Shelf-Life Evaluation of Ingredient Combinations and Technologies for Use in Pet Food Formulations

Poultry co-product chicken frames (CF) and wooden breast (WB) along with ingredient technology use may bring enhanced value to the pet food industry. Therefore, the current study focused on evaluating CF and WB combinations along with sodium alginate and encapsulated calcium lactate pentahydrate (ALGIN) inclusion within a fresh pet food formulation under simulated shelf-life conditions. Fresh chicken frames (CF) and boneless-skinless wooden breast (WB) were ground and allocated randomly to one of ten treatment combinations with either 0.5 or 1.0% added ALGIN. Ground treatments were placed into a form and fill vacuum package and stored using a reach-in refrigerated case for 21 days. Packages were evaluated for instrumental surface color, lipid oxidation, water activity, and pH on days 1, 3, 7, 14 and 21 of the display. Packages of pet food were lighter, less red, and more yellow (p < 0.05) with increasing percentages of CF regardless of ALGIN inclusion, whereas pH was greater (p < 0.05) and lipid oxidation was less (p < 0.05) with increasing percentage of WB. Water activity increased (p < 0.05) when WB and ALGIN inclusion increased. The current results suggest that the use of ALGIN in a poultry co-product pet food formulation can improve shelf-life characteristics such as surface color and lipid oxidation in fresh pet food.

Effects of Guanidinoacetic Acid Supplementation on Productive Performance, Pectoral Myopathies, and Meat Quality of Broiler Chickens

The effects of guanidinoacteic acid (GAA) supplementation on productive performance, pectoral myopathies, and meat quality of broilers were studied. Treatments consisted of corn/soybean-based diets with a GAA supplement (0%, 0.06%, and 0.12%). A total of 546 one-day-old Ross-308 males were randomly allocated to 42 floor pens with 14 replicates (13 birds/pens) for each treatment. The results showed that GAA at doses of 0.06% and 0.12% improved feed conversion, increased the percentage of normal breast, and decreased the severity of wooden breast. Breast muscle myopathy severity was positively correlated with heavy birds and negatively correlated with breast muscle creatine and glycogen. Breast muscle creatine and glycogen correlated positively with normal, less severe pectoral myopathies and meat quality. In conclusion, GAA supplementation improved broiler performance without exacerbating pectoral myopathy or affecting meat quality.

Culinary preparation and processing of meat with wooden breast myopathy

Recently, poultry meat production and consumption has become increased worldwide. Decades of intensive selection in poultry breeding resulted in fast-growing broilers, improved food conversion, low production costs, and high yield of breast meat, as the most valuable part of the carcass. Some side-effects of intensive production and rapid growth of broilers include the appearance of myopathies in breast muscle. Increasing attention has been paid to the defect known as "wooden breast" (WB) due its incidence and severity of anomaly. WB is characterized by the hardness and pale colour of the fillet. These changes lower the consumer acceptance of the meat, and a pronounced WB is unsuitable for culinary and industrial processing. Different procedures can be used to tenderize the meat and include physical and chemical procedures, often combined in industry. Physical procedures comprise the application of heating, mechanical force, ultrasound, electric stimulation, hydrodynamic shock wave-pressure technology, high pressure processing, and pulsed electric field. Chemical procedures include marinating, exposure to the endogenous enzymes, and the use of exoenzymes. In the future, it is necessary to develop optimal tenderizing techniques or combinations of different tenderizing techniques to achieve better sensory quality and improved nutritional value of WB.

Etlik Piliçlerde Odunsu Göğüs Eti Sendromu ve Etkileri

The aim of the study is to present a review about the "Wooden Breast Syndrome" (WBS) syndrome, which is a muscle disorder that has become increasingly important in recent years, and the etiology of the abnormalities caused by this myopathy, and its histological, macroscopic, and microscopic features. Besides, the effects on the visual, sensory, functional, mechanical quality and processing properties of the breast meat of broilers and their negative effects on the poultry industry were also discussed. Since this myopathy gives a hard structure to the pectolaris major muscle, it is called "Wooden Breast" in public. It is assumed that the leading direct and indirect causes of WB syndrome in broilers are pectoral muscle hypertrophy (volume increase in muscle cells), rapid growth rate, and high breast meat yield. Also, age, gender, diet, feed restriction, oxidative stress, genetics, etc. factors are also thought to be effective. However, the etiology of WB syndrome is still unclear in many aspects. As a result of the macroscopic examination of the wooden breast meat, a striking stiffness, swelling, viscous exudate (inflammatory fluid), petechial (purple-red bleeding spots) fluid, and a pale appearance in the pectoral major muscles are observed, and the lesions that occur can be detected by palpation. Due to these visual and sensory defects in breast meat, the consumability of meat decreases and this leads to significant economic losses for the poultry industry.

Serum Creatine Kinase as a Biomarker to Predict Wooden Breast in vivo for Chicken Breeding

The present study aimed to find a blood marker for the prediction of wooden breast (WB) in live broiler to assist the genetic selection of fast-growing chickens. The experiments were carried out with two chicken flocks: 250 male broilers in flock 1 and 100 male and female broilers in flock 2. Both flocks were slaughtered and measured. The breast filets were assessed by combining subjective scoring and compression force at 28 (flock 1 only) and 42 days of age. The enzyme activity in serum and breast tissue (flock 1 only) of normal and affected groups was tested. The results showed that the compression force was significantly different between the normal and affected groups at 28 and 42 days of age (P &lt; 0.001), and it increased significantly with rising WB and WS scores. The serum creatine kinase (CK) value increased significantly with rising compression force at 42 days of age (P &lt; 0.001). The serum CK positively correlated with compression force (r = 0.608; P &lt; 0.001) and the linear regression equation (serum CK = 0.9960∗compression force + 1.884) was established for the line studied. The association between serum CK and compression force is consistent between flocks 1 and 2. In conclusion, our study confirmed that compression force could be the quantitative indicator to differentiate breast filets and found that serum CK could be a candidate biomarker to predict WB in live broilers and assist genetic selection in broiler breeding.

Effect of Aging on the Quality of Breast Meat from Broilers Affected by Wooden Breast Myopathy

This study aimed to evaluate the effects of aging on the quality of breast meat from broilers affected of wooden breast. Samples that were classified as normal (control), moderate (hardness verified only in one region of breast fillet), and severe (hardness verified in all the extension of breast fillet) were evaluated fresh and after three and seven days of aging. Normal samples and samples with a moderate degree of myopathy showed greater water-holding capacity, which may benefit the processing industry of poultry meat. During the aging process, increase was observed in total collagen concentration (from 0.41% in normal samples to 0.56% in samples with severe degree). Samples of chicken breast affected by moderate degree showed higher myofibril fragmentation index (MFI = 115) than normal chicken samples (95.65). Although chicken samples affected with severe degree of wooden breast myopathy are more tender than normal chicken breasts, they produce more exudate, which can be detrimental to the processing of poultry meat. The aging process may improve the reduction of cooking weight loss and protein loss in exudation of broilers’ breasts affected by wooden breast myopathy.

Insights Into Transcriptome Profiles Associated With Wooden Breast Myopathy in Broilers Slaughtered at the Age of 6 or 7 Weeks

Transcriptomes associated with wooden breast (WB) were characterized in broilers at two different market ages. Breasts (Pectoralis major) were collected, 20-min postmortem, from male Ross 308 broilers slaughtered at 6 and 7 weeks of age. The breasts were classified as “non-WB” or “WB” based on palpation hardness scoring (non-WB = no abnormal hardness, WB = consistently hardened). Total RNA was isolated from 16 samples (n = 3 for 6 week non-WB, n = 3 for 6 week WB; n = 5 for 7 week non-WB, n = 5 for 7 week WB). Transcriptome was profiled using a chicken gene expression microarray with one-color hybridization technique, and compared between non-WB and WB samples of the same age. Among 6 week broilers, 910 transcripts were differentially expressed (DE) (false discovery rate, FDR &lt; 0.05). Pathway analysis underlined metabolisms of glucose and lipids along with gap junctions, tight junction, and focal adhesion (FA) signaling as the top enriched pathways. For the 7 week broilers, 1,195 transcripts were identified (FDR &lt; 0.05) with regulation of actin cytoskeleton, mitogen-activated protein kinase (MAPK) signaling, protein processing in endoplasmic reticulum and FA signaling highlighted as the enriched affected pathways. Absolute transcript levels of eight genes (actinin-1 – ACTN1, integrin-linked kinase – ILK, integrin subunit alpha 8 – ITGA8, integrin subunit beta 5 – ITGB5, protein tyrosine kinase 2 – PTK2, paxillin – PXN, talin 1 – TLN1, and vinculin – VCL) of FA signaling pathway were further elucidated using a droplet digital polymerase chain reaction. The results indicated that, in 6 week broilers, ITGA8 abundance in WB was greater than that of non-WB samples (p &lt; 0.05). Concerning 7 week broilers, greater absolute levels of ACTN1, ILK, ITGA8, and TLN1, accompanied with a reduced ITGB5 were found in WB compared with non-WB (p &lt; 0.05). Transcriptional modification of FA signaling underlined the potential of disrupted cell-cell communication that may incite aberrant molecular events in association with development of WB myopathy.

Spaghetti Meat Abnormality in Broilers: Current Understanding and Future Research Directions

Spaghetti meat (SM) is a recent muscular abnormality that affects the Pectoralis major muscle of fast-growing broilers. As the appellative suggests, this condition phenotypically manifests as a loss of integrity of the breast muscle, which appears soft, mushy, and sparsely tight, resembling spaghetti pasta. The incidence of SM can reach up to 20% and its occurrence exerts detrimental effects on meat composition, nutritional value, and technological properties, accounting for an overall decreased meat value and important economic losses related to the necessity to downgrade affected meats. However, due to its recentness, the causative mechanisms are still partially unknown and less investigated compared to other muscular abnormalities (i.e., White Striping and Wooden Breast), for which cellular stress and hypoxia caused by muscle hypertrophy are believed to be the main triggering factors. Within this scenario, the present review aims at providing a clear and concise summary of the available knowledge concerning SM abnormality and concurrently presenting the existing research gaps, as well as the potential future developments in the field.