F. Bovera

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.

Effect of two different protein/fat ratios of the diet on meagre (Argyrosomus regius) traits

Abstract The aim of this study was to evaluate the effect of two diets with different protein/fat ratios (P/F) (diet A: P/F 2.26; diet B: P/F 3.36) on the chemical composition, fatty acid profile and some somatic indexes of meagre (Argyrosomus regius). The trial was carried out on two groups of meagre raised in two different sea cages during 15 months. At the end of the production cycle biometric measures as well as chemical-nutritional analysis of the fillets were conducted on 25 fishes per group. Diet A, with a lower P/F, furnished animals with higher percentages of mesenteric fat (0.48 vs 0.41%; P<0.01) and of fillet yield (51.21 vs 48.12; P<0.01). Moreover, the fillets obtained with the diet A showed higher percentage of fat (3.60 vs 2.41%; P< 0.01), lower moisture (74.10 vs 75.42%; P<0.01), lower losses of water under pressure (16.73 vs 20.20%; P<0.01) and after 48 h of refrigeration (3.08 vs 4.23%; P<0.01). The fatty acids profile of fillets was affected by the diet. Diet A resulted in a higher level of saturated fatty acids (26.44 vs 23.17% of total lipid; P<0.01) and a lower percentage of polyunsaturated fatty acids (31.56 vs 36.08%; P<0.01) in the fillet, mainly due to the lower content of linoleic acid (13.63 vs 19.77%; P<0.01). The atherogenic (AI) and thrombogenic (TI) indexes, which resulted very low in the fish of Group B (AI=0.48 vs 0.60, P<0.01; TI=0.33 vs 0.37, P<0.01), together with the low lipid content of meat in both groups, confirmed the very high nutritional quality of meagre fillets.

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.

Influence of pasture on fatty acid profile of goat milk

The effect of pasture on the fatty acid profile of milk was evaluated using 30 pluriparous goats, which were divided into two homogeneous groups (H and P) of 15 goats each after kidding. Group H (control) goats were housed in a stall and received alfalfa hay, while group P was led to pasture. The goats of both the groups received the same concentrate. Average milk yield did not differ statistically between the groups. The goats of the P group had significantly higher fat content in milk than those of group H (53.7 vs. 61.5 g/day, p < 0.01), while lactose content was significantly higher for group H (66.2 and 61.4 g/day, for groups H and P, respectively, p < 0.05). Among milk fatty acids, pasture significantly affected the percentages of C18:1 cis9, C18:1 trans11, octadecadienoic acid, mono-unsaturated fatty acid and polyunsaturated fatty acid. Pasture highly influenced the c9 t11 conjugated linoleic acid (CLA) (0.778 and 0.513 g/100 g of fat, for group P and H, respectively, p < 0.01), t10 c12 CLA (0.046 vs. 0.029 g/100 g of fat: p < 0.01, for group P and H, respectively, p < 0.01) and SigmaCLA (0.84 vs. 0.56 g/100 g of fat for group P and H, respectively, p < 0.01) concentrations of milk.

Effect of different levels of bee pollen on performance and blood profile of New Zealand White bucks and growth performance of their offspring during summer and winter months

The effect of bee pollen on productive and reproductive performances of adult buck rabbits and their offspring was studied during winter and summer seasons. Forty New Zealand White bucks were equally divided among four groups feeding the same commercial diet and receiving a water solution containing, respectively, 0 (control), 100, 200 and 300 mg bee pollen/kg body weight, twice per week along two experimental periods. The experimental periods were listed for ten weeks both during winter (30-40 weeks of age) and summer seasons (56-66 weeks of age). During the trials body weight, body weight gain, total feed intake, semen quality, fertility and blood constituents were determined. Fertility was determined after natural mating with no treated females. For each season, 80 weaned rabbits obtained from the bucks of the control group were equally divided (20 per group) among 4 levels (0, 100, 200 and 300 mg/kg BW) of bee pollen, given as a water solution twice per week. The offspring sired by bucks given 100, 200 and 300 mg (20 for each group and season) were not administrated bee pollen. The effect of bee pollen on growth performance of rabbits was studied from 4 to 12 weeks of age. Bee pollen at 200 mg/kg BW significantly (p< 0.01) improved semen quality, increased fertility percentage, improved biochemical profiles of blood and helps outstanding of bucks during both seasons. The same concentration of bee pollen increased body weight gain and survival rate and reduced feed intake and feed conversion ratio of offspring up to 12 weeks of age.

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 bee pollen levels on productive, reproductive and blood traits of NZW rabbits

Forty New Zealand White (NZW) rabbit does were equally divided among four groups feeding the same commercial diet and receiving a water solution containing, respectively, 0 (control), 100, 200 and 300 mg bee pollen/kg body weight (BW), 1 week before and after mating during moderate (October-February) and hot seasons (May-September) for three consecutive mating in each season. Does were mated with non-treated adult NZW male rabbits 11 days after kindling. Body weight of does, number of service per conception, conception rate, feed intake, litter size, milk production, blood constituents, weight of kits from birth up to weaning and survival rate were determined. For each season, 80 weaned rabbits originated from the does of the control group (untreated does) were equally divided into four groups (0, 100, 200 and 300 mg/kg BW) of bee pollen, given as a water solution twice per week from 4 to 12 weeks of age. The kit of the does given 100, 200 and 300 mg/kg BW did not receive bee pollen during the growing period (4-12 weeks of age). The effect of bee pollen on growing rabbits performance was studied from 4 to 12 week of age. Bee pollen at 200 mg significantly (p < 0.01) increased body weight of does, conception rate, milk yield, litter size; improved biochemical profiles of blood and helps outstanding of does during both seasons. The same dose of bee pollen significantly increased kit growth and their survival rate until weaning. Growth and feed conversion ratio (FCR) of kits from the treated does during 4-8 weeks of age were significantly better than growth of kits from the untreated does that administrated bee pollen during 4-12 weeks of age. Meanwhile, during the following period (8-12 weeks of age) growth and FCR of kits given bee pollen from the untreated does were significantly better than that of treated does.

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.

In vitro fermentation characteristics of diets with different forage/concentrate ratios: comparison of rumen and faecal inocula.

BACKGROUND The aim of this trial was to evaluate the replacement of rumen fluid with faeces as inoculum in studying the in vitro fermentation characteristics of diets for ruminants using the in vitro gas production technique. Six iso-protein diets with different forage/concentrate ratios were incubated with rumen fluid (RI) or faeces (FI) collected from sheep. RESULTS Most of the fermentation parameters were influenced by diet and inoculum (P < 0.01). With both inocula, organic matter degradability (dOM), cumulative gas production (OMCV) and maximum fermentation rate (R(max) ) increased as the amount of concentrate in the diet increased. R(max) was lower with FI vs RI (P < 0.01); dOM was higher with FI vs RI and the diet × inoculum interaction was significant. As expected, with both inocula, R(max) increased as the neutral detergent fibre content of the diet decreased. Significant correlations were obtained using both inocula between OMCV/dOM and gas/volatile fatty acid (VFA), while the correlation VFA/dOM was significant only with FI. The microbial biomass yield calculated by stoichiometric analysis for all diets was higher with FI vs RI. With FI the organic matter used for microbial growth showed an overall decreasing trend as the amount of concentrate in the diet increased. CONCLUSION The results indicate that both faeces and rumen fluid from sheep have the potential to be used as inoculum for the in vitro gas production technique.