, and improved FCR. Also greater digestibility of crude protein and crude ash was observed but growth during days 8–14 of age and crude fibre digestibility were significantly greater in chicks receiving the multienzyme plus phytase supplement than those receiving phytase alone. Crumble feed supplemented with multienzyme resulted in the highest performance and nutrient digestibility of broilers during days 1–20 of age.

Use of faeces as an alternative inoculum to caecal content to study in vitro feed digestibility in domesticated ostriches ( Struthio camelus var. domesticus )

1. In order to find an alternative source of inoculum to caecal content for studying the in vitro feed digestibility in domesticated ostriches (Struthio camelus var. domesticus), caecal content and faeces of 4 male birds were used as inocula for an in vitro gas production trial. 2. About 1 g of each of 5 substrates (maize silage, CS; alfalfa hay, AH; barley, BG; soybean meal, SM; beet pulp, BP) was weighed, in quadruplicate per inoculum, in 120 ml flasks; 75 ml of anaerobic medium and 4 ml of reducing solution were added and flasks were kept at 39°C. Caecal content and faeces were diluted respectively 1 : 2 (CI) and 1 : 4 (FI) with an anaerobic medium and were injected into the respective flasks (10 ml). 3. Gas production was recorded 22 times up to 120 h of incubation and fermentation characteristics (for instance, degraded organic matter, OMd; potential gas production, A; maximum fermentation rate, R max; time at which it is reached, T max; pH; volatile fatty acid, VFA; ammonia) were studied for each inoculum and substrate. 4. CI and FI showed significant differences in T max (16·37 vs 18·47 h, respectively), propionic (16·47 vs 12·07 mmoles/l) and butyric acid (6·50 vs 7·98 mmoles/l) and ammonia concentration (17·18 vs 19·95 mmoles/l). The substrates, according to their chemical composition, showed different fermentation characteristics. However, the regression equations able to estimate some fermentation characteristics of the caecum from those of faeces were statistically significant and showed R 2-values ranging from 0·87 to 0·99. 5. The differences in fermentation pathways of the two inocula did not appear to influence the rate and extent of OM digestion. Faecal fermentation predicted rates and extent of OM digestion by caecal fermentation in ostriches; consequently, the faeces could be considered as an alternative to caecal content to study feed digestibility in the species, although there is a need to undertake further research.