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Rivista di Storia dell'Università di Torino, V. 8, N. 2 (2019)

Recent studies on the exploitation of larvae meal inclusion in broiler chickens diet report a significant increase of breast muscle, carcass quality and growth performance. The purpose of this study was to investigate the effects of Mealworm (Tenebrio molitor, TM) meal inclusion in broiler chicken diet on global gene expression of four tissues, namely breast muscle, liver, jejunum and caecum. Isonitrogenous and isoenergetic diets were formulated with 0% (control group) and 15% (test group) of TM meal inclusion. 80 one-day-old male broiler chicks (Ross 708) were reared in 10 pens (eight birds/pen): the pens were divided in two groups including five experimental replicates for each diet. The birds were slaughtered at 53 days of age. The tissue samples were collected and stored in RNA Later solution (Ambion) for gene expression analysis. RNA-seq was carried out on Illumina NGS analyzer. The results showed that 117, 118, 119 and 182 RNA transcripts were upregulated and 120, 116, 168 and 126 RNA transcripts were downregulated in breast muscle, liver, jejunum and cecum respectively. In all tissues 25% of downregulated differentially expressed genes (DEG) had a foldchange> four; while the 25% of upregulated DEGs had a foldchange higher than four in breast and liver and>two in intestinal mucosa. A gene ontology analysis showed that only half of DEGs were involved in known biological processes including protein metabolism (30 DEGs), gene expression (30), signal transduction (15), and immune system (21). An expression pathway analysis with Reactome showed that the pathway with minor False Discovery Rate (FDR) was the striated muscle contraction in breast and the peptide chain elongation in the other tissues. The ubiquitin B gene (UBB), that plays an important role in protein's metabolism, was downregulated (-0.8) in breast and upregulated (þ0.57) in liver, whereas the expression of this gene did not change in intestinal mucosa. The differential expression of UBB might suggest an increase of non-lysosomal intracellular protein degradation related to a fast protein turnover in liver and a slow protein turnover in breast. In addition, the ribosomal protein (RPLP) profile, related to peptide chain elongation, was similar: -0.45 mean fold-change in breast and þ0.5 in liver while a moderated increase in intestinal mucosa was observed. No alterations in RNA expression were detected that could discourage the use of larvae mealworm inclusion in broiler chicken diet.

The aims of the study were to evaluate productive performances and environmental impact of double-muscled Piemontese culled cows. In two trials, 39 Piemontese culled cows aged from 46 to 176 mon were fattened using diets commonly applied in farm conditions. The animals were weighed at the beginning and end of the trials. Concentrate and hay intake were recorded daily. After slaughtering, meat, fat and bone yields were recorded and dressing percentage was calculated. The backward linear regression model was employed for statistical analysis. Results showed average body weight (ABW) of cows as (556.97 ± 55.99) kg and relatively low dry matter intake (DMI) [(9.17 ± 0.35) kg d −1 ] during the fattening period. The ratio between DMI and ABW, i.e., ratio between intake and weight (RIW), (1.66 ± 0.18)% was negatively influenced by initial body weight (IBW) and duration of finishing period (D), but age had no effect on RIW. Average daily gain (ADG) was relatively low [(0.55 ± 0.21) kg d −1 ], and was negatively correlated with IBW and D, which implied that lower IBW and shorter D could have higher ADG and vice versa. The dressing percentage (DP) was (59.80 ± 1.83)% and the carcass red meat yield (MY) was (75.17 ± 3.10)%. Nevertheless, N efficiency was very low [(4.35 ± 1.76)%], which must be considered in relation to environmental protection so both animal requirements and a well balanced diet need more attention. In conclusion when Piemontese cows will be culled and fattened, IBW and D should be considered carefully in order to get a reasonable ADG and N efficiency to guarantee productive benefits and environmental protection at the same time.

A key aspect of the sustainability of aquaculture industry is the supply of proteins for aqua feeds as fish meal (FM) is considered a finite resource and has reached very high price (Hardy, 2010). Several alternative have been tested in the past decades and nowadays FM represent only about 10 to 20% of the feed for carnivorous aquaculture species, the rest of protein supply being covered mainly by vegetable proteins (Jobling, 2015). Nevertheless, even if a complete substitution of FM by plant proteins is feasible, it has been highlight that adverse effect can occur for many reasons among which, their content of anti-nutritional factors, unpalatable compounds, inappropriate fatty acid profile, shortage of essential amino acid, and problems related to the inflammation of the digestive tract (Jobling, 2015). At present the interest of researchers about insect meal is increasing. Some studies have been carried out in order to evaluate the use of insect mealsin diets for fish because of their high protein content and since insects are often included in natural fish diets. Recent reviews have highlighted how some insect larvae derived mealscan successful be used in fish diets (Barroso et al., 2014; Makkaret al., 2014; Henry et al., 2015) but new research are requested to confirm these data. As among insect species investigated, black soldier fly (BSF -Hermetia illucens ) meal seems a good candidate due to its valuable nutritional properties, the aim of thisresearchwas to investigate the effects of the inclusion of a defatted BSF in rainbow trout feed on performances, somatic indexes, and some slaughtering and quality parameters.