Effect of dietary supplementation of lysophospholipids on productive performance, nutrient digestibility and carcass quality traits of broiler chickens

An experiment was carried out to evaluate productive performance, nutrient digestibility and carcass quality traits of broiler chickens fed diets supplemented with an exogenous emulsifier based on lysophospholipids prepared by enzymatic conversion of soy lecithin. One thousand seven-hundred and fifty-five one-day-old male Ross 308 chicks were randomly divided into three experimental groups of nine replications each: control group (CON) fed a corn–soybean basal diet, and two groups fed CON diet supplemented with constant (1 kg/ton) or variable (1–1.5 kg/ton) level of emulsifier (CONST and VARI, respectively). At the end of the trial (42 d), birds receiving the emulsifier had a statistically significant (p < 0.05) lower feed conversion rate compared to the control. Body weight and daily weight gain were only slightly influenced by lysophospholipids supplementation, while mortality and feed intake resulted similar among the groups. No statistically significant effect of the emulsifier was observed on nutrient digestibility as well as slaughtering yields, skin pigmentation and incidence of foot pad dermatitis. The results obtained in this study suggest that the use of an emulsifier based on lysophospholipids improves feed efficiency while showed limited effect on carcass quality traits

Occurrence of Breast Meat Abnormalities and Foot Pad Dermatitis in Light-Size Broiler Chicken Hybrids

Only limited information regarding the occurrence of breast meat abnormalities and foot pad dermatitis (FPD) in current broiler genotypes is available. Therefore, this study was conducted to estimate the incidence and severity of breast myopathies (white striping, WS; wooden breast, WB; spaghetti meat, SM) and FPD in two fast-growing chicken hybrids, while simultaneously recording their growth performance. A total of 1560 one-day-old female chicks (780 for each hybrid, A and B; 12 replicates/genotype) were raised in the same environmental conditions and fed the same diet. Productive parameters were recorded at the end of each feeding phase. At slaughter (35 d), the occurrence of meat abnormalities and FPD was assessed on 150 breasts/genotype and on all of the processed birds, respectively. Although comparable growth performance was observed at slaughter, genotype B reported a significantly higher percentage of breasts without meat abnormalities (69% vs. 39%, 75% vs. 41%, 61% vs. 37% for WS, WB and SM, respectively) and also birds without FPD, than genotype A (53% vs. 23%, respectively). Overall, these findings highlight the importance of better understanding the effects of the genotype and the artificial selection applied to fast-growing chicken hybrids on the occurrence of emerging meat abnormalities and FPD even in light-size birds

The role of histidine dipeptides on postmortem acidification of broiler muscles with different energy metabolism

It is generally held that the content of several free amino acids and dipeptides is closely related to the energy-supplying metabolism of skeletal muscles. Metabolic characteristics of muscles are involved in the variability of meat quality due to their ability to influence the patterns of energy metabolism not only in living animal but also during post-mortem time. Within this context, this study aimed at establishing whether the concentration of histidine dipeptides can affect muscle post-mortem metabolism, examining the glycolytic pathway of three chicken muscles (Pectoralis major, extensor iliotibialis lateralis and gastrocnemius internus as glycolytic, intermediate and oxidative-type, respectively) selected based on their histidine dipeptides content and ultimate pH. Thus, a total of 8 carcasses were obtained from the same flock of broiler chickens (Ross 308 strain, females, 49 days of age, 2.8 kg body weight at slaughter) and selected immediately after evisceration from the line of a commercial processing plant. Meat samples of about 1 cm3 were excised from bone-in muscles at 15, 60, 120 and 1,440 min post-mortem, instantly frozen in liquid nitrogen and used for the determination of pH, glycolytic metabolites, buffering capacity as well as histidine dipeptides content through 1H-NMR. Overall results suggest that glycolysis in leg muscles ceased already after 2 h post-mortem, while in breast muscle continued until 24 h, when it exhibited significantly lower pH values (P&lt;0.05). However, considering its remarkable glycolytic potential, Pectoralis major muscle should have exhibited a greater and faster acidification, suggesting that its higher (P&lt;0.05) histidine dipeptides\u2019 content might have prevented a potentially stronger acidification process. Accordingly, breast muscle also showed greater (P&lt;0.05) buffering ability in the pH range 6.0-7.0. Therefore, anserine and carnosine, being highly positively correlated with muscle\u2019s buffering capacity (P&lt;0.001), might play a role in regulating post-mortem pH decline, thus exerting an effect on muscle metabolism during pre-rigor phase and the quality of the forthcoming meat. Overall results also suggest that total histidine dipeptides content along with muscular ultimate pH represent good indicators for the energy-supplying metabolism of chicken muscles

Magnitude of emerging meat quality defects in breast fillets of different commercial meat-type chicken hybrids

Selection for fast-growing and increasing breast meat yield may negatively impact muscle structure and meat quality traits. In the last years, two emerging meat defects have been arisen in breast fillets of fast-growing chicken hybrids: white striping characterized by white parallel striations in the direction of the muscle fibers and poor cohesion of muscle structure with fibers bundles which can be easily pulled away by fingers. A trial was conducted to compare productive performances, cut up yields and incidence of white striping and poor cohesion (absence=normal, presence classified in 2 levels as moderate and severe) in four of the most representative commercial chicken hybrids which were classified as either standard (SBY1 and SBY2) or high (HBY1 and HBY2) breast-yield. A total of 2,160 1-day-old male chicks were equally divided into four experimental groups of 9 replications each, raised in the same experimental conditions and fed the same commercial diets. Birds were slaughtered at about 3.6 kg live weight reached at 48 (SBY1 and HBY2) and 51 d of age (SBY2 and HBY1), respectively. Both HBY1 and HBY2 had a lower daily feed intake if compared with SBY1 and SBY2 (120 and 124 vs 131 and 130 g/day, P&lt;0.01). On the other hand, feed conversion rate was not significantly modified. As expected, HBY1 and HBY2 had higher breast yields than both SBY birds (30.9 and 31.5 vs 28.6 and 28.5%). The total occurrence (moderate and severe) of white striping in all the genotypes was remarkably high (&gt;87%). However, HBY birds had an incidence of about 96% white striped fillets, while its occurrence in SBY groups did not exceed 90%. The overall incidence (moderate and severe) of muscle structure with poor cohesion also resulted extremely high (&gt;90%). Indeed, only 10% of breast fillets from SBY1 birds resulted unaffected by this defect, while 40% of breast fillets from HBY2 showed poor cohesion with severe degree. In conclusion, from this study emerged that all the modern chicken hybrids here tested are affected by a high incidence of breast muscle defects which are particularly pronounced in high breast-yield birds

Influence of genotype and feeding on chemical composition of organi chicken meat

The aim of this study was to evaluate the effects of different genotypes and of feeding on meat chemical composition, including fatty acid profile, of chickens reared under organic conditions. Two meat–type fast-growing (FG) and medium-growing (MG), and one egg-type slow-growing (SG) strains were assigned to 2 different diets differing for the protein source: soybean (SB) and faba bean (FB) in partial substitution of soybean. Genotype markedly affected the meat chemical composition. SG breast and thigh meat showed lower content of lipids (P<0.01) than FG. The highest proportions of polyunsaturated fatty acids (PUFA) n-6 and n-3 and the lowest proportion of monounsaturated (MUFA) (P<0.01), as well as the lowest ratio of PUFA n6/n3 (P<0.01) were found in SG breast and thigh meat. MG showed always intermediate values. As for feeding, FB treatment produced only a slight increment of protein in breast and a decrease of fat and ash in thigh meat. Total PUFA and PUFA n-6 resulted lower in both thigh and breast meat of FB groups compared to SB (P<0.01)

Molecular Pathways and Key Genes Associated With Breast Width and Protein Content in White Striping and Wooden Breast Chicken Pectoral Muscle

Growth-related abnormalities affecting modern chickens, known as White Striping (WS) and Wooden Breast (WB), have been deeply investigated in the last decade. Nevertheless, their precise etiology remains unclear. The present study aimed at providing new insights into the molecular mechanisms involved in their onset by identifying clusters of co-expressed genes (i.e., modules) and key loci associated with phenotypes highly related to the occurrence of these muscular disorders. The data obtained by a Weighted Gene Co-expression Network Analysis (WGCNA) were investigated to identify hub genes associated with the parameters breast width (W) and total crude protein content (PC) of Pectoralis major muscles (PM) previously harvested from 12 fast-growing broilers (6 normal vs. 6 affected by WS/WB). W and PC can be considered markers of the high breast yield of modern broilers and the impaired composition of abnormal fillets, respectively. Among the identified modules, the turquoise (r = -0.90, p &lt; 0.0001) and yellow2 (r = 0.91, p &lt; 0.0001) were those most significantly related to PC and W, and therefore respectively named “protein content” and “width” modules. Functional analysis of the width module evidenced genes involved in the ubiquitin-mediated proteolysis and inflammatory response. GTPase activator activity, PI3K-Akt signaling pathway, collagen catabolic process, and blood vessel development have been detected among the most significant functional categories of the protein content module. The most interconnected hub genes detected for the width module encode for proteins implicated in the adaptive responses to oxidative stress (i.e., THRAP3 and PRPF40A), and a member of the inhibitor of apoptosis family (i.e., BIRC2) involved in contrasting apoptotic events related to the endoplasmic reticulum (ER)-stress. The protein content module showed hub genes coding for different types of collagens (such as COL6A3 and COL5A2), along with MMP2 and SPARC, which are implicated inCollagen type IV catabolism and biosynthesis. Taken together, the present findings suggested that an ER stress condition may underly the inflammatory responses and apoptotic events taking place within affected PM muscles. Moreover, these results support the hypothesis of a role of the Collagen type IV in the cascade of events leading to the occurrence of WS/WB and identify novel actors probably involved in their onset

Effects of in Ovo Administration of Betaine and Choline on Hatchability Results, Growth and Carcass Characteristics and Immune Response of Broiler Chickens

The effect of in ovo administration of different levels of betaine and choline on egg hatchability, immune response, growth and carcass traits of broiler chickens was studied. Four thousand hatching eggs from Ross 308 broiler breeder layers, weighed individually, were incubated for 21 days in a commercial hatchery. At 12th day of incubation, 3456 fertilized eggs were randomly divided into 8 experimental groups of 3 replicates each (144 eggs per replicate): negative control (NC) – not injected; positive control (PC) – injected with 0.5 mL deionized water; Bet 0.25 – injected with 0.5 mL deionized water+0.25 mg soluble betaine; Bet 0.375 – injected with 0.5 mL deionized water+0.375 mg soluble betaine; Bet 0.50 – injected with 0.5 mL deionized water+0.50 mg soluble betaine; Chol 0.25 – injected with 0.5 mL deionized water+0.25 mg soluble choline; Chol 0.375 – injected with 0.5 mL deionized water+0.375 mg soluble choline; Chol 0.50 – injected with 0.5 mL deionized water+0.50 mg soluble choline. Among the hatched chickens, 360 males were randomly chosen (45 for each group) and were grown up to 42nd day of age. The embryo mortality, pecked eggs, infected eggs and hatchability percentages were similar among the experimental groups. The betaine and choline treatments improved hatching weight and final weight of chickens, while reduced feed conversion ratio and abdominal fat percentage. No effect on carcass yield, and breast muscle, leg and wings percentages, as well as on immunoglobulin M (IgM), G (IgG), and total antibody (IgT) titers was observed. The treatments had little effect on internal organs

Impact of Cooking Procedures and Storage Practices at Home on Consumer Exposure to Listeria Monocytogenes and Salmonella Due to the Consumption of Pork Meat

[EN] The objective of this research was to analyze the impact of different cooking procedures (i.e., gas hob and traditional static oven) and levels of cooking (i.e., rare, medium, and well-done) on inactivation of Listeria monocytogenes and Salmonella in pork loin chops. Moreover, the consumer's exposure to both microorganisms after simulation of meat leftover storage at home was assessed. The results showed that well-done cooking in a static oven was the only treatment able to inactivate the tested pathogens. The other cooking combinations allowed to reach in the product temperatures always 73.6 degrees C, decreasing both pathogens between 6 log(10) cfu/g and 7 log(10) cfu/g. However, according to simulation results, the few cells surviving cooking treatments can multiply during storage by consumers up to 1 log(10) cfu/g, with probabilities of 0.059 (gas hob) and 0.035 (static oven) for L. monocytogenes and 0.049 (gas hob) and 0.031 (static oven) for Salmonella. The key factors affecting consumer exposure in relation to storage practices were probability of pathogen occurrence after cooking, doneness degree, time of storage, and time of storage at room temperature. The results of this study can be combined with prevalence data and dose-response models in risk assessment models and included in guidelines for consumers on practices to be followed to manage cooking of pork meat at home.The research leading to these results received funding from the E.U. Seventh Framework Programme under grant agreement KBBE 222738BASELINE (Selection and Improving of Fit-for-Purpose Sampling Procedures for Specific Foods and Risks).De Cesare, A.; Doménech Antich, EM.; Comin, D.; Meluzzi, A.; Manfreda, G. (2017). Impact of Cooking Procedures and Storage Practices at Home on Consumer Exposure to Listeria Monocytogenes and Salmonella Due to the Consumption of Pork Meat. Risk Analysis. 38(4):638-652. https://doi.org/10.1111/risa.12882S63865238

Effect of dietary arginine to lysine ratios on productive performance, meat quality, plasma and muscle metabolomics profile in fast-growing broiler chickens

open7siBackground: Due to the important functions of arginine in poultry, it should be questioned whether the currently adopted dietary Arg:Lys ratios are sufficient to meet the modern broiler requirement in arginine. The present study aimed, therefore, to evaluate the effects of the dietary supplementation of L-arginine in a commercial broiler diet on productive performance, breast meat quality attributes, incidence and severity of breast muscle myopathies and foot pad dermatitis (FPD), and plasma and muscle metabolomics profile in fast-growing broilers. Results: A total of 1,170 1-day-old Ross 308 male chicks was divided into two experimental groups of 9 replicates each fed either a commercial basal diet (CON, digestible Arg:Lys ratio of 1.05,1.05,1.06and1.07 in each feeding phase, respectively) or the same basal diet supplemented on-top with crystalline L-arginine (ARG, digestible Arg:Lys ratio of 1.15,1.15,1.16and1.17, respectively). Productive parameters were determined at the end of each feeding phase (12, 22, 33, 43 d). At slaughter (43 d), incidence and severity of FPD and breast myopathies were assessed, while plasma and breast muscle samples were collected and analyzed by proton nuclear magnetic resonance-spectroscopy. The dietary supplementation of arginine significantly reduced cumulative feed conversion ratio compared to the control diet at 12 d (1.352 vs. 1.401, P&lt;0.05), 22 d (1.398 vs. 1.420; P&lt;0.01) and 33 d (1.494 vs. 1.524; P&lt;0.05), and also tended to improve it in the overall period of trial (1.646 vs. 1.675; P=0.09). Body weight was significantly increased in ARG compared to CON group at 33 d (1,884 vs. 1,829g; P&lt;0.05). No significant effect was observed on meat quality attributes, breast myopathies and FPD occurrence. ARG birds showed significantly higher plasma concentration of arginine and leucine, and lower of acetoacetate, glutamate, adenosine and proline. Arginine and acetate concentrations were higher, whereas acetone and inosine levels were lower in the breast of ARG birds (P&lt;0.05). Conclusions: Taken together, these data showed that increased digestible Arg:Lys ratio had positive effects on feed efficiency in broiler chickens probably via modulation of metabolites that play key roles in energy and protein metabolism.openZampiga, Marco; Laghi, Luca; Petracci, Massimiliano; Zhu, Chenglin; Meluzzi, Adele; Dridi, Sami; Sirri, Federico*Zampiga, Marco; Laghi, Luca; Petracci, Massimiliano; Zhu, Chenglin; Meluzzi, Adele; Dridi, Sami; Sirri, Federico