Untargeted Metabolomics Combined with Sensory Analysis to Evaluate the Chemical Changes in Coppa Piacentina PDO during Different Ripening Times

Ripening time is known to drive the chemical and sensory profiles of dry meat products, thus potentially affecting the final quality of the product. Starting from these background conditions, the aim of this work was to shed light, for the first time, on the chemical modifications of a typical Italian PDO meat product-namely, Coppa Piacentina-during ripening, to find correlations between its sensory quality and the biomarker compounds related to the progress of ripening. The ripening time (from 60 to 240 days) was found to deeply modify the chemical composition of this typical meat product, providing potential biomarkers of both oxidative reactions and sensory attributes. The chemical analyses revealed that there is typically a significant decrease in the moisture content during ripening, likely due to increased dehydration. In addition, the fatty acid profile showed that the distribution of polyunsaturated fatty acids significantly (p < 0.05) decreased during ripening, because of their high susceptibility to oxidation and conversion to intermediate and secondary molecules. An untargeted metabolomics approach, coupled with unsupervised and supervised multivariate statistics, highlighted a significant impact (prediction scores > 1) of lipid oxidation during ripening time, with some metabolites (such as γ -glutamyl-peptides, hydroperoxy-fatty acids, and glutathione) being particularly discriminant in predicting the changes observed. The discriminant metabolites were coherent with the progressive increase of peroxide values determined during the entire ripening period. Finally, the sensory analysis outlined that the highest degree of ripening provided greater color intensity of the lean part, slice firmness, and chewing consistency, with glutathione and γ-glutamyl-glutamic acid establishing the highest number of significant correlations with the sensory attributes evaluated. Taken together, this work highlights the importance and validity of untargeted metabolomics coupled with sensory analysis to investigate the comprehensive chemical and sensory changes to dry meat during ripening.

A mixture of quebracho and chestnut tannins drives butyrate-producing bacteria populations shift in the gut microbiota of weaned piglets

Weaning is a critical period for piglets, in which unbalanced gut microbiota and/or pathogen colonisation can contribute to diseases that interfere with animal performance. Tannins are natural compounds that could be used as functional ingredients to improve gut health in pig farming thanks to their antibacterial, antioxidant, and antidiarrhoeal properties. In this study, a mixture of quebracho and chestnut tannins (1.25%) was evaluated for its efficacy in reducing the negative weaning effects on piglet growth. Microbiota composition was assessed by Illumina MiSeq 16S rRNA gene sequencing of DNA extracted from stools at the end of the trial. Sequence analysis revealed an increase in the genera Shuttleworthia, Pseudobutyrivibrio, Peptococcus, Anaerostipes, and Solobacterium in the tannin-supplemented group. Conversely, this dietary intervention reduced the abundance of the genera Syntrophococcus, Atopobium, Mitsuokella, Sharpea, and Prevotella. The populations of butyrate-producing bacteria were modulated by tannin, and higher butyrate concentrations in stools were detected in the tannin-fed pigs. Co-occurrence analysis revealed that the operational taxonomic units (OTUs) belonging to the families Veillonellaceae, Lachnospiraceae, and Coriobacteriaceae occupied the central part of the network in both the control and the tannin-fed animals. Instead, in the tannin group, the OTUs belonging to the families Acidaminococcaceae, Alcaligenaceae, and Spirochaetaceae characterised its network, whereas Family XIII Incertae Sedis occupied a more central position than in the control group. Conversely, the presence of Desulfovibrionaceae characterised the network of the control group, and this family was not present in the network of the tannin group. Moreover, the prediction of metabolic pathways revealed that the gut microbiome of the tannin group possessed an enhanced potential for carbohydrate transport and metabolism, as well as a lower abundance of pathways related to cell wall/membrane/envelope biogenesis and inorganic ion transport. In conclusion, the tested tannins seem to modulate the gut microbiota, favouring groups of butyrate-producing bacteria.

Implications of Tributyrin on Gut Microbiota Shifts Related to Performances of Weaning Piglets

Alternatives to antibiotic treatments are required owing to the ban on the use of these drugs as growth promoters in food animal production. Tributyrin appears to play a role in improving growth performance in pigs, albeit with varying degrees of effectiveness. So far, very little is known about its effects on gut microbiota composition. In this study, we investigated the gut microbiota changes of piglets receiving, at weaning, 0.2% tributyrin added to their basal diet. Microbiota composition was assessed through 16S-rRNA gene sequencing on stools collected from tributyrin and control groups. The functional profiles of microbial communities were predicted from amplicon abundance data. A comparison between dietary groups revealed that tributyrin strongly modulated gut microbiota composition in piglets, increasing the relative abundance of a number of bacterial genera such as Oscillospira, Oscillibacter, Mucispirillum and Butyrivibrio. These genera were positively correlated to animal average daily gain (ADG) and/or body weight (BW). Based on the function profile prediction, the gut microbiome of the tributyrin group possessed an enhanced potential for energy metabolism and a reduced potential for carbohydrate metabolism. In conclusion, our results indicated that tributyrin can promote changes to gut microbial communities, which could contribute to improving animal performance after weaning.

Effect of a low crude protein diet supplemented with different levels of threonine on growth performance, carcass traits, blood parameters, and immune responses of growing broilers

A study was conducted to evaluate growth performance, carcass traits, blood serum parameters, and immune responses of Ross 308 male broilers fed diets containing 2 different crude protein (CP) levels (97.5 and 100%) and 4 threonine (Thr) levels (100, 110, 120, and 130% of Ross recommendations for starter and grower periods). A completely randomized block design was adopted and main effects (CP and Thr) were arranged in a 2 × 4 factorial approach. Optimum growth performance was achieved when broiler requirements for CP and Thr were 100% satisfied. The 110% Thr inclusion in 97.5% CP diet increased ADG, ADFI, energy intake, and protein intake (Thr, P < 0.01; quadratic, P = 0.01). The G:F (linear, P = 0.05) and energy efficiency (linear, P = 0.04) tended to decreased (Thr, P = 0.09) by increasing Thr supplementation level, whereas protein efficiency tended to increase (CP, P = 0.06) by reducing CP level. The 110% Thr inclusion in 97.5% CP diet increased eviscerated carcass weight (CP × Thr, P = 0.03) and carcass yield (Thr, P = 0.08; quadratic, P = 0.05). The reduction of CP content promoted fat abdominal deposition (CP, P = 0.05). Incremental Thr raised abdominal fat (Thr, P = 0.01; linear, P = 0.01). The 97.5% CP diets resulted in higher serum concentrations of uric acid (CP, P = 0.02), total and high- and low-density lipoprotein-linked cholesterol (CP, P≤ 0.01), and alanine aminotransferase (CP, P = 0.05) and lower (CP, P = 0.01) concentrations of triglycerides and very low density lipoproteins compared with the 100% CP diets. However, the Thr inclusion improved serum lipid profile. Irrespective of CP content, incremental Thr levels up to 120% increased (Thr, P = 0.01) broiler immune responses against Newcastle disease virus and sheep red blood cells. In order to reduce dietary CP content, strategies to increase synthetic amino acid availability, such as the use of encapsulated amino acids, should be taken into account.

Effect of the inclusion of dry pasta by-products at different levels in the diet of typical Italian finishing heavy pigs: Performance, carcass characteristics, and ham quality

The effect of pasta inclusion in finishing pig diets was evaluated on growth performance, carcass characteristics, and ham quality. Pigs (144) were assigned to 4 diets with different pasta levels: 0 (control, corn-based diet), 30, 60, or 80%. Pigs fed pasta had greater (linear, P<0.01) feed intakes than controls. Pasta increased (quadratic, P<0.01) carcass weight and dressing percentage reaching the highest values at 30% inclusion level, and reduced (linear, P<0.01) the Longissimus thoracis et lumborum thickness. Pasta decreased (linear, P<0.01) linoleic acid and polyunsaturated fatty acid levels in subcutaneous (fresh and seasoned hams) and intramuscular (seasoned hams) fat, and enhanced saturated fatty acid content in subcutaneous fat (fresh hams: quadratic, P<0.01; seasoned hams: linear, P=0.03). Proteolysis index, colour, weight losses, and sensory properties (excepted extraneous taste) of the hams were unaffected by the pasta. Pasta could be considered as an ingredient in the diet for typical Italian finishing heavy pigs.

Characterization of protected designation of origin Italian meat products obtained from heavy pigs fed barley-based diets

A study was conducted to evaluate the quality and sensory properties of protected designation of origin (PDO) Parma ham and Piacentina neck obtained from heavy pigs (Italian Duroc × Italian Large White) fed barley-based diets. Four diets were tested: 1) a corn-based diet (control), 2) the control diet with 80% of a normal-amylose hulled barley variety (Cometa), 3) the control diet with 80% of a normal-amylose hulless barley variety (Astartis), and 4) the control diet with 80% of a low-amylose hulless barley variety (Alamo). All the meat products were analyzed for physicochemical and color parameters. The dry-cured hams and necks were also evaluated for sensory properties. The data of physicochemical, color, and sensory parameters were separately analyzed by multivariate factor analysis, and interpretation of each extracted factor was based on specific original variables loading on each one. The meat products obtained from pigs fed the barley-based diets differed from those obtained from the control pigs on the PUFA factors characterized by C18:2-6 and omega-3:omega-6 ratio. In particular, the meat products obtained from pigs fed the barley-based diets had a lower content of C18:2-6 and a higher omega-3:omega-6 ratio ( < 0.05) than the control. In fresh hams, iodine number and SFA (C16:0 and C18:0) in addition to PUFA and omega-3:omega-6 ratio loaded on the PUFA/SFA factor. The fresh hams produced from pigs fed the barley-based diets had subcutaneous fat (SC) with a lower iodine number and a higher SFA level compared with those produced from the control pigs ( < 0.05). A sex effect was measured for PUFA/SFA and oleic acid factors. In particular, the barrow SC had a lower SFA content, higher PUFA and C18:1-9 levels, and a higher iodine number ( < 0.05) than the gilt SC. There were no appreciable differences in the color and sensory properties of meat products obtained from pigs fed the different diets. The hams from barrows differed from those obtained from gilts on the lean properties factor describing properties related to aspect and odor of dry-cured hams. Indeed, the hams from barrows were depreciated compared with the hams from gilts for minor intensity, brightness, and uniformity of the lean, pinkish intermuscular fat and cured odor. In conclusion, barley could be used as a replacement for corn in heavy pig diets for the production of PDO Italian products without negative effects on the physicochemical, color, or sensory characteristics of meat products.

Microencapsulated lysine and low-protein diets: effects on performance, carcass characteristics and nitrogen excretion in heavy growing-finishing pigs

Two studies were conducted to assess the effects of dietary protein and Lys reduction on growth performance, carcass quality, N excretion, and plasma N profile in growing-finishing pigs from 35 to 180 kg. The growing trial was conducted with 72 gilts and 72 barrows with 6 pens per treatment and 6 gilts or 6 barrows per pen. Four diets with the same DE and NE were compared: 1) control diet, 2) diet with protein content reduced by 3% units compared with the control diet and supplemented with Lys HCl to match the requirements according to the 2012 NRC (FLys), 3) diet similar to FLys for protein level but supplemented with only 50% of the Lys HCl provided with FLys (-50% FLys), and 4) diet similar to FLys and -50% Flys for protein level with microencapsulated Lys added to supply 20% of the Lys provided by FLys (-80% MLys). Pigs fed the FLys diet performed in a similar manner and showed similar carcass characteristics to the control pigs. Pigs fed the -50% FLys diet had the lightest BW (P < 0.01) as well as the lightest carcass (P = 0.02) and trimmed thigh (P = 0.04) weights. Pigs fed the -80% MLys diet showed growth performance and carcass characteristics similar to the control pigs. The N balance study was conducted with 8 barrows arranged in a double replicated 4 × 4 Latin square design. The control pigs had greater (P < 0.01) N intake and urinary and total N excretion compared with pigs fed the low-protein diets. The reduction of the dietary protein concentration by 3% units decreased total N excretion by an average of 24.5% and the greatest reduction of total N excretion was obtained by the -80% MLys diet (26.12%) compared with the control diet throughout the trial. No effect of dietary treatment was observed on the plasma concentrations of ammonia, urea, and total AA in the 80-kg pigs. Decreased plasma ammonia (P < 0.01) and urea (P = 0.03) concentrations were detected in the 120-kg pigs fed the low-protein diets. The 160-kg pigs fed the -80% MLys pigs had less total AA, indispensable AA in particular (P < 0.01), than pigs fed the other diets and decreased ammonia (P < 0.01) and urea (P = 0.05) concentrations than the control pigs. The results showed that the use of microencapsulated Lys, compared with both Lys HCl and dietary protein-bound Lys, can save CP and synthetic AA in diet formulation and can reduce N excretion in manure without adversely affecting the growth performance and carcass quality of heavy growing-finishing pigs.

Review of predictive models for Fusarium head blight and related mycotoxin contamination in wheat

Mould growth and mycotoxin production are related to plant stress caused by environmental factors such as: extreme weather; insect damage; inadequate storage conditions and incorrect fertilization; these predispose plants to mycotoxin contamination in the field. Fusarium species infect wheat during the flowering period. In addition to losses of yield, these fungi can also synthesize toxic components (mycotoxins) in suitable environmental conditions, thus threatening animal and human health. Given the severe consequences and the fact that mycotoxins affect production throughout the world, the ability to predict Fusarium head blight (FHB) and deoxynivalenol (DON) and other mycotoxin contamination is important to reduce the year-to-year risk for producers. Owing to these dangerous consequences in Argentina, Belgium, Canada, Italy, the United States and in Europe, computer models, based on weather variables (temperature, rainfall and moisture level), have been developed to predict the occurrence of FHB and DON contamination in wheat.