1,721,063 research outputs found
Improving welfare conditions of broiler chicken in Italy. Effects on performances, carcass and meat quality
No full textA trial was carried out to evaluate the influence of improved housing conditions for broilers kept on litter on productivity, carcass and meat quality traits. A total of 33,000 Ross 508 female broiler chickens were divided into two groups Welfare (WLF) and Standard (STD) and reared under different stocking density (14 vs. 19 birds/sq m), litter (wood shaving) amount (3.5 vs. 2.5 kg/sq m) and light:dark regimen (18:6 vs. 23:1). Birds were slaughtered at 40 or 50 d of age. Environmental temperature and humidity as well as litter moisture did not change between the two housing conditions. WLF birds reached a higher body weight but had a slight worse feed efficiency, whereas no differences were found in carcass traits. Breast meat quality evaluation showed higher moisture content and poorer water holding capacity in WLF birds
Effect of dietary supplementation of lysophospholipids on productive performance, nutrient digestibility and carcass quality traits of broiler chickens
Full text linkAn 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
Effect of spaghetti-meat abnormality on quality and histological traits of broiler breast fillets
Full text linkDuring the last few years, the increasing growth rate and meat yield of modern broiler hybrids caused the appearance of several breast muscle abnormalities, such as white striping and wooden breast. Recently, a new myopathy termed spaghetti-meat (SM) characterized by extremely soft and friable pectoralis major when palpated after chilling has emerged. Since the occurrence of SM is often associated with white striping (WS), this study aimed at evaluating the effects of SM and/or WS conditions on meat quality and histological traits in broilers. For this purpose, 96 pectoralis major muscles were selected from homogeneous flocks (47 d of age and 2.8 kg of live weight at slaughter) into two independent trials and classified as follows: 24 Normal (N), 24 WS, 24 SM and 24 WS/SM. Each fillet was cut in order to separate the superficial layer from the deep one and both used to assess
proximate composition, histological features, colour, pH and protein profile. Data were analyses by two-way ANOVA using abnormality and sampling position as the main variables. Proximate composition was found to be significantly modified according the type of abnormality, especially in the superficial layer of the fillets. The SM and WS/SM groups had a remarkable decrease in total protein content coupled with an increased moisture level (p<.001), while WS group was associated with higher lipid content. Histological evaluations of abnormal samples evidenced several degenerative aspects that almost completely concern the superficial layer of the fillets. The SM samples showed poor fibres uniformity and a progressive rarefaction of the endo- and peri-mysial connective tissue. The WS fillets exhibited necrosis and lysis of fibres, fibrosis, lipidosis, loss of cross striation and vacuolar degeneration, while WS/SM fillets exhibited intermediate histological features. No relevant effect on meat colour has been detected,
however abnormal fillets showed increased yellowness (b) and ultimate pH values (p<.001). Moreover, both WS and SM abnormalities were associated with a more intense proteolytic degradation of muscle tissue (p<.001), which led to the formation of high molecular-weight protein fragments. In conclusion, both muscle myopathies mainly affect the superficial layer of pectoralis major muscle, while deep section is poorly involved. Furthermore, if compared with WS, SM abnormality is associated with a more remarkable alteration of the proximate composition and quality traits of the meat
Detection of differentially expressed genes in broiler pectoralis major muscle affected by White Striping - Wooden Breast myopathies
Full text linkWhite Striping and Wooden Breast (WS/WB) are abnormalities increasingly occurring in the fillets of high breast yield and growth rate chicken hybrids. These defects lead to consistent economic losses for poultry meat industry, as affected broiler fillets present an impaired visual appearance that negatively affects consumers' acceptability. Previous studies have highlighted in affected fillets a severely damaged muscle, showing profound inflammation, fibrosis, and lipidosis. The present study investigated the differentially expressed genes and pathways linked to the compositional changes observed in WS/WB breast muscles, in order to outline a more complete framework of the gene networks related to the occurrence of this complex pathological picture. The biochemical composition was performed on 20 pectoralis major samples obtained from high breast yield and growth rate broilers (10 affected vs. 10 normal) and 12 out of the 20 samples were used for the microarray gene expression profiling (6 affected vs. 6 normal). The obtained results indicate strong changes in muscle mineral composition, coupled to an increased deposition of fat. In addition, 204 differentially expressed genes (DEG) were found: 102 up-regulated and 102 down-regulated in affected breasts. The gene expression pathways found more altered in WS/WB muscles are those related to muscle development, polysaccharide metabolic processes, proteoglycans synthesis, inflammation, and calcium signaling pathway. On the whole, the findings suggest that a multifactorial and complex etiology is associated with the occurrence of WS/WB muscle abnormalities, contributing to further defining the transcription patterns associated with these myopathies
Preliminary monitoring of the presence of perfluoroalkyl substances in Italian eggs from different breeding systems
Full text linkPerfluoroalkylated substances (PFASs) are a wide cluster of fluorinated molecules largely engaged industrially and commercially for many purposes. Because of the strength of the fluorine-carbon bond, PFASs show a firm tenacity against thermal degradation, hydrolysis, photolysis and biodegradation. On the other hand, such chemical stability gives them persistent environmental pollutant feature. In 2012, EFSA published a scientific report on PFASs in food, mentioning their adverse effects on health. Based on observational studies evidences, EFSA has recommended a tolerable daily intake (TDI) for the two most known PFASs, i.e. PFOS 150 ng/kg b.w./day and PFOA 1500 ng/kg b.w./day. The aim of this study was to monitor, for the first time, the level of contamination of PFASs in chicken eggs laid in Northern Italy. The eggs were collected from different rearing systems, in order to search a correlation between this variable and the contamination of PFASs. In this study four PFASs [perfluoro-nnonanoic acid (PFNA), perfluoro-noctanoic- acid (PFOA), sodium perfluoro-1- hexanesulfonate (PFHxS) and sodium perfluoro- 1-octanesulfonate (PFOS)] were analyzed by liquid chromatography-tandem mass spectrometer (LC-MS/MS). 132 eggs were analyzed, split up in 11 groups according to the geographical origin and rearing system. Results accord with literature data available for chicken eggs: almost all the samples show a PFASs contamination level under the limit of quantification (LOQ) of 0.25 ng/mL. No significant difference results from the rearing system, attesting an equal distribution and a concentration of PFASs detectable under the limit of quantification
Investigating differences of Pectoralis major muscle vimentin and desmin gene expression between broilers selected for different growth-rates
No full textPerfluoroalkyl contaminants in eggs from backyard chickens reared in Italy
Full text linkPer- and poly-fluoroalkyl substances (PFASs) are persistent and bioaccumulative compounds with adverse impacts on the environment and human health. Diet is one of the main sources of exposure to PFASs. Recently, the EFSA established a tolerable weekly intake (TWI) limit (4.4ng/kg b.w.) for a mixture of the four major PFASs. Eggs and egg products can contribute to this intake, with their contamination possibly dependent on the husbandry system. Monitoring Italian eggs from backyard chickens revealed a relatively uniform PFAS contamination, with perfluoro-1-octanesulfonate being the most abundant. Contamination was detected to be significantly higher in eggs from backyard chickens than in eggs from commercial laying hens, consistent with a previous Italian study. According to the recently set TWI value, the consumption of eggs from backyard chickens could contribute significantly to dietary intake of PFASs (up to 29% of the TWI in children, considering the lower bound approach)
Influence of genotype and feeding on chemical composition of organi chicken meat
Full text linkThe 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)
Muscle Abnormalities and Meat Quality Consequences in Modern Turkey Hybrids
Full text linkTurkey meat is the second most consumed poultry meat worldwide and represents an economic source of high-quality protein for human consumption. To fulfill the increasing demand for turkey meat, breeding companies have been selecting genetic lines with increased growth potential and breast muscle proportion. Moreover, the progressive shift toward further processed products has emphasized the need for higher standards in poultry meat to improve its technological characteristics and functional properties (i.e., water-holding capacity). However, as observed for broiler chickens, a growing body of scientific evidence suggests that the intense selection for the aforementioned traits could be associated with a greater occurrence of growth-related myopathies and abnormalities and, consequently, to increased downgrading rates and overall reduction of meat quality characteristics. In the past, muscle abnormalities such as deep pectoral myopathy, pale-soft-and-exudative-like meat, and focal myopathy have been reported in turkey lines selected for increased growth rate. In addition, the presence of white striations in the superficial layer of pectoralis major muscle, as well as the tendency of muscle fiber bundles to separate resulting in an altered breast muscle structure, has been detected in commercial turkey abattoirs. Furthermore, past investigations revealed the presence of another quality issue depicted by an overall toughening of the breast muscle. These meat abnormalities seem to macroscopically overlap the white striping, spaghetti meat, and wooden breast conditions observed in pectoral muscle of fast-growing, high-breast-yield chicken hybrids, respectively. Considering the high economic impact of these growth-related abnormalities in broilers, there is an increasing interest of the turkey industry in estimating the occurrence and the impact of these meat quality issues also in the modern turkey lines. Studies have been recently conducted to assess the effect of the genotype on the occurrence of these emerging growth-related defects and to evaluate how meat quality properties are affected by white-striping condition in turkeys, respectively. Therefore, this review aims to provide a critical overview of the current understanding regarding the growth-related abnormalities and their impact on meat quality in modern turkey hybrids with the hope that this information may improve the knowledge concerning their overall effect on poultry meat
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