Performance, carcass, gastrointestinal tract and meat quality traits, and selected blood parameters of broilers fed diets supplemented with humic substances

BACKGROUND: The effects of humic substances (HS) on quality traits (colour, water‐holding capacity, and pH) of breast and thigh meats and on blood minerals (calcium and phosphorus) and on metabolites (glucose, total protein, triglyceride and cholesterols) as well as on the performance, carcass, and gastrointestinal tract (gut) traits of broilers were studied. In total, 480 male chicks (ROSS 308) were allocated to four treatments, each with five replicates containing 24 birds. While control birds were fed a diet (mash form) with no additives (0 HS), other treatment birds were fed with diets containing HS at 0.5 (0.5 HS), 1.0 (1 HS) or 1.5 (1.5 HS) g kg^?1 from 1 to 42 days of age. RESULTS: The body and carcass weights and feed efficiency increased (P < 0.05) by 1.5 HS, and blood cholesterol decreased (P < 0.05) by 1 HS and 1.5 HS compared to 0 HS. The 0.5 HS decreased (P < 0.10) low‐density lipoprotein compared to 0 HS. The 0.5 HS resulted in thigh meat and breast meat that were lighter and darker than those found in the other groups and 1.5 HS respectively (P < 0.01). CONCLUSION: Feeding with a diet containing HS caused a measurable variation in the meat quality and blood cholesterol as well as the performance, carcass, and gut traits of broilers. Copyright © 2011 Society of Chemical Industry     

Effect of Echinacea purpurea L. on oxidative status and meat quality in Arbor Acres broilers

BACKGROUND: Echinacea purpurea L. (EP) is a popular herbal antioxidant and immunomodulator. The present study was conducted to evaluate the effects of EP on meat quality and oxidative status in broilers. Two hundred and fifty (1‐day‐old) male broilers (Arbor Acres) were randomly allocated to five groups including the control (corn‐soybean meal diet) and 0.1, 0.5, 1.0 and 2.0% EP powder groups, with two replicates per treatment group. RESULTS: The results indicated that the addition of 0.5% and 1.0% EP significantly increased water‐holding capacity and decreased storage loss of breast and thigh fillets at 35 days old. For fillet colour, L* (lightness) values were lower, and a* (redness) and b* (yellowness) values were higher with EP supplementation. Lower crude fat contents were observed in EP groups in comparison with control at 35 days of age in breast and thigh fillets, respectively. Production of malondialdehyde was slightly reduced in serum of EP supplemented birds compared to the control group. Results for Trolox equivalent antioxidant capacity, catalase and superoxide dismutase were significantly higher for the 0.5, 1.0 and 2.0% EP supplemental groups than control group in serum. Liver and spleen tissues results showed that the antioxidative enzymes activities were higher with EP powder at 35 days of age. CONCLUSION: Dried EP can be used as a feed additive to improve the meat quality and oxidative status in Arbor Acres broilers. Copyright © 2012 Society of Chemical Industry     

Effect of Camelina sativa expeller cake on performance and meat quality of broilers

The experiment was conducted to measure the effects of Camelina sativa expeller on the performance of broiler chickens and on the sensory quality and fatty acid composition of broiler meat. One‐day‐old broiler chickens were randomly allocated to the three dietary treatments which lasted 37 days. Experimental diets contained 0, 5 or 10% C. sativa expeller. Feed and water were offered ad libitum. The birds were weighed at the beginning, at 14 days and at the end of the trial at 37 days. Feed intake was recorded between weighings. C. sativa expeller reduced the growth of the birds linearly (P < 0.001). It also depressed their feed intake and feed conversion ratio during the starter phase (1–14 days). C. sativa did not cause any significant enlargement of the thyroid gland, nor were any liver lesions observed. Feeding of C. sativa significantly (P < 0.001) increased the omega‐3 fatty acid level in broiler meat. This was mainly due to an increase in α‐linolenic acid (18:3, n‐3). Feeding did not seem to have any adverse effect on the sensory quality of broiler meat. Meat from female broilers produced by feeding 5% C. sativa in the diet was significantly (P = 0.02) more tender than meat produced by feeding 10% C. sativa. Copyright © 2007 Society of Chemical Industry     

Dietary supplementation of α-tocopheryl acetate on α-tocopherol levels in duck tissues and its influence on meat storage stability

The effect of feeding three levels of α‐tocopheryl acetate on quality and stability of duck meat was studied. Day‐old white Peking ducklings (n = 75) were assigned to three dietary treatments (n = 25) 20 mg α‐tocopheryl acetate per kg feed (E20, control), 400 mg α‐tocopheryl acetate per kg feed (E400) and 1000 mg α‐tocopheryl acetate per kg feed (E1000). α‐Tocopherol concentrations in breast, thigh, liver and heart tissues were significantly (P < 0.05) increased, in a dose‐dependent manner. Supplementation also enhanced oxidative stability of duck muscle. Breast muscle was more susceptible to lipid oxidation than thigh muscle for all groups studied, even though breast muscle contained higher α‐tocopherol levels than thigh muscle. These findings are significant because previous studies using chickens and turkeys showed that breast meat was always more stable than thigh meat and that thigh meat always had higher α‐tocopherol levels than breast meat. Supplementation with α‐tocopheryl acetate did not improve the colour stability of duck meat.     

Influence of growth rate on occurrences of pale muscle in broilers

BACKGROUND: Pale broiler breast meat is a defect in commercial production operations. The incidence of pale broiler breast meat was examined in two commercial processing plants which had average growth rates of 59 g day^?1 and 46 g day^?1 and final average weights of 3.36 kg and 1.93 kg. Color measurements of dorsal and ventral surfaces and pH were completed to evaluate the impact of selection for growth on meat water‐holding capacity. RESULTS: L* greater than 60 were observed in 57% of broilers selected for greater yield and 26% of slower growing broilers. Average L* between 10 growers was significantly different (P = 0.001). Pearson's correlation coefficients for pH and L* were ? 0.51 and ? 0.27 for the faster growing broilers and slower growing broilers, respectively. The Pearson correlation coefficients between water‐holding capacity and L* and pH was ? 0.35 and 0.42, respectively. There was a higher correlation between production factors (age, weight and grower) and a* and b* than L* for ventral surface measurements. CONCLUSION: Breasts from broilers selected for faster growth tend to have lighter color. Weak correlation with water‐holding capacity suggests that quality remains the same and light color is probably related to other factors. Copyright © 2011 Society of Chemical Industry     

Nutrient digestibility and performance of broiler chickens fed regular or green canola biodiesel press cakes produced using a micro‐scale process

BACKGROUND: World interest in biodiesel production from canola seed is expanding. There is little information on the nutritive value of biodiesel by‐products produced from micro‐scale production processes. Hence this trial was conducted to determine the nutritional value of regular and green canola biodiesel press cake for broilers. RESULTS: The digestibility of dry matter, neutral detergent fibre, and nitrogen retention were higher (P < 0.05) for birds fed regular or green canola press cake compared with canola meal. Ether extract digestibility was higher (P < 0.05) for birds fed regular press cake than canola meal, while green press cake and canola meal did not differ. There was no improvement in body weight gain (P > 0.05), while feed conversion was only modestly improved (P < 0.05) by the inclusion of regular or green canola press cake. CONCLUSIONS: Since the performance of broilers fed canola biodiesel press cakes was similar to those fed canola meal, it is difficult to justify a premium to be paid for canola press cake over canola meal. In addition, there was no difference in the performance of broilers fed biodiesel press cake obtained from green or regular canola seed. As green seeds are generally available at a lower price than regular seed, there may be some incentive to choose green canola seed for producing biodiesel and biodiesel press cake for use in poultry production. Copyright © 2009 Society of Chemical Industry     

Comparison of normal and low‐lignin hull/high‐oil groat oat as energy sources for broiler chicks

BACKGROUND: Oats are not widely utilised in poultry rations. The principal reason for this is their high fibre content. Fibre is not very digestible by poultry and its presence impairs the digestibility of energy and other nutrients. A new low‐lignin hull/high‐oil groat (LLH/HOG) oat was developed recently and the present study was conducted to determine its nutritional value for poultry. RESULTS: In experiment 1, gain of broiler chicks fed the control was higher (P < 0.01) than that of birds fed normal oat. Gain and intake of birds fed LLH/HOG oat were superior (P < 0.01) to those of birds fed normal oat. Feed conversion (FC) was higher for birds fed the control than for birds fed normal oat (P < 0.01), while FC for birds fed the control and LLH/HOG oat did not differ (P > 0.05). FC was better for birds fed LLH/HOG than for birds fed normal oat (P < 0.01). In experiment 2, weight gain (P < 0.01), feed intake (P < 0.01) and FC (P = 0.07) declined as the level of LLH/HOG oat in the diet increased. CONCLUSION: Feeding LLH/HOG oat to broilers improved weight gain and FC compared with feeding normal oat. These results give a strong indication that LLH/HOG oat is superior to normal oat as an energy source for poultry. However, despite improvements in chemical composition, LLH/HOG oat is still inferior to wheat for use in broiler rations. Copyright © 2009 Society of Chemical Industry     

Meat fatty acid and cholesterol level of free-range broilers fed on grasshoppers on alpine rangeland in the Tibetan Plateau

BACKGROUND: Meat safety and nutrition are major concerns of consumers. The development of distinctive poultry production methods based on locally available natural resources is important. Grasshoppers are rich in important nutrients and occur in dense concentrations in most rangelands of northern China. Foraging chickens could be used to suppress grasshopper infestations. However, knowledge of the fatty acid content of meat from free‐range broilers reared on alpine rangeland is required. RESULTS: Rearing conditions and diet did not significantly (P > 0.05) affect concentrations of saturated fatty acid (SFA), arachidonic acid, docosahexaenoic acid or the ratio of total n‐6 to total n‐3 fatty acids. Breast muscle of chickens that had consumed grasshoppers contained significantly (P < 0.05) less monounsaturated fatty acid, but the ratio of polyunsaturated fatty acids (PUFA)/SFA and contents of total n‐3, total n‐6 and PUFA were significantly (P > 0.05) higher than intensively reared birds. Compared with meat from intensively reared birds, meat from free‐range broilers had less cholesterol and higher concentrations of total lipid and phospholipids. CONCLUSION: Chickens eating grasshoppers in rangeland produce superior quality meat and reduce the grasshopper populations that damage the pastures. This provides an economic system of enhanced poultry‐meat production, which derives benefits from natural resources rather than artificial additives. Copyright © 2012 Society of Chemical Industry     

Consumer sensory characteristics of broiler and indigenous chicken meat: A South African example

The objective of the current study was to determine the effect of breed on carcass characteristics, post-mortem pH changes and consumer sensory characteristics of broilers and indigenous chicken meat. Sixty birds from each breed were slaughtered at six weeks. The carcasses were dissected manually and the organs were weighed. Post-mortem pH and sensory evaluation were determined from the breast muscle of each bird. Broilers were heavier than the indigenous chickens. Dressing percentage was, however, higher in indigenous birds than broilers (P < 0.05). There were no breed effects on ultimate pH (P > 0.05). The consumers had a higher score for meat that was roasted than the meat that was cooked (P < 0.05). The consumers gave higher sensory scores (except for flavour and off-flavour intensity) for meat from broilers than for meat from the indigenous birds.     

Amino Acid Composition of Breast and Thigh Meat from Broilers Produced in Four Locations of the United States

Broiler breast and thigh meat samples from birds grown and processed in four locations of the United States were analyzed for amino acid composition. On a percent protein basis amounts of valine, leucine, isoleucine, and histidine were significantly greater (p < 0.01) in breast meat and glycine, hydroxyproline, hydroxylysine, threonine, and serine were greater in thigh meat. Area of production and/or related management practices appeared to influence the concentrations of about half the amino acids. Meat from male broilers had more hydroxyproline than did meat from females.     

苦杏仁对肉鸡生长性能和肉品质及肝脏抗氧化能力的影响

通过在肉鸡饲料中添加不同剂量的苦杏仁粉,评价其对肉鸡生长性能、肉品质及肝脏抗氧化能力的影响,探究苦杏仁在畜禽生产中应用及最适添加量,为饲料中抗营养因子的开发利用提供试验依据。试验将100只1日龄AA肉鸡,随机分为4组,每组25只;对照组(C组)饲喂基础全价饲料,低剂量组(L组)饲喂含4.5 g/kg苦杏仁粉的基础全价饲料,中剂量组(M组)饲喂含9 g/kg苦杏仁粉的基础全价饲料,高剂量组(H组)饲喂含17 g/kg苦杏仁粉的基础全价饲料,试验周期为45 d。结果表明,与C组相比,H组肉鸡的终末体重和平均日增重极显著降低(P<0.01),料重比极显著升高(P<0.01),而L组、M组肉鸡的末体重和平均日增重及料重比无显著差异(P>0.05);肌肉放置24 h和48 h后,H组肌肉肉色显著降低(P<0.05),肌肉剪切力极显著增加(P<0.01);L组胸肌粗蛋白质含量显著升高(P<0.05),M组、L组差异不显著(P>0.05)。饲料中添加不同剂量的苦杏仁粉均增强肉鸡肝脏中SOD、CAT和GSH-PX的活性(P<0.05)。试验说明,饲料中添加的低剂量(4.5 g/kg)和中剂量(9 g/kg)苦杏仁粉均可改善肉鸡肉品质和增强肝脏抗氧化性能,其中以添加9 g/kg苦杏仁的效果最佳。而添加高剂量(17 g/kg)的苦杏仁粉虽能增强肉鸡肝脏的抗氧化能力,但会导致肉鸡的生长性能和肉品质降低。     

High-pressure-induced changes in the characteristics of low-fat and high-fat sausages

The purpose of this study was to analyse the consequences of applying high pressures (100 and 300 MPa for 5 and 20 min) on characteristics such as water and fat binding properties, texture, colour, microstructure and microbiology of low-fat (90 g kg⁻¹, LF) and high-fat (247 g kg⁻¹, HF) meat emulsions. Pressurising of LF and HF samples at 300 MPa caused a decline (P<0·05) in emulsion stability, which was more pronounced at the higher pressure. The influence of high pressures on emulsion texture varies according to fat content. In HF samples, high pressure caused a decrease (P<0·05) in Kramer shear force and Kramer energy, regardless of pressure intensity or time. Pressurisation generally caused increase (P<0·05) in the colour lightness parameter in sausages; the effect on redness and yellowness, however, was dependent on fat content, pressure intensity and pressure time. © 1997 SCI.     

FATTY ACID COMPOSITION OF LIPIDS FROM BROILERS FED SATURATED AND UNSATURATED FATS

SUMMARY— The effect of feeding saturated fat (tallow) and unsaturated fat (safflower oil) to broilers on the change in fatty acid composition of lipids deposited in broiler tissues at 4, 6, 8, and 10 wk of age was determined. Fatty acids from raw and cooked skin, excluding that on the neck and third wing joint, breast meat, thigh meat, and abdominal fat were identified by using gas liquid chromatography. Fatty acids from water in which carcasses were cooked were also identified. The degree of unsaturation of fatty acids in these tissues wars influenced by the degree of unsaturated fatty acids in the diet and tended to assume the fatty acid composition of the diet. In some cases, however, the higher levels of certain fatty acids in depot fat was not present in broilers fed the higher levels in the diet. Fatty acids in the larger amounts in all broiler tissues were palmitic, stearic, ofeic, and linoleic but varied in amount among the different age broilers fed the same ration as well as different rations. In most cases there tended to be an inverse relationship between oleic and linoleic acids in the tissues. Lipids from cooked tissues contained a larger amount of 18-carbon unsaturated fatty acids than the other fatty acids combined. Fatty acids collected from cooking water were similar to those in cooked tissues. The presence of 13- and 25-carbon chain fatty acids noted in tissues of 4 wk-old broilers suggests a difference in the metabolism of fat in different age birds. Futher research is needed to substantiate this finding.     

Kinetics of ascorbic acid degradation and colour change in ground cashew apples treated at high temperatures (100–180 °C)

Ascorbic acid (AA) degradation and colour changes, measured by the lightness index (L*), were determined in cashew apples (at low dissolved O₂ concentrations) heated at high temperature (100–180 °C) in a hermetically sealed cell. A nonisothermal method was developed to estimate thermal degradation kinetics. The results showed that reaction kinetics during heat treatments were well represented by first‐order reactions. The temperature dependence of the kinetic constants was described by an Arrhenius type equation. The activation energy (E_a) for AA degradation and lightness index were 94 ± 3 and 98 ± 3 kJ mol^?1, respectively. The reaction rate constant at 140 °C for AA degradation (64 × 10^?5 ± 3 × 10^?5 s^?1) was twice that for the lightness index change (33 × 10^?5 ± 2 × 10^?5 s^?1). Results allow generating temperature profiles of heat processes that would help preserve the AA of cashew apples as well as control the colour formation during high‐temperature processes.     

Eating quality of beef from biotypes included in the PGI “Ternera Asturiana” showing distinct physicochemical characteristics and tenderization pattern

Different biotypes of the Protected Geographical Indication (PGI) “Ternera Asturiana” were studied to determine if their differences in physicochemical characteristics and tenderization pattern during maturation (3 to 21 days) had an effect on the consumer evaluation of beef palatability. Biotype affected significantly pH, water holding capacity, chemical composition (P < 0.001) and meat lightness (P < 0.05). Ageing time affected significantly (P < 0.05) colour, meat toughness and sensory attributes in a different way within each biotype. Multivariate analysis showed two different meat groups: 1) meat from mh-genotypes, characterized by high juice losses, lightness (L*), protein content and high sensory acceptability at intermediate (7 and 14 days) ageing times; 2) meat from rustic (AM) breed and biotypes free of myostatin mutation (AV (+/+) and AV × AM), showing higher intramuscular fat, myoglobin content, and instrumental toughness and requiring longer storage times (21 days). This should be taken into account for the proper post-mortem management and commercialization of each product to achieve its best sensory quality.     

Performance and carcass characteristics of growing pigs and broilers fed diets containing micronised barley,ground barley,wheat and maize

Two swine starter/grower/finisher trials utilising 216 24‐day‐old pigs and one 40‐day broiler growth trial utilising 1920 1‐day‐old chicks were conducted to determine the influence of dietary micronised dehulled barley (MDB) as a replacement for hulled barley (HB), wheat (W) and maize (M) on live performance, carcass and meat measurements, organ weights (swine), plasma urea nitrogen (PUN) level (swine) and intestinal digesta viscosity (broilers). Dehulling and micronising the barley reduced crude protein by 20%, neutral detergent fibre by 17% and amino acids by varying amounts. Replacing M or W with MDB in swine diets had no effect (P > 0.05) on any measured parameter, with the exception of decreased PUN (P = 0.03) when MDB replaced 100% of W. Broilers fed W, M or HB generally had similar live performance, carcass traits and digesta viscosity, with the exception of reduced (P < 0.05) average daily gain and average daily feed intake for HB during the first 20 days of the trial. However, broilers fed MDB had slightly reduced (P = 0.05) live performance during each phase of the trial and greatly increased (P = 0.01) digesta viscosity. Addition of a commercial enzyme product to the diets reversed the reduced performance and increased the digesta viscosity of the MDB diet, but generally had no influence in the W, M and HB diets. These results suggest that MDB can be utilised in swine diets without affecting performance, but that reduced performance may result from its use in broiler diets. © 2001 Society of Chemical Industry     

Composition of phospholipid fraction in raw chicken meat and pre-cooked chicken patties: influence of feeding fat sources and processing technology

The effect of dietary lipid sources (animal fat, AF vs. vegetable oil, VO) was investigated on the phospholipid (PL) fraction of raw chicken meat and pre-cooked chicken patties. PL classes were determined on extracted lipids by high-performance liquid chromatography (HPLC) connected with an evaporative light-scattering detector (ELSD). The HPLC-ELSD method showed good intraday repeatability (less than 5% for different PL) and limits of detection ranging from 0.006 mg/mL (phosphatidylethanolamine) to 0.045 mg/mL (sphingomyelin). Diet did not consistently influence PL in chicken breast. A significant difference was assessed in meat batter where total PL were at levels of 349.0 and 388.2 mg/100 g of product in batter from broilers fed AF and VO diet, respectively. Cooking oil absorption caused an important decrease in PL (lower than 300 mg/100 g of product in pre-fried patties). Diet was an effective means to control the PL fatty acid profile in chicken, particularly the levels of polyunsaturated fatty acids (PUFA). In minced breast and thigh and meat batter from birds fed a VO-supplemented diet, the relative amount of PUFA was 46, 81 and 28% higher than that determined in the corresponding samples obtained from broilers fed an AF-based diet.     

Apoptosis during postmortem conditioning and its relationship to duck meat quality

The aim of this work was to examine the relationship of skeletal muscle apoptosis and postmortem development of meat quality. Colour, cooking loss, myofibril fragmentation index (MFI) and shear force of duck breast and thigh meat postmortem were measured, and changes of positive nuclei were assessed with Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphophate nick end-labelling method (TUNEL). Correlation analysis revealed that apoptosis were positively correlated with colour (L^∗, a^∗ and b^∗), cooking loss and MFI (P < 0.05), while it is negatively correlated with shear force (P < 0.05). Our results indicate the growing level of duck skeletal muscle cell apoptosis was associated with the postmortem development of meat quality traits such as meat colour, water holding capacity and tenderness.     

饲粮双低菜粕水平对黄羽肉鸡生长性能、血液指标及肉品质的影响

本试验旨在研究饲粮双低菜粕水平对1~63日龄黄羽肉鸡生产性能、血液生化及肉品质的影响。试验选用1日龄快长型黄羽肉公鸡1 200只,随机分为5组,每组6个重复,每个重复40只鸡。处理Ⅰ-Ⅴ小鸡阶段双低菜粕添加水平为0%、2.5%、5%、7.5%、10%;中鸡阶段为0%、3%、6%、9%、12%;大鸡阶段为0%、7%、10.5%、14%、17.5%,试验期为63d。结果表明:与对照组相比,双低菜粕添加量为10%时可显著降低1~21日龄试鸡日增重,并提高饲料增重比(P0.05),各阶段双低菜粕添加量为5%、6%和10.5%时可显著降低63日龄试鸡体重(P0.05),当添加量达到10%、12%和17.5%时可显著提高1~63日龄试鸡饲料增重比(P0.05);各阶段饲粮双低菜粕添加量达到10%、12%和17.5%时显著降低了63日龄试鸡血浆游离T_3和游离T_4含量(P0.05),但各组间63日龄试鸡血浆谷草转氨酶、肌酸激酶、乳酸脱氢酶活性和肝脏谷胱甘肽硫转移酶活性均未见明显变化(P0.05),肝脏切片分析未见明显病变;各阶段添加10%、12%和17.5%的双低菜粕可显著降低63日龄试鸡屠宰后45 min的胸肉L*值,并提高a*值(P0.05),但对63日龄试鸡胸肉的感官风味及屠宰后96 h的pH、L*、a*、b*则无显著影响(P0.05)。试验结果提示,在快长型黄羽肉鸡饲粮小鸡阶段、中鸡阶段和大鸡阶段分别添加2.5%、3%和7%的双低菜粕(硫代葡萄糖甙含量为7.01μmol/g)未影响黄羽肉鸡的生长、甲状腺激素水平、机体抗氧化功能及肉品质。     

Detection of discoloration in thermally processed blue crab meat

This study objectively and quantifiably examined the effect of a series of factors on blue crab meat discoloration. Factors explored include heating process, animal harvest location, and position of meat within a container. A Spectrogard colorimeter was used to collect visual reflectance spectra between 380 and 720 nm. Meat degree of coloration was characterised objectively and rapidly by using lightness (L), red–green (a) and yellow–blue (b) colour values. Results showed that meat became darker with increasing heating process; crab harvest location had significant effect on the lightness of the flesh; and meat that is located in the bottom of a can was darker than that in the top. This study will serve as a baseline for the development of a coloration quality control system. © 1999 Society of Chemical Industry