Impact of galactooligosaccharides delivered in ovo on mitigating negative effects of heat stress on performance and welfare of broilers.

Galactooligosaccharides (GOS) delivered in ovo improve intestinal health of broiler chickens. This study aimed to demonstrate the impact of in ovo stimulation with GOS prebiotic on day 12 of egg incubation on performance and welfare traits in broiler chickens. The incubating eggs were divided into 3 groups, based on the substance injected in ovo: 3.5 mg of GOS dissolved in 0.2 mL physiological saline (GOS), 0.2 mL physiological saline (S), or uninjected controls (C). Constant heat stress (HS) was induced on days 32 to 42 post-hatch by increasing environmental temperature to 30°C. Thermoneutral (TN) animals were kept at 25°C. The performance (body weight [BW], daily feed intake [DFI], daily weight gain [DWG], and feed conversion rate [FCR]) were measured and mortality was scored for starter (days 0 to 13), grower (days 14 to 27), and finisher (days 28 to 42) feeding phases. Rectal temperature was scored on days 32 to 42. Food-pad dermatitis (FPD) was scored post-mortem (day 42). GOS increased (P < 0.01) BW on day 42 (2.892 kg in GOS vs. 2.758 kg in C). Heat stress significantly reduced (P < 0.01) final BW (2.516 kg in TN vs. 3.110 kg in HS). During finisher phase, DFI was significantly higher in GOS vs. C (173.2 g vs. 165.7 g; P < 0.05). FCR calculated for the entire rearing period (days 0 to 42) ranged from 1.701 in C to 1.653 in GOS (P < 0.05). GOS improved FCR in HS animals during finisher phase (P < 0.05). Rectal temperature of GOS chickens under HS reached 42.5°C 1 day earlier than C and S (P < 0.05), which suggests that those birds recovered earlier from the high environmental temperature. Heat stress increased (P < 0.05) mortality about 5 times compared to TN during finisher phase (from 1.59% in TN to 7.69% in HS). GOS decreased FPD in TN conditions by 20% (no lesions in 81% in GOS vs. 60% in C). GOS delivered in ovo mitigated negative effects of HS on performance and welfare in broiler chickens.

Comparison of 2 commercial turkey hybrids: productivity, occurrence of breast myopathies, and meat quality properties.

This study was undertaken to compare productive performance, occurrence of breast myopathies, chemical composition, and technological properties of the meat in 2 dominant commercial turkey hybrids. A total of 972 1-day-old male turkey poults (equally divided in hybrid A and B) were randomly distributed in 18 floor pens. Overall, productive performance resulted similar between the genotypes, although they showed different growth profile (turkeys from group B grew up faster up to 84 d). Regarding the occurrence of myopathies, the percentage of breasts affected by white striping was markedly higher in both genotypes (46 vs. 60% of severe lesions, respectively for A and B; P < 0.05), while the occurrence of spaghetti meat-like condition was negligible. The histological features of the different categories of meat abnormalities resulted similar to those previously described for chicken hybrids. The technological traits such as ultimate pH, lightness, redness, marinade uptake, cooking losses, and shear force were not significantly affected by the genotype. However, turkeys from group B exhibited lower yellowness (b*, 0.50 vs. 1.04; P < 0.05) and higher drip losses (1.34 vs. 1.26%; P < 0.05). The shelf-life test on thigh meat showed no significant changes in meat color over the storage time in both hybrids, whereas thigh meat from group A showed absolute lower values of lightness (L*) and yellowness (b*) (P < 0.05). Lipid oxidation of thigh meat significantly increased during storage, although no significant difference was found between the hybrids. Proximate composition and intramuscular collagen properties resulted similar between genetic lines with the exception of total fat content (1.55 vs. 1.21%, respectively for A and B; P < 0.05). The genotype had a moderate effect on fatty acid families of breast meat as only monounsaturated fatty acid content was significantly affected (31.7 vs. 29.8%, respectively for A and B). In conclusion, the overall productive traits of commercial turkeys, including the occurrence of muscle myopathies, as well as quality attributes of fresh and refrigerated meat were only slightly affected by the genotype.

Effect of different arginine-to-lysine ratios in broiler chicken diets on the occurrence of breast myopathies and meat quality attributes.

This study was carried out to evaluate the effect of different digestible arginine-to-lysine (dig Arg:Lys) ratio in broiler diets on the occurrence of breast myopathies, productivity, and meat quality traits. A total of 1,755 1-day-old Ross 308 male chicks was randomly divided in 3 experimental groups (9 replications/group): CON, fed a 4 feeding-phases commercial diet (dig Arg:Lys ratio = 1.05, 1.05, 1.06, 1.07, respectively in starter, grower I, grower II and finisher phase), and ARG2 and ARG3 groups fed CON diet supplemented respectively with 20 and 30% higher levels of crystalline L-arginine (dig Arg:Lys ratio = 1.25, 1.25, 1.26, 1.27 and 1.35, 1.35, 1.36, 1.37, respectively). Productive performance was recorded throughout the rearing cycle. At processing (43 d), breasts (n = 150/group) were randomly collected to evaluate the incidence and severity of white striping (WS), wooden breast (WB), and spaghetti meat (SM) defects (3-points scale). Meat quality traits, such as color, pH, drip and cook losses, marinade performances, and proximate composition were determined on 12 fillets/group. Although productive performance and meat quality traits resulted not significantly affected, the occurrence of some breast myopathies was modified by the dietary treatments. ARG2 and ARG3 exhibited a significantly higher percentage of breast without WS compared to CON (28 and 41 vs. 17%, respectively; P < 0.001). ARG3 reported the lowest percentage of breasts with severe WS (11 vs. 27 and 31%, respectively for ARG3, ARG2, and CON; P < 0.001) and the highest of those showing no SM abnormality (81 vs. 69 and 65%, respectively for ARG3, ARG2, and CON; P < 0.01). Furthermore, a numerical reduction of breasts with severe WB was observed in ARG3 (12 vs. 25 and 19%, respectively for ARG3, ARG2, and CON; P = 0.12). In conclusion, the dietary supplementation of arginine to increase the dig Arg:Lys ratio by about 30% in respect to the current recommendations for broiler chickens has positive implications on the occurrence of some breast meat abnormalities.

Avian model to mitigate gut-derived immune response and oxidative stress during heat.

The tissue injury at the early stages of the heat stress response triggers release of inflammatory and oxidative agents from intestinal content into the milieu of the body. Intestinal homeostasis (i.e., eubiosis) improves the barrier function and mitigates the gut-derived influx of endotoxins. In this study we have analyzed the mitigating role of embryonic stimulation of the gut homeostasis in chickens on immune and oxidative responses to heat. The animal trial was conducted on broiler chickens. The treatment included a single in ovo injection of the galactooligosaccharides (GOS) prebiotic into the air cell of the egg on day 12 of incubation. Control eggs were in ovo injected with the same volume of sterile physiological saline. After hatching, birds were raised in group pens (6 pens/group, 25 birds/pen). Short-term, mild heat stress was induced on day 32 post-hatching by increase in the ambient temperature above the thermal comfort (30 °C for 8.5 h). The spleen was harvested from randomly selected individuals. The relative gene expression study was conducted with RT-qPCR. The two gene panels were analyzed: (1) immune response genes (IL-1ß, IL-2, IL-4, IL-6, IL-12p40 and IL-17) and (2) stress response genes (HSP25, HSP70, HSP90, BAG3, CAT and SOD). Data were evaluated by the analysis of variance in a 2 × 2 factorial design that included in ovo treatment and ambient temperature as factors. We have found that the immune-related and stress-related gene expression signatures were triggered in animals subjected to heat but with unbalanced intestinal flora (i.e., dysbiotic, without in ovo stimulation with GOS). These animals had increased expression of the genes involved in the immune responses (IL-4 and IL17) and stress responses (HSP25, HSP70, HSP90, CAT and SOD) to short-term heat stress that indicated presence of inflammatory and oxidative mediators (P < 0.05). The individuals that were in ovo stimulated with GOS did not mount the anti-inflammatory or antioxidative responses. Heat shock proteins (HSP25 and HSP70) were increased in both groups challenged with heat, which indicated their role in adaptation to heat.

Variability and interaction of some egg physical and eggshell quality attributes during the entire laying hen cycle.

The aim of this study was to investigate the variability and relationships between some egg physical (egg weight, width, length, shape index, and surface area) and eggshell parameters (weight and percentage, thickness, breaking strength, and L*, a*, and b* values) during the entire laying hen cycle. A total of 8,000 eggs was collected every 5 wk, from 30 to 81 wk of hen age (10 samplings of 400 eggs/house), in 2 identical poultry houses equipped with enriched cages. For the statistical analysis, ANOVA, Bivariate Correlation, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis were used. An increase of egg weight, length, and eggshell lightness (L*) associated with a reduction of eggshell percentage, breaking strength, and redness (a*) was observed as the hen aged (P < 0.05). Overall, the coefficients of variation resulted in <5% in width, length, shape index, and egg surface area; from 5 to 10% of egg weight, shell weight, shell percentage, shell thickness, L*, and b*; and >10% of eggshell breaking strength and a*. According to the PCA, the highest changes during the laying cycle are related to egg physical parameters (32%) and to eggshell breaking strength, percentage, and thickness (26%). The egg physical parameters appeared to be strongly correlated to each other, whereas a slight correlation between eggshell breaking strength and color attributes were evidenced (-0.231 and 0.289, respectively, for L* and a*; P < 0.01). Hierarchical cluster analysis, based on principal components of the overall egg attributes, is hereby considered, and evidenced dissimilarities for eggs laid from peak production up for 39 wk of hen age from the eggs laid afterwards. The latter group could also be divided into 2 subgroups, one comprising eggs laid from 44 and 53 wk of hen age and the other from 58 wk to the end. In conclusion, the large dataset created in this study allowed to extrapolate some robust information regarding the variability and correlations of the egg physical and eggshell quality attributes throughout the entire laying hen cycle.

Effect of EU electrical stunning conditions on breast meat quality of broiler chickens.

Electrical stunning is still the main stunning method used worldwide in commercial poultry plants. The stunning procedures in water bath stunners affect both bird welfare and meat quality attributes. The European Union (EU) Council Regulation 1099/2009 on the protection of the animal at the time of killing established the minimum current flow through an individual bird at a specified frequency to assure an effective stun that must last until the bird's death. The aim of this study was to compare the effect of the application of different stunning current flows on the prevalence of hemorrhages (classified as 1 = no lesion, 2 = moderate, and 3 = severe lesion) and some quality traits (pHu, color, drip and cooking losses, and shear force) of chicken breast meat. A total of 12 flocks of broiler chickens, each equally divided into light, medium, and heavy sizes, was submitted either to the stunning condition usually adopted before the entry into force of the current EU regulation (90 mA/bird, 400 Hz) (OLD) or to that enforced by it (150 mA/bird, 400 Hz) (NEW). Overall, the prevalence of severe hemorrhages dramatically increased in the NEW group in comparison with the OLD one (55 vs. 27%; P < 0.001) and particularly in heavy-sized birds (72 vs. 25%; P < 0.001). In general, meat quality attributes were not affected by the stunning conditions with the exception of drip loss that resulted lower in NEW than OLD birds (1.01 vs. 1.27; P < 0.001). In conclusion, the adoption of a higher current flow, as suggested by the EU regulation to protect animals at the time of killing, increases the prevalence of breast hemorrhages while maintaining meat quality traits with a possible beneficial effect on water holding capacity of fresh meat.

Effect of different levels of dietary zinc, manganese, and copper from organic or inorganic sources on performance, bacterial chondronecrosis, intramuscular collagen characteristics, and occurrence of meat quality defects of broiler chickens.

The aim of the experiment was to assess the effects of 2 dietary levels of trace minerals (TM) zinc, manganese, and copper either from organic (OTM) or inorganic (ITM) sources on broiler performance, carcass traits, intramuscular collagen (IMC) properties, occurrence of hock burns (HB), foot pad dermatitis (FPD), femoral and tibia head necrosis, and breast muscle abnormalities (white striping, WS; wooden breast, WB; poor cohesion, PC). A total of 3,600 one-day-old male chicks were randomly assigned to one of 4 dietary treatments in a 2 × 2 factorial arrangement (9 replicates of 100 birds/dietary treatment). Birds were slaughtered at 31 (thinning) and 51 d of age. Body weight, daily weight gain (DWG), feed intake, feed conversion rate (FCR), and mortality were determined. A significant effect of the source of TM supplementation was found only in 51-day-old chickens. Birds of the OTM groups were heavier (P < 0.05), with a higher (P < 0.05) DWG and a better FCR (P < 0.05) compared with those of the ITM groups. OTM significantly reduced the lesion scores of femoral head (P = 0.004) and total leg (femur + tibia, P = 0.02) compared to ITM, which is mainly caused by the reduction of the percentages of femoral head transitional degeneration (FHT, P = 0.04) and femoral head necrosis (FHN, P = 0.07). Carcass traits were similar among the experimental groups. No alleviating effect of TM administration on the incidence of FPD and HB in 31- and 51-day-old chickens was found. Similarly, the occurrence and the degrees of WS and WB in 51-day-old chickens was affected neither by the doses nor by the source of TM supplied. IMC characteristics of broiler pectoral muscle were not affected (P > 0.05) by the different sources and doses of TM administrated.

Fatty acid composition of chicken breast meat is dependent on genotype-related variation of FADS1 and FADS2 gene expression and desaturating activity.

In Western countries the dietary guidance emphasizes the need to decrease the intake of saturated fatty acids and to replace them with polyunsaturated fatty acids (PUFA), particularly long chain n-3 PUFA (LC-PUFA). The production of poultry meat having a lower fat content and healthier fatty acid (FA) profile is a hot topic for the poultry industry, and the possibility to identify genotypes able to produce meat with a higher LC-PUFA content deserves attention. The aims of the present study were to evidence in chicken (i) a genotype-related different expression of the desaturating enzymes delta-6 (Δ6, EC 1.14.99.25), delta-5 (Δ5, EC 1.14.19.) and delta-9 (Δ9, EC 1.14.19.1); (ii) the impact of the hypothesized different expression on the meat FA composition; (iii) the distribution of desaturase products in the different lipid classes. Slow (SG), medium (MG) and fast (FG) growing chickens fed the same diet were evaluated either for the relative expression of FADS1, FADS2 and SCD1 genes in liver (by q-PCR), or for the FA composition of breast meat. MG and particularly SG birds showed a greater expression of FADS2 and FADS1 genes, a higher Δ6 and Δ5 activity (estimated using desaturase indices), and consequently a higher LC-PUFA content in the breast meat than FG birds. The relationship between genotype and desaturating ability was demonstrated, with a significant impact on the PUFA content of breast meat. Due to the high consumption rate of avian meat, the identification of the best genotypes for meat production could represent an important goal not only for the food industry, but also for the improvement of human nutrition.

Relationship between pectoralis major muscle histology and quality traits of chicken meat.

A trial was conducted to evaluate the influence of myodegeneration of pectoralis major muscle on quality traits and chemical composition of breast meat of heavy-size male broilers. For this purpose, a total of 72 pectoralis major muscles were randomly collected from broilers farmed under homogeneous conditions and graded into three categories (mild, n=22; moderate, n=33; and severe, n=17) based on the presence of abnormal fibers (giant fibers, fibers with hyaline degeneration, and damaged and/or necrotic fibers) evaluated by histological and immunohistochemical analysis. Color, pH, drip loss, Allo-Kramer shear values, and chemical composition (moisture, proteins, total lipids, ashes, and collagen) were determined on nonmarinated breast meat. Purge loss and cook loss, total yield, and Allo-Kramer shear values were measured on vacuum-tumbled samples. Samples showing moderate myodegeneration had the highest mean cross-sectional area of the fibers, while samples with severe myodegeneration had myofibers of different diameter and without the characteristic polygonal shape, multifocal degeneration and necrosis, as well as infiltration of CD3-immunoreactive cells. Cooking losses of nonmarinated meat were lower in the mild group with respect to moderate and severe groups (21.4 vs. 24.7 and 24.7%; P<0.001). Breast muscles with severe damage, in comparison with mild degenerated samples, showed higher moisture (75.4 vs. 74.4%; P<0.05) and lower protein percentages (21.1 vs. 22.6%; P<0.001). The lipid percentage of severely degenerated samples was higher than that from moderate group (2.94 vs. 2.36; P<0.05), while collagen content was not modified by histological lesion levels. Marinated meat from the mild group had higher uptake and total marinade yield after cooking. In conclusion, almost all breast fillets of heavy broiler chickens produced under intensive farming systems had histological lesions, which reflected on the chemical composition of the meat and the impaired water holding/binding capacities of the meat.

Comparison of breast muscle traits and meat quality characteristics in 2 commercial chicken hybrids.

A trial was conducted to compare muscle traits and meat quality characteristics of the pectoralis muscle in 2 chicken commercial hybrids having standard (SBY) and high breast yield (HBY), respectively. A total of 2,124 one-day-old male chicks, equally divided into 2 experimental groups represented by strains (SBY and HBY), were grown using homogenous conditions and fed the same standard diets until reaching live weight of 4.2 kg at 53 and 55 d for the SBY and HBY groups, respectively. Thirty-six birds per each genotype were randomly selected, and their pectoralis major muscles were used to assess meat quality properties (color attributes, pH, drip loss, cook loss, Allo-Kramer shear values after cooking, moisture, proteins, total lipids, and ashes) as well as histological traits (cross-sectional area, frequency of abnormal fibers, and intramuscular fat infiltration). As expected, HBY genotype had higher breast yield (31.0 vs. 30.0%; P ≤ 0.05). Histological evaluations showed that HBY pectoralis muscles had higher cross-sectional fiber area coupled with a dramatically higher (P ≤ 0.001) incidence of abnormal fibers and more abundant infiltration of intramuscular fat. Moreover, histopathological anomalous features such as central nuclei, proliferation of endomysial and perimysial collagen, inflammatory infiltrate, and necrosis of the fibers were also observed. As for meat quality, SBY hybrid showed lower ultimate pH values (5.97 vs. 6.07; P ≤ 0.01), whereas overall color parameters were not affected by genotype. Breast meat from the HBY genotype also exhibited significantly lower ability to retain liquid during refrigerated storage (drip loss, 2.46 vs. 2.06%; P ≤ 0.05) and cooking (26.2 vs. 21.1%; P ≤ 0.05) as well as higher shear-force values (2.59 vs. 2.11 kg/g; P ≤ 0.001). Finally, with regard to chemical composition, significant differences (P ≤ 0.05) were detected in protein (22.8 vs. 23.5%) and lipid (1.65 vs. 1.82%) contents, which were significantly lower in the HBY hybrid, whereas moisture content tended (P = 0.07) to be inferior in the SBY hybrid.

Modified-atmosphere packaging of hen table eggs: effects on pathogen and spoilage bacteria.

As part of a more comprehensive research activity on the use of modified-atmosphere packaging for the improvement of quality and functional properties of table eggs, the effects of air, 100% CO(2), and 100% O(2) packaging were also evaluated on the survival of experimentally inoculated pathogen bacteria (Salmonella Enteritidis, Escherichia coli, and Listeria monocytogenes) as well as on spoilage bacteria (total aerobic mesophilic bacteria) on table eggs during 30 d of storage at 4, 25, and 37°C by colony count method. In general, temperatures played a major role, rather than gasses, in influencing the bacterial survival. In particular, the lowest microbial loads were registered at 4°C on E. coli and spoilage bacteria, whereas 37°C was the best storage temperature to avoid the psychrotropic microorganism L. monocytogenes development regardless of the gas used. One hundred percent CO(2) packaging, in association with a low storage temperature (4°C), had a significant positive effect in reducing Salmonella loads. On eggs inoculated with L. monocytogenes and stored at 4°C as well as on eggs containing only spoilage bacteria and stored at 25°C, 100% CO(2) resulted the best gas in comparison with air and O(2). One hundred percent CO(2) packaging showed no negative effect on pathogen survival compared with air. Although further improvements are required to control RH within packaging to limit bacteria growth/survival, in view of the positive effects of CO(2) packaging on quality traits of table eggs, 100% CO(2) packaging might represent a promising innovative technique for the maintenance of egg characteristics during transport, retail, and domestic storage.

Effect of sequential feeding on nitrogen excretion, productivity, and meat quality of broiler chickens.

The aim of this trial was to investigate the effect of a 24-h cycle sequential feeding program on nitrogen excretion, incidence of foot pad lesions, productive performance, quality traits, and chemical composition of broiler chicken breast meat. In total, 1,320 one-day-old male Cobb 700 chicks were split into 2 groups of 6 replicates each. From 1 to 10 d of age, all of the chickens received the same prestarter diet (ME 3,058 kcal/kg; CP 226 g/kg). The control group (CON) received 1 of 3 diets for 24-h cycles: starter (ME 3,162 kcal/kg; CP 205 g/kg), grower (ME 3,224 kcal/kg; CP 192 g/kg), and finisher diets (ME 3,242 kcal/kg; CP 184 g/kg) from d 11 to 18, 19 to 38, and 39 to 44 of age, respectively. The sequential feeding group (SF) received the same diets as the CON birds for half of the day, and then low-protein and isoenergetic diets for the remaining half of the day. Birds submitted to the SF program showed better utilization of dietary nitrogen compared with the CON birds (45.0 vs. 46.1% of N excreted/N ingested, respectively; P < 0.05), and consequently the SF birds had lower nitrogen excretion compared with the CON birds (24.8 vs. 25.9 N g/kg of BW, respectively; P < 0.01). The SF birds exhibited a significantly lower incidence (7 vs. 13%) of foot pad lesions and consumed 70 g of feed/bird more than the CON birds. The SF birds also had a significantly higher feed conversion rate compared with that of the CON birds (1.84 vs. 1.78, respectively). The SF breast meat exhibited a significantly lower ultimate pH, a higher cook loss, and a lower lipid content compared with the values found for the CON group. The SF approach in poultry husbandry had positive repercussions on environmental and animal welfare aspects, but adversely affected feed efficiency, and altered some meat traits (mainly pH and cook loss).

Effect of fast-, medium- and slow-growing strains on meat quality of chickens reared under the organic farming method.

The characteristics of meat quality, chemical and fatty acid composition, from fast-growing (FG) and medium-growing (MG) meat-type and slow-growing (SG) egg-type chickens reared under organic conditions were compared. Three-hundred and sixty 1-day-old male chicks, equally divided into three experimental groups represented by strains (FG: Cobb 700, MG: Naked neck Kabir and SG: Brown Classic Lohman) were housed into three poultry houses with outdoor pasture availability of 10 m(2)/bird located in the same Research Centre of the University of Perugia. All the birds were fed ad libitum the same diets formulated according to the European Union (EU) Regulations by using organic raw materials. Birds from the FG and MG groups were raised until 81 days, whereas birds from the SG group were raised until 96 days in order to achieve an acceptable market live weight. SG birds showed significantly (P < 0.01) higher breast meat drip and cook losses, Allo-Kramer shear values and collagen content. In comparison with FG and SG, MG exhibited a higher breast meat pH (5.86% v. 5.79% and 5.78%, respectively; P < 0.01) and a lower lightness (54.88% v. 57.81% and 56.98%, respectively; P < 0.05). Genotype dramatically affected the lipid content as well as the fatty acid composition of both breast and thigh meat. SG exhibited the lowest content of lipid, both in breast and in thigh meat, the lowest proportions of monounsaturated fatty acids (MUFA) and the highest proportions of polyunsaturated fatty acids (PUFA). The total n-3 PUFA of SG breast meat was double that of FG meat and intermediate with respect to MG birds (8.07% v. 4.07% v. 5.14% total fatty acids; P < 0.01). The fatty acid composition of thigh meat is similar to that of breast meat, but the differences among genotypes are less pronounced. Total saturated fatty acids were not affected by the genotype. In conclusion, meat functional properties of FG and MG strains appeared much more attractive both for industry and consumer (lower drip and cook losses and higher tenderness), whereas from a nutritional point of view, meat from SG appeared healthier (less fat and higher content of n-3 PUFA) and thus might better fit with the consumer's expectations of organic products.

Survey of skin pigmentation of yellow-skinned broiler chickens.

The appearance of whole carcass and skin-on cut-up products is an important attribute that deeply affects the consumer's choice. Skin pigmentation is affected mainly by genetics, concentration and dietary source of pigments, health status of the birds, and scalding-plucking conditions during slaughtering, although other factors might play an important role. Retailers request batches of broiler chicken carcasses characterized by uniform skin pigmentation to be sold as whole carcass or parts. The aim of this study was to evaluate the variability of skin color of yellow-skinned broilers reared under intensive conditions. For the study, a total of 2,300 medium size broiler chickens (2,300 to 2,500 g of live weight) from 23 flocks (100 birds/flock; n = 12 flocks of males and n = 11 flocks of females; n = 12 flocks of Ross 508 and n = 11 flocks of Ross 308) were randomly selected in a single slaughterhouse. The color measurements were carried out on both breast and thigh pterylae as well as on shank skin adopting the L* a* b* system and using a Minolta colorimeter CR 300. The overall range in measured yellowness (b*) was fairly large for all skin color measurement positions. For breast, a mean value of 22.77 (SD = 5.12) was observed, with values ranging from 7.45 to 39.12. Average values of thigh and shank were 20.23 (SD = 5.02; range 1.99 to 37.82) and 53.99 (SD = 8.13; range 24.22 to 78.65), respectively. A higher skin yellowness was observed in females in all body parts as well as in Ross 308. Yellowness values of breast and thigh were significantly correlated (r = 0.85; P < 0.01), suggesting that the color evaluation may be carried out only on one measurement position of the skin.

Influence of partial and complete caponization on chicken meat quality.

Caponization is a surgical technique adopted to alter the sexual maturation of male chickens with the aim of improving the quality characteristics of carcass and meat. Under commercial conditions within each flock, about 10% of the birds usually result with incomplete caponization and are called slips. A trial was conducted to compare quality traits of breast and thigh meat from capons (n = 12), slips (n = 12), and cocks (unoperated birds; n = 12) (Hubbard x Golden Comet) reared together and processed at 180 d old under commercial conditions. Capons exhibited the highest (P < 0.01) values of breast and thigh meat lightness and yellowness as well as the lowest values of redness (P < 0.01) compared with cocks and slips. These variations in meat color were related to a lower concentration of heme pigments in both breast and thigh meat from capons. Capons and slips presented lower Allo-Kramer shear values of cooked breast meat (P < 0.05) in comparison with cocks. As for chemical composition, capons showed a higher content of total lipid, cholesterol, and ash both in breast and thigh meat. Total saturated, monounsaturated, and polyunsaturated fatty acids were not strongly affected by caponization. However, capons exhibited a significantly higher (P < 0.01) content of linoleic and linolenic acids as well as a lower content of arachidonic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids in respect to slips and cocks. Overall, this study indicated that caponization can affect the main meat quality traits with special regards to appearance (color), texture, and composition. Finally, it was found that slips present intermediate meat quality characteristics between capons and cocks.

Effect of less intensive rearing conditions on litter characteristics, growth performance, carcase injuries and meat quality of broilers.

1. The objective was to compare the effect of two litter types (wheat straw and wood shavings) and two different rearing conditions (Treated and Control) on welfare indicators, broiler performance, carcase injuries, particularly hock and foot pad dermatitis (FPD), litter characteristics and meat quality. 2. Treated conditions were characterised by a low stocking density (11 birds/m(2)), short photoperiod (16 h light: 8 h dark) and a large amount of litter (3 to 4.5 kg/m(2), respectively, for wheat straw or wood shavings). Control conditions were a high stocking density (14 birds/m(2)), long photoperiod (23 h light:1 h dark) and small amount of litter (2.3 to 3 kg/m(2), respectively, for wheat straw or wood shavings). In addition, the effects of two widely used litter materials, wheat straw and wood shavings, were investigated. 3. The combined effects of lower stocking density, greater amount of litter material and a photoperiod similar to the natural one, reduced the occurrence of FPD in Treated groups keeping the FPD score under the European threshold. 4. Improved rearing conditions led to faster growth rate associated with inferior feed efficiency, whereas litter type exerted negligible effects on broiler performance. 5. Litter moisture content, nitrogen and ammonia released by the litter were lower in Treated groups than Control groups. The use of wood shavings resulted in lower moisture and nitrogen concentrations in the litter.

Survey of chicken rearing conditions in Italy: effects of litter quality and stocking density on productivity, foot dermatitis and carcase injuries.

1. A survey was carried out to assess some welfare indicators in broilers reared by the largest poultry companies in Italy, to determine whether they accord with European proposal COM (2005) 221 final. 2. Productive traits, carcase injuries and foot dermatitis were recorded from 279,640 broiler chickens reared in winter and in summer in 5 farms representative of the Italian production system. 3. The densities currently used in Italy are in accordance with the European proposal, which recommends that broilers are kept at a density lower than 30 to 32 kg live weight/m(2) and not exceeding 38 to 40 kg live weight/m(2). 4. Season markedly influenced broiler welfare status, with the worst score collected in winter cycles, when the recommended limit of 50 points for foot pad dermatitis was exceeded. 5. Stocking density is not a straightforward indicator for bird welfare; there was no relationship between stocking density and lesion incidence or mortality rate. 6. The control of environmental conditions, particularly litter quality, appears to be a key issue for broiler welfare.

The influence of the season and market class of broiler chickens on breast meat quality traits.

The influence of the season and market class of broiler chickens on breast meat quality traits was determined on a total of 18 flocks reared and processed under commercial conditions. According to the Italian poultry production system the following classes of birds were considered: light size (1.2 kg of carcass weight; n = 90) and medium size (1.8 kg of carcass weight; n = 90), represented by females slaughtered at 40 and 52 d old, respectively, whereas heavy size were 57-d-old male broilers (2.4 kg of carcass weight; n = 90). After slaughter, 15 carcasses per flock (n = 270) were randomly collected during winter (n = 135) and summer (n = 135) seasons and used at 24 h postmortem to determine breast (pectoralis major) meat color (lightness, redness, and yellowness), pH, drip and cook loss, as well as Allo-Kramer (AK) shear values. Furthermore, pectoralis minor muscles were used to determine lipid, protein, moisture, and ash content. Finally, because the flocks included white- and yellow-skinned broilers, the color of the carcass skin was measured to assess the relationship between skin and raw breast meat color. With regard to the season, breast meat from birds slaughtered during summer exhibited a paler and less red color, lower pH, higher drip and cook losses, lower AK-shear, and a higher content of moisture and a lower content of protein and ash. In respect to medium and heavy birds, light broilers produced breast meat with higher values of redness, lower pH and cook loss, higher AK-shear values, and a higher content of moisture and ash. Finally, a positive correlation (r = +0.92; P < or = 0.001) between skin and breast meat yellowness was found. These results indicate that during summer, broiler breast meat undergoes a depression of its functionality and quality. Moreover, the market class of birds also determined some differences in breast meat quality attributes.

Improvement of stored turkey semen quality as a result of He-Ne laser irradiation.

Two experiments were carried out to evaluate the effects of He-Ne laser irradiation at various energy doses on the quality of stored turkey semen. Four semen pools were used in Experiment 1. Each pool was divided into 10 aliquots, nine of which were irradiated with energy doses ranging from 0.144 to 10.8 J/cm2 while the tenth one was not irradiated (control). Each sample was evaluated for motility immediately after irradiation, 24 and 48 h later. Energy doses ranging from 3.24 to 5.4 J/cm2 had higher (P <0.01) sperm motility index (SMI) value compared to the control and samples irradiated with lower and higher laser doses. The energy dose of 3.96 J/cm2 was selected for Experiment 2 to obtain further insight on its effects on turkey sperm preservation for up to 60 h. Each pool of four semen was divided into two aliquots: one represented the control and the other one was irradiated with He-Ne laser at an energy dose of 3.96 J/cm2. Each sample was evaluated for motility and viability immediately after irradiation and then at 12 h intervals up to 60 h. The cell energy charge was also measured by HPLC. Exposure to 3.96 J/cm2 increased the SMI and viability of turkey semen stored for 60 h compared to the control (P <0.05). The cell energy charge of irradiated samples was 200% higher than in the control. Laser irradiation increased the longevity of stored turkey spermatozoa, and might be a useful technique to enhance semen quality in long-term storage.

Fatty acid composition and productive traits of broiler fed diets containing conjugated linoleic acid.

An experiment was carried out to evaluate the transfer of dietary CLA to broiler chicken tissues (breast, drumstick meat, skin, and abdominal fat) and its effect on productive traits and on carcass yields of birds. Cobb 500 females (n=360), divided into three groups, received from 22 d to slaughtering age (47 d) a grower diet supplemented with 2% conjugated linoleic acid (CLA) source containing 60% CLA methyl esters (CLA2) or 4% CLA source (CLA4). The control group had no supplementation. The addition of CLA source to chicken diet decreased the content of monounsaturated fatty acid (MUFA) (oleic and palmitoleic acids) in breast and drumstick meat. The deposition of CLA in muscles significantly increased as the dietary CLA increased, whereas only little amounts of CLA were detected in the control group. Arachidonic acid (ARA) content was significantly depressed and linearly related to the addition of CLA to the chicken diet. Other non-CLA polyunsaturated fatty acids (PUFA) were little affected by the dietary CLA supplementation. Saturated fatty acids (myristic and stearic acids) significantly increased about 30% in abdominal fat pad of both treated groups enhancing the firmness of abdominal fat. Productive performances--as well as carcass yields--were similar across dietary treatment of birds.